Ibrahim M. Abdel-Fattah, Amal A. abd-Elmotaal and Howida. E. Hassan( 2019). A technical and economic study for the effect of irrigation water scheduling on cotton yield productivityNature and Science 2019;17(11)
Abstract: To find out the impact of different scenarios of irrigation scheduling i.e. when to irrigate and how much water should be applied using the CropWat computer model which reflects the response of yield to water, particularly under the water deficit status. The aim of the present work was to improve the productivity of each unit of water and land for cotton crop (Gossypium barbadence L) in Kafr El-Sheikh Governorate, which represents the circumstances and conditions of North Nile Delta region. That governorate has the largest cotton cultivated acreage in Egypt. So, in this regard, twenty different scenarios of irrigation scheduling were tested using CropWat model during the two successive cotton growing seasons of 2016 and 2017. Four different irrigation intervals of 8, 12, 16 and 20 days were the selected intervals, while 20, 30, 40, 50, and 60 mm were the net applied irrigation water under each investigated irrigation timing. Therefore, by using CropWat model in evaluating the impact of different scenarios of irrigation scheduling on the economic return of water and land in North Nile Delta region, following are
the main findings: (1) Ripening growth stage or said the last season stage is the most sensitive stage regarding water deficit, increasing water applied and/or shortening the irrigation interval during the second half of the growing cotton season becomes recommended. (2) Under each irrigation interval, reduction in percentages of , CWP and economic return of water unit are decreased with increasing net irrigation. On the other hand, cotton yield and net revenue are increased. (3) By elongating irrigation interval from 8, 12, 16 and 20 days under each net irrigation, percentage reduction in Et and cotton yield, CWP but return of water unit are increased. (4) Further studies using CropWat computer model should be done to find out the impact of different scenarios of irrigation scheduling on crop water productivity for different crops.
Keywords: (irrigation scheduling, CropWat, Cotton crop, water deficit, crop water use ( ), , Net revenue, Economic efficiency, Economic return of land unit , Economic return of water unit.)
