Crop water requirement and irrigation schedule for major crops of Indo–gangetic plain using CROPWAT model

Abstract

In view of increasing groundwater pumping to meet irrigation demand of major crops there is a need to use groundwater efficiently. A study was conducted at Rasoolpur jatan village of Muzaffarnagar district to determine the crop water requirement (Et ) c and irrigation scheduling of sugarcane, maize and wheat using CROPWAT 8.0 model. In the study area, reference evapotranspiration (ET ) varied from 1.89 to 7.33 mm day 1 o similarly effective rainfall (R ) varied from 0 to 148.4 mm. At the initial stage ET of eff c maize and wheat were found to be lower (28.8 mm and 36.4 mm) and for sugarcane it was maximum (50.6 mm). During the mid–season stage water requirement (ET ) for c wheat was minimum (141.4 mm) and maximum for sugarcane (1098.9 mm). The peak water requirement was 9.27 mm day–1 with application efficiency of 60%. The average crop water demand estimated for sugarcane, maize and wheat were 1580 mm, 387.7 mm and 315.4 mm whereas net irrigation requirement (NIR) were 1072 mm,138.2 mm and 192.1 mm, respectively. Proper irrigation scheduling can save 20.05 ha–m and 2.64 ha–m of groundwater in sugarcane and wheat. The study shows that R was not eff sufficient to meet the water requirement of sugarcane, maize and wheat crops. Hence irrigation is needed to meet water requirement of crops and appropriate scheduling practice may be followed in the study area to reduce the load on the groundwater.