冲沟不同部位土壤机械组成及抗冲性差异

选取3类典型冲沟(活跃、较活跃和稳定)的集水区、沟头和沟床土壤,探明冲沟不同空间部位土壤机械组成特性及其抗冲性差异,结果表明:1活跃、较活跃冲沟土壤质地均为砂质壤土,稳定冲沟各部位土壤质地各不相同;黏粒含量、粉粒含量总体为活跃冲沟较活跃冲沟稳定冲沟;细砂粒含量为较活跃冲沟活跃冲沟稳定冲沟;粗砂粒含量则是活跃冲沟较活跃冲沟稳定冲沟。23类冲沟各部位土壤抗冲性均是沟床最高,而3类冲沟同一部位抗冲性大小比较中,沟头和沟床土壤抗冲性为稳定冲沟较活跃冲沟活跃冲沟,集水区以活跃冲沟土壤抗冲性最小,较活跃与稳定冲沟的土壤抗冲性相当。3线性回归分析表明:砂粒含量是影响3类冲沟各部位土壤抗冲性的主要指标,黏粒含量影响稳定冲沟各部位土壤抗冲性,粉粒含量与较活跃冲沟沟头、稳定冲沟集水区和沟床的土壤抗冲性有关。研究结果从土壤机械组成和土壤抗侵蚀性的关系角度为冲沟研究提供一定的理论参考。

The Difference of Soil Mechanical Composition and Soil Anti-scourability on Different Positions of Gullies

The gully area with tattered landform and loosen soil structure has threated to degraded ecosystem restoration in dry-hot valley. For ascertaining the difference characteristics of soil mechanical composition and soil anti-scourability(ANS), the soil on three different gully positions (the gully watershed, gully heard and gully bed) of different activities gullies (the active gully, semi-active gully and stable gully) had been selected. The research results indicated that the soil texture on active gully and semi-active gully were sandy loam, but that were various on different position of stable gully. Soil clay content and silt content from maximum to minimum showed the order of between and among stable gully, semi-active gully and active gully. Coarse sand content was completely opposite of the former. Fine sand content from maximum to minimum showed the order of semi-active gully, active gully and stable gully. Comparing each position of three activities gullies, the soil ANS on gully beds were the highest. Comparing same position of three activities gullies, the soil ANS on gully heard and gully bed from highest to lowest showed the order of stable gully, semi-active gully and active gully. The soil ANS on active gully watershed was the lowest and the soil ANS on semi-active gully watershed was similar to stable gully watershed. The linear regression analysis indicated that the sand content was the main indicator affecting the soil ANS on three different gully positions of different activities gullies. The clay content was the main indicator affecting the soil ANS on three gully positions of stable gully. The silt content associated with the soil ANS to the semi-active gully head also between the stable gully watershed and gully bed. The research results can be expected to provide theoretical references for the further study on the relationship between soil texture and soil anti-erosion.