LAUSR

Wind erosion is a major cause of land desertification and sandstorm formation in arid and semi-arid areas. The objective of this study was to evaluate the potential of soybeans crude extract induced calcium carbonate precipitation (SICP) on reducing wind erosion risk of sandy soil. Field tests were carried out in Ulan Buh Desert, Ningxia Hui Autonomous Region, China. Results showed that the SICP method could significantly enhance the surface strength and wind erosion resistance of the topsoil. The optimal cementation solution (urea-CaCl2) concentration and spraying volume, according to experiments conducted on sandy land, were 0.2 mol/L and 4 L/m2, respectively. Under this condition, the CaCO3 content was approximately 0.45%, the surface strength of sandy soil could reach 306.2 kPa, and the depth of wind erosion was approximately zero, after 30 d completion of SICP treatment. Soil surface strength declined with the increase of time, and long-term sand fixation effects of SICP treatment varied depending on topography. Whereas wind erosion in the top area of the windward slope was remarkable, sandy soils on the bottom area of the windward slope still maintained a relatively high level of surface strength and a low degree of wind erosion 12 month after SICP treatment. Scanning electron microscopy (SEM) tests with energy dispersive X-ray (EDX) confirmed the precipitation of CaCO3 and its bridge effect. These findings suggested that the SICP method is a promising candidate to protect sandy soil from wind erosion in desert areas.