Shifting cultivation Oldest form of agriculture in Africa Slash and burn Four steps 1. cut primary forest

2. Burn remaining vegetation: ash acts like a fertilizer 3. Plant for 2 to 3 consecutive years 4. Fallow for about 20 years

Three stages of S/B and Fallow

Typical Village

Old self-sufficient patterns Rarely exist Creation of markets People aim for surplus Trade with surrounding villages

Current Practice: Rotational Bush Fallow 2 to 10 years Requires supplementary methods such as fertilizers or manure Not all farmers have these

More affluent farmers have cattle for plowing and manure

Intercropping Old pattern Spreads risk Discouraged by “modern” scientists Can help prevent erosion

Desertification Land severely degraded Brings desert- like conditions An underlying cause of declining food production

Sahel in the 1970s and 1990s Millions of people and cattle died

Areas looks like this and causes many people to flee (produces refugees)

African droughts are common But are accelerated by – population increases, both human and animal –cutting trees

Final Stages of Desertification

Forests (tree cover) prevent erosion

Thin layer of soils over rock Hard to bring back the land into production

Use of plow and monocropping promotes desertification

Cash crops like cotton promote desertification

Increased need for fuelwood promotes desertification Blaming the victim More forests cut by loggers

Major problems Desertification Deforestation Soil Erosion

Desertification deforestation irrigation increased population of humans and animals drought conditions accelerate

Deforestation fuelwood construction shifting cultivation commercial logging

Soil Erosion Deforestation Monocropping; cash crops Use of plow Soils lose fertility

Other environmental issues Wildlife Toxic waste dumping

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)

Better agricultural policies and assistance to rural populations Allow intercropping Natural fertilizers Cull livestock Urban jobs

Irrigation could be a solution but Salinization because of poor drainage of the soils

Nile is famous example of salinization

salt buildup Inhibits plant growth and yields