Hisham M. MohammedIDetermination of crop coefficients, water requirements and water productivity for summer maize (Zea mays L.) under central Gezira clay soil conditions, Sudan

Abstract

Understanding crop water needs is essential for irrigation scheduling and water saving in an arid region because of its limited water supply. This research was, therefore, conducted to determine growth stage specific Kc and crop water use for maize (Zea mays L.) cultivar Hudaiba2 at the Experimental Farm, University of Gezira, during summer seasons 2015/16 (first season) and 2016/17 (second season) to estimate crop coefficients (Kc), crop water requirements (CWR) and water productivity (WP) of maize cultivar Hudaiba2. The reference evapotranspiration (ETo) was calculated using the FAO computer program (CROPWAT). Actual crop evapotranspiration (ETc) was estimated by the gravimetric method. Crop coefficients were derived from the relationship between reference evapotranspiration and actual crop evapotranspiration. The results showed that crop coefficients values for maize were 0.49 and 0.46 for initial stages, 1.30, and 1.32 for the mid stages and then decreased gradually to 0.47 and 0.40 for the late stages, in the first and second season; respectively. The peak Kc occurred during the period 60 to 70 days after sowing (DAS), coinciding with the maximum ETc of 7.24 and 8.22 mm/day at the mid-season stage for maize. The crop consumptive water uses of maize were 547 and 505.1 mm (5470 and 5051 m3/ha) for the total growing period in the first and second season; respectively. The mean yield of maize was 4238.5 kg/ha and the crop water productivity was 0.72 kg/m3. For this reason Kc value must be used to calculate the applied water to increase the yield and water productivity.