The field trials in Xinxiang Henan province from 1985 to 1987, showedthat the grain yield, the protein yield and the nutrient quality of winterwheat are significantly influenced by irrigation. During the growing periodof winter wheat, wether the weather is drying or wetting, irrigation canincrease grain yield and protein yield. In the drying year, irrigation canincrease the 1000-grain weight, grain yield, protein content and lysinecontent; but in the wetting year can decrease the 1000-grain weight andprotei...