1 - Enhancing crop water productivity under increasing water scarcity in South Africa

Abstract

Agricultural productivity in South Africa is threatened by the increasing water scarcity as the country is ranked among the 30 driest countries in the world. The challenge is exacerbated by population growth, migration, changing diets, and increasing frequency and intensity of drought, which increase pressure on already depleted and scarce water resources. The multiple challenges have negatively affected crop water productivity in the country. This study explored the opportunities to increase crop water productivity (output per unit water consumed) under water scarcity conditions in South Africa. Although irrigation may provide immediate options to improve crop water productivity in response to droughts and mid-season dry spells, there should be considerations on the availability and accessibility of water and energy for irrigation requirements. The country also faces energy supply challenges and irrigation expansion could aggravate the existing challenges if not well-managed. Groundwater use and water marketing are considered as options to alleviate water scarcity challenges, but the extent to which they can bring relief on the stressed water resources is not yet known. Tapping into groundwater also requires reliable energy resources, which brings into the fore the need for a water-energy nexus planning to enhance agricultural and water productivity. These issues are critical for a sector that is dominated by poorly resourced smallholder farmers. Options to enhance crop water productivity include rainwater harvesting and soil water conservation technologies.