中文摘要：

通过短期连续耕作45次,模拟长期耕作对土壤水分分布的影响,利用TDR法按冬小麦5个生长期测定对照区与试验区（实施45次强烈耕作）土壤耕层（0-16.5cm）水分。结果表明,试验区土壤含水量比对照区低8.74%～25.49%,而土壤含水量变异性却比对照区高11.9%～399.8%,表明强烈耕作增大了土壤耕层含水量在坡面的变异性。对照区与试验区土壤含水量分布的差异主要表现在坡顶和肩坡,这种差异可能主要是由耕作侵蚀引起的。耕作侵蚀使上坡土壤发生流失,使土壤贮水性下降,导致试验区上坡土壤耕层含水量显著减小;耕作沉积使下坡土壤发生累积,但对试验区下坡土壤耕层含水量无显著影响。

英文摘要：

In this study, consecutive tillage by hoeing was performed 45 times in an orthic regosol with thin soil layers, to simulate the impact of long-term tillage on soil moisture at different slope positions and different period. Soil water content of till layer was measured on 30-day-interval period using time-domain reflectometry （TDR） in different slope positions of the control plot and the treatment plot（plowed 45 times）. The results showed that： A notable decrease in the depth of the soil profiles on the treatment plot occurred at the summit and shoulder slope positions, and an increase of the thickness of the soil profiles was found at the toeslope position, compared with those of the control plot. Intense tillage resulted in a decrease of soil water content by 8.745-25.49% and an increase of variation in soil water content by 11.9%-399.8% for the soil layers of 0--16.5 cm as compared with control plot. Soil water content at the upper slope positions of the treatment plot was less than that of the control plot due to decreasing in depth of the soil profiles under intense tillage. However, no significant differences between the control plot and the treatment plot were found at the bottom positions, showing that an increase of depth of soil profiles at the bottom positions induced by tillage, had little impact on soil water content in till layer. Tillage resulted in an intense downslope transport of soil layer and the variation in soil water content at the summit and shoulder slope positions in steeply sloping fields.