CALULATION OF CROP WATER REQUIREMENT FOR SOME CROPS IN ABU GHRAB.

Abstract

The study was initiated to estimate the water requirements for somewinter and summer crops using a metrological depth available from Al-Raadexperimental station. Blaney – Griddle equations by FAO was used to estimatethe potential evapotranspiration. The plant factors for each crops were usedfrom those a variable from FAO. The results of this study showed that thepotential evapotranspiration for central of Iraq was 1990 mm / year. Months ofMay , June , July , August and September showed 75% of this potentialevapotranspiration . The crop water requirement for winter crops was between305 mm for broad beans and 440 mm for bersean . Other crop waterrequirements were between these ranges . For the summer crops the waterrequirements were ranged between 950 mm for cotton to 551 mm for Potato ,other crops such as sunflower , soybean , season water requirements betweenthexs figanes . All the finfing of crop water requirements by the calculationmethod were lie between the ranges recommended by FAO , except the Alfalfacrops water requirement value exceed these ranges.