CALULATION OF CROP WATER REQUIREMENT FOR SOME CROPS IN ABU GHRAB

Abstract

The study was initiated to estimate the water requirements for some winter and summer crops using a metrological depth available from Al-Raad experimental station. Blaney – Griddle equations by FAO was used to estimate the potential evapotranspiration. The plant factors for each crops were used from those a variable from FAO. The results of this study showed that the potential evapotranspiration for central of Iraq was 1990 mm / year. Months of May , June , July , August and September showed 75% of this potential evapotranspiration . The crop water requirement for winter crops was between 305 mm for broad beans and 440 mm for bersean . Other crop water requirements were between these ranges . For the summer crops the water requirements were ranged between 950 mm for cotton to 551 mm for Potato , other crops such as sunflower , soybean , season water requirements between thexs figanes . All the finfing of crop water requirements by the calculation method were lie between the ranges recommended by FAO , except the Alfalfa crops water requirement value exceed these ranges.