Dr. Nicholas Brozović
Dr. Derek M. Heeren
Dr. Lameck Odhiambo
Date of this Version
Chandra, A. (2020). Water-Energy-Food Linkages in Shared Smallholder Irrigation Schemes. MS thesis. University of Nebraska-Lincoln
Irrigation is a policy focus in Sub-Saharan Africa and is viewed as an important mechanism to improve farmers’ income and livelihoods while reducing the impacts of climate change. Water, energy, and food are linked in intricate ways in irrigated agriculture, and understanding the interplay of these components is crucial for sustainable and profitable crop production. Although studies have been conducted in different parts of the world to understand water and energy use at a field scale under large irrigation systems, little is known about linkages under farmer-managed mechanized irrigated schemes in Sub-Saharan Africa. This study evaluates water-energy-food linkages, engineering and economic performance, current irrigation decision making, and challenges faced around water management in a community-based mechanized irrigation scheme. The research synthesizes intraseasonal water and energy use data for selected crops in a shared center-pivot irrigation scheme in Rwanda. The major cultivated crops are maize and beans (French beans, dry beans, common beans). A daily soil-water balance is central to estimate actual irrigation water requirement (IWR) and is simulated in FAO-CROPWAT 8.0. The study further investigates the variation in water requirements, and the relationship and impacts of this variability on crop yield. Assessment of irrigation performance is done by estimating and comparing crop water productivity (CWP) and crop water use efficiency with global and local averages. Observed irrigation decision-making analyses demonstrate a lack of irrigation planning during growth stages and significant field-to-field variation in irrigation; this is linked to yield reduction in major crops. An econometric model assessment is used to understand the relationship between yield and energy inputs. The energy use assessment includes both direct (electricity) and indirect energy inputs (fertilizers, pesticides, machinery, labor, etc.). This study has implications for understanding irrigation policies in the context of the water-energy-food nexus and decision-making in Sub-Saharan Africa.
Advisors: Nicholas Brozović and Derek M. Heeren