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Published byJemimah Hensley Modified over 8 years ago
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Shifting cultivation Oldest form of agriculture in Africa Slash and burn Four steps 1. cut primary forest
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2. Burn remaining vegetation: ash acts like a fertilizer 3. Plant for 2 to 3 consecutive years 4. Fallow for about 20 years
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Three stages of S/B and Fallow
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Typical Village
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Old self-sufficient patterns Rarely exist Creation of markets People aim for surplus Trade with surrounding villages
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Current Practice: Rotational Bush Fallow 2 to 10 years Requires supplementary methods such as fertilizers or manure Not all farmers have these
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More affluent farmers have cattle for plowing and manure
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Intercropping Old pattern Spreads risk Discouraged by “modern” scientists Can help prevent erosion
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Desertification Land severely degraded Brings desert- like conditions An underlying cause of declining food production
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Sahel in the 1970s and 1990s Millions of people and cattle died
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Areas looks like this and causes many people to flee (produces refugees)
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African droughts are common But are accelerated by – population increases, both human and animal –cutting trees
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Final Stages of Desertification
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Forests (tree cover) prevent erosion
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Thin layer of soils over rock Hard to bring back the land into production
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Use of plow and monocropping promotes desertification
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Cash crops like cotton promote desertification
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Increased need for fuelwood promotes desertification Blaming the victim More forests cut by loggers
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Major problems Desertification Deforestation Soil Erosion
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Desertification deforestation irrigation increased population of humans and animals drought conditions accelerate
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Deforestation fuelwood construction shifting cultivation commercial logging
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Soil Erosion Deforestation Monocropping; cash crops Use of plow Soils lose fertility
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Other environmental issues Wildlife Toxic waste dumping
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What can be done? Afforestation (tree planting programs) –especially for women as they are responsible for fuelwood Better design of irrigation –water from rivers –build dams (old approach)
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Better agricultural policies and assistance to rural populations Allow intercropping Natural fertilizers Cull livestock Urban jobs
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Irrigation could be a solution but Salinization because of poor drainage of the soils
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Nile is famous example of salinization
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salt buildup Inhibits plant growth and yields
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