Aeolian Sand and Sand Dunes

Abstract

To explore the cultivation effects on soil texture at local and regional scales during the expansion of oases, a field survey combined with remote sensing monitoring was conducted in the arid desert regions in Xinjiang, Northwest China. We evaluated possible changes by comparing cultivated and uncultivated lands in 2019 with paired reference lands from the Second National Soil Survey of China. The results showed that the clay content and the silt content in cultivated land increased with cultivation years (p < 0.05), while the sand content decreased. A comparison of the clay plus silt content between 2019 and the late 1970s revealed the accumulation of fine particles in the center of oases and the removal of fine particles at their edges. Our results also demonstrate that sand content increased in the newly reclaimed land, the uncultivated land at the edge of the oases, and the sandy land. A comparison of 15 paired reference samples indicated that in most plots, clay content and silt content in croplands are higher than in adjacent uncultivated lands, although some plots showed a decreasing trend, implying that agricultural cultivation dose not always increase fine particles. We conclude that the initial difference in soil texture before reclamation and reclamation history jointly result in differences in soil texture between cultivated and adjacent uncultivated lands. During oasis expansion, the reclamation of the sandy land can reduce wind erosion, suggesting that appropriate agricultural reclamation and conservation measures can mitigate the adverse effects of changes in soil texture.