Effects of Different Cropland Reclamation Periods on Soil Particle Size and Nutrients From the Perspective of Wind Erosion in the Mu Us Sandy Land

Abstract

Land use changes could notably influence the magnitude and distribution of wind erosion. In recent decades, land reclamation flourished in the Mu Us Sandy Land (MUSL) to supplement cultivated lands (CLs) occupied by urbanization. To analyze the effects of land reclamation on wind erosion, the soil texture and soil nutrients in arable and uncultivated lands should be evaluated. In this study, we collected 54 paired soil samples from CLs and nearby uncultivated lands (NULs) in the MUSL considering land use data pertaining to different phases. Then, the soil particle distribution (PSD) and contents of soil organic carbon (SOC) and total nitrogen (TN) were measured in the laboratory. The results indicated that after 1–15 years (Yr) of cultivation, compared to the NULs, particles ranging from 60 to 400 μm obviously decreased. With increasing number of cultivation years, the wind sorting effects accumulated, and the content of erodible particles susceptible to wind erosion decreased. Among the CLs with different cultivation years, new CLs exhibited the highest erodible particle content, and medium CLs exhibited the lowest erodible particle fraction content. The SOC contents in the medium and fine sand groups among the new CLs was significantly influenced by wind erosion, whereas the TN content was primarily controlled by nitrogenous fertilizer application. After cultivation for longer than 40 years, the total SOC and TN contents in the CLs were significantly higher than those in the NULs. Among the CLs, the wind sorting effects and number of cultivation years obviously influenced the SOC content, whereas the TN content in the CLs was mainly influenced by nitrogenous fertilizer utilization. Rapid urbanization of Shaanxi Province, a new round of national ecological policy adjustments and altered wind environments are the main reasons for the development of new CLs, and a superior location and soil physicochemical properties contribute to the occurrence of old CLs. Based on the above analysis, we propose that conservative cultivation is the key to the protection of new CLs from wind erosion hazards.