秸秆还田下灌水量对土壤水分运移特性研究

Effects of Irrigation Amount on the Characteristics of Soil Water Migration Under Straw Returning

为了研究不同秸秆还田量在灌水量下的水分运移规律,采用室内土柱试验,对不同秸秆还田量和灌水量条件下土壤水分运移分布特性进行了模拟研究。研究结果表明:到达秸秆还田层与不还田层交界处,还田量0.5%、1.0%、1.5%、2.0%的处理与不还田相比,累积入渗量多出0.96%、4.3%、7.31%、11.98%,表明秸秆还田量的增加使土壤的保水能力增加。在相同灌水量下,同一土层含水率主要表现为秸秆含量越高,土壤含水率越高;秸秆还田量相同时,在1.0 V灌水量基础上增大灌水量至1.5 V时,在秸秆还田层内,土壤含水率提高了2.53%,在秸秆还田层以下,土壤含水率提高了11.52%,这可能是因为随着灌水量增大,秸秆还田层土壤中孔隙逐渐地被水分填充,土壤的导水率能力增大,促进了水分向下移动,从而改善了土壤入渗能力。

In order to study the water transport law under different straw returning amount and irrigation amount,a study on the soil water migration and distribution characteristics under different straw return amount and irrigation amount is conducted through soil column test in laboratory. The results show that： the accumulation infiltration amount of the treatments with returning amount of 0.5%,1%,1.5%,2% is0.96%,4.3%,7.31% and 11.98%,respectively,more than that in the no returning field at the boundary between the straw returning layer and the no returning soil layer,which indicates that the increase of the straw returning amount to the soil increased the water retention capacity of the soil. Under the same irrigation amount,the water content of the same soil layer mainly shows that： the higher the content of straw,the higher the soil water content,and when the irrigation water amount is increased from 1.0 V to 1.5 V,the soil moisture content is increased by 2.53% and 11.52% in the straw returning layer and under the straw returning layer,respectively. This maybe because that with the increase of irrigation amount,the pores in the soil of the straw returning layer are gradually filled with water and the water conductivity of the soil is increased,which promotes the downward movement of the water,thus improving the infiltration capacity of the soil.