旱地冬小麦施肥效应研究

Study on the Effect of Fertilization on Winter Wheat Under Rainfed Conditions

旱地条件下,施肥提高冬小麦生育前期土壤含水量和土壤水势,而在冬小麦接近成熟和收获时,施肥处理的土壤含水量和土壤水势均低于对照,从而使冬小麦吸收利用更多的土壤水分。施肥增大早地冬小麦绿叶面积和延迟叶片衰老,从而降低土壤蒸发,增加蒸腾用水潜势和光合潜势,但净同化率不一定提高。施肥增加旱地冬小麦总的水分利用(ET)和蒸腾用水(T),增加地上部生物产量,同时,旱地施肥增加冬小麦的每株有效分蘖数和每穗粒数,增加籽粒产量。因此,冬小麦的水分利用效率提高。

Fertilization can improve soil moisture content and soil moisture potentialprior to the development of winter wheat,while nearly in wheat mature stageand harvesting stage,soil moisture content and soil moisture potential in fer-tilizer treatment is lower than in the cnotrol whereby to make winter wheattake up more soil water.Fertilization can increase leaf area and inhibit leafaging of winter wheat,thus,reducing soil moisture evaporation,and increasingwater use potential through transpiration and photosynthetic potential,but netassimilation rate can not be improved.Fertilization can increase soil water useefficiency by winter wheat in rainfed land and water use by evaportranspira-tion(ET)and increase biomass of the above ground parts.At the same time,fertilization to rainfed land can increase the effective tillers per plant and seednumbers per ear so as to improve grain yield.Therefore,water use efficiencyby winter wheat can be greatly improved.