不同土壤水分和不同覆盖条件下麦田水分动态和增产机理研究

A STUDY OF WATER DYNAMICS AND YIELD-INCREASING MECHANISM OF WINTER WHEAT FIELDS IN DIFFERENT SOIL WATER AND MULCHING CONDITIONS

1997年 1月至 1 998年 6月在郑州水分试验场进行了小麦田覆盖期、覆盖量和土壤水分处理试验 .结果表明 ,覆盖是一种行之有效的保墒增产措施 .不同覆盖期、不同覆盖量和不同土壤水分对小麦干物重、叶面积、蒸腾强度、产量和水分利用效率有着显著的影响 .覆盖期、覆盖量和土壤水分含量的最佳结合点为 :冬前小麦停止生长之日、55%～ 70 %土壤相对湿度、450 0～ 60 0 0 kg/ hm2覆盖量 .在此状况下 ,产量可增加 1 8.5% ,水分利用效率提高 2 2 .1 % .

From Jan. 1997 to June 1998, experiments on mulching date, amount of straw used for mulching and soil water content in winter wheat fields were carried out. The results indicate that straw mulching is an effective measure for preserving soil water and increasing crop yield. Different amount of straw, different mulching time and different soil water content have a great influence on the dry matter weight, leaf area, intensity of transpiration, yield and water use efficiency of winter wheat. The optimum mulching date in the North China plain is the end of December when winter wheat stops growing. The optimum straw amount used for mulching is about 4500—6000 kg/hm 2, and the optimum soil water content is 55%—70% of relative soil humidity. Under the combination of above conditions, the yield of winter wheat increased by 18.5% and water use efficiency raised by 22.2%.