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

【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 P0.05,and the difference mostly came from the soil layer above 140 or 160 cm.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.