Effects of dry sowing and wet emergence on vegetation diversity and soil nutrients in an oasis-desert ecotone

The oasis-desert ecotone serves as an important buffer zone for ecosystem stability. However, how its vegetation diversity and soil environment respond to the “dry sowing and wet emergence” technique in cotton fields of southern Xinjiang remains unclear. This study was conducted in the oasis-desert ecotone of the Xiaohaizi Irrigation District, Tumushuke City, Third Division, southern Xinjiang, China. Two monitoring sites, A (dominated by small shrubs and herbs) and B (dominated by trees, shrubs, and herbs), were selected on the basis of vegetation types in the ecotone. Four monitoring points were established at varying distances (150-3000 m) from the cotton fields. The spatial distribution characteristics of vegetation diversity in the ecotone and its relationship with the soil environment were systematically evaluated using vegetation surveys, remote sensing data, and soil physicochemical analysis. The results were as follows: (1) Vegetation diversity in the ecotone decreased significantly with increasing distance from the cotton fields (PPP=0.024), whereas site B was influenced by available phosphorus (P=0.042), highlighting differences in the driving factors between the two communities. (4) After the implementation of the “dry sowing and wet emergence” technique, the peak normalized difference vegetation index during the growing season showed a decreasing trend at both monitoring sites A and B, indicating that this technique has had an adverse impact on vegetation growth in the ecotone.