Soil Problems in Africa

Eric Battisti ESS 315

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

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

And on top of that…

• Rampant deforestation• Overgrazing• Irresponsible irrigation practices• Lure of cash crops

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

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

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

References• 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