1. Soil Problems in Africa Eric Battisti ESS 315

2. Initial Soil Problems Tropical regions in general have less fertile soil compared to temperate regions Geologic parent material is lacking in essential minerals High temperatures accelerate chemical weathering Humid areas suffer from high acidity and toxic levels of aluminum and iron Most arable soils are coarse, without enough clay to absorb and hold moisture

3. Latosols (the original presentation) Laterite is reddish to yellow brown iron rich, humus-poor soil that hardens irreversibly when dried and exposed to air Latosols are low in MgO, Sulfates, Nitrogen and Phosophorus Latosols are found in or near the surface of 15% of sub-Saharan West African Soils, the highest concentration of latosols anywhere in the world The process of turning Latosols into arable land requires extensive treatments to reduce acidity and trace metals

4. And on top of that… Rampant deforestation Overgrazing Irresponsible irrigation practices Lure of cash crops

6. Farming and Famine Currently 75% of Africa’s farmlands are severely degraded Africa looses an estimated $4 Billion of soil nutrients a year Fertilizer use is lowest in the world 85% of African farmland looses nutrients an annual rate of 30 kilograms per hectare

7. Growth Expectations Increase in urbanization as countries develop facilitates erosion By 2020 continued erosion could lead to an estimated drop of 17-30% in crop yields Increases in population would lead to an increase in imported grain from 43 million tons to 60 million tons

8. Quick Fixes? Availability of appropriate fertilizers to African farmers Global awareness of the problem (dirt isn’t media friendly) Improve tilling techniques and crop rotation Stop clearing of new land for farming and replenish ‘dead’ soil with nutrients

9. References http://www.globalchange.umich.edu/globalchange2/current/lectures/lan d_deg/land_deg.html http://www.globalchange.umich.edu/globalchange2/current/lectures/lan d_deg/land_deg.html http://home.windstream.net/bsundquist1/se3.html#Dc3 http://edro.files.wordpress.com/2008/02/once-a-forest.jpg http://forests.org/archive/africa/afsickea.htm http://www.newscientist.com/article/dn8929-soil-health-crisis-threatens- africas-food-supply.html http://www.newscientist.com/article/dn8929-soil-health-crisis-threatens- africas-food-supply.html