Improving Water Use Efficiency Through Innovative Technologies in Irrigation and Agriculture in the Fergana Valley

Abstract

Final report on ET-based irrigation scheduling research in Fergana Valley, Uzbekistan. Fergana Valley farmers still use the Soviet era method of irrigation which divides the irrigated areas in hydromodule zones (HMZ). Each HMZ has a set of crop–specific recommendations for irrigation based the soil characteristics (thickness of soil layers, soil texture) and depth of groundwater table. These recommendations have not been revised against changes in cultivars and fluctuations in groundwater table during past decades. The ET-based irrigation scheduling method has the potential to replace subjective daily water management decisions at WUA level with crop water demand-based decisions to improve water use efficiency while reducing salinity and waterlogging problems. A study was conducted in which farmer fields falling under HMZ I, II and VIII were selected. The fields were split into two – one receiving irrigation using traditional HMZ method and the other receiving irrigation based on the weather station-based ET and soil moisture data. Results from the two year study indicate that there can be a saving of approx. 25-35% saving of water in cotton crop and 32-53% saving in winter wheat crop without any loss of productivity if the weather station-based irrigation advisory system is adopted in the three HMZs. Similar levels of savings can be expected for the other zones which could not be studied for lack of sufficient financial support.