Sediment particle size characteristics and their relationship with soil nutrients at the southern edge of the Hobq Desert

The ecological environment of the desert-oasis transition zone on the southern edge of the Hobq Desert is highly sensitive and plays a key role in regional comprehensive management of desertification and the restoration of degraded vegetation. This study selects three typical underlying surfaces from three sample sites as research subjects. It employs methods such as grain size analysis and redundancy analysis to explore the sediment grain size characteristics and nutrient characteristics at depths of 0–5 cm, 10–15 cm, and 25–30 cm, and their relationships. The research indicates that the sediment particle composition in the transition zone was primarily composed of fine sand and medium sand, followed by silt and very fine sand. The average particle size of the sediments ranged from 0.113–0.241 mm, with good to moderate sorting, skewness predominantly showing near symmetry and positive skew distribution, and kurtosis ranging from medium-wide to narrow peak shapes. In the sample site D, the average particle size of the sediments showed a significant negative correlation with skewness, while in the sample site B, the average particle size was significantly positively correlated with kurtosis, and the sorting coefficient was highly significantly positively correlated with skewness. In the sample site W, there was no obvious correlation among the sediment particle size parameters. The contents of SOC and TN showed significant differences in depth and region, while the contents of TP and TK were relatively stable. The sorting coefficient was identified as the main factor influencing soil nutrients. This study provides a scientific basis for desertification prevention and control in the transition zone of the desert oasis on the southern edge of the Hobq Desert.