Improving Irrigation: Water Conservation in Agricultural Use and Rebound Effects

Improving irrigation in smallholder farmer agriculture in South Africa has the potential to substantially increase productivity, improving food security and local livelihoods. However, increased irrigation also threatens to erode water security as increased productivity increases the incentives to expand cultivation.

Lipscomb is working with a team, including 4D Climate Solutions and their partner, the National University of Lesotho, to test a novel water irrigation solution (GrowSmart) that they are marketing to farmers across Lesotho. The irrigation system is powered by solar panels and has IoT (Internet of Things) sensors in the soil and polytunnels which limit water extraction to the amount necessary for optimal cultivation and help create a suitable environment for growing vegetables in tunnels.

4D Climate Solutions has an initial contract with the Lesotho Evangelical Church of Southern Africa (LECSA) to integrate GrowSmart systems into some of the church’s farmland (LECSA owns half of the land in all of Lesotho). The team is testing the extent to which the irrigation systems increase irrigation, increase yields, and impact the overall water used by the system (the automatic cutoff of the system based on sensor readings substantially reduces the amount of water used).

Researchers expect the system to increase the number of farmers irrigating, but to reduce the total water used by each irrigator. They are interested in the overall impact on yields as well as the overall impact on water security. Combining field observations with satellite imagery will allow us to understand the overall impact of the interventions on greenness and land use in treatment versus control subbasins.