Clay's Variation characteristics in the Compound Soil of Arsenic Sandstone and Sand under Corn Conditions

Abstract

By studying the variation features of 0-70cm soil layer clay particles composited by mixture of Pisha sandstone and sand in different proportions, theory basis is provided in order to promote the sustainable utilization of Mu Us Sandy Land. Three types of composite soil patterns that the mixing ratios were 1:1, 1:2 and 1:5 respectively between Pisha sandstone and sand were set in Fuping, Shannxi from 2010 to 2012; soil clay content was measured after crop harvesting, to analyze the change features of clay particles in composite soil of different mixing ratio. In three types of composite soil, clay particles are mainly concentrated at 0-30cm on the soil surface, clay content is low subsoil. In terms of the mixing ratio of different Pisha sandstone and sand, on account of the higher proportion of Pisha sandstone in 1:1 composite soil, the clay content is the highest in topsoil, the size relationship of which is 1:1>1:2>1:5. With the increase of planting years, clay - enriched soil layer has a tendency of downward transport, especially the remarkable downward transport for the clay in topsoil, in addition, the clay ratio in subsoil has a small increase. The change features of clay particle in composite soil will result in desertification tendency for the composite topsoil and the loam tendency for the subsoil. Suitable arable layer in the entire soil profile may tend to become thicker, which is more conducive to plant growth.