Improving Soil Properties by Sand Application in the Saline-Alkali Area of the Middle and Lower Reaches of the Yellow River, China

Abstract

Excessive soil salinity is a problem that makes soil unusable for agriculture, and most current research focuses on either chemical supplements or water conservation measures. Nevertheless, more information is needed about how sand treatment affects soil quality. In this study, a field experiment assessed the effect of sand application and cropping year on soil properties in an arid and semi-arid saline-sodic agricultural ecosystem. We found that sand application significantly improved the saline–alkali soil’s physical (i.e., pH, EC, TSC, BD), chemical (i.e., OC, AN, AP), and enzyme activity (i.e., Amy, Ure, Alp, Cat) properties, and that soil AN, AP, as well as TSC, were the crucial factors affecting soil properties. Simultaneously, soil properties gradually improved along with increasing cropping years, although these increases gradually became small. Our findings highlight the potential of sand as a soil supplement to enhance soil quality and structure in semi-arid agricultural ecosystems, especially when considering the cost.