Sub-Saharan Africa, with the highest fertility rate in theworld, faces increasing demographic pressure on its naturalresource base. As a result of rapid population growth andgrowing land constraints, cultivated land per capita has fallen by40 percent since 1965, from 0.5 to about 0.3 hectare perperson.At the same time, land quality has fallen. Data onnutrient balances over the past 30 years suggest that Africansoils have sustained annual net losses of nitrogen, phosphorus,and potassium on the order of 22, 2.5, and 15 kilograms (kg)per hectare respectively.This soil mining may contribute fromone-third to as much as 80 percent of farm output in somelocations. Failure to replenish soil fertility—from organic orinorganic sources—leads to unsustainable output and incomesin agriculture.
Publication year
2004
Authors
Franzel, S.; Place F; Reij C; Tembo G
Language
English
Keywords
development, highlands, management, research, watershed management, sustainable
