Effects of Soil Texture Reconstruction on Soil Hydraulic Properties in Shanxi-Shaanxi-Mongolia Region

Abstract

[Objective] The effects of soil texture reconstruction on soil hydraulic properties in the Shanxi-Shaanxi-Inner Mongolia region, and the improvement effect of different amounts of arsenic sandstone on sandy loess were studied, in order to providing theoretical basis for the restoration work of sandy land in the region. [Methods] Pisha sandstone and sandy loess were combined in different ratios, and the saturated water conductivity, soil water characteristic curve, available soil water-holding capacity, and other indexes were measured. [Results] ① As the proportion of Pisha sandstone increased (0%~100%), the content of sand particles (0.05~2 mm) in the reconstructed soil decreased by 8.1%~33.5%, while the content of silt particles (0.002~0.05 mm) and clay particles (<0.002 mm) increased by 5.2%~21.0% and 2.9%~12.5%, respectively. When the content of Pisha sandstone in the reconstructed soil reached 75%, the reconstructed soil texture changed from sandy loam to loam. The Ks value of the reconstructed soil at 10 ℃ was 4.07×10-6 m/s, which is similar to the Ks value of a typical Huangmian soil under natural field conditions; ② The effects of Pisha sandstone content on the soil water characteristic curve occurred primarily in the range of high suction. When the ratio of sandy loess to Pisha sandstone was 25∶75, the soil water-holding capacity was the largest among seven ratio treatments; ③ The soil water retention capacity of reconstructed soil tended to increase as the proportion of Pisha sandstone increased. Saturated water content (θs) and residual water content (θr) values also increased. [Conclusion] The available soil water-holding capacity of the reconstituted soil was greater than observed for the other treatments when the ratio of sandy loess to Pisha sandstone was 25∶75 (soil bulk density was 1.41 g/cm3). This ratio is recommended as an optimal soil reconstruction method for this region.

Keywords

• texture reconstruction
• saturated water conductivity
• soil water characteristic curve
• pisha sandstone
• sandy loess