Evaluation of furrow irrigation performance: Case of Kasinthula Cane Growers Scheme in Malawi

Abstract

Surface irrigation is associated with low irrigation efficiencies and exerts a lot of pressure on water resources. Despite this, the irrigation method remains dominant in Malawi and other sub-Saharan Africa countries. A need exists to improve surface irrigation efficiencies in the wake of water scarcity. Applications of surface irrigation simulation, evaluation and design (SIRMOD) software in improving surface irrigation performance have been reported worldwide. However, no documentation exists on SIRMOD application in Malawi. A study was therefore conducted to investigate how furrow irrigation system performance could be improved at Kasinthula Cane Growers Scheme in Malawi using SIRMOD software. Field data collected from the scheme were used to calibrate the model before simulating water advance and recession times. Statistical comparisons of the simulated advance and recession times with corresponding observed field data showed that the model closely simulated field conditions; hence, it was deemed suitable for the scheme. Results from SIRMOD optimization procedure indicated that application efficiencies could be improved by 32–63% through reductions in furrow lengths, water inflow sizes and inflow cutoff times. The study established the need for Malawi and other developing countries to develop policies on optimization of irrigation performance using computer models such as SIRMOD.