浑善达克沙地土地沙漠化过程中土壤粒度与养分变化研究

 浑善达克沙地土壤空间异质性大,流动沙丘粒度组成和非沙漠化土地养分含量都存在极显著差异。随着土地沙漠化的发展,土壤表层通常形成粗化层,土壤中的重要养分有机碳（SOC）和全氮（TN）的含量显著下降,且SOC含量比TN含量存在更大的空间差异和随沙漠化土地发展更快的下降速率,致使土壤表层C/N值存在明显下降趋势。沙漠化土地表层土壤中SOC含量和TN含量与土壤粘粒含量和粗粉沙含量之间存在很好的相关性,尤其与土壤粘粒含量的相关性非常高；而且与TN含量的相关性高于与SOC含量的相关性。各种原因引起的土壤风蚀是造成沙漠化发展中土壤过程的主要动力因素,严重影响着土壤的稳定与土壤细物质和养分的迁移。

Soil Characteristics Changes in Desertification Processes in Hunshandake Sandy Land, Northern China

Soil spatial heterogeneity is very huge in Hunshandake Sandy Land. Soil grain size on shifting dunes and soil nutrient content on non-desertified lands exist very obvious difference. With the development of land desertification, a coarse sands accumulation layer often formed in the surface of soil, and the content of soil organic carbon (SOC) and the total Nitrogen (TN) both decrease obviously. Moreover, the content of SOC has bigger spatial difference than the content of TN. With the increase of desertification severity, the content of SOC decreases much faster than the content of TN, causing the ratio of C and N decrease obviously. There are close correlation between the content of SOC, the content of TN and the clay particles content in top soil layers of desertified lands. Soil wind erosion is the main driving factor of soil developing process in land desertification, and it seriously affect the soil stability, the transfer of soil fine material composition and nutrient.