The burden of acid soils for crop production in sub-Saharan Africa

Abstract

Acid soils are widespread across sub-Saharan Africa. Agricultural lime can be used to alleviate production constraints associated with soil acidity, but lime is not widely available in the region, and it is unclear how profitable its use would be. To guide potential investments in lime market development, we estimated the profitability of acid soil remediation through liming. Crop yield loss to soil acidity occurs on 32.7 M ha, or 23% of sub-Saharan Africa’s cropland. The burden of acid soils is $6.0 billion (6% of the current production value), and 70% of that could be profitably alleviated. Under prevailing conditions, liming would be profitable in the year of application on 4.6 M ha, with an average profitability of $340 ha-1, and on 5.7 M ha when considering the multiple years that liming has an effect. Intensification of crop production and lower relative lime/output prices could make liming profitable on more cropland.