EVALUATION OF SOIL QUALITY AND ANALYSIS OF DRIVING FACTORS OF JUJUBE FORESTS IN THE LOESS HILLY AREAS WITH ABANDONED MOUNTAINS

The evolution mechanism of soil quality of abandoned montane jujube forests in loess hilly areas is still unclear.In this study, we analyzed the driving mechanism of soil quality (SQ) by using principal component analysis, fuzzy evaluation and partial least squares structural equation modeling PLS-SEM with different abandonment years (1, 6, 10, 15, and 20 years) in montane jujube forests and abandoned grasslands in Yanchuan County.The results showed that the number of years of abandonment significantly increased the soil quality index (SQI), and the 20-year abandonment of date palm forest reached the highest value (0.669), which was significantly higher than that of abandonment of grassland (0.331).The results of structural equation modeling showed that organic carbon (SOC), quick-acting phosphorus (AP), total nitrogen (TN) and urease activity (URE) positively drove the SQ, while soil water content (SWC) and pH had negative effects on it.Long-term abandonment promotes ecological recovery by improving soil nutrients and microbial enzyme activities, and provides a scientific basis for the management of degraded date palm forests in loess hilly areas.