干旱区生态环境知识资源中心

In order to understand the illuviation of CaCO3 and the deposition of clay, we chose a plot of 700 m x 900 m in the Arid Agriculture Experimental Station (AAES) of Wu Chuan in Inner Mongolia of China to serve as the study area. The study area is located in the arid and semiarid region, CaCO3 were widely exist in the soil profiles. 80 soil profiles were undertaken. We measured CaCO3 contents and soil textures. The study indicates that soil CaCO3 was mainly in sub-surface horizons. The range of CaCO3 content was from 6.7 g kg(-1) (humus horizon) to 231.1 g kg(-1) (calcic horizon). The means of CaCO3 contents varied in the order Bk > C > AB > A, and there were same trend for clay fractions. The illuviation of CaCO3 and the deposition of clay are concurrent and interactive. Usually, there is a higher clay fraction in the calcic horizon because of flocculation. Through the research, we can further study the association between CaCO3 illuvation and clay deposition.