E) Wetlands
• Chinampa system- world’s most productive agriculture, using banks next to water, maximizes productive edge. Swampy or marshy land ideal for this development. System of water-land nutrient exchange in harmonic effect. (Mexico and Thailand)
• Ducks (main livestock) cycle nutrients, return potash to water and land.
• Fish are marginal feeders
• Azolla (a fern) contains Anabeana (nitrogen fixing bacteria). Can be scooped up and used as a mulch on land.
• Trellis crop over water saves space. Can be harvested by small boat.
• Occasionally streams are drained and nitrogen rich mud scooped onto banks.
• Marshes and wetlands support rich yields of wild rice (zizania aquatica), freshwater mussels, fish, and honey- producing species (marsh marigold)
F) Estuaries
• Rich species area (oysters, fish, sea grass, mollusks, fowl, geese)
• Sea grass (zostera) good insulation
• Can make traps and high tide ponds for catching or raising fish, mollusks.
• Spartina- mulch; catches silt from land, good fodder, returns nutrient from sea to land.
Climatic Differences
Three very basic divisions: cold/hot/dry or temperate/tropical/desert
Temperate: Soil contains nutrients and elements. Cultivation cautiously possible; natural mulch develops. Mulch (humus) either applied on top of soil (small areas) or cut/grazed in cycles for larger areas. Amount of humus in soil determines “fertility”. Smaller fields with deep rooted deciduous trees ensures nutrient cycling plus new nutrients, but best strategy for cropping is “no tillage” cultivation.
Tropical: Plants hold 80-90% of nutrients. Clean cultivation in the European mode is disaster. No mulch develops under forest. Biomass is critical. Bare soil leads to development of concrete-like layer below three meters of soil (caliche). Later comes erosion. Strategies: nitrogenous ground cover may be critical precursor to agriculture (desmodium, sesbiana, dolichos) e.g. barley/dolichos mixture is ideal; as is desmodium under a tree crop. Problems may be summer or winter dry and winter competition. This is solved by use of drip irrigation, selective grazing in advanced tree crops. 4-6 large trees/acre (acacia albida, leucaena) in crop as nutrient-recycling strategy. Essential to incorporate as much tree crop as possible, otherwise, waterculture- e.g. paddy rice, where nutrient is bound to algae and mud. Also essential to replace low nutrition plants (lettuce) with high nutrition tropical plants (kangkong, edible chrysanthemums, hibiscus spp. Etc.)
Desert: Nutrients plentiful but need humus and water for release. Must concentrate on soil cycle, plant
cycle, and water cycle in arid environments. Desert strategies are basically water-connected; great attention must be paid to “waste water” use in mulch, flood flow and runoff techniques. Deep-rooted trees need mulch plus drip irrigation in establishment. Mulch can be planted in deserts as legumes, tamarisk, casuarinas.
httpv://www.youtube.com/watch?v=tenh8gKBhBA
httpv://www.youtube.com/watch?v=ZNG2TU2hRg8