In commercial vegetables production, irrigation is crucial to achieve the crop return, both in term of yield quantity and quality. Therefore, irrigation of vegetable crops is often performed inefficiently since farmers tend to over-irrigate crops. The difficulty in estimating the vegetable crops water requirements, the different irrigation systems utilized, the large number of plant species/cultivars, and the peculiar production conditions (small-scale farm, high-intensive cultivation methods) are other variables that contribute to the such inefficiency. Many agronomic, engineering, and management technologies are discussed to improve crop performances and to reduce non-productive water use in irrigated agriculture, which in turn lead to higher WUE. Generally speaking, to maximize WUE, it is necessary both to conserve water and to promote maximal crop growth. The former requires minimizing losses through runoff, seepage, evaporation and transpiration by weeds. The latter task includes planting high-yielding crops/cultivars well adapted to the local soil and climate. It also includes optimizing growing conditions by proper timing and performance of planting and harvesting, tillage, fertilization and pest control. New precision irrigation technologies for scheduling irrigation and up-to-dated irrigation systems would enable growers to apply water and agrochemicals more precisely and site specifically to match soil and plant status and needs as estimated by wireless sensors.
Keywords: Evapotranspiration, crop water requirements, irrigation water efficiency, irrigation method