| The experiments during 2002~2003 indicated that the yields of 6 varieties of winter wheat responded differently to straw mulching due to the discrepancies of their physiological and ecological traits, and the straw mulching treatments showed an obvious water-saving effect. The varieties 8901 and 6365 were not sensitive to low temperature of straw mulching in spring, and their yield and WUE were increased under straw mulching. It was the accumulation effects of yield components that led to the difference of the yield. The integrated order of WUE of the 6 varieties, under mulch and full irrigation, non-mulch and full irrigation, and non-mulch and deficit irrigation, showed the same law as the total dry matter accumulation and its distribution to spike, stem and leaves, but the contrary law to its distribution to yellow leaves. |