岩溶区坡地耕作侵蚀过程中的土壤再分布研究

On Soil Redistribution Induced by Tillage Erosion in Karst Area

对耕作侵蚀引起的土壤空间再分布进行研究,有利于改革不合理的耕作方式和治理坡耕地水土流失。本文以重庆市中梁山为例用示踪法对坡耕地进行试验研究。结果表明:随着坡度的增大,耕作后示踪剂在示踪区的含量越来越少;它的最大值出现的位置离基线越来越远,值越来越小;沿耕作方向移动的距离越来越远。这种规律性以锄头和铁锹顺坡明显,等高和踩锹顺坡不明显。从本区耕作侵蚀的角度考虑,等高耕作方式明显要优于顺坡耕作;在顺坡耕作中踩锹优于锄头和铁锹。最后还结合岩溶山区特殊的自然环境条件,讨论了耕作侵蚀对石漠化的影响。

Study on soil redistribution by tillage erosion can reform the irrational farming methods and control sloping farmland erosion. A research on tillage experiment with tracer method on sloping farmland was conducted in karst area of Zhongliang-mountain in Chongqing city, the results showed that the tracer concentration in tracer district decreased after farming, but still remained high level. With the increase of the slope gradient, the tracer concentration in the tracer district decreased and the maximum concentration occurred not only farther from the baseline but also became lower; the shift distance of tracer became longer along the tillage direction. Those above-phenomena were more obvious in hoe or shovel downslope tillage than those of contour tillage and trample-shovel downslope tillage. Taking tillage erosion into consideration, contour-tillage method obviously is superior to downslope tillage, and trampling-shovel method is superior to hoe and shovel in downslope tillage. The impact of tillage erosion on the rocky desertification was also discussed by combining the conditions of natural environment in Karst mountain area in the paper.