Supported by the National Natural Science Foundation of China (Nos.42177317, 41630858)
为探究南方崩岗侵蚀区不同植被类型下土壤抗剪强度的分布规律，明确崩岗治理后土壤基本性质对抗剪强度的影响。以3种不同植被类型下崩岗各部位表层土壤为研究对象，对土壤基本性质的变化规律、抗剪强度参数变化特征及其影响因素，利用路径分析和主成分分析进行研究。结果表明，土壤抗剪强度由大到小依次为林地 > 柑橘地 > 灌木地 > 草地 > 侵蚀区，且柑橘地较灌木地土壤抗剪强度提高了29.74%。随地势降低，毛管孔隙度总体呈升高趋势，黏粒、粉粒等细颗粒物质占比也不断上升，汇聚于坡下。随着恢复时间增加，土壤养分含量逐渐上升。土壤黏聚力在同种植被类型下，随着恢复年限增加，表现为递增趋势，内摩擦角则表现为缓慢递减趋势，均表现为上坡最大。其中有机质、饱和导水率与黏聚力存在极显著相关关系，含水率、容重与内摩擦角也存在极显著相关关系。试验以总孔隙、毛管孔隙、黏粒含量和土壤饱和导水率来表征土壤饱和状态下的抗剪强度，建立了预测方程（R2=0.80，RMSE=5.95），结果表明该方程的可信度和预测精度均较高。研究结果揭示了不同植被类型抗剪强度的控制因素，可为南方崩岗侵蚀区恢复过程提供一定的参考。
Objective This study was designed to explore the distribution of soil shear strength under different vegetation restorations types in the erosion area of Benggang in southern Jiangxi, and to clarify the influence of soil basic properties on shear strength after restoration.Method The surface soil of various parts of the Benggang under three different vegetation types was used as our research object. We analyzed and studied the changes in soil basic properties and the change characteristics of shear strength parameters and their influencing factors using Path analysis and principal component analysis.Result The results showed that the shear strength from high to low was forest > arboreal forest > scrubland > grassland > erosion area, and the soil shear strength of arboreal forest was 29.74% higher than that of scrubland. As the terrain decreases, the capillary pores were increasing, and the proportion of fine particles such as clay particles and powder particles was also increased and converged under the lower slope. Moreover, the soil nutrient content was gradually increased as the recovery time increased. The cohesion of Benggang soil showed an increasing trend as the recovery period increased while the internal friction angle showed a slowly decreasing trend, and reached the maximum on the upper slope. Importantly, the cohesive force had a very significant correlation with organic matter and saturated hydraulic conductivity, and the internal friction angle also had a significant correlation with water content and bulk density. The total pores, capillary pores, clay content and soil saturated hydraulic conductivity were selected to characterize the shear strength of the soil undersaturation and a prediction equation (R2 = 0.80, RMSE = 5.95) was established, and it showed high reliability in prediction accuracy.Conclusion The research results reveal the control factors of shear strength under different vegetation types, which can provide a certain reference for soil restoration processes in the southern Benggang eroded area.
文慧,倪世民,王艺彤,王军光,蔡崇法.赣南崩岗区不同植被类型粉砂质土壤抗剪强度及其影响因素[J].土壤学报,2022,59(6):1517-1526. DOI:10.11766/trxb202012240707 WEN Hui, NI Shimin, WANG Yitong, WANG Junguang, CAI Chongfa. A Study on Silty Soil Shear Strength and Its Influencing Factors in Different Vegetation Types in Benggang Erosion Area of Southern Jiangxi[J]. Acta Pedologica Sinica,2022,59(6):1517-1526.复制