Effects of small-scale irrigation systems on crop productivity and electricity requirements in Ethiopia, Rwanda, and Uganda through an integrated system modeling approach

Agriculture is the backbone of East Africa's economy, with a contribution of up to 50% of the Gross Domestic Product (GDP) in some countries. Currently, less than 3% of the total cultivated area in Eastern Africa uses some form of irrigation and is mostly non-pressurized. More than 75% of the cultivated crops grow with traditional seeds by subsistence farmers that rely on traditional agricultural practices. At the same time, fertilizer use ranges between 2 and 14 kg/ha, below the average use in Sub-Saharan Africa. Meanwhile, electricity providers frequently struggle with low and unpredictable demand, which challenges their financial sustainability in rural areas. As a result, agricultural productivity is meager and electricity infrastructure is underutilized. The use of electricity, particularly for irrigation, has the potential to boost agricultural productivity and improve electric utility financial performance. This study focuses on finding opportunities for co-investment in electricity and small-scale irrigation infrastructure in Rwanda and Uganda through improved agricultural practices for maize, potato, beans, onion, and tomato. To study the link between electricity use and increased agricultural productivity, we combined the biophysical crop growth model, AquaCrop, with a simplified engineering-based irrigation model that uses climate, soil, and crop physiology data as inputs on a district-level basis. The irrigation model estimates electricity demand for irrigation from AquaCrop's simulated crop yields and irrigation requirements under a variety of scenarios. Furthermore, we assessed the water sufficiency per district via a reduced form hydrology model. We found that irrigation, fertility, and, to a lesser extent, cultivar type should go hand in hand to increase productivity. Additionally, we found that projected electricity and hydrology resources are substantial enough to grant potential benefits from combined planning of electricity and irrigation infrastructure in most districts. These results suggest that integrating a regional decision support system that estimates yield improvements, electricity demand for irrigation, and water sufficiency, could help inform decision-makers about opportunities for co-investment in electricity and agriculture.