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Permaculture Design Certificate Course by Mind Map: Permaculture Design Certificate Course

1. Module 11: Dryland Strategies

1.1. Module 11a

1.1.1. Modules 11.1 to 11.10 11.1 – Chapter 11 Course Notes; Part One [PDF] Drylands: Precipitation, Temperature and Soils This chapter is about the drylands, a climate defined by little rain and lots of evaporation, one in which we must be very careful with water and soils. In this climate, soils can easily become salted, and all systems, not just housing, need protection from the sun, the main strategy being anti-evaporation. While deserts are often associated with being exceptionally hot, drylands aren’t necessarily so, some being amongst the coldest places on earth. Drylands are one of the longest human-inhabited systems on the planet, and they are also amongst the most damaged. All of this makes them an opportunity to demonstrate how carefully designed systems can lead us to permanent productivity. Continued... 11.2 – Introduction to Dryland Stratagies [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Recognize that drylands are the longest inhabited, thus most damaged, systems - Summarize the basic strategies that are integral to living in the drylands BRIEF OVERVIEW Drylands is the climate that lacks rain, has high evaporation, and is most easily damaged. We have to be very careful with water, as well as soils, which are easily salted. We have to shade out the sun from not only our houses but also our systems. Animals systems have to be carefully managed, cycling them for long periods over large areas. Drylands are some of the longest inhabited and most severely damaged systems on earth, and now desertification is increasing worldwide. Here, there is the opportunity to demonstrate the permanent productivity provided by thoughtful design, and there is then the potential to help many people who are suffering in this climate. KEY TAKEAWAYS - Drylands lack rain and have high evaporation, so we must be very careful with water and soils, shading both our houses and systems. - Animals systems require careful management with long cycles over large areas. - Desertification is increasing worldwide, but with careful design, we can demonstrate permanent productivity and landscape rehabilitation. 11.3 – Dryland Stratagies [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Define a desert in terms of precipitation and evaporation - Give examples of nature using anti-evaporation strategies - Realize that dryland strategies can be used in whatever climate we live, for times of drought - Provide a basic overview of the different kinds of arid landscapes BRIEF OVERVIEW Dryland strategies can be adapted to wherever we live, as we all have dry periods, and this is the most pressing problem in land management. Deforesting desert borders and salting soils is continually expanding the desert. Even without these things, there are natural years of drought caused by fluctuations in the earth’s orbit, as well as the sun and moon cycles. Our initial strategies have to be anti-evaporation, and we can look to nature for guidance. Trees have several methods: deciduous varieties lose their leaves, some have waxy leaves, some have gel, and others have large water storage organs. Animals, too, have strategies. Certain frogs go dormant to wait for rains, while other animals migrate out of the desert or to oases. Most desert animals live in burrows and are nocturnal. Unfortunately, potentially useful desert species are becoming extinct. Deserts around the world all have their niches — cactuses of the US, fruit in Asia, root crops in Africa, seeds in Australia — but they are all defined by having more potential evaporation than rainfall. Most desert are hot, but some can be very cold. They usually border savannas and, left undisturbed, will have an eye-level appearance of a low forest. Ants and termites, as opposed to worms, are soil aerators and break down organic matter. Vegetation occurs in a mosaic, waiting for the right conditions. Runoff can go inland to salt flats rather than to rivers, and the landscape is constantly eroding via wind and rain events. True desert (hyper-arid) has very little vegetation except for oases and ephemeral plants after rains, which are only two centimeters a year. Dry savannas can get between 75-100 centimeters, while semi-arid gets around 15 to 40 and arid only 15 to 20. The evaporation potential for these areas is between 100 and 700 centimeters a year. There are only three sources of water: exotic rivers, oases, and aquifers. Trees, too, add water through transpiration, and vegetative cover is anti-evaporative. Thus, pioneering species and earthworks for soaking water are crucial in this climate. KEY TAKEAWAYS - Dryland strategies can be adapted to wherever we are, and they are important as these dry periods are the most pressing problems in land management. - We can get dryland strategies from observing how plants and animals handle the conditions. - Drylands are defined by potential evaporation being more than rainfall. - They have three sources of water: exotic rivers, oases, and aquifers. - And, it’s important that we put water into those water sources through vegetation and water harvesting. - We can set up systems to take advantage of rare rain events, using earthworks and gravity to re-vegetate the landscape. 11.4 – Precipitation [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Recognize that precipitation is more than rainfall - Note that rainfall averages are meaningless in deserts - Explain how water cycles through the desert after a rainfall BRIEF OVERVIEW Precipitation is water that touches the soil. Reliable rains do occur in some deserts, those with monsoon borders and near westerly coasts, but many have rare and irregular rainfall. Rainfall averages are meaningless, and deserts are floods waiting to happen. Some deserts are treeless landscapes with only fog catchers to gather moisture, but when plants are established, they can harvest 80% more water than rainfall. After rains, deserts burst to life because everything is taking advantage of life cycling opportunities. Then, the water evaporates, and everything goes back to its place of origin. In the desert, 88% of water evaporates or rushes through, so we must design systems to harvest it and safely store it. When we can establish trees and shrubs, plants will begin to add more moisture to the air. KEY TAKEAWAYS - Precipitation is water that touches the soil In deserts, averages are meaningless and, generally, rains are irregular. - After rains, deserts burst to life because it is a life cycling opportunity. - 88% of water evaporates and rushes through the desert. - We need to establish systems for harvesting and safely storing water in the desert. 11.5 – Temperature [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Outline the general pattern of temperatures in deserts - Discuss the behavior of temperature with regards to depth in the soil - Illustrate the varying amounts of humidity found at different levels of soil - Generalize the survival habits of most desert animals BRIEF OVERVIEW Temperatures are quite extreme in the desert, but there is a general pattern. Things begin to heat up around seven in the morning, moving into peak temperatures between twelve and three. At this time, heat begins to rise, and temperature fall from three to eight then drop rapidly until about midnight. The coldest time is just before dawn. Temperature in soil changes the deeper it is. There is little effect (from the external temperature) at 30 centimeters and almost none at two meters. Near the surface, soils hold more heat than air, and on south-facing slopes, they can get up to 60-70 degrees Celsius. Desert temperatures of 30-plus degrees are common, with recorded cases reaching over 50 degrees. Desert animals burrow, or they find high refuges in low shrubs or up posts. They need shade, and often the population of large animals corresponds to the amount of caves available. A large proportion of animals in the desert are subterranean and nocturnal, and we need to take a hint from them. Humidity in the soil, especially with sand dunes, also changes with depth. At one meter, there is about four percent humidity, but at two to six meters, there is somewhere between 10 and 20 percent. Between 20 and 60 meters deep, the soil is possibly saturated, and these are the layers where temperatures are much cooler. KEY TAKEAWAYS - There is a general pattern to daytime desert temperatures. - Temperatures in soils changes in relation to the depth, becoming cooler and more stable. - Animals in the desert are largely subterranean and nocturnal, which offers clues for how to survive there. - Humidity in soils also changes in relation to depth, becoming more saturated further down. 11.6 – Climatic Factors in Drylands [ANMTN] BRIEF OVERVIEW Climatic factors in drylands are distinct. Air temperature minimums occur around seven a.m. with the maximum around eight p.m, and soil temperatures lag behind. At midday, birds begin to soar thermal winds, and whirlwinds are present from then until dusk. Rainfall is always less than evaporation. Dust storms are created by strong cold downdraft winds before storms. Drylands are floods waiting to happen. 11.7 – Soil [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Examine alkaline desert soils, and unlock their high nutritional content - Identify where best to locate home gardens, and how to balance pH levels there - Explain why biocides are particularly problematic in deserts BRIEF OVERVIEW Alkalinity is nearly always dominant in desert soils, especially near waterways, where most people want to settle. There is high nutritional content to unlock in the soils, and water and pH levels are important to consider for doing so. In the meantime, missing trace minerals like zinc, copper, manganese and so on will show up in leaf analysis via yellowing, thinning, and curling, but they can be added as foliar sprays. Soils can also be non-wetting and salted, and this can be addressed with bentonite, humus, and swales, as well as raised beds with sunken tops. Home gardens are possible close to scarps and areas where salinity levels aren’t as high. Location is key. Desert climates are fragile and require good management, so large trials should be avoided until everything is assessed. Mineral contents can be very high and even toxic. Humus can help to buffer these toxins. Phosphate is very important and can be acquired through bird manure, forests, pond bottoms, and mulches of casuarina and palms. Many trace elements aren’t available until pH levels are fixed, but they can be added as foliar sprays. It’s important to be careful with nitrogen, as too much greenery on trees can create drought stress. Sulfur and mulch pits (where the water isn’t salty) will help to bring the pH balance down. Poisons in the desert are particularly problematic because of the lack of water and slow decomposition rates. Biocides become even more dangerous, and they seep through sands into the water tables, where concentrations build up and cycle back through the system. It’s easy to green the desert on aquifers and chemicals, but the effect on the system is ultimately devastating. KEY TAKEAWAYS - Desert soils are primarily alkaline, especially near water. - Trace minerals, like zinc and iron, may be present but locked up in the alkaline soils. - Home gardens are possible, but location — away from salty plains — is very important. - Desert soils are fragile, so large trials should be put off until everything is tested and analyzed. - Poisons, due to lack of water and slow decomposition, are even more dangerous in the desert. 11.8 – Pot System [ANMTN] BRIEF OVERVIEW An unglazed pot buried into a humus-rich pit will slowly leak water out, and the planting pit will stay moist, making it an efficient way to grow herbs and vegetables. 11.9 – Landscape Features in Deserts [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Recognize the different things that have affected the angular desert landscape - Give examples of erosion landscape features in drylands - Differentiate between the three main forms of deserts: ergs, Hamada, and regs BRIEF OVERVIEW There are many features in the desert landscape, and they form mosaics of vegetation. The landscape is very angular. Wind, water, and water infiltration all have a huge effect, as do rock and soil types. Shading affects opportunities for growth and habitat, especially when blocking the western sun. Fire frequency, considering the date of last fire, explains and lot about the regeneration rates, as does knowing when the last heavy rain (at least 12 mm) was. The desert landscape is the easiest to damage and hardest to repair. Erosion features are plentiful, and many of them are caused by poor human decisions. Wadis drain into the open plain country. Classic desert features include canyons, mesas, scarps, and pediments. Folded basins and ranges occur when landscapes crack, open, and turn into valleys, and these often happen near mountains. There are three main forms of deserts. Ergs are sand dune formations of different sizes and types. Hamada consist of rock pavement with large scattered boulders. Regs have extensive areas of gravel surface. As areas become more humid, these landscapes are softened with vegetation. KEY TAKEAWAYS - Many different desert features form a mosaic of vegetation that allows us to read the landscape. - Deserts are angular, affected largely by wind, water, water infiltration, rock and soil types, and shade. - When the last fire and last heavy rain occurred tells us a lot about the growth processes in the desert. - Erosion features—canyons, mesas, scarps, pediments, folded basins—are classic for the desert. - There are three main forms of desert: ergs, hamadas, and regs. 11.10 – Desert Valley Profile in Fold Mountains [ANMTN] BRIEF OVERVIEW Valleys in fold mountains have distinct profiles that are topped with hard laterite or sandstone plateaus that have extremely thin soils, as well as hardy plants and reptiles. Moving down are scar cliffs of scree with bunch grasses, some trees, and mammal/reptile shelters. Infiltration on the cliffs is good because sediment is coarse. Below this, outwash plains have sandy clays with fast runoff that can be made fertile with swales. Flood out areas have sandy soils with scattered trees and good infiltration, so grasses grow well after rains. Stick-nesting rats and mound-building birds settle here. Past the flood areas, there are silt deposits from flood flows and large trees with deep taproots. Burrowing reptiles and small mammals inhabit this area. Finally, there sandy river beds or wadis, which will grow densely with trees and vines if left un-grazed. Moving back up, there are rocky, rugged cliffs with possible springs and hardy trees. Then, dry, rocky hills are scattered with grasses and shrubs after rains.

1.1.2. Modules 11.11 to 11.20 11.11 – Total Desert Strategies [ANMTN] BRIEF OVERVIEW The headwaters of exotic rivers are the best area for creating swales forests and generating vegetation downstream. Isolated rock dome hills, scarps, and folds in the plains create many sites for runoff collections with small dams and swale forests. Pelleted seed can be sent upwind into areas with soil imprinting. Oases and deflation hollows provide possibilities for settlements and dune stabilization projects. Flood-out areas and pans can yield crops after heavy rains. Stability can be positively affected by occasional rains, fencing, manure/mulch, and good earthwork techniques. Negative effects come from overgrazing, feral animals, insect plagues, flash floods, and lightning storms causing fire. The largest negative factor is inappropriate investment and political policies. 11.12 – Scarps and Wadis [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Define scarps and wadis - Explain how water flows through scarps and wadis - Discuss how to create water catchment systems to hydrate these landscapes BRIEF OVERVIEW Scarps and wadis are fault line fractures in desert plains with cliffs that have sloping pediment at the base. Though the sharp, angular shapes look dramatic, they are very fragile. Wadis are at right angles to scarp cliffs and occur in repeated cracking patterns. Mesa are isolated pieces of scarp, and buttes are scarp sections capped with durable geological material where cliffs, scarp faces, were much softer. Water flows to cracks, down the cliffs, and join together to move through the wadi and into the desert plains. This upper flow creates scour holes at the top edge of the cliffs, and it can come over the sides like a curtain, undercutting cliff faces to form caves, which become habitats for wildlife and potentially people. Large rain events are very dangerous and can move huge boulders and lots of rocks. Water flows can be slowed by using stone or cement dams (there is no clay) at the top of the cliff, top scarp gutters to direct water, base pipe flush dams to irrigate, adjusted scour holes, and overflowing dams at the base. All of these, save the scour holes, will silt up and need cleaning. Top surfaces are very hard and can only be planted with hardy trees, but wadi floors can have deep sands, silts, and rocks. They can be installed with low rock walls (with a clear channel through the middle) to harvest water and silt but allow large events to move through. Walls can also be built on contour in the plains to pick up big flows, where twenty hectares of catchment can provide one hectare of crop. Modern earth-working and surveying equipment can establish systems easily, as we only need half a meter to a meter of water absorbed into each field to produce a grain crop and maintain palm and fruit trees. A windmill near the edge of a windy scarp can pump water to tanks up the cliff, and that can be cycled back down. Channels can be cut on the top surfaces to catch more water. Rocks and caves are plentiful for construction, and fencing is only needed at the entrance, as cliff walls surround the rest. Once a wadi is protected from overgrazing, it can become a very productive place. KEY TAKEAWAYS - Wadis and scarps are fault line fractures in desert plains, with cliffs that have sloping pediments at their base. - Water flows to cracks that lead to the cliffs, sending merging flows to wadi floors, and they join and empty into the desert plains. - Water can be slowed and harvested with top dams, scarp gutters, scour holes, and overflowing base dams. - Low rock walls can help to capture silt and water along the wadi floor and on contour in the plains. - 20 hectares or catchment can provide one hectare of crop. - With modern earth-working and surveying equipment, a stable system can be achieved easily. 11.13 – Development of a Desert Scarp Profile [ANMTN] BRIEF OVERVIEW Condensation leaf drip from the forest helps to create a humid landscape. The humid landscape has an S-curl profile. As the humid landscape begins to disappear, a head slope cliff appears. This head slope develops a scree slope. Finally, the angular profile of the desert scarp emerges. 11.14 – Scarp and Wadi Drainage [ANMTN] BRIEF OVERVIEW Scarp and wadi systems drain water from the upper erosion surface. Traditional settlements were located in wadi pediment slopes, above the floodwater. Outside of the wadi, on the lower erosion surface, there are flat-top vertical mesas and rock hills rising out of the landscape. 11.15 – Scour Holes [ANMTN] BRIEF OVERVIEW Scour holes occur at the top of the wadi valley cliff, before the water falls over the wadi floor. Streams of water scour out holes, some of which can be enlarged into cisterns. They are important to wildlife, and old scour holes that are filled with sand can be rimmed with rocks to plant trees. Mark As Complete 11.16 – Sandstone Valley Scarps and Caves [ANMTN] BRIEF OVERVIEW Sandy, semi-arid valleys have a succession of scarps, caves, and ledges with a deep sand flood plain. These are more complex landscapes than true desert scarps and can be designed. Clay soils occur on the pediment slopes, and deep silt sands on the flood plains. 11.17 – Scarp and Wadi Elevation [ANMTN] BRIEF OVERVIEW The features of traditional and some wadi settlements can show us how productive some desert spaces can be. Cave houses can be built into the internal scarps of wadis with facades and shading trellises on the front. Guttering systems can be installed atop cliffs, directing potentially damaging runoff water to storage. Adjusting pediment slopes and using spoils from cave excavation (from the housing) can create access routes. Side channels can feed water from gabion silt fields and well-shaded dams into the side canyons. The flattish floors of the wadi can be irrigated and cultivated, and the main channel can be used to direct water flows away from fields. A windmill can be positioned above a well to pump fresh water to water storage uphill, so it can be gravity-fed back to the house. 11.18 – Scarp and Wadi Plan [ANMTN] BRIEF OVERVIEW A wadi system that has been designed for settlement has obvious characteristics. Dams will be on the upper surfaces for flood collection, and they can be fed to shade-protected tanks and ponds for irrigation for wall-banked fields on the wadi floor. These fields gradually fall downhill in a series, and they hold an average of half to a meter each of floodwater for infiltration to trees and crops. Outside the wadi, swale lines on the pediment slopes capture surface runoff for large rain events, and the swales can support productive trees and opportunistic crops. A windmill can be installed in line with the wadi entrance, and it can pull up water that has been infiltrated through this design to recycle back to the tanks. 11.19 – Residuals, Domes and Inselbergs [VIDEO] BRIEF OVERVIEW Residual domes are simple compared to wadis and scarps, as they are just one large rock. The domes don’t usually have deep valleys but simply slope steeply into sandy soil. Small valleys may be worn in and have vegetation and even trees, but large trees and humus can be developed on the shady side, where shelters may already exist. Domes are 100% runoff, and they can be harvested with the same (as wadis and scarps) ratio of twenty to one catchment to cultivation of crops, fruit trees, and palms. Steep shaded cliffs can possibly provide tiny rock dams for extra, gravity-fed water. On smaller domes (10-20 meters across), a concrete gutter lead water to an underground tank with shade over it. The tank can support ferns, which frogs will use for habitat, and can have a wildlife ramp to support desert biodiversity. That water can also be used to create a small garden. KEY TAKEAWAYS - Residual domes are just one large rock with steep sloping sides that generally meet sandy soils. - They are 100% runoff, and that water can be harvested for small gardens. 11.20 – Rock Dome Water Led to Vegetation [ANMTN] BRIEF OVERVIEW Rock domes are 100% rain runoff surface that can easily be led off to storage or irrigation. There can be stone-carved or concrete gutters directing rainwater to walled fields at least 1/20 the size of the catchment area of the dome. Concrete gutters can lead runoff to field infiltration or concrete-lined cisterns just underground with thick thatched roofs to prevent evaporation, as well as stop large animals from drinking all the water. Splash rocks around the pond will grow ferns and provide habitat for frogs, while fish can feed on flies and desert insects.

1.1.3. Modules 11.21 to 11.30 11.21 – Inselbergs [ANMTN] BRIEF OVERVIEW Inselbergs are isolated hills rising abruptly out of plains and are often granite or metamorphic sandstones. When rains occur, runoff is a guarantee, but surrounding soils are very sandy, requiring sound strategy. The shady sides of inselbergs will support forests, if they are pioneered with well-directed runoff water. Caves, often on the shady side, make good shelters. On the sunny side, gutters can direct water to sand filled dams, inside of which we can garden. Beyond the dams, plastic-lined sheet “wells” can be installed to capture overflow for more gardening and shade trees. 11.22 – Fold Mountains [VIDEO] BRIEF OVERVIEW Fold mountains are extensive desert features that have characteristics of both scarps and inselbergs. Synclines flex downward with eroded hollows and rivers cutting through them, while anticlines raise up into high backs with vertical side valleys. Along the spines of fold mountains, rivers can create long valleys that can have large oval lakes if the exits are dammed. In fold mountains, there are more opportunities for appropriate open water storages. In addition to rivers, there is also snow melt from the typically nearby mountains. Strata acreate palisade-like formations from the interaction between soft and hard rock that act as natural swales. The soaked water from these can be sourced with bored holes, and when regulated, they can be permanent water supplies. Dry streams provide potential catchment but can’t be dammed, so they can be bled to clear water dams with contour diversions. Forests around these dams can create shade, and silt will drop in the contour trench for easy excavation. KEY TAKEAWAYS - Fold mountains have synclines that flex downwards into eroded hollows and anticlines raise up into high backs that often have vertical valleys and rivers. - Many opportunities exist for appropriate open water catchments in fold mountains. 11.23 – Desert Mountain Profile [ANMTN] BRIEF OVERVIEW First, the fold is created by continental drift. Valleys form in weak rock. Basin and range landscapes evolve with alternate wide valleys of the synclines and narrow valleys of the anticlines. Flatiron rock forms on the steep inter-slopes. 11.24 – Fold Mountains [ANMTN] BRIEF OVERVIEW First, the fold is created by continental drift. Valleys form in weak rock. Basin and range landscapes evolve with alternate wide valleys of the synclines and narrow valleys of the anticlines. Flatiron rock forms on the steep inter-slopes. 11.25 – Headwater Stream Diversion [ANMTN] BRIEF OVERVIEW Fast-moving water runoff from fold mountain systems can be designed to go into dams and infiltrate to soil storages. With a bleed-out point on the extremity of a bend and flow restrictors just down stream, water is led into silt traps onto reed beds and into shaded dams of clear water. The silt trap can be cleaned out regularly to add fertility to tree-growing systems. 11.26 – Dune Country [VIDEO] BRIEF OVERVIEW Sand dunes occur on solid surfaces and are formed by the wind. They come in many forms: Traverses are across winds, longitudes are with winds, obliques are slanted to winds, crescents curve away from winds, seas are wave forms with lobe edges, and isolated dunes form dull crescents. After good rains, dunes can be planted with hardy annual legumes (moth bean or yam bean), hardy grains (sorgum or millet), and/or desert legume trees (acacia or prosopis). A little organic fertilizer will help them grow, and they should be mulched with straw, which will be long-lasting in the desert. After a year, larger trees can be planted between the legumes, and the base of the dune will become stable. Seed pellets can also help with re-vegetating a pitted landscape. The pellets, as well as organic material, collect in the pits. Mixed with deterrents, like neem powder and bitter tea, the seed pellets are safe from animals, and the clay balls wait for rains, at which time they will melt and pioneering seeds can germinate. The plants then stabilize the dune. Coastal dunes, blown apart by wind rather than rain, can be stabilized with brush fences. Installed a meter high and in seven-meter squares, the fences act like windbreak shelters for young trees to get a start. Inside the dunes, there is a lens of moisture that tree roots can reach, and thus they stabilize the dunes. Trees can be helped with special techniques for planting. By inserting a basket or box with organic material about 30 centimeters into the dune, a seedling has fertilizer and shelter from harsh weather conditions. This works well to speed up the process to re-stabilization. KEY TAKEAWAYS - Sand dunes are formed on hard surfaces by wind. - After good rains, sand dunes can be planted to hardy plants that can survive the climate. - Trees and vegetation help to stabilize dunes. 11.27 – Machine Blades for Pitting [ANMTN] BRIEF OVERVIEW By using trailing discs behind a tractor, we can pit desert landscapes to prevent runoff and dust storms. The pits are good seed sites that capture nutrients, native seeds, and layers of sand. 11.28 – Dune Stabilisation [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - List many elements that can help to stabilise dunes - Elaborate as to how to begin tree systems for dune stabilisation BRIEF OVERVIEW Stability can be provided by pebbles and vegetation, as well as naturally occurring lichen, fungi, and algae mats, but stabilization can also come from tars, oils and glues, which lock in moisture. Salt crusts can also stabilize, but they must be protected from hoofs, cars, and plowing. In urgent situations, pebbles, brush fencing, and tar can help. The fencing should be a meter tall and spaced in seven meter squares, inside of which hardy tree species can be planted. They should be planted at least 15 centimeters below the surface to help them avoid lethal temperatures. Trees — the prosopis is great for this — eventually grow to heights where they cast their own shade to keep roots cool. Once these types of cover ups are established, other plant species can be established, and with a root net below, more organic fertilizers can be added. KEY TAKEAWAYS - Stability is naturally provided by pebbles, vegetation, lichen, fungi, and algae mats. - Stabilization can also be provided with tars, oils, and glues, which can lock in moisture. - Salt crusts also stabilize, but they shouldn’t be damage by hooves, cars, or plows. - Establishing tree systems will stabilize the dunes more permanently. 11.29 – Dune Stabilisation Strategies [ANMTN] BRIEF OVERVIEW Shifting crescent-shaped sand dunes can be stabilized with brush fences staked across the wind. This creates and oval dune with a swale on the steeper, upwind side that can infiltrate water, which allows the dune to be planted with appropriate, adapted vegetation for further stability. A lens of damp soil forms at the base of the dune, and large trees, like acasia and presopas, can greatly aid this process if planted at the center of the dune. Smaller trees and bushes can be planted down the sloping sides. 11.30 – Depressions and Basins [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Explain how depressions and gilgais form BRIEF OVERVIEW Depressions and basins are low, flat, almost circular features. They can be large enough to hold salt lakes. They can be clay or salt pans where water evaporates and leaves deposits. Clay pans can be treated with gypsum to drain better or bentonite to seal better. Gilgais are small depressions created from the swelling and shrinking of clays, and they pick up organic matter from the wind. KEY TAKEAWAYS - Depressions are low, flat, almost circular features. - They can be large enough to hold salt lakes. They are where water evaporates and leaves deposits of either salt or clay.

1.1.4. Modules 11.31 to 11.40 11.31 – Scalds [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Define scalds - Illustrate how to use low banks to repair a scald BRIEF OVERVIEW Scolds are clay surfaces with a slope that has a flow in and a flow out of it. Clay was the original subsoil, and sandy loam topsoil has eroded away, often due to overgrazing. The surface can be cut and a low bank built on the upslope such that water builds up a third of the way to the higher bank. This area will build up silt and sediment and can be seeded to trees. Above it, we can plant cover vegetation. Once the sediment creates a terrace, the process is repeated, and doing so twice repairs the entire landscape. The banks must be kept low, so they don’t drown plants. KEY TAKEAWAYS - Scolds are clay surfaces with a slope, allowing flows in and out. - Clay is the original subsoil, and sandy-loamy topsoil has completely eroded, usually from overgrazing. - The surface can be cut, a bank installed upslope, and build-ups of silt, water, and sediment will repair the landscape. 11.32 – Revegetation of Scalds [ANMTN] BRIEF OVERVIEW Scarred clay pans that have been washed by floods can be re-vegetated by using a road grader to side-cast clay ridges to the uphill side, creating retention banks across the water flow. Banks twenty-centimeters high will have holes on the downhill side, and they will back-flood water a third of the way up the slope, aiding infiltration. Vegetation can be initiated after the first good rain. The trenches only fill during major events. Over time, the banks level out and new banks can be installed to supply new planting. Eventually, the scar is healed. 11.33 – Claypans [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Recognize what happens within clay pans and how they can vegetate the landscape BRIEF OVERVIEW Clay pans don’t overflow but fill with water that soaks into a thin lens or evaporates, leaving behind clay deposits. Grasses grow, and waterfowl make nests. Outside the pans, there is reedy vegetation, and animals move into to take advantage as the pan dries. The pans can be ripped or pitted and then seeded to vegetate them. Once the vegetation survives, it will open up the pan to more infiltration and wildlife, rejuvenating the landscape. The pan can also be ridged in a meter-high checkerboard pattern to grow tress on the mounds. This eventually creates marshland full of organic life cycles. KEY TAKEAWAYS - Clay pans don’t overflow. They hold water until it evaporates, leaving behind clay deposits. - These systems can be vegetated by ripping or pitting them and then seeding the area. - Once vegetation is established, the pan opens up to more plants and wildlife, eventually becoming marshland. 11.34 – Saltpans and Salt Lakes [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Realize how salt pans are formed and how to buffer the salt-lake effect BRIEF OVERVIEW Salt pans are features of the desert, and they are literally lakes of evaporated moisture with salt left behind. The salt is washed down from saline or salted landscapes or from deep, salty waters that have been pumped up for irrigation. The margins can be planted to salt-tolerant trees, such as tamarisk. The tamarisk can be planted around the lake, creating an edge of organic matter that buffers the salt-lake effect. Then, less tolerant species can be planted around that. These landscapes take a long, long time to recover. KEY TAKEAWAYS - Salt pans are lakes of evaporated moisture that has left salt behind. - The margins can be planted with salt-tolerant trees to create an organic buffer around the lake. - The landscape takes a very long time to recover. 11.35 – Gilgais [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Relate what gilgais are, how they are formed, and what overgrazing does to them BRIEF OVERVIEW Gilgais are small patches of clay, three to four meters wide and six to 20 centimeters deep. They are caused by the swelling and shrinking of clay, and they often appear in groups that eventually merge to become hollows. These become shallow pools that link up to create very fertile and bio-diverse areas with lots of birds and wildlife. However, overgrazing stresses the plants out, and that can turn the pools into mounds of sand, destroying the life around them. KEY TAKEAWAYS - Gigais are small depressions formed by the swelling and shrinking of clay. - They are three or four meters wide and six to 20 centimeters deep. - They turn into pools that link up to create very fertile areas. - Overgrazing can stress out plants and cause gilgais to become sand mounds instead of pools. 11.36 – Flood-Outs, Gullies and Badlands [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Define flood-outs - Provide strategies for diverting waters from gullies and stopping erosion - Explain how to begin repairing badlands BRIEF OVERVIEW Flood-outs are continuously widening valleys with flat floors. Streams are shallow (2-8 cm deep) and at least 20 meters wide, often in a braided pattern. Water soaks over wide pans, and when overgrazed these turn into gullies. Gullies have streams that become deep channels, and they need to be cut off at the head, diverting water sideways to overflow gently onto the landscape. Large gullies then need to be planted, and gabions can be installed to create silt fields. Soils here are fragile and have recent sediment and shale, so it is imperative to avoid overgrazing, driving, or any disruption while the gully repairs itself. On the landscape above, rip lines can be cut from the gullies down to take off erosion pressure. Small gullies can likely be filled, drained, and/or cut through to stop erosion. Badlands are often too expansive to repair fully, but it begins with silt dams in valleys. They should be small and frequent, absorbing the water flows and creating fertile silt fields. Stone gabions half a meter high can build up sediment behind them and spread the flow of water. If there are no boulders, very sturdy fences can be put in and covered with wire on both sides to create a silt field where the water reaches them and a splash guard where it departs. Pioneering legumes can then improve the soil and a diverse polyculture can be gradually installed. Ultimately, very controlled forest crops can be part of the system. KEY TAKEAWAYS - Flood-outs are widening valleys with very shallow, very wide streams, often flowing in braids. - Gullies are the result of flood-outs being overgrazed, and the streams become deep channels. - Gullies should be stopped at the head, the water diverted to passive overflows and the gully planted. - Badlands can begin reparations with silt dams and gabion weirs to spread water and create planting spaces. 11.37 – Strategies for Healing Active Gully Erosion [ANMTN] BRIEF OVERVIEW Strategies for healing gully erosion include filling small gullies and planting them to trees and diverting headwaters with check dams and deflector banks, moving the water out to diversion drains, swales, and spreader banks. The swales hold water off the side walls while growing trees, and the spreader banks disperse water gentle down the hill. Gabions can be installed on the gully floor with trees planted on the silt fields and at the sides of the gully to add stability. 11.38 – Riplines Divert Water from Gully Erosion [ANMTN] BRIEF OVERVIEW Gully erosion can be prevented by interceptor banks, spreader drains, grassed spillways, and dam walls just below cuts to divert water to swales on contour. This can be improved with rip lines between swales that flow out toward the ridges from the gully erosion lip. Gabions in the gully act as sediment-catching weirs that allow trees to be planted on the sediments and gully sides. 11.39 – A series of Weirs and Gabions [ANMTN] BRIEF OVERVIEW Gully erosion can be controlled by strong wire fences with wire overlaying the ground on both sides, the upslope side for sediment catching and the downhill as a splash guard. Stone-filled wire cages act as weirs, slowing the flow and settling sediment behind them as level terraces. If they remain only about half a meter high and are spaced in even rows about ten meters apart they are more likely to survive severe floods. 11.40 – Stony Desert [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Illustrate making windrowed stone downslope of swales to vegetate the landscape BRIEF OVERVIEW tone gibber deserts, or regs, are large areas covered with stones revealed by wind erosion. The stones can be windrowed on contour with swales upslope, and the stones provide condensation and soak in runoff. Trees can be planted below the windrowed mounds and vegetation above the swales. Insects, reptiles, and small birds move into the stone piles, leaving manure and decomposing bodies. Between windrows, the ground can be ripped and vegetated. When we windrow in stages to grow trees, we can reduce erosion, and the wind actually brings in new dust and organic matter from outside. On steep slopes, windrows can direct water to irrigation channels. We are working to maximize absorption. KEY TAKEAWAYS - Stone gibber deserts are large areas covered in stones uncovered by wind erosion. - Windrows of the stones can be used to harvest and soak more water, as well as prevent erosion, acquire new organic material, and vegetate the area.

1.1.5. Modules 11.41 to 11.50 11.41 – Gibber Desert in Windrows [ANMTN] BRIEF OVERVIEW Stone deserts can be easily worked and material side-casted downhill to form swales with stone piles downslope for excellent tree-planting sites on contour. The area can be ripped on contour down to twenty centimeters to maximize water infiltration. Swales can be spaced at a distance of ten times the height of mature trees to provide shade and wind buffering. 11.42 – Lower Foothills and Plains [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Discuss harvesting the water flow and growing trees on the relatively level plains BRIEF OVERVIEW Lower foothills and plains have slope, but it is very hard to see without an eye level or observing sheet flow. It is often browsed down and nearly dead. Circle swales between 20 and 100 meters across can be installed by casting out a ditch. This stops sheet flow and absorbs all the water that falls within the circle. Trees can be planted around the outside of the bank and vegetation in the trench. Gradually, the circle can be planted and grazed. Also, long, shallow swales are easy and cheap to install, and they collect a lot of water. Trees can be planted below the berms, and the back-flood is a thin sheet of water over the earth behind the swale, the land under which can be planted as the water recedes. Another option is to direct the water to walled fields for cultivating different crops. These areas can be quickly recovered. KEY TAKEAWAYS - Lower foothills and plains have slopes, though they are hard to detect. - Circle swales or long swales can be installed to stop sheet flows and help to vegetate the area. 11.43 – Ditch and Bank Landscape in Plains [ANMTN] BRIEF OVERVIEW A circular disc and mound pan system on a flat plain landscape can prevent all water runoff. All water falling in a pan of roughly twenty to thirty meters in diameter soaks into the landscape along the sides, where forage species can grow. Hardy trees can be planted inside the pan and around the ditch. Pellet seeds can help to begin vegetating the ditches. With these pans covering the landscape, a large proportion of desert can be greened up. 11.44 – Yeomans' Shallow Swales [ANMTN] BRIEF OVERVIEW Shallow swale banks are easy and cheap to install on very flat desert landscape. The mounds can be used to grow trees, and swivel pipes can be installed to bleed to fields for opportunistic crops. Mark As Complete 11.45 – Swale Construction [ANMTN] BRIEF OVERVIEW Surface runoff water infiltration can be great for starting growing systems. Swales by roadsides provide tree water for growing shade to cool urban streets. They infiltrate water between two and twenty-four hours and provide ample irrigation after early vegetation establishment. Trees will shade the swales, which have vines up the trees, shrubs at the sides, and semi-aquatics at the base. The roadside swale has no mound but needs a dead level sill at the sides, yet the base depth can vary if necessary. The base can be ripped, sanded, graveled, or planted. Dry dams (limonia) fed by hard surface runoff are surrounded by compacted earth walls that hold one to 1.5 meters of flood water until it soaks into the ground. Limonias have overflow provided by rock-base spillways, and diverse forests establish in the base of the dam. 11.46 – Harvesting of Water in Arid Lands [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Recognize the role that salt plays when harvesting water in the desert landscape BRIEF OVERVIEW When harvesting water in arid lands, water is the limiting factor for designers because we need water that is 700 PPM or less of salt. That means that we have to harvest the water before it has a chance to mix with salty water or before it runs off of hard surfaces. But, we can’t waste a drop of water, so we must divert all wastewater and sheet-flowing water to gardens. Our goal is to slow the water down, spread it out, and give it time to soak into the landscape. KEY TAKEAWAYS - Water harvesting in arid areas is limited by the need for water to be 700 PPM or less of salt. - Water should be harvested before it can mix with salty water or before it leaves hard surfaces. - We need to slow water down, spread it out, and let it soak into the landscape. 11.47 – The Conservation of Rainwater [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - List sources from which water can be harvested - Outline basic strategies for harvesting and storing roof water for domestic use - Generalize settlements with regards to water, access, and structures BRIEF OVERVIEW Roof water can be stored in tanks or sealed wells to supply drinking water. Runoff from hard surfaces of all kinds can be stored in roofed tanks. Swales along roadsides are the cheapest way to catch water, and they can be ripped in the base then graveled or sanded to increase absorption. Extra diversion drains from outside sources can lead to the swales, doubling their harvesting capacity. For settlements, water should be the first consideration, followed by access routes and then structures. Houses can then be orientated to the environment, and roadside swales will provide shade trees, as well as extra material. Lawns should be excluded from design, and under-mulch drip irrigation should be used for cultivation. Gravel reed beds can be clean grey water, and dry composting toilets can save tens of thousands of liters of water per household per year. We know that one millimeter of rain on one square meter of surface provides one liter of water, so we can use this to plan catchments. Domestic water tanks up to 100,000 liters in volume can be constructed of concrete for long-lasting, economically sound water storage. They can be built under buildings to act as a cool thermal mass or as the walls of cellars. Very large tanks can be roofed to catch their own water, and when paired with a windmill or solar pump, water can be sent to storages upslope to be gravity-fed back down. Rainwater doesn’t go stagnant. If tanks are properly screened, then mosquitoes are not a problem. A natural anaerobic decomposition occurs at the bottom of tanks, which helps to keep the water clean and clear. A suspended bag of limestone, dolomite, marble, or shells can help to keep the water hard and prevent trouble with toxins. KEY TAKEAWAYS - Roof water should be stored in tanks or sealed wells for drinking water. - Hard surfaces of any kind can supply runoff for storage. Swales along roadsides are the cheapest catchments for non-drinking water. - Development designers should first consider water then access then structures. - Gravel reed beds can clean grey water, and dry composting toilets can eliminate black waste water. - Rainwater doesn’t go stagnant. It lasts for years. 11.49 – Large Tanks Forming Foundations [ANMTN] BRIEF OVERVIEW Large underground tanks can form foundations for uphill barns. They can be filled from roof catchments, and a space can be left between them to form a cool cellar. Water will then gravity flow to the house or irrigation from a pipe installed at the bottom of the tank and an overflow at the top of it. 11.48 – Bare Rock Slab with Gutter to Storage [ANMTN] BRIEF OVERVIEW A bare rock slab can be fitted with a concrete gutter to lead all water to a shallow limonia that can overflow to a roofed storage tank for the house, stock animals, or wildlife. 11.50 – Swales for Roof Drip [ANMTN] BRIEF OVERVIEW Small domestic garden swales can be filled with pebbles, fed from a roof drip, and provide a shaded water source for a vine trellis.

1.1.6. Modules 11.51 to 11.62 11.51 – Water Harvesting on Open Sites for Tanks or Cisterns [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Explain how water harvesting in earth tanks can create an oasis BRIEF OVERVIEW In areas with good clays, earth tanks can be built in the ground, and they should be deep and narrow to minimized surface area, reducing evaporation. The earth around the tanks can be shaped to drain into them at particular points of input, creating a catchment area while eliminating erosive worries. With swales, tanks, and cisterns, 30 centimeters or more of rain can create a suburban oasis. Water can be directed into settlements to easily supply all the water needs, and the value of this water harvesting far outweighs the cost of the necessary construction. KEY TAKEAWAYS - Earth tanks can be built in the ground where soils are clay. - They should be narrow, deep, and roofed to minimize evaporation. - The area surrounding the tanks can be shaped to drain into them at specific points of entry to prevent erosion. 11.52 – Run-Off Agriculture [ANMTN] BRIEF OVERVIEW Traditional use of runoff in scarps and pediment areas starts by slowing the runoff from top surfaces through the vertical side wadi and down to the entrance, as well as encouraging hardy trees to slow the water flows in big events. Near the entrance, a diversion drain can be excavated at the base of the scarp cliff to direct water back to the entrance. At the top of the external pediment, wells can be installed to access the lens of water below. Swales and brush fences can be installed to slow and control floods and feed opportunistic fields. 11.53 – Clay Catchement Sloping to Cistern [ANMTN] BRIEF OVERVIEW In country that isn’t too steep and has high clay content in the soil, a small clay catchment can be shaped to direct runoff water. A roofed and shaded underground cistern can be designed to store the water. Mounds can be built at the sides to act as silt traps for cleaning the water, as well as stop animals from entering and drowning. Mark As Complete 11.54 – Strategies in Headwaters [ANMTN] BRIEF OVERVIEW The strategies in headwaters change with slope angles. Absorption wells, one-meter-wide and four-meter-deep, and/or boomerang rock walls can be installed at an eighteen-degree slope. At fourteen degrees, there can be meter-high, silt-spreading terraces. Swales spaced at roughly thirty meters can be installed on slopes of seven degrees, and they can connect to foothill limonia or dams. Below this, there are usually salt pans or basin lakes. 11.55 – Water Spreading [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Analyze the normal runoff on overgrazed lands and how to prevent salinization - Give examples of impediments that prevent water absorption and harvesting - Outline how to approach designing a desert landscape for stability BRIEF OVERVIEW Overgrazed landscapes lose most rainwater to runoff, so dry streams become torrents full of debris, which eventually spreads out over lower plains. In this case, the water either picks up salt on the way down or goes to the ocean, but it is lost to us. We need to catch it high in the landscape and soak it into soils. This will help to de-salt aquifers with designs to flush them with fresh water from dams, swales, tree lines, deep-ripped contours, lines of stones, and natural rock palisades. For stability, 70 to 80 percent of land needs to be designed for forests and water harvesting, whereas only 20 to 30 percent should be integrated crop production. Possible water systems should be the deciding factor for designed placement patterns, and settlements should be placed off of devastating water flows, which can be diverted with oversized earthworks. In deserts, 88% of water is lost to runoff and evaporation and only 12% available to plants, whereas those figures are the opposite in forested areas. We can use maximum 24-hour rainfall stats to over-estimate catchment and storage systems. Higher, smaller streams move faster, which makes them more destructive. Large, low-lying streams slow water flows. Storages and retardation basins reduce or delay flood peaks, and the destructive flows are interrupted by retention banks, swales, and swamps. Decreases in vegetation cause increases in runoff. Heavy rains after hot, dry summers cause the most erosion, and broad-scale fires and cultivation before rains cause massive erosive problems. But, we can design well so that these large rain events can provide for our needs. Roofs, roads, car parks, concreted structures, and compacted grounds must be accounted for, as do non-wetting sands, hard clays, and rocks for their fast runoff. Sand storms should be monitored because they can seal natural intakes for aquifers, which will slow spring flows. Infiltration rates need to be considered, and artificial intakes are necessary over large areas. With rainfall data, we can estimate runoff and design to make the most of it. KEY TAKEAWAYS - On overgrazed landscapes, most water is lost to runoff and evaporation. - Runoff water goes to the low plains, picking up salt or draining the ocean, so that we can no longer use it. - Dams, swales, tree lines, deep-ripped contours, lines of stones, and natural stone palisades can all help to stop, spread, and soak water into soil. - Storages and retardation basins reduce and delay flood peaks, and retention banks, swales, and swamps interrupt destructive water flows. - With rainfall data, we can estimate potential runoff and design to both lessen its destructive effects and harvest it for productive use. 11.56 – Salt in Landscape Water [ANMTN] BRIEF OVERVIEW The salt in landscape water that has drained from a wadi rapidly picks up as it drains from plains. Shallow groundwater moving slowly also picks up salt. Saltwater can be as dense as 400 parts per million within a few hundred meters of a wadi entrance, so windmills should be located close to the hills, drawing fresh water from the mid-depths. Below that water are very salty leads we don’t want to interfere with. 11.57 – Halting and Absorbing Water Run-Off [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Summarize the basics of how to stop, spread, and soak water in the desert - Identify the different catchment techniques available for different soils and landscapes BRIEF OVERVIEW We want to stop, spread, and soak water into the ground. This will make a destructive force, flooding water flows, into a life-enhancing force. We want to soak the water into perched aquifers, being careful to avoid the deeper saltwater leads. Then, minimum, modest use of aquifers can be for growing drought-tolerant trees. Streams should have broad intakes so that they don’t clog, and they can be de-silted, with the silt used as a growing medium. Once these systems are established, the trees will regulate them. In the meantime, it’s sensible to install depth-marking steel pegs to monitor the silt levels. In clay, the base of swales can be ripped and gypsum added to increase infiltration. On sandy slopes, erosion can be interrupted with exaggerated swale banks with trees, which will eventually become level terraces. The level terraces will pacify water flows and can be planted back to crops, and this will continuously recharge the landscape and possibly make permanent springs. Dams store water visibly, but swales can soak water over kilometers of land. Swales systems can take overflows out of the back of dams to hydrate the landscape. Really, settlements only need two dams, one for clean water and one for swimming. KEY TAKEAWAYS - We want to stop, spread, and soak water into soils. - Modestly using aquifers to establish drought-tolerant trees helps to establish a self-regulating recharge system. - Swales and level, vegetated terraces can spread and soak water to continuously recharge aquifers and even create permanent springs. - Settlements only need two dams, one for clean water and one for swimming. 11.58 – Designs for Sorting Preferred Solids [ANMTN] BRIEF OVERVIEW We can design patterned waterways to deposit and sort materials. A stepped cascade can catch heavy metals on the hollows. Silt traps are created by deepening and widening water courses. Steering the flow into the main channel creates scour holes, while steering the flow out creates deposits of materials like logs, organic matter, and silt. 11.59 – Limonia [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Define what a limonia is and explain how to build one - Elaborate on how to develop and maintain an orchard in a limonia BRIEF OVERVIEW A limonia is an unusual feature that captures hard surface runoff from huge rocks. Essentially, they are dry dams with good soils and used to produce self-irrigated orchards with a date palm over-story. They are constructed by building a large earth bank, roughly a meter high and two meters wide that traps water and creates an ephemeral lake during rain events. There are level spillways about 40 centimeters high at the ends of the wall, where they butt up against the stone, and emergency gabions to allow safe overflow in serious rains. Establishing the orchard can be difficult during the early stages, but once more canopy is there, the trees shade the system and provide organic matter. A little cultivation between the trees will help the ground soak in more water, and opportunistic crops can be planted there after rain events. This system should not be grazed. KEY TAKEAWAYS - Limonia capture hard-surface runoff form large rocks — inselbergs — in the desert. - They are huge earth banks that create ephemeral lakes during rain events, and this supports self-irrigating orchards with date palm over-stories. 11.60 – Aquifer Intake Areas [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Appraise the landscape for aquifer intake areas - Examine potential issues with aquifer intakes and how to address them - Recognize what qanats are BRIEF OVERVIEW Aquifer intake areas include ridges, plateaus, and slopes of detritus, both geological and organic material. Channels can be dug below the surface to infiltrate water deep into the ground, and dense forests are the classic infiltration systems. Loose gravel, shattered and soluble rocks, dune sand caps, high slopes of limestone, and fissures all help to recharge water. Flat areas can work as perched aquifers in sands above clay soils and desert pavements, causing water to seep out of the dune base to provide for local trees. Volcanic ash, mudslides, and fine dusts and sands blown in from overgrazed or cultivated plains can clog intakes, so we have to look out for them. Windbreaks help with dusts from outside areas. Intake areas can be increased with tree-planting on ridges, deep interceptor drains, ripped rock pavement and capstone, diversion drains to wells, boulder banks, pits and swales. Trees keep systems maintained and stop dusts for clogging them. Qanats, underground canals, can bring water to the surface in a constant flow. KEY TAKEAWAYS - Aquifer intakes include ridges, plateaus, and slopes of geological and/or organic detritus. - Channels dug on contour below the surface can help water infiltrate deep into the landscape. - Dense forests are great infiltrators, which also regulate harvesting systems. - Loose gravel, shattered and soluble rocks, dune sand caps, high slope limestone, and fissures all help to recharge water. - We have to work to protect intakes, removing debris from volcanic ash, wind-blown dust and sand, and mudslides. - Intake areas can be increased by planting trees, installing interceptor drains, ripping rock pavement, diverting water to wells, creating boulder banks, digging pits, and constructing swales. 11.61 – Aquifer Intake Areas [ANMTN] BRIEF OVERVIEW The intakes of aquifers are different, and we can help recharge them by design. In sediments above impervious rock layers, aquifers can be perched water tables. Shallow sand aquifers can be accessed with a pipe to be easily pumped and recharged. Bore holes are recharged by hill country, but care is necessary not to draw saltwater up from below the lens. 11.62 – Qanats [ANMTN] BRIEF OVERVIEW Qanats are ancient systems of underground water tunnels. A shaft is excavated until it hits fresh water tables, and an underground tunnel is started on the hills just below the intake areas, moving down, away from the hill — not quite horizontally — towards flatter areas. The excavated material is taken up through a repeated set of shafts in a line to make the extraction of tailings easier. Eventually, the qanat reaches the surface with a continuous flow of water that can’t be turned off.

1.2. Module 11b

1.2.1. Modules 11b.1 to 11b.10 11b.1 – Chapter 11 Course Notes; Part Two [PDF] Infiltration, Stabilisation, and Harvesting Infiltration is when water soaks into soils (or other materials), and infiltration rates differ with each type of material. In desert climates, where clay soils are often alkaline, slightly acidic sands can be spread a meter deep to enhance water infiltration and storage, and this arrangement creates ideal gardens because roots can break up the clay beneath and add humus to the sands. This sand-clay soil preparation actually occurs naturally at the exits of canyons, where floods distribute material. On grander landscapes, deep swales will interrupt water flows, catching debris and water, eventually forming level terraces, or in areas with quick-draining soils, layers of clay, gley, or tar can seal gardens to retain moisture. Continued... 11b.2 – Infiltration [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Define infiltration, noting the rates at which it occurs in different materials - Realize the potential of spreading sand over clay soils - Give examples of methods for spreading and capturing water in desert gardens BRIEF OVERVIEW Infiltration is the soakage of water into soils or other materials, and rain infiltrates at different speeds into different materials. An inch of water (25mm) will take two or three hours to soak into fine dust soils, six to 36 hours into clay loams, and up to 48 hours into heavy clays. Neutral or slightly acidic sand can be spread a meter deep over alkaline clay soils to store water for longer periods of time. This makes ideal gardens because trees and plant roots will break up the clays and provide organic matter — humus — in the sands. This type of system occurs naturally at discharge points of canyons, where moisture distributes material. Deep swales interrupt water flow. They can catch sands and gravels to create intentionally designed growing spaces, level terraces of clay soils. In other areas, layers of clay, gley, or tar can be used to seal gardens. This would drown plants in humid climates but helps them thrive in deserts. KEY TAKEAWAYS - Infiltration is the soakage of water into soils and other materials. - Rain infiltrates at different speeds into different materials. - Neutral or acidic sands can be added atop alkaline clays to create ideal gardens. - Swales interrupt water flow and can catch sands/gravel to create designed growing spaces. - Clay, gley, or tar can be used to seal gardens in spaces that drain to quickly. 11b.3 – Slope Stabilisation for Infiltration [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Explain how clumping grasses can be used to increase slope stabilization - List other possibilities for infiltration elements BRIEF OVERVIEW Slope stabilization can begin with how to plant perennial clumping vegetation, which will establish roots to increase stabilization and infiltration. Planted on slopes, these clumping grasses will slow moisture down and collect detritus. The moisture will then soak into the detritus and move to the root zones, further stabilizing the slope. These plantings can be on contour or in crescents with the points upslope, which will build up soils to create good planting zones. In colder drylands, tussock grasses and mosses perform these same functions. Swales, wadi dams, level gardens, and soakage pit are all water infiltration elements. Swales are the easiest to install and cover large stretches of landscape. Wadi dams create level silt fields and are good for local food forests. KEY TAKEAWAYS - Perennial clumping vegetation planted on contour or in upward facing crescent increases stabilization and infiltration. - Tussock grasses and mosses perform the same stabilizing and infiltrating functions in colder drylands. - Swales, wadi dams, level gardens, and soakage pits are also water infiltration elements. 11b.4 – Floodwater Harvesting [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Recognize that floodwaters can be as much a benefit as a disaster - Describe how to build a flood pan for catching nutrient-rich material on the plains - Analyze the needs of opportunistic gardens that work in inconsistent but flooding rains BRIEF OVERVIEW Floodwaters can be a disaster, but they can also be a solution because there is a lot to harvest in them. They create delta like deposits at the mouths of wadis, and floods are rich in nutrients from collected manures, organic material, shells, and so on. We can also design flood pan patterns across the plains, with each pan draining to the same corner where a silt trap collects fertile materials. A low earth bank should be around the pan, and it should be stabilized on the inside with rocks and on the outside with hardy plants. We can garden in the pan, surrounding the nutrient-rich silt traps, and we can plant stick cuttings into the wall to further stabilize it and add organic matter inside the pan. With rains of eight centimeters or more, we can expect runoff, and these opportunistic gardens will ideally harvest from areas 15 to 27 times their size. While the floods are inconsistent, the system must be set up to receive the water and deposits when the events do happen. KEY TAKEAWAYS - Floodwaters can be disastrous, or with the right design, they can be solution. - Flood pan patterns across the landscape can provide fertile, opportunistic gardens after rain events. - While rains may be inconsistent, we must be prepared to take full advantage when they do come. 11b.5 – Braided Streams [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Illustrate what a braided stream is - Explain different methods for extending the braiding in the streams - Outline how using planting pans can help to vegetate these areas BRIEF OVERVIEW Braided stream patterns spread water flows from a main channel to many small ones coming off it and moving back in. The smaller streams are vegetated and create a continuous deposition of silt and sand. It’s possible to extend braids of water by installing a notched weir where the natural braiding begins. The weir can spread and create more numerous braids. At spots, placed rocks or concrete can cause the braided flows to split again, extending the effect even further. The braided pattern will begin to form rough diamond shapes, which can be transformed into planting pans. Notches (deep holes) with rocks around them can be installed where the braided streams cross, and this will increase the amount of soakage. The whole landscape can then be vegetated. This is a great way to maximize water before it hits rivers or salt pans and becomes unusable. KEY TAKEAWAYS - Braided stream patterns occur naturally on desert plains and spread water out from the main channel. - Braided streams can be extended and created by installing notched weirs. - As the braided streams cross, forming rough diamonds in the soil, deep holes can be installed as silt traps, which can be planted around. - The pattern allows us to maximize water soakage before it reaches rivers or salt pans, where we lose it. 11b.6 – Braided Streams and Notches Weir [ANMTN] BRIEF OVERVIEW A natural braid pattern occurs in sands at the center of a floodplain. Notched weirs will spread water across a floodplain. A notched weir with a concrete sill as a spreader wall will initiate braiding patterns in sandy rivers to help disperse the flow. 11b.7 – Notches Weir (Elevation) [ANMTN] BRIEF OVERVIEW A notched weir well anchored in the base and sides of the stream, with the bank of notches level to each other, enables us to widen, slow, and harvest the floodwaters. 11b.8 – Scour Holes [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Discuss the effects of flood events in terms of scour holes - Relate how scour holes are naturally formed or can be designed - List other useful elements that can be created around a scour hole in a river BRIEF OVERVIEW Scour holes work like desert lagoons, and they are abundant with both aquatic and terrestrial life. They are formed by rivers that pass through narrow gaps, where the flows increase in power and dig into the earth. We can also design scour holes. By creating two compact earth banks that lead runoff into the river, the added water and velocity scours a deep spot in the river. If we start to shape the river around the scour hole, we can collect detritus. We can add a deep channel and earth bank where trees will grow. We can add flood bank fields to capture moisture, silt, and organic matter. We can put up a fence that collects extra mulches and firewood. Without floods, scour holes still fill with seepage from deep sands. This seepage can be increased by installing sand dams up stream. Over time, trees will naturally grow around the scour holes, preventing evaporation. These make great swimming holes. KEY TAKEAWAYS - Scour holes are like desert lagoons, rich in aquatic and terrestrial life, that form when river flows are narrowed and, thus, dig deep into the earth. - We can design earth works to create the same effect. - Around our designed scour holes, we can include tree systems, flood bank fields, and mulch collection systems. - Scour holes continually fill with water seepage from deep sands, which can be enhanced by installing sand dams upstream. 11b.9 – Scour Hole Lagoon, Mulch Fence [ANMTN] BRIEF OVERVIEW Solid earth rock and cement walls can be designed to curve into a desert river, stopping just before the bank to create scour hole lagoons. Strong fences constructed to curve away from the river will work as mulch and silt traps. Swales and fields can be designed to hold and infiltrate water, and bordering trees capture the backwater silt deposition. 11b.10 – Sandy River Beds [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Describe the ecology that forms around sandy river beds in the desert BRIEF OVERVIEW Deep sands fill river valleys. In them, we can observe that palms and large trees grow in sheltered river bays. The river banks go down to the river with one side being soft and sandy and the other rocky. Tree species will grow with respect to the conditions, some preferring the rocks and others the deep sands. Burrowing animals prefer the silt side, where they can dig. We can observe this, even when it is dry, and take advantage in our designs. KEY TAKEAWAYS - Palms and large trees grow in sheltered river bays. - Sandy river banks occur on one side of the river, and on the other side, there will be rocky banks. - Trees and animals will choose the conditions, or side of the river, more suited to their needs. - This can be observed even when systems are dry and taken advantage of in designs.

1.2.2. Modules 11b.11 to 11b.20 11b.11 – Pitting in Sands and Light Soils [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Explain how pitting works as a water absorption system on a broad-scale - Relate different ways of pitting, small and large BRIEF OVERVIEW Pitting is a great broad-scale system, particularly suited to sands and soft soils. It insures that no runoff event will happen without water absorption, and the pits catch organic matter to add fertility and natural seeding. For small pitting, a simple disc can be towed to leave divots across the landscape, roughly on contour. Seeds can then be added, and many will natural accrue. For large pits—half a meter to a meter wide, three-quarters of a meter apart, and a third of meter deep—the excavation should be side-cast downhill, as with a swale, and they, too, should be roughly on contour. Both types of pits will green up, and they will continue to grow even in droughts. As with any desert revitalization, it’s very important to manage grazing animals. KEY TAKEAWAYS - Pitting is a broad-scale system that works well in sands and soft soils. - Small pits can be added using a towed disc that creates divots across the landscape, roughly on contour. - Large pits are about half a meter wide, three-quarters of a meter apart, and a third of a meter deep, with the side-cast downhill. - These pits will support growth during droughts. 11b.12 – Spilling Water Downslope in Fragile Soils [VIDEO] BRIEF OVERVIEW When spilling water over fragile soils, we have to be very careful not to form erosion gullies. We can assess the force of water flows by observing the ends of drainage pipes or where diversion drains discharge. If we can stop this erosion, that’s a good result. Long spreader banks with level sill spillways are good method, and the spillways can possibly be stabilized with vegetation but could require stones or concrete. Splash pools for spillways and pipes will prevent erosive gullies, and these can be made of concretes, rocks, or even clumping grasses, if there is enough water. Lastly, u-shaped channels can be filled with boulders, rocks, and gravel to slow water flows and allow them to drain on level. KEY TAKEAWAYS - We have to be very careful not to from erosion gullies in fragile soils. - Spreader banks with level spillways, splash pools, and u-shaped channel filled with stone are all good methods for pacifying erosive water flows. 11b.13 – Very Long Spreader Banks [ANMTN] BRIEF OVERVIEW Long spreader banks take long concentrated erosive flows and passively sheet the water down hill. In crucial areas, a concrete core can be added to insure a perfectly passive flow. 11b.14 – Grassed Spillways with Steering Banks [ANMTN] BRIEF OVERVIEW Water can be dropped safely downslope after crossing a level sill spreader bank then being contained between to steering banks. After passing through grasses and legumes, the clean water can be picked up in a tail drain and rerouted to its end use. The area should be fenced to prevent grazing stock damage. 11b.15 – Sealed Spillways to Splash Pools [ANMTN] BRIEF OVERVIEW Where water has to be dropped downhill in dry land, it can be done in open pipes that splash into stone or concrete spillways to reduce the chance of erosion. 11b.16 – Sand Dams and Clearwater Resevoirs [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Contrast sand dams and clear-water reservoirs - Illustrate the relationship between sand dams and clear-water reservoirs - Describe the proper construction of a sand dam and clear-water reservoir - Explain how sand dams can be used to grow trees and opportunistic crops - Give examples of how sand dams and clear-water reservoirs benefit a community BRIEF OVERVIEW Sand dams and clear-water reservoirs are almost opposites, but a sand dam is needed to create the reservoir. These are best created in the gently sloping foothills, where water surges. The sand dam wall needs to be built of rock or concrete, keyed well into the valley walls, so that it can handle the intense pressure of water and material build up. The downslope side of the wall needs a sloping curve form to act as a splash guard, and on the inside, there needs to be a constructed channel filled with rocks. The top of the wall should be completely level. The channel will move clear water to the side, where it will fill a contour dam. This contour dam will be between 1/10 and 1/20 the size of the sand dam, and it should be five to nine meters deep. Trees should be planted around it to provide shade and protection from evaporation. Trees can also be planted in the bays that collect silt and organic material upstream of the silt dam, and these can be used for opportunistic crops as well. Downhill of the sand dam, water seepage will allow for another forest to be grown. One or two of these can make an enormous difference to a community. The clear-water reservoir will stay full throughout droughts. Wildlife will be attracted to the trees and drop manures that will enrich the soil. Scour holes downslope will be continuously recharged, making for much appreciated swimming spots. KEY TAKEAWAYS - Sand dams are needed to create clear-water reservoirs. - This combination works best in the gently sloping foothills, where water flows surge. - Sand dam walls should be built of strong material and keyed several meters into the valley walls. - A channel on the upside of the sand dam wall will lead water to a clear-water reservoir elsewhere. - Trees should be planted around the reservoir, in the bays upslope in the sand dam, and just below the sand dam wall. 11b.17 – Clearwater Dam [ANMTN] BRIEF OVERVIEW Sand dams and clear-water dams work in tandem and can be installed in dry lands. The dam wall must be installed very securely into the flood banks. A series of deep bays should be cut into the upstream banks and planted with trees for stability. A concrete wall will be a splash apron and a low spillway for low-flow event, and a rock-filled canal should direct water to the clear water dam. A safe downhill u-shaped spillway with a gravel base covered in shingles then boulders can prevent erosion in flooding events. The clear-water dam can be planted to shade trees and should be only 1/10 the surface area of the sand dam. Downstream seepage forests and opportunistic crops can be grown after flood events. 11b.18 – Dams [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Relate how barrier dams work differently in drylands as opposed to in stable country - Summarize an appropriate method for building sand dams BRIEF OVERVIEW Barrier dams in wooded valleys and stable country can last hundreds of years, but when they are set up in drylands, they will fill with silts and sediment. Clear-water dams have to be built off the valley and bled water from sand dams through channels and silt traps, and they need to be fenced off from livestock. The base floor of a dam needs to be clay or solid rock. After floods, the sand dam’s level silt field can be planted to opportunistic crops. The dams are built in stages, going up roughly a meter at a time as the fill. The same can be done with gabions. Then, as we incorporate these systems, we are turning the problem of erosion into the solution of water filtration. KEY TAKEAWAYS - Barrier dams in drylands fill with silt and sediment. - Clear-water dams have to be built off the valley and bled water from sand dams. - Dams are built in stages, going up a piece at a time, as the silt field levels behind them. - This system turn the problem of erosion into the solution of water filtration. 11b.19 – Clearwater Dam Bled off Sandtrap [ANMTN] BRIEF OVERVIEW A clear-water dam can be bled off near the back off a sand-trap dam with a diversion drain that has a silt trap. This could also lead to a swale for a productive tree system. It will need to be fenced and planted to trees for protection. The sand-trap barrier dam can have a fitted weir with a sloping grill over a small concrete canal, leading to another clear-water dam or swale. A splash apron needs to be installed to avoid erosion. Dry river beds through folds develop very different species from one side to the other because river leaves silt on one side and erodes the other, exposing rock. The silt bank will have the most burrowing animals and can be planted to hardy shrubs. The deep silt can be planted to floodplain trees, and the rock bank should be planted to hardy trees that can grow through rock crevices. 11b.20 – Rock Holes [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Define rock basins and how we can increase their water harvesting BRIEF OVERVIEW Rock basins naturally occur and behave like water tanks. They are created by a scouring effect from water flows that deepen and open up holes in the rock. Salt erosion, boosted by evaporation, can do the same thing. Then, we can fill these holes with pebbles or roof them to prevent evaporation. Gutters can be installed to increase the moisture led to them, and the holes can be enlarged for added harvest. Any advantages like this equate to extending our growing systems. KEY TAKEAWAYS - Rock basins are natural water tanks created by scouring effects of water flows. - Rock holes can be protected from evaporation, given gutters, and enlarged to aid in water harvesting and storage. - These little advantages help us extend our growing systems.

1.2.3. Modules 11b.21 to 11b.30 11b.21 – Evaporation and Evapotranspiration [VIDEO] BRIEF OVERVIEW Our design concerns in the drylands are about preventing evaporation, but we also must think about evapotranspiration. While there is more potential evaporation than rainfall, unless we have created open-air dams, there is no water to actually be evaporated. To grow crops, we need stored water or moisture stored in soil. We can also create situations where still air lowers evaporation rates, something called the oasis effect. On the other hand, the clothesline effect is produced when winds, especially hot and dry ones, take the moisture out of things quicker. To prevent the clothesline effect, we need thick windbreaks and/or trees scattered throughout fields. Carefully selected trees will require much less water than is lost to the effect, and using hardy desert legumes will help the crop. Productive fields should be no larger than 2000 square meters. In smaller home gardens, it’s possible to screen out almost all winds and provide 50% shade. KEY TAKEAWAYS - Our design concerns are about preventing evaporation, but we also must think of evapotranspiration. - The oasis effect is when still air lowers the evapotranspiration rate. The clothesline effect is when winds speed up the drying rate. - We can prevent the clothesline effect by including thick windbreaks around our fields and/or trees scattered throughout them. - Productive dryland fields should only be about 2000 square meters, so that they can remain sheltered. 11b.22 – Conservation of Water in Transit [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Outline the two water transit issues that cause massive losses of water - Describe qanats as an alternative to modern piping - List techniques that help minimize evaporation in open water storages - Illustrate how to tap into headwater aquifers for sweetwater - Realize the water saving effect of deep mulches BRIEF OVERVIEW Large volumes of water can be lost in transit due to evaporation and leaking. Modern piping is the most efficient way to prevent this. When that isn’t available, ancient systems called qanats can be used. Qanats start with a shaft that reaches down to spring lines of water, and they consist of several shafts from the surface that extend a gallery that moves a steady flow of water until it breaks the surface downslope. When water is at the surface, however, it must be protected from evaporation. This starts by supplying roofing and/or floating raft gardens. Windbreaks can also help with the clothesline effect. It is much preferable, then, to have several small systems that are deep and can be covered than a large system that will lose a lot of water to evaporation. Using a nearly horizontal pipe, it’s also possible to tap into headwater aquifers that will supply water at pressure. Then, with sweet water, we can create miracles in the desert because there is plenty of sun. Solar pumps and windmills can also move water up to high tanks to be gravity-fed back down. Lastly, putting ten to fifteen inches of mulch greatly reduces evaporation, sometimes reducing irrigation requirements by 90%. KEY TAKEAWAYS - Large volumes of water can be lost in transit, either via evaporation or leakage. - Qanats are ancient systems that move constant water flows to the surface via shafts and a gallery. - Water at the surface must be protected with roofs, floating gardens, and windbreaks. - Systems should be numerous and small, as opposed to large, which is more susceptible to evaporation. - Headwater aquifers are possible by installing nearly horizontal pipes. - Solar pumps and windmills can pump water to high tanks that will gravity-feed water back down. - Mulch greatly…greatly!...reduces evaporation. 11b.23 – Structure of Dams [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Summarize the basic shape and orientation of efficient dryland dams - Recognize the need to have trees ready for the right opportunity to establish them BRIEF OVERVIEW Dryland dams are most effective in deep conical forms with a V-shape moving back to a point of entry. They are ideally oriented east-to-west in a shaded valley, and they should be arranged in small series. When half-full, upper dams should be drained into lower dams to create one full dam rather than two half-empty ones, as this reduces evaporation. Several small series of three dams works more efficiently than a large system of twenty dams. Water can be pumped to larger header tanks to extend seasons, but it is imperative to be ready to establish more trees during good years. Trees should be ready in a nursery, and an extension site should be carefully chosen and prepared. When extended our systems, it is important to move in modest, manageable increments, establishing strong systems that will sustain. KEY TAKEAWAYS - Dams are most effective as deep conical structures with V-shaped surface areas. - They are ideally oriented east-to-west in shaded valleys. - Dams should be in small series, with lower dams kept full as opposed to higher dams being half-full. - To extend systems, we must be ready — trees in nursery, sites chosen and prepared — for good years. - Systems should be extended modestly. 11b.24 – Three Dams in Series Reduce Evaporation [ANMTN] BRIEF OVERVIEW Three dams in a series can reduce evaporation by carefully siphoning down from one dam to the next. When the top two are half-empty, the top should be siphoned to the lower one. Then, when the bottom two are both half-empty, the higher should be siphoned into the lower. All desert dams should be conical in section and maximize depth to surface area. The surface to volume ratio increases as the water level drops, which increases evaporation. Keeping the water as deep as possible for as long as possible can reduce evaporation by up to forty percent. 11b.25 – The Desert House [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Identify the necessary considerations for constructing a comfortable desert dwelling - Give examples of features that can make desert homes energy-efficient - Describe the arrangement of homes and buildings in desert community BRIEF OVERVIEW Desert homes are designed similarly to those in the sub-tropics, where summers require cooling and winters warmth. The temperatures also have more drastic changes the further away from the ocean they are. There are many features that make these homes energy-efficient. There is usually a centrally located, shaded courtyard to extend the coolness of the home. Evaporation — from charcoal, hessian cloth, unglazed pots, damp bark, etc. — is used for its cooling effect. East-to-west openings tend to be narrow to control the amount of sun and shade, and north-to-south areas are wider. Massive walls store heat and cool, and all surfaces are painted mat white to reflect the sun, helping to cool and providing indirect light. Windows are small and grilled. Ventilation is designed to enhance evaporative cooling, and trellises shade everything, open spaces, walls, and roofs. Around 30% of the living space will actually be outdoors. Houses are often nestled together to share energy functions. Streets should be narrow and shaded with trees or trellises, and north-south streets should be few and far between, preventing winds from ripping through. Buildings should be multi-storied to enhance shade, and all thermal mass—streets, parking areas, homes—should be shaded. Another classic desert home feature is to have canvass awning over windows, once again creating more functional shade. KEY TAKEAWAYS - Desert house design focuses on cooling in the summer and warming in the winter. - Homes are designed to take advantage of natural cooling features: shaded courtyards, evaporation, large walls, etc. - Trellises and trees should be used to shade all thermal masses: streets, walls, roofs, parking areas, etc. - Houses are close together to shade energy functions, and buildings should be multi-storied to create more shade. - Streets should be narrow and north-south passageways minimal. 11b.26 – Isolated and Multiple Storey Housing [ANMTN] BRIEF OVERVIEW Desert settlements require thoughtful design with connected shade elements, as well as careful attention to orientation and angles of the sun. Extensive trellised courtyards, shade trees, and shaded gardens create sources of cool air that can be drawn through living spaces. The hard surfaces of roads and footpaths can be connected to swales that will grow trees to provide shade for reducing general ground heat stress. 11b.27 – Site Conditions [VIDEO] BRIEF OVERVIEW More than any other climate, where we settle in deserts makes a major difference, so we have to be very careful about selecting sites. Water access is the first priority, and only five percent of the landscape has good runoff. Settlements should also be at least 20 meters above the lowest plains so that they are out of the frost zones. Water catchments need to be near housing, and groundwater should only be a back up source of water. Options for underground housing, caves or earth-covered shelters, should be explored. Flat, parapet roof areas can extend production, helps to cool the house, and offer space for water storage. KEY TAKEAWAYS - Where we settle in deserts makes a major difference. - Water access is first priority and only five percent of the landscape has the right runoff. - Settlements should be 20 meters over the lowest plains. - Water catchments should be near houses and groundwater left as an emergency water source. - Underground housing is a great, efficient option. - Flat, parapet roofs can be used for gardens, cooling, and water storage. 11b.28 – Underground and Earth Sheltered [VIDEO] BRIEF OVERVIEW Underground homes can be easily carved out of soft rock with modern mining equipment. Sites ideally will have hard cap rock surfaces above them, but this can be done with concrete. Ventilation and light shafts are very important. Compost toilets can be installed near the doors. Walls can be cut and smoothed by hand, leaving channels to run electricity and plumbing. Water tanks can be carved into the house from above and piped down, and wastewater can be piped through the front to reed beds that led to gardens. Solar panels and solar-heated water tanks can be installed on the “roof”. The front entrance can have a glasshouse in front of it, which can be shaded in the summer and used as a heat pump in the winter. Hot caves can be created by using upslope features with overhanging entrances to catch rising heat, and these make great dry storages. Cold caves can be created by carving into dips to catch falling air, and these make wonderful food storage areas. Living spaces are generally level, and these homes require very little maintenance and last for a very long time. KEY TAKEAWAYS - Underground homes can be easily carved out of soft rock with modern mining equipment. - Homes need ventilation and light shafts. - Water tanks can be carved out from above, and wastewater can be piped out of the front to gardens. - Solar panels and solar water heaters can be installed on the roof. - Glasshouses work well at the entrance, shading heat in the summer and creating a heat pump in winter. - Hot caves catch heat coming up and make great dry storages. - Cold caves harvest falling, cool air for great food storages. - These living spaces are low-maintenance and long-lasting. 11b.29 – Large Shallow Leach Fields [ANMTN] BRIEF OVERVIEW Where enough water is available, low-flush toilets can let water into soakage beds where trees can rapidly take up nutrients and transpire water. A pit that is five meters by five meters by half a meter deep is filled with boulders on the bottom, small rocks, and gravel on top. Cardboard or layers of newspaper covered with straw over the pit will soak up nitrates and ammonias. Large trees must surround it to function efficiently. 11b.30 – Forestieri House [ANMTN] BRIEF OVERVIEW The Forestiere House in Fresno, California, is a famous example of underground housing, with bedrooms, bathrooms, kitchen, lounges and so on. There are many fruit trees and vine crops in courtyards, with only their crowns visible at the earth’s surface. The temperature is constant, with very little variation throughout the year. Good ventilation is necessary for the removal of naturally occurring radon gas. Mark As Complete

1.2.4. Modules 11b.31 to 11b.40 11b.31 – Cave Houses [ANMTN] BRIEF OVERVIEW Cave houses in Coober Pedy, Australia, are built with a bench cut entry on the shade side of a hill. Mining machinery is used to excavate intricate designs. Light shafts with reflectors are used to illuminate rooms, and solar chimneys vent heat, steam, and gases. Façades are built on to the house faces and equipped with vine trellises. Temperatures are a constant twenty-five degrees Centigrade. Mark As Complete 11b.32 – Caves with Cool or Warm Air Supply [ANMTN] BRIEF OVERVIEW Caves can store cool or warm air by design. Warm air rising into a cave can be trapped using high internal roof space, and the cave can be used for dry storage. A glass entrance facing the sun can increase the warm air function. Cold night air falls into a cave with a low internal floor space. A trellised entry on the shade side with a sill to prevent water entry and solar chimney for keep cold air in help to make this into a cold storage. Cave houses are generally horizontal and can have both of these. Mark As Complete 11b.33 – Earth Sheltered Housing [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Summarize the construction of an earth-sheltered house to create cave conditions BRIEF OVERVIEW We can imitate the conditions of a cave by using concrete walls and roofing with earth piled up to the eaves and over the roof. With good clay soil, bulldozers and earth-moving equipment can quickly consolidate the materials necessary. Another simple option is to build a turkey nest dam and put a roof over it. This will be a cool, solid, flood-proof, fire-proof home, and it can be sealed inside with thin gabion walls that have been rendered. This makes a fast, cheap, and highly efficient house. KEY TAKEAWAYS - Earth-sheltered housing imitates the conditions of caves. - We can build turkey nest dams and roof them for sturdy, cheap, and highly efficient homes. 11b.34 – Earth Sheltered Surface Housing [ANMTN] BRIEF OVERVIEW Earth-sheltered surface houses work well in deserts where caves aren’t possible. Concrete walls and roofs will support earth banks and an earth roof, duplicating cave conditions with no risk of flooding. Deciduous vines can shelter sun-facing walls in summer and open them up to sun in winter. Light shafts open the rooms to sun, and solar chimneys keep it ventilated. 11b.35 – Surface Housing [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Explain where and how surface housing sites can be prepared - Give examples of ways to easily cool surface housing - Give examples of methods for efficiently heating surface housing BRIEF OVERVIEW Surface housing in the desert can be in excavated or hill-steeped slopes, compacted by bulldozers, and they’ll outperform mud bricks. The earth works can be installed to drain water away from the roof, and interior walls can be constructed. In unstable lands or lands that flood, it’s best to be above the ground, and another thing, especially in granite or volcanic rock, one should always test for radon before living underground. Houses built into a hill are easy to cool. A shaded, cold source can be created on the earth’s surface with a cold-air tunnel, 20 meters long and at least a meter deep, leading into the house. Where the air enters the house, evaporation features can further the cooling effects. Another option is putting a rooftop feature that forces breezes down into the house and over the evaporation features. Solar chimneys can help to pull hot air out of the house and circulate the cooler air. Internal courtyards and trellises also add to the cooling effort. Heating is also available through design. There should be an outdoor shade house kitchen for the summer, but winter kitchens can be inside to help with heating. Thermal mass walls can also be constructed at windows to absorb daytime sun and heat the home. Glasshouses can be attached to the house for added heat in the winter, and they can also work as cool air draws in the summer. Seedlings can be started early in the spring, autumn crops can be ripened later, and winter greens can be grown in the glasshouse. KEY TAKEAWAYS - Surface housing in the desert can be on excavated or hill-stepped slopes, outlasting mud bricks. - Underground housing isn’t viable where lands are unstable, flood, or have radon. - Houses can be cooled with cold-air tunnels, evaporation features, forced air streams, internal courtyards, and solar chimneys. - Houses can be warmed with indoor winter kitchens, thermal mass walls near windows, and attached glasshouses. 11b.36 – Hill Stepped Houses Compacted by Bulldozer [ANMTN] BRIEF OVERVIEW Where soils have sufficient clay content, a bulldozer can quickly build a turkey nest dam that can be left open on the sun side. When roofed, it works as a cool desert house, safe from flooding. They can outperform all other forms of aboveground earth houses in cost, energy efficiency performance, and durability. 11b.37 – Cool Air Tunnel [ANMTN] BRIEF OVERVIEW Earth tunnels are great cooling devices for desert homes. They must be a minimum meter deep and twenty meters long. They should ideally slope downwards from a shaded air intake. Large unglazed pots, pans of water, wet charcoal trays, or drip-fed hessian cloth provide evaporative cooling. 11b.38 – Placement of Vegetation Around Dryland Houses [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Arrange the vegetation around a desert home to maximize efficiency BRIEF OVERVIEW The placement of vegetation around desert housing is crucial. The western wall should be completely shaded at all times, requiring evergreen trees and vines, to cut afternoon heat gain. The eastern side can have deciduous trees and vines, blocking the sun in warmer times and allowing some sun in in the winter. Houses should be elongated, running east to west, and allow winter sun into all rooms but no summer sun, so trellised, deciduous vines work great here. All of this makes a huge savings on energy, and it’s all accomplished by thoughtful design with vegetation. KEY TAKEAWAYS - The placement of vegetation around a desert house makes huge energy-saving difference. - Evergreen trees and vines should shade the western wall at all times, preventing afternoon heat gain. - Deciduous trees and vines on the eastern side can block summer sun but allow some winter sun in. - The house should be long, stretched east-to-west, to allow winter sun in but block summer sun with deciduous vine trellises. - Shutters should be outside, not inside, with lattice or slats to allow air to move through. 11b.39 – Correct Placement of Systems Around the House [ANMTN] BRIEF OVERVIEW Good placement of systems around a desert house maximizes efficiency and lowers running cost. No windows should be on the western walls, and they should be covered with evergreen trellis crop. A cool air tunnel and paved shade house with an outdoor kitchen and extended trellis on the shade side also provide sources of cool air. A water tank should be under the trellis. External blinds will prevent heat before it enters the house, and solar chimneys will cycle hot air out of the house. A paved trellis over the sun-side of the house can have crop leading to a garden-edge, earth-bank swale, and deciduous and palm trees can be planted on the sun side of the house. The main kitchen garden should be on the sun side with a deciduous vine trellis above it. House grey water can pass through a grass trap and reed bed and be fed to kitchen gardens. Swale orchards with main crop garden inter-swales are positioned directly above the house garden, with diversion drains helping to maximize garden soakage, increasing hydration. If near a wadi, check dams can be installed with diversion drains to increase hydration to the house garden area, and opportunistic crops can be planted in the wadi silt fields after flood events. 11b.40 – Home Energy Conservation [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - List simple methods for creating an energy-efficient desert home BRIEF OVERVIEW Home energy conservation is easy to achieve in the desert. Hot water can be supplied by solar hot water panels or black tubing on the roof. Evacuated hot water pipes, another option, can also supply water hot enough to cut down on the energy required for boiling water to cook. Solar electricity is easy to produce because there is an abundance of sun. Wastewater can be fed through reed beds and used to grow firewood, and a rocket stove can use that firewood very efficiently. Once established, almost all energy needs are the supplied for virtually no cost. KEY TAKEAWAYS - Home energy is easy and inexpensive in the desert. - Hot water can come from solar hot water panels, black tubing on the roof, or evacuated hot water pipes. - Solar electricity is easy to manage because there is so much sun. - Wastewater can go to growing firewood, which can be used efficiently to run a rocket stove for cooking.

1.2.5. Modules 11b.41 to 11b.50 11b.41 – House Water Conservation [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Outline a plan for conserving water in and around a desert house BRIEF OVERVIEW Home water conservation is obviously a must in the desert. Showers should be used minimally, and the showerheads in them should be minimum-flow heads. Wastewater should be used to either grow gardens or firewood, letting none of it escape. Waterless compost toilets will eliminate using water in toilets. Roof water, no matter how spare, should be caught in tanks on the shade side of the house, and the tanks should either be underground or shade trellised. KEY TAKEAWAYS - Water conservation is hugely important in the desert. - Showers should be minimally used and have low-flow showerheads. - Wastewater should be used grow gardens or produce firewood. - Toilets should be dry composting toilets. Roof water should be caught in tanks that are kept out of the sun. 11b.42 – The Desert Garden [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Contrast concerns in the desert garden with those in a garden elsewhere - Provide solutions for the challenges faced in a desert garden - Describe where to locate and how to manage a desert garden BRIEF OVERVIEW Desert gardens are different from gardens in other climates. Growers must be careful about soluble elements. Soils tend to have extreme pH levels, usually leaning to alkaline. Water use must be very carefully monitored, and there is a need for lots of shade for the garden. Wild and domestic animals will be a huge issue. The low level of resources will result in low levels of nutrition, so gardens must also be abundant. There are solutions for most issues. Protection for the garden can be supplied quickly with earth banks and fencing, Shade needs to average about 75%, and this is supplied by lots and lots of vine trellises. Soil has to be tested for deficiencies, particularly in zinc, phosphorus, iron and manganese, but it must also be checked for excess boron, nitrates, and fluorine. Salt content can’t be ignored, and rain runoff can help to flush away the salts. Garden crops should be carefully selected to be self-shading, deep-rooted, and hardy, while trees need to be drought-tolerant and hardy, like olives, pomegranate, palms, mulberry, and others. Gardens and houses should be near runoff areas. Vegetables should be under shade with trellises almost all the way around the garden. Wastewater soaks can move through reed beds into flood beds for crops. Everything should receive deep mulches. Peas and beans have to be a constant in the crop rotations to add fertility. Normal companion planting with hardy flowers is still a part of the garden. Every wall and roof should support a trellis. In outer areas, it’s useful to look for corridors of naturally sandy areas, which will soak in water. Any soak area, especially one with shade, can be used as a niche garden and planted to hardy, fruit species. KEY TAKEAWAYS - Desert gardens are very different from those in other climates. - Special consideration must be given to soluble elements, pH levels, water use, shade, and animals. - Crops and trees have to be carefully selected so that they can withstand dryland conditions. - Trellises and vining crops play a major role in shading the garden and should be present on all walls and roofs. - In the outer areas, corridors of sandy soil signify water soak areas and potential for growing niche crops. 11b.43 – Matching Up Earth Bed, Irrigation, Soil, and Plant Species [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - List important elements to include in garden plans - Arrange the kitchen garden for a desert home, noting which crops to favor - Relate the basic approaches to cultivating perennial and annual crops BRIEF OVERVIEW Gardens provide physical exercise, mental health, food for the family, and possibly cash. Beds should be planned with companion planting and seasonal succession. Plans for water should include mulch pits with ledges, circle gardens around leaky pots, flood beds, mulch baskets, and other water conserving techniques. These techniques will all work if approached with discipline and regularity. Cultivating plants requires special attention. Perennials and trees are best kept in the shade and in pots, waiting for the ideal time — after rain — to plant out. Trees should be planted in a soaked hole, topped with plenty of mulch, and shaded, with a preliminary pH check. Seedlings need to be planted in cool times, like evenings, with shade and wind protection. Tubers and bulbs can simply be pushed into mulch. Seeds can be scattered over sieved compost, covered with hessian cloth and watered, and the hessian cloth can then be removed after the seeds have germinated. Lenses of fine soil atop thick mulches are good for fine seeds, such as carrots. Gardens can be instant, but the soil isn’t at its best until a few years later. Three to six beds, roughly a meter wide and four meters long, can be rotated. Plantings should be grouped like families, with special favor shown to salt-tolerant plants like onions and tomatoes and special attention shown to less tolerant plants like peppers. Gladiolas, marigolds, and crotalarias are great companion plants for repelling insects and providing wind protection. Staple crops for a family can be grown in spaces of 20 to 30 square meters, and gardens should be small and shaded with trellised vine crops. Beds can be raised with sunken tops, and both greywater and rainwater runoff need to be taken full advantage of, with no sprinklers but all subsurface irrigation. KEY TAKEAWAYS - Gardens supply physical exercise, mental health, food for the family, and potentially cash. - Beds should be planned with companion planting and seasonal successions. - Water has to be planned for, using both greywater and rainwater runoff in sub-surface irrigation. - Cultivating plants requires special attention and particular techniques for different species. 11b.44 – Earthshaping within Gardens [ANMTN] BRIEF OVERVIEW There are many types of earth-shaping for desert gardens. Mulch pits of 30 centimeters deep and sixty centimeters across with the excavated soil around the sides can be filled with good compost and mulch at the bottom and used to plant trees. A mulch hole that is 60 centimeters wide and 80 centimeters deep is lined with a thick layer of paper, cardboard, or leaves at the bottom and filled with household waste, wool, ashes, and even metal waste, and the excavated dirt forms a ring around the hole with vegetables planted just on the inside of the mound. North-south ridges can be planted at the sides for shading seedlings, and the footpaths between them should be mulched heavily. Mulch baskets, two to three meters across, work for preserving hydration, and boxes of mulch over alkaline sands with drip lines do the same. Broad flood bays about three meters across can grow crops like carrots, or top-watered raised beds can work for areas with salty water supply. 11b.45 – Plants in Difficult Soils [ANMTN] BRIEF OVERVIEW There are different treatments for planting in difficult soils. Cowcrete, or platin, layers need to be cracked up and the holes filled with humus and organic waste before planting trees low enough to get its roots into damp sands. Cracking clay soils can be filled with sand and gypsum dust before planting. Alkaline sands can receive retention gels, seaweed, bentonite, sulfur, and minerals, and seedlings can be planted in biodegradable pots to adjust as they grow. Deep sands should be layered with plastic, thick cardboard, or very thick leaves, as well as being amended with retention gels, seaweed, nutrients, and bentonite and seedlings started in biodegradable pots. Hard shale can be shattered, the holes filled with soil and compost before planting. Hard pans can be ripped to half a meter deep to create tree lines and improve water infiltration. 11b.46 – Keyhole Bed [ANMTN] BRIEF OVERVIEW Keyhole beds have a one-meter wide circle footpath with a half-meter wide entry path, and the planting beds are one to two meters across with a windbreak around the outside. A tomato polyculture keyhole can be inter-planted with marigolds and dwarf nasturtiums, with chives at the entrance and basil surrounding the inner circle. Fava beans can be planted as a winter harvest or green manure between the tomatoes. The area should be wind-sheltered and covered in thick mulch. 11b.47 – Staple Foods [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Define staple foods and contrast them with other crops - Identify plants appropriate for mulching and creating humus in the desert - Describe an effective method for cultivating fruit trees - Recognize why it is that people in the desert won’t readily change their methods BRIEF OVERVIEW Staple foods are those that make up 50-plus percent of our diet when in season. A good home garden can easily supply 20 types of vegetables, six to nine different fruits, and three to six meats, but there are generally only two to four staple foods. Intensive grazing from industry has destroyed most of the useful vegetation (and potentially domesticated local animals) from the desert, but our systems need to focus on readying the best selected seeds, tubers, and roots for next season, looking ahead for our food supply. Mulch and humus production is integral to success in the desert setting. Nitrogen can come from edible tree legumes and plant legumes, whereas carbon mulch is produced well with edge barrier species, like clumping grasses. Plants with a high gel factor, such as the ice plant, can have edible parts, provide insulation for the ground, and catch wind-blown organic matter and soils to enhance the humus. Fruit trees should have interplants, as well as ground covers. The interplants can be coppiced or pollarded just before cooler seasons so that they provide shade in the heat and rich humus production in cooler times. High shade from thin-leafed legumes and palms provide a natural shade house, and the humus production from the trees is very rich. Using wastewater to get these systems moving will also greatly speed up the situation. People won’t easily change in the desert because the stakes are so high. If something goes wrong, the results are dire, so we have to trial crops, demonstrating how to use them in the system, how to grow them, and how to eat them. We also must establish the benefits of creating soil humus and utilizing wastewater when creating gardens. KEY TAKEAWAYS - Staple crops make over half of our diet when they are in season, and there are usually only two to four staple varieties. - Mulch and humus production are crucial to establishing desert gardens. - Fruit trees should be inter-planted with high shade coming from thin-leafed legumes and palms, as well as ground covers. - Utilizing wastewater greatly enhances the production of desert gardens. - People in the desert don’t easily change what they do, so it is necessary to demonstrate new trees and plants. 11b.48 – Vines [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - List the different functions that vines perform in desert gardens - Outline how vines are prescribed over and around desert gardens - Arrange vines to make a desert house more comfortable BRIEF OVERVIEW Vines play a bigger role in desert gardens than in any other climate. They are food, climate control, and water extension, and different types of vines — deciduous, evergreen, gel — have roles to play. Over gardens, spaced one to two meters apart, deciduous vines should supply about 50% shade. Along the easterly side of gardens, deciduous vines, spaced to give about 30% shade, will extend nighttime moisture. On the western edge of the garden, dense evergreen vines should be designed to block about 75% of the intense afternoon sun. Along the sun side of the garden, crop vines should grow to provide about 20% shade. The shade side of the garden doesn’t require a feature. The same thing can be done with houses. Vines can be grown beyond the window shades, stretching from the rooftop out to the edge of a veranda. They can be trellised from building to building or from buildings to perimeter walls, providing shade for the streets and creating an oasis effect. There are lots of fast-growing vines, and they can be watered with the wastewater from cleaning our spaces. These vines can produce mulch (and sticks for rocket stoves), and the humus and water will make the system boom. KEY TAKEAWAYS - Vines play are larger role in desert than in any other climate. - Gardens should be shaded with vines: deciduous vines provide 50% shade from above and 30% shade on the east, evergreen blocks out 75% of the sun on the west, and crop vines give 20% shade from the sun side. - Houses, too, can use vines to shade all sides, creating a cool oasis effect. 11b.49 – Plan of Vines Over Garden [ANMTN] BRIEF OVERVIEW Main kitchen gardens need to be covered in trellis, with only 50% light permeating in from the east and only five to ten percent from the west, both ends of the bed blocked with pole crops. Deciduous fruiting vines can be grown as a roof, and palms can provide more shade. A sunken plastic liner with a one-meter retaining border on the outside will help retain moisture, and deeply mulched footpaths are also great in this regard. 11b.50 – Fencing [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Identify the need for fencing and the cheapest options available - Realize the natural options for constructing fences BRIEF OVERVIEW Fences need to be designed well to keep wild and domesticated animals out of our lush systems, which will look very attractive in arid landscapes. The most fencing required will likely be for extended areas used for milk and draft animals, and electric fencing is the cheapest option if it is available. Natural fencing solutions do exist. It’s possible to start with a thorny hedge of dead plants that protect a new, living hedge as it establishes itself. Cacti, such as the prickly pear, can provide living, productive hedges. Ha ha fences are possible but should have at least one side stone-faced, and a thorny hedge on the garden side will help to make a much higher fence. Even a large guard dog is worth the cost of feeding it. When an area is fenced from local stock animals, many plants will appear, and the soils will grow, especially along the fencing. Key Takeaways Fences need to be designed well to keep out both wild and domestic animals. Extended areas for milk and draft animals will require the most fencing. Electric fencing is the cheapest option, but there are natural alternatives, like thorny hedges and ha ha fences. Fenced areas will enable many new plants to naturally establish and help to collect new soils. Mark As Complete

1.2.6. Modules 11b.51 to 11b.55 11b.51 – Desert Soils [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Give examples of challenges and solutions with desert soils - Explain how nitrates build up, how nutrients are used up, and how to prevent both BRIEF OVERVIEW We have to be very careful with desert soils. Heat and moisture decompose humus to produce too many nitrates, which will kill young plants. Soils need a thick top mulch, up to 45 centimeters atop new tree roots. Fire and plowing will use up nitrogen, sulfur, and phosphorus, and in turn, this will extend desert margins. Instead, after rains, grasses can be slashed or rolled and left on the ground. There are many variations of soil treatment for the desert. In free-draining or non-wetting sands, bentonite will help them begin to hold moisture. With sealed clays, gypsum will help to open them up to absorbing water. Salted soils (or water) require raised mounds that can be flooded but drained, and these will provide the chance to create organic matter and start moving out of the salted situation. Swales can be used as tracks, filled with sand or gravel, to produce more organic matter. In extremely salted situation, the topsoil may have to be removed then replaced with good topsoil, and the gardens will have to have deep drainage across them to keep the new topsoil from becoming salted. KEY TAKEAWAYS - Soils require special care in the desert, watching out for too many nitrates and avoiding plowing and burning. - Soil treatments include bentonite for problematic sands, gypsum for sealed clays, and flooded raised beds for salted soils. - In extremely salted soils, the topsoil may have to be replaced, and the new gardens will require deep drainage to avoid salting over again. 11b.52 – Desalting of Soils in Gardens [ANMTN] BRIEF OVERVIEW Gardens can be de-salted. It starts by removing all soil down to possibly two meters deep. Roughly fifteen centimeters of shingle should be added at the bottom. New topsoil has to be brought in to go atop the shingle, and drains should be installed (one to 1.5 meters across, two meters deep) that reach below the shale. If shingle is not available, soil can be removed to 40 centimeters and new sandy soil brought in, and the same deep drains installed. The drains should cross over the middle of the bed and drain into wells downslope. The beds should be flushed regularly with low-salinity water. 11b.53 – Desert Mulches [VIDEO] BRIEF OVERVIEW Mulches everywhere are valuable, but they are particularly so in the deserts. They can come from many sources. Flood-collected and wind-swept mulches provide a great diversity of organic matter. Mulch crops can be grown specifically for mulch pruning. Household solid wastes, even things like ashes, bones, cardboard, blankets, wool, coffee grounds and so on, can make great mulches. Of course, crops waste and weeds can be used as well. As a rule, if it has lived, then it can live again (by nurturing the soil). In deserts, mulches can be combined with many other useful functions. Lowering pH levels is possible with mildly acidic mulches, like coffee grounds or pine needles. Up to 30% of the garden area should be devoted to windbreaks, which can supply both crops and mulch material. After rains, there is good grass production, which can be harvested for mulch, reducing the risk of wildfires. Fires in growing areas, in fact, should be stopped completely and grazing must be regulated for the sake of mulch production. Then, mulches will keep fertility within our systems. KEY TAKEAWAYS - Mulches are important in any garden but particularly in desert gardens. - Sources of mulch are huge and varied: flood-harvested, wind-swept, manure-d, and household waste materials all make great mulches. - As an element of multi-functional design, mulches can also be created from other systematic functions, like windbreaks, shading elements, and crop waste. 11b.54 – Mulched Garden Beds [ANMTN] BRIEF OVERVIEW Deep-mulch gardens, 18-20 centimeters, preserve waters and produce rich humus. Paper, cardboard, surplus sod, woolen rugs, carpets, and cotton cloth make good sheet mulch on the soil surface. The sheet mulch should be sprinkled with compost or aged manure. The top mulch can be straw, leaves, detritus, weeds, prunings, kitchen scraps, bones, ashes, seaweed, pine needles, woodchips, and/or manures. Advance plantings and tree seedlings can be planted before the sheet mulch, and mulch can be added around them, staying off the stem. Stones can weigh down mulches. Seedlings can be planted in compost pockets. Tubers can be planted in holes just below the sheet mulch or just on top. Fine seeds can be sprinkled onto soil lenses (two to three centimeters deep) above high quality mulch mixed with manure. 11b.55 – Food and Shelter for Harvested Wildlife, Crop [ANMTN] BRIEF OVERVIEW Swales at 70 to 100 meters apart can grow tree legumes for animal fodder, and hardy trees that can be regularly cut for mulch for crops in the swales. Grasses and grains can be grown on ripped soils in the inter-swales. Surplus mulch can be fed into the swale system. The whole things is designed to oversupply mulch.

1.3. Module 11c

1.3.1. Modules 11c.1 to 11c.10 11c.1 – Chapter 11 Course Notes; Part Three [PDF] Irrigation System and Strategies In the desert, reducing the clothesline effect with windbreaks is the first priority in creating an irrigation system, and using drip irrigation is the most efficient way of delivering water. Windbreaks not only buffer winds from drying out the soil, but the vegetation also adds humidity to areas immediately surrounding them. Drip irrigation can then be set up on timers, a common technology, to deliver specific amounts of water to different garden beds, which can separately have plants with varied water needs. Other efficient means of irrigating include using reed beds to clean greywater on its way to wicking beds, burying unglazed pots with gardens around them, sinking pipes to deliver water at the root level (underground), inverting leaky bottles next to plants, and installing pebble-filled tubes to deliver water while protecting it from the sun. Efficient irrigation centers around minimizing wind and evaporation. Continued... 11c.2 – Garden Irrigation Systems [VIDEO] BRIEF OVERVIEW Drip irrigation is, no doubt, the most efficient way to irrigate. Trees and plants can get exactly what they need where and when they need it. Then, the most efficient design element for aiding irrigation is the windbreak, which buffers the wind, stopping the clothesline effect, and increases generally humidity in an area. In fact, before calculating what is needed via irrigation, it’s best to minimize the amount needed with sensible design. Trees and plants all require different amounts of water according to their specie and age. It’s hard for one system to adjust for all of this, but timers are available and can water in exact amounts in exact spaces. There are even moisture and rain sensors that can prevent watering when it isn’t necessary. The systems will quickly pay for themselves in time saved and increased production. Ultimately, once the plants are established, this technology will be relied on less and less. There are other efficient methods for irrigating. Greywater from sinks and showers can be cleaned by moving it through a reed bed, and it can flow on to water a series of wicking beds. Unglazed pots can leak into gardens built around them. Sunken pipes can deliver water to trees at the root level. Leaky, inverted bottles with holes in the caps can drip right next to trees or plants. Pebble-filled tubes can move water to the ground, all the while protecting it from sunlight. The key to efficient irrigation is reducing the wind and evaporation. KEY TAKEAWAYS - Drip irrigation is the most efficient method, and wind breaks are the most beneficial design element for watering plants. - Trees and plants all require different amounts of water according to their age and specie. - Timers are available that can deliver exact amounts of water to exact places. - Other efficient irrigation methods include unglazed pots, sunken pipes, leaky inverted bottles, and pebble-filled tubes. - Reducing the wind and evaporation is the first objective in creating efficient irrigation systems. 11c.3 – Subsurface Irrigation Systems [VIDEO] BRIEF OVERVIEW Subsurface irrigation either drips or seeps water below the surface. We can start by using this to create our windbreaks. Reed beds (one square meter of surface area per person) can be set up to collect domestic water, clean the suspended nutrients from it, and distribute it through a movable output, such as a hose. Swales are the the best example of subsurface seepage, as they put hundreds of liters of water beneath the soil. Seepage pipes, with some maintenance, can also do this, as can drip-irrigation to buried vertical pipes with gravel at their bottoms. Homemade systems can be made out pipes with cloth-covered slats cut into them and/or stretched plastic sheeting curved into a half-pipe about 60 centimeters wide buried 30-40 centimeters below the surface. Greywater can be fed through these systems to grow fruit and leaf crops. KEY TAKEAWAYS - Subsurface irrigation either drips and seeps below the surface. - Reed beds should measure one square meter per person and can collect, clean, and distribute domestic water. - Examples of subsurface irrigation include swales, seepage pipes, and buried plastic sheeting. 11c.4 – Micropore and Seepage Lines [ANMTN] BRIEF OVERVIEW Main-crops, raised-bed gardens should have drip-line irrigation, furrows and ridges on contour, and half-a-meter-deep mulched footpaths. The mulched footpaths can be added to the ridges after a growing season. The footpaths are refilled with each new planting. 11c.5 – Trickle Irrigation [ANMTN] BRIEF OVERVIEW Drip irrigation can be directed to pebble-filled clay pipes to allow water to wet soils below fifteen centimeters. The pipes should be ten to fifteen centimeters wide, 30 to 40 deep, and open at both ends. Liquid, organic fertilizer can also be applied through the pipe. 11c.6 – Domestic Waste Water Channels [ANMTN] BRIEF OVERVIEW Waste water can be drained into a pipe buried 40 centimeters deep and cut at 40-centimeter intervals with screen wrapped around the holes to allow water to seep out at root level. In deep sands, a plastic-lined trench can help. 11c.7 – Arbor System [ANMTN] BRIEF OVERVIEW An arbor system can be grow productive trees for a septic tank leach field, but it’s important tree roots don’t clog the pipes. Half-pipes of 30-50 centimeters in diameter can have two slotted flow pipes inside, which are surrounded by gravel. Then, tree roots that enter the half-pipe are naturally air-pruned. 11c.8 – Condensation Strategies [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - List different strategies for taking advantage of condensation drip in the desert BRIEF OVERVIEW There are many ways to take advantage of condensation. Plastic shields around trees will supply shelter, but they can also be filled with weeds and organic matter, which will help to create condensation. Stone mulches will shade the root zone but also provide condensation drip, as well as housing for and manure from little animals. Vertical sheeting beneath the surface can be used with high value crops, preventing water from seeping away from the root zone. Deep mulches and pit mulches around trees help to retain water, and in both cases, the mulch itself produces its own condensation. In extreme circumstance, survival pits can be created, with a sheet of plastic weighted around the edges and the center sunken to funnel condensation water to root level. KEY TAKEAWAYS - In the desert, it’s important to take advantage of condensation. - Condensation can be collected with plastic shields, stone mulches, vertical sheeting, deep mulches, and survival pits. 11c.9 – Desert Settlement - Broad Strategies [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Establish water as the limiting factor of desert settlements - Identify where settlements should be located and what the basic requirements are BRIEF OVERVIEW The limiting factor of desert settlements is the management and availability of water. Most settlements destroy themselves via the overuse and polluting of waters, as well as the overuse of forests for firewood and fodder. Over-expansion — not limiting growth — is another huge issue. Along with managing pastoral animals, which can horribly damage system, all of these things must be considered carefully for sustainable settlements. Firewood, windbreaks, and basic foods need to be guaranteed for systems to be stable, and these can become possible with good settlement placement, near water or where water can be influenced. Generally, the foothills, with runoff coming from upslope, is a viable position. Then, once these things are established, system designs can favor wood and water while discouraging dust and heat. We must design for worst case scenarios and resist expansion in the better years. KEY TAKEAWAYS - Water management and availability are the limiting factor of desert settlements. - Most settlements destroy themselves via overusing and polluting water, as well as forests. - Over-expansion is also a major issue for desert settlements, so populations must be limited. - Settlements have to have firewood, windbreaks, and basic staples guaranteed. - Placement is crucial, the foothills, where water runoff comes for upslope, is ideal. - We have to design for the worst scenarios and avoid expanding when times are good. 11c.10 – Dust in Settlements [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Recognize the conditions that are most likely to cause dust storms - Explain how settlements can prevent dust storms BRIEF OVERVIEW Dust storms need to be excluded from settlements. They usually happen around summer, in mid-to-late afternoon, in front of a thunderstorm. Soils that are plowed, unstable, bare, or overly compacted can go up in the air easily, and they’ll begin to form dust devils across the landscape. In these circumstances, many things—herds of animals, a tractor, a passing car, a pocket of hot air—can kick off a storm, and the dust itself will continually heat the air, not stopping until nightfall. Settlements can help to prevent dust storms with specific considerations. Roads should be sealed along wind lines, and dirt roads should only be across the wind. Fences and windbreaks are necessary fixtures. Landscapes, especially downwind, should be pitted and vegetated. Useful trees should be planted in lines and grown on town wastewater. This is very important, as aside from the physical issue, dust can cause serious health problems, like asthma, eye and lung infections, sinus issues, and the spread of human pathogens. KEY TAKEAWAYS - Dust storms usually occur during the summer, after three in the afternoon, just in front of thunderstorms. - Plowed, unstable, bare, heated, and overly compacted soils all go up in the air easily. - Dust storms can be triggered by herds of animals, a tractor or car passing, or hot air pockets. - Settlements need to take precautions to prevent and exclude dust storms. - Dust can cause serious health issues.

1.3.2. Modules 11c.11 to 11c.20 11c.11 – Hedges and Windbreaks [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Examine the many functions hedges and windbreaks can perform in desert settlements BRIEF OVERVIEW Hedges and windbreaks are an integral part of desert semblances, and they can be grown on wastewater or swales. They provide many services and products, including fodder for small animals, shelter for crops, actual crops, root barriers from invasive plants, and mulch. Crops can use their drip lines for moisture, and because they are often spiky and hostile, they make great animal barriers. Vines will also grow up them as if trellises. Trees also moderate groundwater, and with enough, they are beneficial to the broader area. Planted on contour, in protected zones, they make life much more comfortable in desert settlements. KEY TAKEAWAYS - Hedges and windbreaks are integral to desert settlements. - They can be grown on wastewater or swales. - They provide products, like crops, fodder, and mulch. - They perform additional functions, like shelter, root barriers, drip lines, and animal barriers. - Hedges and settlements are vital for making desert climates comfortable to live in. 11c.12 – Williams Description of North African Polycultures [ANMTN] BRIEF OVERVIEW Date palm over-story food forests can have thirteen-plus fruit trees in the understory, as well as small main gardens as partly shaded crop fields. 11c.13 – Planting and Vegetation in Settlements [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Summarize the types of plants and vegetation well-suited to desert systems - Describe the tree belts around desert settlements, including their various functions - Realize potential uses for coppicing systems within the tree belt BRIEF OVERVIEW The plants for desert systems are very specific and well adapted to the climate. We should concentrate on things have at least two functions, often food and shade. Perennials, as well as local varieties, are where much of the focus should be. And, there should be plenty of vine trellises. Lawns use far too much water, but it is possible to use drought-resistant, carpeting plants in small spaces. Ideally, trees should be hardy enough to survive on swales with little to no maintenance, and a belt of forest 300-400 meters wide should encircle in the settlement. These trees can also be used for fuel, mulch, forage, and supplements. Fruit trees should also be connected to swale systems, as well as hard surface runoff areas for extra irrigation. Outside tree belts, landscapes should be pitted to reforest itself. Fuel wood can be grown off of wastewater, and the trees can be coppiced in cycles of four-to-six years, with the leaves being fermented for extra fuel from a bio-digester. Beyond these systems, animals can be grazed on long, six-to-nine year rotations, using a low number of high quality stock on large pieces of land. KEY TAKEAWAYS - Plant selection in the desert is very specific, focused on multi-function, hardy perennials. - There should be plenty of vine trellises. Settlements should be surrounded by a 300-to-400-meter-thick tree system that can both provide protection and products, like fuel wood and mulch. - Beyond the settlement’s tree belt, low numbers of quality stock animals can be grazed on large areas of land, using a six-to-nine-year cycle. 11c.14 – Fields in Drylands [ANMTN] BRIEF OVERVIEW Field crops in dry land need both windbreaks and inter-crop shade and should be planted on long, narrow inter-swale fields. The contour swales should be as little as 20 meters apart in extreme deserts and up to 80 meters apart in cooler deserts. Crop residue and clipped brush should be added to the swales with sulfur and gypsum in clay soils or bentonite in sand soils. Palms, presopis, leucaena, and cauarina with shrubs underneath them and native regrowth on the sides make for a stable system. 11c.15 – Settlement Layout [ANMTN] BRIEF OVERVIEW Dry land settlements need careful designs to be sustainable. Swales need to be integrated as water soaks, with waste water fed to trees downslope and sewage fed to cycled fuel forest. There should be a centrally located collective of a settling pond with a primary digester, chipper, alcohol ferment digester, and methane engine house, with clear water routed to fuel forests. There should be a commerce center, shared car park, and shaded walkways. There should be a wide windbreak (400 meters thick) to shelter the settlement and prevent dust storms. Rangelands should be pitted and planted and carefully maintained for animal products, with shared livestock loading ramps, yards, milking sheds, and shearing sheds. The entry road should be downslope and crosswind, with attached swales. Narrow roads are shaded and run east-west with swales for runoff. Swales are installed to catch all village waste water. 11c.16 – Plant Themes for Drylands; Tree Establishment in Deserts [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Outline how and which trees should be used to extend systems in deserts - List the things necessary for preparing desert lands to give trees the best chance - Give examples of techniques that can be used to retain moisture BRIEF OVERVIEW Trees are valued for fruit, forage, and seed, so they should be carefully established, using only trees we know to be successful for extending systems. Nurseries are very important to the system, and replication through grafting, budding, and seeding are used to increase the number of productive trees. In the desert, areas must be really prepared to give trees the best chance. They should only be planted at the coolest time of year and at the coolest time of day. They should be planted in swales or pits with diversion drains leading to them and always mulched heavily. Ground covers may be succulents, which insulate the surface, or legumes that will fix nitrogen. Drip irrigation should be in place for at least the first couple of years, and young tree trunks may need to be planted white or cloaked in burlap. Shade should be supplied, perhaps by a palm frond, and fencing should be installed to keep animals at bay. Hardy tree legumes should be planted as support species, providing shade, fertility, and mulch. Retaining moisture is another obvious and constant concern. Shading plants in the morning will help to extend night condensation, and that moisture will reduce stress caused by heat. Cinder ash mulch pits are good for capturing cool air from the night, as well as moisture. In shady, dry country, trees can be planted in mud-lined pits, which provide shade, wind-protection, and moisture (absorbed in the mud lining). KEY TAKEAWAYS - Trees are valued from many things in the desert, so we must be careful when establishing them. -Planting areas must be strategically and thoughtfully planned for young trees. - Consideration include temperature, mulch, moisture, shade, ground covers, irrigation, tree trunks, and support species. - Moisture is crucial and can be extended via morning shade, cinder ash mulch, and mud-lined planting pits. 11c.17 – Tree Establishment in Deserts [ANMTN] BRIEF OVERVIEW Ideally, tree-planting in the desert will include a groundcover, a light-proof layer, mulch, wind guards, a stone root-spreading zone, sunburn protection, shade, a guard dog, fencing to keep out grazers, a mulch/nutrient/water retention pit, legume intercrops, insect control, and a mud-lined pit with a rim for protecting young seedlings from the sun. 11c.18 – Pits and Hollows Shaded for Morning Sun [ANMTN] BRIEF OVERVIEW Pits and hollows are an advantage in dry lands because the supply shade and protection. Seedlings planted in trenches have shade. Trenches should be flushed regularly with fresh water to prevent salt build-up. Early in the day, heat is less of a factor than water. 11c.19 – Large Lanzarote Condenser Pits [ANMTN] BRIEF OVERVIEW Condensation pits, as traditionally done on The Canary Islands, are dug eight to ten meters across and one to three meters deep. Each is planted with one tree or vine, and the inside is mulched with cinder ash. The shade side of the pit is deeper to provide extra shade. 11c.20 – Special Preparation of Soils for Tree Planting [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Explain how to deal with large cracks in clay soils - Provide a practical approach for beginning to cultivate in calcrete BRIEF OVERVIEW Clay can crack down to a half a meter deep, leaving roots exposed, ultimately killing them. Instead, we can fill these cracks with coarse river sand and plant in them after rain. The same effect can be created artificial with rip lines. In these situations, gypsum can be added to increase root penetration. Pioneer trees can also be added to the cracks with seed pellets, waiting for rains to germinate. In concrete, soils can be broken up with bulldozers, shattering out rip lines. Then, sulfur and minerals can be added to the soil, and mulch pits can be installed through the area to help with planting trees and creating slightly acidic humus, which will help to soften the concrete. Legume interplants will also help to add fertility, as well as mulch material. Near coasts, dried, finely chopped seaweed can provide a gel mulch, helping to retain more moisture for longer. KEY TAKEAWAYS - Cracks in clay soils can be filled with coarse river sands and planted with trees. - Bulldozers can make rip lines in concrete, and those soils can be improved with sulfur, minerals, and mulch pits. - Near the coast, dried and chopped seaweed makes very good mulch.

1.3.3. Modules 11c.21 to 11c.30 11c.21 – The Revegetation of Hostile Areas [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Identify where and how to begin revegetating degraded desert landscapes BRIEF OVERVIEW In permaculture, we are often working with degraded landscapes, which have been salted, dried, and/or weeded. We have to start with succession in a small, manageable area and expand from there. In deserts, we can get advantages from working upwind and upslope, and we have to seed optimistically with seed pellets, both on the slopes and in pitted areas. The most important aspect of vegetating desert areas is being ready for the right conditions when they come. KEY TAKEAWAYS - Permaculture often involved working with degraded landscapes. - These landscapes should be revitalized through succession planting in small areas and expanding out from there. - In deserts, working upwind and upslope with seed pellets and pitted soils helps to prepare the site for when the right conditions arrive. - Being ready is crucial to vegetating the desert. 11c.22 – Strategies for Revegetation of Hostile Areas [ANMTN] BRIEF OVERVIEW For cultivating hostile areas, install primary windbreak swales across the hot winds. The open desert should be covered with clay pelleted seeds that can wait for rain. Pitting and seeding should occur with different drift fences around a nuclei planted to support local settlement. 11c.23 – Creating a Forest in Drylands [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Describe the unusual nesting habits of large ground birds - Provide a tactical way of imitating ground bird nests when reforesting the desert BRIEF OVERVIEW We can look to an unusual example by observing large, ground birds that excavate shallow pits and create incubating compost for eggs. They leave a hollow in the top of the compost mound and cover the whole thing—between five-to-twelve-meters wide and one-to-six-meters deep—with soil. Temperatures in the nest are then maintained by opening and closing air vents in the soil. These sites can germinate the incubi of a forest. We can start with wide swales, five-to-ten meters across, laid out on contour with 30-to100 meters between them so that they pick up water runoff. In them, we can install hollows every 10-to-20 meters and fill them with wood chips, twigs, sticks, manures, crop waste, and so on, finally covering them with a deep layer (a meter-plus) of sand. While these are waiting for rain, we should have hundreds of pioneering legumes and nurse trees growing in pots, ready to be planted in the nuclei when conditions are right. Once the nuclei are established, more pioneering and permanent trees can be planted between them, with the original support trees slashed for organic mulch. This helps to build a mycelium web for forests to grow in. KEY TAKEAWAYS - Large, ground birds excavate shallow pits and create incubating compost for their eggs, and forests can germinate in this nuclei. - We can create forests in the desert using something similar to these bird nests in very wide swales. - Trees can be grown in succession within these swales to create a mycelium bed for growing new trees. 11c.24 – Mallee Fowl Nest [ANMTN] BRIEF OVERVIEW We can use the example of Australian ground birds and pack rat nests, which have great composting and water retention, to make special niche beds in the base of swales for growing higher quality trees. 11c.25 – Planting Trees on Hard Soils, Slope, and Minor Systems [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Explain how to construct and use net-and-pan systems to vegetate difficult landscapes - Realize which plants should be included in these systems, and in which order BRIEF OVERVIEW With hard soils, slopes, and minor systems, we have to begin with recovering planting, and net-and-pan systems are one of the best ways. Tiny pans are cut out to plant trees in, and little diversion drains (at roughly 1:500) connect them, allowing no runoff water to escape without going past a little tree with manure and mulch. This provides stability. Plant pans can be different sizes depending on conditions, and in gully-like runoffs, they can have larger, boomerang earth banks that pacify water flows while overflowing into diversion ditches. The pans should be planted with hard pioneers, and once those are established, shrubs should go between them, ultimately followed by long-term climax trees. In the end, lots of mulch will be on the ground, soaking up the water, and the roots of the plants will interconnect and stabilize the soil. KEY TAKEAWAYS - Net-and-pan systems are a great way to recover vegetation on hard and/or sloped slopes. - Tiny pans are cut out for planting trees, and the pans are connected with diversion drains. - Pans should be planted with pioneers, with shrubs between them after they establish and climax trees cultivated last. - The area will eventually be covered with natural forest mulch to soak up water and interconnected roots to stabilize soils. 11c.26 – Net and Pan [ANMTN] BRIEF OVERVIEW Net-and-pan is a recovery planting system that interrupts sheet runoff with an absorption system of diversion drains connecting pans. Hardier trees are in the upper slopes, and less hardy trees are on the lower slopes, where soils are better. Mark As Complete 11c.27 – Net and Pan (Elevation) [ANMTN] BRIEF OVERVIEW Net-and-pan in elevation can have pans dug to hold up to half a meter of water in rains. The slope between the pans can be cleared of rocks, weeds, and clumping grasses, which can all be used as mulch inside the pan. Then, hardy tree legumes can be planted between the pans to help control erosion and supply mulch. 11c.28 – A Developed Swale [ANMTN] BRIEF OVERVIEW A well-developed swale can have many elements. A trellis can be stretched over the trench. The lower side can have productive trees, bananas, and sweet potatoes (as a ground cover). There can also be planted niches in the swale mound. If the swale is over clay, it can be ripped, and bentonite can be added to sand or gypsum to clay swale bottoms. Mulch, gravels, or coarse sand can be added to the base layer. Many crops can be grown under the trellis. Irrigation and mulch need to be supplied for two to three years, as the trees grow. Then, everything is provided from the swale. 11c.29 – Runnel Traps [ANMTN] BRIEF OVERVIEW Silt traps across runoffs in sands and eroding soils spread the water and hold the silt, forming small level terraces that can be planted to hardy tree and shrub legumes. Clumping grasses, logs, stones, straw bales, or wire netting all help to build mini-deltas of silts, leaves, and detritus, which are instrumental in starting the regeneration of soils. 11c.30 – Boomerangs [ANMTN] BRIEF OVERVIEW Where large rills flow on awkward, steep, or restricted sites, boomerang pans hold silt and water for spaced out tree sites. The erosion rill of the water is divided and each boomerang overflows into others. Each pan should hold up to a half a meter of water, and the boomerang can be stabilized with rocks, the tree mulched with them as well.

1.3.4. Modules 11c.31 to 11c.38 11c.31 – Recruitment [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Illustrate how we can have trees and animals interact while still regrowing forests - Recognize the need for land and seeds to be prepared for regeneration BRIEF OVERVIEW Native trees can live hundreds of years but regeneration almost stops completely with grazing animals. Stumps in the desert often re-sprout in the rain, but these are eaten by grazing animals. Instead, we can allow the strongest sprout to grow and trim the others to be fed to the animals as fodder. With this method, trees will regrow quickly, and the roots will go deeper and deeper. Fire also causes regenerative problems, and we need to stop them, especially those instigated by humans. We need adequate rains and good seeds to encourage growth, first germinating seeds and then hopefully keeping them going a couple of months later. For this, we have to be prepared for recovery, with pelleted seeds waiting for rain and earthworks in place for harvesting water. KEY TAKEAWAYS - Native trees live hundreds of years in the desert, but regeneration is stops due to grazing animals and fire. - Stumps in the desert often sprout after rains and can be used to regrow trees and feed livestock. - We have to work to vegetate landscapes, being ready with seed pellets and water-harvesting earthworks. 11c.32 – Wraiths and Golems [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - List useful things that are blown across the desert landscape - Devise systems for collecting wind-blown debris in deserts to repair the landscape BRIEF OVERVIEW Wraiths and golems are the apparitions the blow across landscapes when it’s just about lifeless. Many things are dispersed by wind in the desert: manure pellets, dust, seed pods, leaves, seed heads, entire plants. We need to set up systems — pits, swales, depression, brush fences, tree lines — to trap this material. These become beneficial gathering elements, continuously creating tiny layers of soil, and this is the final place where seeds of all sorts and all sorts of plants come to rest. We need to recognize the function of these plants as pioneers, rather than identifying so many as noxious weeds. KEY TAKEAWAYS - The wind disperses many things across the desert landscape. - We need to set up systems to trap this wind-blown material. - These gathering elements become beneficial soil builders and places for pioneering seeds to germinate. 11c.33 – Arid Area Grasses and Forbs [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Realize the many uses for dryland grasses - Describe how grasses can be cultivated, with special attention to nitrates BRIEF OVERVIEW Grasses and forbs in drylands come in great diversity, and a good mix can of perennial grasses in a range can keep animals healthy. Dryland grasses have more nutrition than the ones in humid areas. Grains (for humans), forage (for poultry), and hay are all possible, but they should usually be grazed before flowering, as we don’t want dead material mixed in with them. Grasses can be grown between swales, but they need to be checked after rains. If they are over-manured than might have too much nitrate, which isn’t safe for food or fodder but can be used in mulch pits. When established, sections of grass can pick up nutrients, and grassed diversion drains can help to filter nitrates. Grasses can be used for green hay, with mats, canes, and thatches being all different kinds of grass. The seed heads can be used to feed poultry. Grass can be planted in waterways for depositions. Grasslands can be established with pitted and broad-scale seeding with pellets. KEY TAKEAWAYS - Dryland grasses and forbs come in great diversity. - These perennial grasses can support animals, as they are much more nutritious than grasses in humid areas. - Strips of grasses should be grown between swales. - Grasses should be checked for too much nitrate, which isn’t suitable for food or animal fodder. - Grasslands can be established with pitting and broad-scale seeding. 11c.34 – Desert Aquatic and Swamp Species [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Illustrate how swamps in deserts interact with the dry landscape - Explain how reeds and rushes can be useful elements for cleaning water and for providing energy BRIEF OVERVIEW Believe it or not, there are famous swamps in deserts, and they are often formed where small acidic areas are surrounded by expanses of alkalinity. The space in between the two is a neutral zone. As well, anywhere water stands in the desert, aquatic plants, like reeds and algae, are quick to move in. Reeds and rushes are great for filtering water. They can filter out dissolved salts and fecal material, cleaning up water enough for irrigation. They can take out over-abundances of nitrogen material and metals. Biogas can be produced from town wastewater and reed beds, and that water can then feed windbreaks, helping to reduce sanitation problems. KEY TAKEAWAYS - Swamps do occur in the desert, around spots of acidity or in places where water stands. - Reeds, rushes, and algae offer great filtering services for waters with dissolved salt, fecal material, too much nitrogen, or metals. - Town wastewater and reed beds can be used to produce biogas and windbreaks, while they reduce sanitation problems. 11c.35 – Animal Systems in Arid Areas [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Give a breakdown of the animals included in desert systems, including wildlife - Describe the one-hectare safety net designs for domesticated animals - Analyze the need to be careful when reintroducing livestock to the landscape after rains BRIEF OVERVIEW Animal systems in the desert are very specific. Most small livestock, like poultry, do very well, even ducks and geese, but rabbits don’t work in cages and require special, shaded habitats. Large domestic animals need to be carefully selected, creating small, high-quality herds rather than large herds, and they should be rotational grazed on around 15 different runs, allowing areas to rest for several years. There are large, fast-moving nomadic animals that follow the rains, and there are small, sedentary animals that require particular habitats. Plague specialists, like locusts, can be used as bird feed when they disrupt systems, and lizards and snakes, which can be unfortunately be dangerous, can help control pests. It’s important to prepare safety nets for drought cycles. This begins with a hectare surrounded by windbreak hedges that supply forage. Animals will require shade-houses with good bedding, a water supply, salt licks, and mineral blocks. High quality forage can be grown on swales within the windbreak. Animals should be kept penned up. In times of drought, the system will grow off of their urine, manure, and bedding (added to the swales), and the forage will cycle back to them. On this one hectare, 20-plus animals can be looked after, whereas in open lands one animal can require 1 to 6 hectares, or even 60 in degraded landscapes. These forage systems is saved for survival. When we reintroduce stock to the system after rains, we have to be very careful. Rains can cause concentrations of toxins in plants, so stock should not be grazed intensively for four-to-six weeks after the rains to avoid problems. They should be limited, and they should be moved slowly. We need to know about these cycles and manage stock with caution. KEY TAKEAWAYS - Most small stock animals work very well in desert systems, but large animals require more consideration. - Herds should be high quality but low numbers. - Emergency forage systems can be set up on one hectare, in place for drought, and they can support up to twenty breed-stock animals. - After rains, grazing animals should be very cautiously reintroduced to ranges. 11c.36 – Layout for Drought Survival of Livestock [ANMTN] BRIEF OVERVIEW During severe drought, a survival shelter for livestock can support up to 30 animals on just one hectare, preserving breed stock for several farmers. There should be a thatched roof shelter with a urea lick and molasses lick, as well as a water trough fed from a well or bore pump. The shelter should be surrounded by four fields, fenced with perennial hedges of forage trees. The hectare should be fully swale-d and planted to animal forage species, so they can be cut daily to feed the animals. Manure and bedding waste should be returned to the swale trenches. 11c.37 – Desertification and the Salting of Soils [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - List the causes for desertification and salting of the soils - Summarize the process by which landscapes become salted - Discuss viable solutions for preventing and reversing desertification BRIEF OVERVIEW Desertification and salting of soils is one of the worst and most important problems for us, as a planet, to solve. This is occurring due to overgrazing, deforestation, settling of nomads, cropping in areas with low rains, and extensive clearing. Excessive use of water via pumps is drying upper aquifers, leading us to deeper, more saline waters, and when both surface soils and the aquifers dry out, production stops. Natural repair systems are slow, and deep erosion, gullies, and dust storms begin to cause more damage. These situations are preventable if we are willing to adapt the systems, and the early signs are observable. Wind effects dry and erode the landscape. Soils collapse into hollows and pans. Water flows speed up due to lack of vegetation. All of this, and especially the deforestation of hills, causes the salting of lower soils, and the ultimate effect will be the death of all trees there. Salinity comes from different sources: cyclic salt evaporated from the sea and dropped in rains, connate salt sediments from old marine periods, leach salts from rock minerals, and salts stored in undisturbed (but currently disturbed) country. We create detrimental effects by clearing, cropping, and grazing, so we need clearing to be banned in all areas of question. In the desert, salt problems surprisingly also increase with two or three consecutive wet seasons with flooding, due to extra evaporation. Over-irrigation also creates a similar effect. Drains can be installed as temporary solutions, but we must plant a diversity of trees to fix this. We have to create systems that recharge the aquifers. We need twenty times the area for rehydration than the area we are irrigating, just to break even on the water used. When it all dries up, extra water runs off at greater speed on hard surfaces, and tree planting will no longer work. So, we need reconstructive earthworks. Interceptor contour banks about 1.5-meters deep should be sealed so that the water soaks into the base of the trench. These should be positioned near the tops of hills to cut off overland flow, and this creates our own intakes for aquifers and rivers. These look like swales, but the inside slopes are sealed. Contour banks at 1:5000 help to slowly move rainwater towards valleys, diluting salt waters. In about three years, greenery will start to show up and trees regrow. Lower down, banks can go on contour every vertical three meters along slopes of ten-to-fifteen degrees, and we can start to tree this up again. As the slope flattens to five degrees or less, spacing needs to be no more than three hundred meters. Overflows need to be level sills that open to natural flows. All seepage from these systems needs to be directed or blocked. KEY TAKEAWAYS - Desertification and the salting of soils is a major problem for the planet, and we must address it. - We are causing it through overgrazing, deforestation, settling (of nomads), cropping, and clearing. - Surface soils dry out, aquifers dry up, extreme erosion exposes hard surfaces, and production stops. - We can read signs to help us prevent this: wind dries and erodes landscapes, soils collapse into hollows and pans, and water flows speed up. - Salinity comes from many sources: dropped in rain from evaporated sea, sediments from old marine periods, rock minerals, and newly disturbed country. - More evaporation for consecutive rainy season floods and irrigation cause more salting. - Drains are a temporary solution for salting, and planting trees is the long-term approach. - Rehydrating earthworks helps to recharge aquifers and grow new vegetation. 11c.38 – Cold and Montane Deserts [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Define cold montane deserts and identify specific characteristics - Explain how and where to cultivate trees and harvest water in cold montane deserts - Describe different survival strategies for this environment - Recognize that cold rather than dry can be the limiting factor here BRIEF OVERVIEW Cold montane deserts are high, dry, cold deserts with extreme temperature changes because they are often distant from coasts. These are often high alpine landscapes, where air is hot and clear with high radiation. The plants and animals are often wooly to protect them, and houses need to be solid with a good fuel supply. A good fuel supply is a very important design element. Trees grow very slowly, but river banks will grow trees well. Snow melts quickly in these deserts, evaporating directly into the air, so trees also help to slow this, sending the melt to streams instead. Swales can also help to shelter snows for more water infiltration, and trees should be planted to create shading rather than focusing only on contour. Water flows can also be increased by adding snow traps and fences around swales. This is a storage climate, combining dryland and cold. Hardy grains in small, sheltered fields and root crops are staples. Piles of stone and deep mulch help to moderate soil temperatures and protect roots. Rocks help to warm the soils. Streams and lakes will have very good fish and will attract other animals. Chickens and guinea pigs survive well when their housing is attached to glasshouses or kitchens for extra warmth. Thermal mass walls next to windows help to passively heat homes, and entries into houses need to be double air-locked and well sealed. External areas get very stressed by cold winds, so internal areas can help to extend growing seasons. Earth-sheltered houses work very well because they trap the heat. We can design rocket heaters with wall flues that will help the thermal mass wall. Clothes need to be water- and wind- proof, and we should be careful of radiation burn at the high altitude. Species of deciduous trees are more regulated by temperatures than moisture. Saps, rather than sugar pods, store starches. Evergreen trees are usually conifers with snow-shedding shapes and air-trapping forms. Birds move through the system, eating berries and spreading their seeds. The migration of animals is more due to altitude and temperature, as opposed to rain. Most plants will be different, though some grains and legumes will transfer. Cold, rather the dry, is the limit because the growing days are less. KEY TAKEAWAYS - Cold montane deserts are high, dry, cold deserts with extreme temperatures caused by continental locations. - Houses need to be solid, with thermal mass for warming, and fuel needs to be in good supply. - Growing fuel wood is a crucial design element, and it is aided by rivers, streams, and shaded swales. - This is a storage climate, combining drylands and cold, with grains and root crops as winter staples. - We can combat cold winds with interior growing spaces, earth-sheltered housing, wind- and water- proof clothing, and thermal mass rocket stoves. - Most plants will be very different and behave differently here than in other dryland areas.

2. Module 10: Humid Tropics

2.1. Modules 10.1 to 10.10

2.1.1. 10.1 – Chapter 10 Course Notes [PDF] Climate in the Humid Tropics This chapter is about the humid tropics, a dynamic climate with heavy rains and shallow soils that has many layers of life and very speedy decomposition processes. The rapid life cycles equate to great potential but also potentially damaging the landscape very quickly. The heat and moisture additionally cause several health concerns with things like sanitation, waste management, and massive weather events. Houses here must be designed differently, accounting for the heat and humidity, and garden designs have to account for long hours of vertical sun. Continued...

2.1.2. 10.2 – Introduction to the Humid Tropics [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Provide the basic characteristics of soil in the humid tropics - Recognize the areas of greatest concern in the humid tropics - Point out that industrial agriculture has failed in this climate BRIEF OVERVIEW The humid tropics is a very dynamic climate. There are heavy rains and shallow soils that create many layers of life, as well as very quick decomposition processes. While this means high potential, it also equates to a high potential for damage. There are serious health concerns, particularly around waste and sanitation, not to mention the need for shelter in massive weather events and the rising water being a serious issue for low coral islands. Houses in the tropics are designed differently, to provide cross ventilation, and garden designs have to account for long periods of vertical sun. Conventional and industrial agriculture have failed in this climate, so permaculture has a real possibility to demonstrate how systems can be productive and permanent. KEY TAKEAWAYS - The humid tropics is a dynamic climate with lots of rain, shallow soils, quick decomposition, and many layers of life. - There is a high potential for damage, including health issues caused by garbage and sanitation, massive weather events, and rising tides. - Houses and gardens must be designed differently to account for the heat and sun. - Conventional agriculture has failed in this climate, so there is great potential for permaculture to establish productive, permanent systems.

2.1.3. 10.3 – The Humid Tropics [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Differentiate the different climates within the tropics - Illustrate how abundant rain, fast decomposition, and bad techniques create poor soils - List serious health and home concerns faced in the humid tropics BRIEF OVERVIEW Climatic types are different, and it’s important that we recognize them. In this chapter, we are covering the humid tropics, so the arid tropics, which requires its own approaches, will be covered in the dry lands chapter later on. Design is in relation to climate, and the permaculture view of that might be very different than the meteorological. Soils and climate types determine how we design. In the humid tropics, soils should be concentrated on creating convenient sources of mulch while establishing polycultural stability. Appropriate housing, built to handle both the heat and humidity, is completely different than in cold climates, and that is crucial to effective design. Heat and rain cause rapid nutrient leaching, and biomass — up to 80% of it — is held up in living systems. Thus, humus production is a priority in tropical soils because bare soils, intensive clearing, and frequent burning can quickly get a system into big trouble. Ancient civilizations flourished using polycultures dominated by palm trees, but mechanized monocultures have been a disastrous failure. Even so, the proven systems based on diverse perennial fodder and food still receives little developmental funding. Health issues are also a serious concern in the tropics. Heat, humidity, and constant growth can cause lethargy, while water-borne and mosquito-borne illnesses are nearly impossible to control. Houses have to be carefully designed to be comfortable and functional. Gardens should be created to emulate forests, with high shade from palms and legumes to moderate vertical sunlight, excessive heat, abundant light, and heavy rains. KEY TAKEAWAYS - Design is related to types of climates, and permaculture takes a unique view of that. - In the humid tropics, establishing soil building systems for perennial food production is key. - Permanent polycultures have flourished, but mechanized monocultures have failed. - Health issues are caused by heat, humidity, and constant growth creating lethargy, as well as water-borne and mosquito-borne illnesses. - Houses and gardens have to be designed carefully to moderate vertical sunlight, excessive heat, abundant light, and heavy rains.

2.1.4. 10.4 – Climatic Types [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Summarize the wet tropics, including location, population, conditions, and challenges - Explain the wet/dry tropics, including location, population, conditions, and concerns - Compare and contrast the monsoon tropics with the wet/dry tropics BRIEF OVERVIEW The wet tropics occupies about ten percent of the earth and holds about six percent of the population, with concentrations of people being where production can be sustained. Sustainable systems usually have wet terraces with acidic soil (anaerobic conditions), and the acidity is often neutralized by the alkalinity of volcanic soils. The coasts of Central America, Sri Lanka, Malaysia, Borneo, and New Guinea are all classic examples of this climate, often based around wet coasts and river basins. Generally, there is lots of vertical sun, constant temperatures, and levels of humidity that are 80% or more, and rainfall is between 160 centimeters to 350 centimeters annually. Clearing and cropping open the opportunity for wildfires and serious nutrient leaching, and soils then erode very quickly and look like deserts. Naturally, the wet tropics have rounded landscapes with rotting rocks and weathered streamlines. Though runoff and evaporation are high, the abundance of water remains, and coasts and lowlands are often swamps. Rivers reach the coasts as deltas and create the tropical mangroves, the lushest eco-systems on earth. Transportation is usually along rivers because roads are expensive to build and maintain. Growth rate is extremely rapid and continuous. Forests are very layered with many levels of shade and little sunlight reaching the floor. Tropical forests are incredibly diverse (up to 800 species per square kilometer), and the canopies mainly consists of broad-leaf trees and vines with separate epiphyte (living on moisture and nutrients form the air and leaf fall) ecosystems living amongst them. Anything on the ground is consumed quickly by fungi. The mangroves are large in specie numbers and area, with abundant plant and aquatic life (but no natural grazers), such that 85% of the nutrients are in plants and animals, leaving the soils thin and infertile. Thus, soils in the tropics can easily leach and erode if the cover is taken off of them. Houses have steep roofs and low walls for good ventilation, and they are oriented to the wind. The walls are located in full shade and generally permeable with screens, and the kitchens are outside. The roof is steep both for the ventilation and so that it can shed volcanic ash that would build up and get heavy when it is wet. Hygienic toilets are very important, and dry composting toilets are ideal. Clean drinking water and insect control/screening are also critical. The wet/dry tropics occupies fifteen percent of the earth’s surface, and they usually have dry winters with clear skies but hot, wet summers, almost requiring two garden systems. Temperatures can get up into the low 40s and down to the low 20s, and this climate fills the space between the wet tropics and deserts. Here, streams are often seasonal and rains more erratic, causing bigger flooding and erosion problems. Hills are still rounded, swamps and lakes still extensive, but river bars become an issue due to constant changes. This climate has large savannas and grasslands that support large grazing herds. If these diverse grazers are changed to overgrazing cattle, the risk for fire and erosion rise dramatically. Animals that live up in trees only exist in valleys or where there are tree clump islands. The soils are more fertile than the tropics, but they lean towards alkaline as the land nears the deserts. Cultivation still leaches the soil, and more erratic rains and winds decrease the soil. Concerns change from the wet tropics. Small water storage systems are important, and wind breaks become an essential part of design. Tree legume coppice alley cultures are a useful cultivation method, spacing out the landscape with organic matter. We can now carefully select and manage local animals with sensitive grazing cycles, similar to how natural herds work. There is a lot of grass growth, which makes for mulch production, and we can introduce trees as our crop and the foraging of animals. We need to reduce fire as much as possible as a strategy because fires can be devastating, especially if followed by rain. Fuel and structural timber forest can be established as opposed to taking it from the natural landscape, a major issue of landscape deterioration. Water retention via soakage pits and swales is now necessary to slow up water. Landscape rehabilitation using pioneering sequences is something to be considered and can be achieved over large areas. The monsoon tropics is our last climatic type within the humid tropics, and it is really a sub-climate of the wet/dry tropics. The monsoon tropics occupies about ten percent of the earth’s surface and supports a very large population. It is created by summer winds coming onshore to bring rains, and winter winds blowing offshore to cool the climate, much more so than happens in the typical wet/dry. Drought is common but unpredictable as a result of the unpredictable nature of these winds, and activities often hinge on the monsoon rains arriving. Natural forests here are dry, deciduous trees, which drop their leaves in dry season and regain them within a couple of weeks of the rains starting. The trees are spaced further apart, allowing a dense understory to grow. Unfortunately, due to the pressures of population, much of the monsoon tropics has been cleared. The grasslands stretch to the desert margins, and before the extensive clearing, they supported large animals. Additionally, there are estuaries and coastal mangroves in which traditional societies still harvest. Soils in the inland of the monsoon tropics are often laterite, high in iron and aluminum oxide. Though this type of soil does make good bricks, it cracks easily in the dry season and isn’t particularly fertile. This can make survival in this environment difficult, and many of the populations within it are impoverished and struggle. For permaculture design, the strategies for the monsoon tropics are similar to those used in the wet/dry tropics, and this can genuinely help these societies once again reach consistent abundance. KEY TAKEAWAYS - The wet tropics has a thin layer of acidic topsoil, making the landscape susceptible to damage. Wet tropical forest are extremely diverse with most of the nutrients locked up in living systems. - The wet/dry tropics have wet, hot summers and dry, clear winters, so seasonal growing conditions are vastly different. - In the wet/dry tropics, small water catchments and preventing wildfires is integral to survival. - The monsoon tropics is a sub-climate of the wet/dry tropics, with coastal rains blowing onshore in the summer and winds blowing offshore, creating a cooler climate in the winter. Strategies for the monsoon tropics are similar for those used in the wet/dry tropics.

2.1.5. 10.5 – The Structure of a Wet Tropical Forest [ANMTN] BRIEF OVERVIEW Tropical forests are very dense and tall, so it is possible to plant very dense and productive assemblies near villages and structures, which will also supply shade and cooling. In broad-scale areas, the assemblies should be simplified. Upper layers of the forest should be production palms, with thin-foliage legumes and larger fruit/nut trees beneath them, and other fruit and nut trees below that. The sun won’t directly reach below these three layers, but the ground can be planted with shade-tolerant plants like cacao, coffee, and ginger, as well as many other species. Productive vines, like vanilla and black pepper, can be grown up the legume trees and tall palm trunks.

2.1.6. 10.6 – Tropical Soils [VIDEO] LEARNING OBJECTIVES At the end of this video you should be able to: - Explain why tropical soils can be particularly problematic - Give examples of techniques that can be used to improve tropical soils - Recognize how termites and ants replace worms as an integral component of soil life - Discover different sources of mulch and what each contributes to the soil BRIEF OVERVIEW Tropical soils have particular problems. Except for where new volcanism occurs, soils are old and heavily leached, making them deficient in calcium and silica. Old volcanic areas have soils of clay that degrades quickly, so the creation of humus with green manures and legumes is the first priority. They can also be improved with rock dust (especially basalt), poultry manure for phosphate, lime to raise pH levels, and mulches from bamboo and cane grasses to add silica and calcium. Cement and coral powders can also supply essential nutrients and lessen acidity. Fertilizers should be spread out and added in small amounts every six weeks, as opposed to adding lots every few months. Annual groundcovers should be replaced by perennials for stability. Soil types change and techniques change in other areas. On coral islands, soils will be alkaline and often have hard cement-like layers. In this case, deep mulch pits will help to break up the harden layers by adding acidity so that trees roots can establish. Even areas with new volcanism can still degrade quickly, so in order to maintain fertility, it’s important to include plenty of manure, mulches, and legume intercrops. Deep granite soils with large rocks, however, drain very quickly and consume mulches. For cultivating these spaces, tree legumes need to establish a root net to slow draining, palms can then be planted around mulch pits, and fruit trees can be inter-planted once the palms establish a canopy and the legumes are dropped as mulch. For gardens, raised beds can be lined with layers of cardboard or carpet and filled with sand and loam before being topped with heavy mulch. In the humid tropics, termites and ants are the integral component of soil life, much more so than worms. Termites bring rotten rock and moisture to the surface, with galleries above and below the ground for farming fungi. The architectural above ground structures are often the only thing alkaline in the landscape, and trees sometimes congregate around them. Particular fruit trees that aren’t damaged by ants and termites can be selected for these areas. Sources of mulch for the tropics are important because things break down much more quickly. Wood breaks down rapidly, and logs, sticks and palm fronds can be used to rapidly build soil. Palm fronds and even trunks provide phosphate, and bamboos, canes, and casuarinas slow down the decomposition process, while adding silica and calcium. Water weeds and emergent plants are good for mulch, and hedge rows can be designed for animal forage (it grows as fast and better than pastures). Green manure groundcovers can be used to totally control the ground. Logs and rough mulch piles across the slope can be used to create fertile gardens. Deep mulching, 20 to 25 centimeters, is essential for establishing gardens, and burning organic matter is never necessary nor an option. KEY TAKEAWAYS - Tropical soils tend to be acidic, as well as old and leached, which makes them poor. - There are many easily-applied, natural methods for re-establishing and maintaining nutrients in these soils, and creating humus is key. - Coral islands tend to be alkaline with hard layers that can be broken up with deep mulch pits. - Deep granite sands require the establishing of root net from tree legumes and a canopy from mulch-pit palms before they can be planted with fruit trees. - Termites and ants are a bigger part of tropical soil life than are worms. - Mulching in the tropics is a major part of the gardening strategy and new soil creation.

2.1.7. 10.7 – Broadscale Tree Crop in Loose Granite Sands [ANMTN] BRIEF OVERVIEW Tropical tree crops in deep, quick-draining granite sands make for a difficult situation. Fast-growing legumes should be planted as a canopy with palms planted on mulch pits for an over-story canopy over that. Adapted legume trees and native vegetation can then build up organic matter to return humus creation in the soil.

2.1.8. 10.8 – Gardening in Coarse Granitic Sands [ANMTN] BRIEF OVERVIEW Trenching is how we garden in coarse granite sands. Dug to be 1.2 meters wide, trenches should be filled with thick layers of cardboard, paper, carpet or even leaves to create a sealed layer that holds water and leached mulch. In humid tropics, branches and poles can be the next layer, with logs along the edges, helping to raise the bed. In the dry tropics, the sunken profile is preferable. The main growing medium should be sand mixed with humus, with a seepage pipe for household greywater laid the length of the bed. The surface should then be mulched to reduce evaporation.

2.1.9. 10.9 – Tropical Clays [ANMTN] BRIEF OVERVIEW In tropical clays, the positive and negative charges change as the acidity or alkalinity lower and rises in the soil. Moving higher on the pH scale, the soil is more negative, and moving lower, the soil charge becomes more positive. This is the cation change capacity and ionic bonds on soil particles.

2.1.10. 10.10 – Log Barriers on Slope [ANMTN] BRIEF OVERVIEW It is possible to pin logs on cleared slopes, where they will quickly rot down. They can be planted with bananas, legumes trees, and clumping canes, with dense legume groundcovers between them. This will feed the soil and increase humidity until, when