重庆市岩溶区不同石漠化程度下土壤磁化率特征分析

On Soil Magnetic Susceptibility of Karst District of Chongqing under Different Rocky Desertification

对重庆市岩溶区不同石漠化程度下的土壤磁化率、有机质质量分数进行分析,结果表明,土壤磁化率χ_(lf)和χ_(fd)平均值随着石漠化程度的加深而增大,χ_(fd)>10%,表明土壤样品存在有相当质量分数的SP颗粒;轻度撂荒地剖面之外其它样地的χ_(lf)与χ_(fd)之间都呈现出正相关性;植被覆盖好的区域土壤有机质平均质量分数高于低植被覆盖区域,重度撂荒地土壤中有机质质量分数与χ_(fd)呈明显负相关性,说明土壤中有机质(特别是富里酸等物质)对土壤中多畴或单畴的磁性矿物可以有效地溶解,而对超顺磁粒径范畴磁性颗粒不能有效溶解.

By studying the soil magnetic susceptibility and organic matter content under the different rocky desertification in Karst area of Chongqing. The results show that the average values of soil magnetic %lf and %fd increased as the rocky desertification intensifying, and %fd is larger than 10 % , indicating that there is a significant amount of SP particles in the soil samples. Except for the mildly abandoned land, Xif an〈^ Xfd are positively correlated. The average content of soil organic matter in the good vegetation covered area is more than that in the low vegetation coverage area, and the content of organic matter in severely aban-doned land soil is negatively correlated with -^fd, indicating that organic matter （especially fulvic acid） could effectively dissolve the multidomain or single-domain magnetic minerals in the soil, and the superparamag-netic particles can not be effectively dissolved by the organic matter.