Effect of straw mulching on soil moisture and water use efficiency of winter wheat in dryland | 秸秆覆盖对旱地土壤水分及冬小麦水分利用效率的影响

Chinese. 研究秸秆覆盖方式与覆盖量对冬小麦田土壤水分及冬小麦产量和水分利用效率的影响。在陕西渭北旱塬，通过连续2年（2007-2009）的不同秸秆覆盖方式（全程覆盖、生育期覆盖、不覆盖（CK）与不同覆盖量（9 000， 6 000，3 000 kg/hm2）的大田试验，研究秸秆覆盖对土壤水分及冬小麦产量和水分利用效率的影响。2年的定位试验结果表明，同一覆盖方式不同覆盖量处理的土壤含水量与覆盖量呈正相关；同一覆盖量不同覆盖方式下土壤含水量表现为全程覆盖优于生育期覆盖和CK；全程覆盖方式9 000，6 000和3 000 kg/hm2覆盖量处理0～200 cm土层平均含水量较生育期覆盖分别提高了11.5%，10.0%和8.0%，较CK分别提高了19.2%，12.9%和8.8%；全程覆盖方式和生育期覆盖方式下，小麦的水分利用效率均以覆盖量为3 000 kg/hm2处理最大，其中全程覆盖方式的水分利用效率较CK增加了31.5%(P0.05)，生育期覆盖方式下2年平均的水分利用效率较CK增加了12.8% (P0.05)；不同覆盖量在全程覆盖方式下冬小麦产量较CK增加41.1%～65.7%(P0.05)，在生育期覆盖方式下冬小麦产量较CK增加了27.1%～30.2%(P0.05)。同一秸秆覆盖方式不同覆盖量均可增加冬小麦产量，而同一覆盖量下以全程覆盖方式的增产效果较优；覆盖量为3 000 kg/hm2时，2种覆盖方式的冬小麦水分利用效率均最大。

English. The study was to explore the ways and the cover amount of straw mulch on winter wheat field with soil moisture, winter wheat yield and water use efficiency. A two-year field experiment including the straw mulching in various ways covering the growth period and fallow, growth period, no-tillage and different amounts made up of 9 000, 6 000, 3 000 kg/hm2 was set in Weibei Loess Plateau of Shaanxi Province to make clear the effect of straw mulch on yield, soil moisture and water utilization efficiency of wheat winter from Sep. 2007 to Jun. 2009. The result indicated that soil water content and amount covered by the different amounts of coverage in the same mulching mode was positively correlated. The soil moisture content of full period which covered the different ways in the same amount of coverage was superior to that in growth stages and control. While the straw mulching quantity was 9 000 kg/hm2, 6 000 kg/hm2 and 3 000 kg/hm2, in the 0-200 cm layer, soil moisture content of full coverage increased by 11.5%, 10.0% and 8.0% respectively compared with the growth stages coverage, increased by 19.2%, 12.9% and 8.8% compared with the control. Whether the full or growth stage coverage, the water use efficiency (WUE) was always the largest in the amount of 3 000 kg/hm2. Compared with the control, the WUE of full coverage was remarkably increased by 31.5% (P0.05), and the growth stage was significantly enhanced by 12.8% (P0.05) in average of two years. With the straw mulching amount of 9 000 kg/hm2, 6 000 kg/hm2 and 3 000 kg/hm2, the winter wheat yield of the full stage coverage in different mulching modes was remarkably increased by 41.1%-65.7% (P0.05) than the control, that of the growth stage was also increased by 27.1%-30.2% (P0.05). Two-year preliminary study showed that the crop yield could increase the straw mulch of different ways in the same volume.In the same amount of coverage, the production of entire period and fallow methods was better than that of other growth period and ways. In the 3 000 kg/hm2 coverage, the WUE of two patterns were all the greatest.