The College of Geography and Tourism at Chongqing Normal University
The National Natural Science Foundation of China (General Program, Key Program, Major Research Plan)
不同岩层倾向会影响喀斯特槽谷区侵蚀坡面的水土流/漏失和土壤微生物，从而导致侵蚀坡面的顺/逆层坡面土壤质量差异较大，为准确评价喀斯特槽谷区顺/逆层坡侵蚀坡面的土壤质量特征，以重庆市青木关喀斯特槽谷区顺/逆层坡面的5种典型土地利用类型（林地，草地，裸地，玉米地，辣椒地）为研究对象，利用主成分分析法结合Norm值建立评价指标最小数据集（minimum data set ，MDS），并通过非线性土壤质量评价方法和隶属度函数对喀斯特槽谷区顺/逆层坡面的土壤质量进行评价。结果表明：1）喀斯特槽谷区土壤质量评价指标最小数据集（MDS）包括毛管持水量，毛管孔隙度，全磷。2）通过非线性土壤质量评价方法可知，逆层坡土壤质量（0.519）优于顺层坡（0.451），其中逆层坡林地土壤质量最优（0.653），辣椒地土壤质量最差（0.426）；3）非线性评价方法在顺/逆层坡的决定系数R2均高于隶属度函数，因此喀斯特槽谷区更适合采用非线性评分模型；4）顺/逆层坡侵蚀坡面的土壤质量障碍因子差异显著，仅有全氮为共同的障碍因子。综上可知，适当增加草地和乔木林的覆盖更能提高喀斯特槽谷区土壤质量，该研究结果可因地制宜地为喀斯特槽谷区顺/逆层坡侵蚀坡面的土壤质量调控和生态恢复提供依据。
The Different rock strata inclinations can affect the soil flow/leakage and soil microorganisms on the erosion slope which results in the great difference of soil quality on the dip/anti-dip slope in the karst trough valley. In order to accurately evaluate the soil quality characteristics of dip/anti-dip slope erosion slope in Qingmuguan Karst trough valley, five typical? land use types (forest land, grassland, bare land, corn land, pepper land) were taken as the research objects. and there were 12 physical and chemical indexes as total data set (TDS). The principal component analysis method was used to combine the norm value to establish the minimum data set (MDS) of the evaluation index, and the soil quality in the study area was evaluated by membership function and nonlinear soil quality evaluation methods. The results showed as follows: 1) The minimum data set of soil quality evaluation indexes (MDS) in karst troughs valleys included capillary water capacity, capillary porosity and total phosphorus. 2) According to the nonlinear soil quality evaluation method, the soil quality of anti-dip slope (0.519) was better than that of dip slope (0.451). The soil quality of anti-dip slope forest land was the best (0.653), and that of pepper land was the worst (0.426). 3) The determination coefficient R2 of the nonlinear evaluation method is higher than the membership function for the dip slope and the anti-dip slope, so the non-linear scoring model is more suitable for the karst trough valley; 4) There were significant differences in soil quality barrier factors, and only total nitrogen was the common barrier factor. In conclusion, it is more beneficial to restore and improve soil quality by appropriately increasing grassland and forest cover in karst trough valley. The results of this study can provide basis for soil quality control and rational fertilization of slope erosion dip/anti-dip slope in karst trough valley according to local conditions.