渭北旱原夏闲期麦田不同耕作措施的土壤贮水效应

Effect of tillage on soil moisture storage in summer fallow period of winter wheat field in Weibei dry-land

【目的】研究免耕、深松和翻耕麦田夏闲期土壤贮水能力,揭示3种耕作方式麦田土壤蓄水保墒能力产生差异的机理。【方法】选取渭北旱原中等产量水平的旱作麦田,于2007和2008年麦田夏闲期,研究免耕、深松和翻耕3种耕作方式下,麦田0~300 cm土层土壤贮水量和降雨后土壤水分的时空变化特征。【结果】2007和2008年夏闲前后,免耕、深松处理0~300 cm土层土壤含水量较翻耕处理分别提高47.2%,55.6%和38.9%,22.2%,均达到显著水平（＜0.05）,并且3种耕作方式土壤贮水量的差异主要体现在160或140 cm以上土层;免耕和深松土壤贮水效果总体优于翻耕处理,但免耕和深松处理在2007和2008年的土壤贮水效果有一定差异,前者深松优于免耕,差异不显著,而后者免耕显著优于深松;夏闲期＜10 mm降雨后3,7和13 d,免耕和深松土壤0~100 cm土层含水量均高于翻耕农田,而免耕和深松土壤水分的差异主要出现在降雨后7 d;10~30 mm降雨后7 d,免耕和深松土壤0~200 cm土层含水量明显高于翻耕土壤,但在降雨后1和3 d无显著差异。【结论】夏闲期免耕和深松耕作方式较翻耕方式显著提高了土壤的贮水能力，其机理主要在于免耕和深松耕作方式增强了降雨后土壤的蓄水保墒能力。

【Objective】 In order to reveal the mechanism of difference in soil water conservation between no-tillage,subsoiling and deep plowing,the water-holding capacity of the 3 tillage treatments during summer fallow period of winter wheat field was studied.【Method】 A field experiment of wheat field in summer fallow period under 3 treatments of no-tillage,subsoiling and deep plowing was conducted in Weibei dry-land in 2007 and 2008.【Result】 The soil volumetric moisture content of no tillage and subsoiling increased by 47.2% ,55.6% and 38.9% ,22.2% in 0--300 cm compared to deep plowing in 2007 and 2008 respectively,and reached significant level at P〈0.05 ,and the difference mostly came from the soil layer above 140 or 160 era. The difference of soil water storage ability between no tillage and subsoiling depended on the situation of rain, the water storage capacity of no-tillage field was better than that of subsoiling in the year which rainfall and rain frequency was less, while it was equivalent in the year which rainfall and rain frequency was more. The soil moisture content of no-tillage and subsoiling was higher than that of deep plowing in 3,7 and 13 d after 〈10 mm rain in 0--100 cm soil layer. But the soil moisture content of no-tillage differed from that of subsoiling in 7 d after rain. After 10--30 mm rain,the soil moisture content showed no difference among 3 treatments on 1 and 3 d. The distinction focused on the 7d after rain. At the same time, the soil moisture fluctuated between 0-- 100 cm on 1 and 3 d after rain,while it was between 100--200 cm in 7 d after rain. [Conclusion] No tillage and subsoiling improved the soil water storage compared to deep plowing significantly, and the mechanism of improving soil water storage mostly came from the fact that no tillage and subsoiling enhanced the soil moisture conversation after rain.