Influence of drought on winter wheat yield in China during 1961-2000

Assuming that the winter wheat varieties,cultivating measures and soil characteristics were under current condition,the influence of drought in 1961-2000 on winter wheat yield in China was simulated with WOFOST crop model.The results indicated that the average yield decrease induced by drought was 4.6% for whole winter wheat region and 12% for northern China in 1961-1980,which was more serious than that in 1981-2000.The drought effects on the winter wheat yields kept a constant roughly,although the precipitation during the growing period had decreased over the last 40 years.The correlation coefficients were then calculated between precipitation and impact of drought on yields,the results indicat that there were significant correlation between spring precipitati- on and yield loss induced by drought,while the correlation were not significant between precipitation in growing pe- riod and yield loss.This point out the importance of the spring precipitation for winter wheat production in northern China.