Irrigation water use efficiency: A water balance approach

Abstract

AbstractIrrigated agriculture plays a major role in the livelihoods of nations all over the world and with the agricultural water use sector being the largest of all water use sectors, there have been increased expectations that the sector should increase efficiency. Irrigation efficiency should be assessed by applying a water balance and the purpose of an irrigation system is to apply the desired amount of water, at the correct application rate and uniformly to the whole field, at the right time, with the least amount of nonbeneficial water consumption (losses), and as economically as possible. The fraction of the water abstracted from the source that can be utilized by the plant, can be called the beneficial water use component, and optimized irrigation water supply is therefore aimed at maximizing this component. A water use framework that covers four levels of water management infrastructure: the water source, bulk conveyance system, the irrigation scheme, and the irrigation farm can be used to improve irrigation efficiency. The water balance approach can be applied at any level, within defined boundaries, or across all levels to assess performance within the whole Water Management Area.