黄土地区影响土壤膨胀性的因子分析

Factors influencing swelling of soils in Loess Plateau

为了探讨影响黄土地区土壤结构稳定性的机理,对黄土高原几种典型土壤类型的膨胀率进行了测定,系统分析了颗粒组成、碳酸钙含量以及有机质含量对土壤膨胀性的影响。结果表明,颗粒组成是影响土壤膨胀率的主要因子,土壤膨胀率与粉砂粒及粘粒含量呈显著正相关关系,并且粘粒对土壤膨胀性具有双重作用;土壤膨胀性与碳酸钙含量呈显著负相关关系,经脱钙处理后土壤膨胀率增加,增幅在14.47%-36.92%;土壤膨胀性与有机质含量相关性不明显,但去除有机质后土壤膨胀率明显增加,增幅在12.24%-62.99%,说明有机质对土壤膨胀性实际上也有着极为明显的抑制作用。

The swelling rate of several typical soils in Loess Plateau was measured and the influence of particle fraction,content of CaCO3 and organic matter on soil swelling rate was analyzed in order to probe into the mechanism of soil structure stability. The results showed that the soil particle fraction was one of the most important influential factors on soil swelling rate, the maximum of soil swelling rate showed significantly positive correlation with silt particle and day content （〈0.02 mm）,and showed significantly neg- ative correlation with the content of CaCO3,and the soil swelling rate increased after removing CaCO3,the increase range is 14.47% -36.92% ,of which the clay particle had double effects on soil swelling rate. The influence of organic matter on soil swelling rate was not obvious in appearance from the analysis of correlation. but the soil swelling rate increaled after removing soil organic matter, the increase range,is 12.24%- 62.99 % ,which showed that soil organic matter signiticantly restrained the soil swellig rate.