A Review of Water Footprints for Irrigated Vegetables under Conservation Agriculture in the Ethiopian Highlands

Abstract

Water footprint (WF) accounting has the potential to provide crop water use metrics and can assist farmers to improve water uses. However, WFs for smallholder irrigated vegetables under conservation agriculture (CA) practices have not been accounted in the Ethiopian highlands. This research was conducted aiming to better understand the potential advantages of irrigated technologies for saving water in the sub-humid highlands. Results showed that the highest irrigation water saving (25%) was found under CA for overhead irrigation application on tomato in the dry period while the lowest water saving (9%) was found under CA compared with CT under Majipump drip system of onion. On the other hand, the evapotranspiration (ET) in the conventional tillage (CT) under the overhead irrigation, when compared with the CA, was in the ranges of 38-96% while the value is lowered to the range of 7-10% for drip irrigation. In the dry phase of vegetable production, blue WF in CA was reduced by about 1.7 times when compared with the CT while the green water was reduced by about 5.7 times when compared with the CT. In general, the total WF was about 2.2 times lower under the CA when compared with the CT.