Abstract: "Based on the data obtained from 4-year field experiments conducted at Wuwei Irrigation Experimental Station,the Decision Support System for Agrotechnology Transfer(DSSAT) Cropping Systems Model was calibrated and validated.Then the model was used to simulate the crop water consumption and agricultural water use for spring wheat under traditional irrigation conditions in Shiyang River Basin from 1985 to 2006.The results showed that seasonal water requirement for spring wheat was 526.4 mm and mean annual evapotranspiration was 658.5 mm under winter flood irrigation conditions.About 159.1 mm water was required during the period from jointing to booting stage,which accounted for 30.2% of total water consumption in whole growing season.It was very important for spring wheat during filling stage.If the irrigation was lack at this stage,the grain yield would drop significantly.As for the agricultural water use,the results showed that it was very high in 1990's,which had reached 50.5×108 m3.The mean annual value was about 5.05×108 m3,which increased by 25.5% in comparison with 1980's.However,after 2000,the annual agricultural water use had dropped from 5.05×108 m3 in 1990's down to 3.17×108 m3,due to a series of policies which led to closures of illegal irrigation wells and adjust of planting structure. "

Key words: Crop water consumption, Agricultural water use, Spring wheat, DSSAT model

CLC Number: 

• S512.12