Evapotranspiration-based Irrigation Scheduling: A Promising Tool for Uzbek Farmers

Date: 15.02.2016.

Water Users Association (WUA) farmers of Fergana Valley took part in consultation and training sessions on improving irrigation water management at field and farm levels through adoption of water-saving technologies. Photo by Dr. Vinay Nangia.

Irrigated agriculture is the backbone of Uzbekistan’s economy. Therefore, efficient irrigation water management is of crucial importance to the sustainable crop production in the country.  Since independence, Uzbekistan has made significant efforts including institutional reforms to implement integrated water resources management (IWRM) to maintain and improve irrigation capacity. These efforts are much needed for better water management at a regional scale to improve irrigation water management at field and farm levels through adoption of water-saving technologies such as evapotranspiration (ET)-based irrigation scheduling, drip irrigation, and crop monitoring sensors.

Under the CGIAR Dryland Systems CRP in Central Asia, ICARDA scientists, in partnership with Scientific Information Center of the Interstate Coordination Water Commission of the Central Asia (SIC-ICWC) and Khorezm Rural Advisory Support Service (KRASS) have completed a research study in irrigated farmlands of Fergana Valley and Khorezm implementing ET-based irrigation scheduling decision-support tool.

At present, Fergana Valley farmers use the Soviet era-developed method of irrigation which divides the irrigated areas in Hydro Module Zones (HMZ). Each HMZ has a set of crop-specific recommendations for irrigation based on 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 evapotranspiration (ET)-based irrigation scheduling method has the potential to replace subjective daily water management decisions at Water Users Association (WUA) level with crop water demand-based decisions to improve water-use efficiency while reducing salinity and waterlogging problems.

Results from the two year study (2013-2015) showed that there can be a 32-35% saving of water when irrigation is applied using the ET-based scheduling method. The pilot plots are representative of 35% of irrigated area in Fergana Valley and 50% in Khorezm area. If this methodology is widely adopted by the WUAs of both locations, large amounts of water can be saved which can be diverted for supporting downstream ecosystem services, expanding irrigated agriculture or for industrial and municipal purposes.

In order to ensure success of the research beyond the project lifecycle, farmers from participating WUAs, local water management authorities, national partners as well as scientists academia were involved. Consultation and training took place at every steps of the research – stakeholder consultation workshop was organized to draft work plans and explain the methodology; training sessions were provided for equipment installed in the fields, all tools were translated into local language; handbooks were developed and distributed during farmer field days and an open access database was created to store and share all the study outputs.

For more information please read the report Improving Water Use Efficiency Through Innovative Technologies in Irrigation and Agriculture in the Fergana Valley.

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