耕作侵蚀对紫色土坡耕地土壤水分分布的影响  

Spatial Distribution of Soil Moisture in Relation to Soil Redistribution by Intense Tillage in Purple Soils

作　　者：李富程[1,2,3] 张建辉[1] 

机构地区：[1]中国科学院水利部成都山地灾害与环境研究所,成都610041 [2]西南科技大学环境与资源学院,四川绵阳621010 [3]中国科学院研究生院,北京100039

出　　处：《水土保持学报》2013年第1期220-223,262,共5页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(41271242);中国科学院成都山地所"一三五"方向性项目(SDS-135-1206)

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。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.

关 键 词：耕作侵蚀 土壤水分再分布 变异性 紫色土 

分 类 号：S152.7[农业科学—土壤学] S157.1[农业科学—农业基础科学]