Increasing Productivity Through Enhanced Water Use Efficiency in Marginal Soils

Water scarcity is a major limiting factor in reducing crop yields in the arid and semi-arid regions of Africa. The continent’s growing population will require sustainable food security, despite these conditions. Enhancing water use efficiency (WUE) in the marginal soils of Africa’s arid and semi-arid regions is vital for food production on the continent. The purpose of this chapter is to discuss conservation agriculture (CA) and in situ rainwater harvesting (RH) as potential practices to enhance WUE in Africa’s marginal soils. The application of CA was found to conserve both soil and water, thus enhancing WUE and crop yield. CA was found to increase water infiltration up to 40% in marginal soils, compared to conventional tillage (CT). The application of RH practices was found to increase soil water content, infiltration, soil fertility and crop yields in marginal soils. Notably, however, the benefits of both CA and RH for WUE are site-specific. The conclusion reached, is that both CA and RH have the potential to enhance WUE in marginal soils in arid and semi-arid regions, thus increasing crop yield, but site conditions are important when selecting the appropriate CA and RH practices.