Abstract:

To explain the effect of Zenia insignis litter on soil fertility and its mechanism, the relationship between soil fertility and physicochemical properties of different plant litter and soil were studied through the relative determination and correlation analysis. From August 2022 to September 2023, the main distribution points of Zenia insignis plantation were selected as the investigation and research plots in Yizhou District and surrounding counties and districts of Hechi City, Guangxi. The results showed that: (1) from the perspective of basic soil physical and chemical characteristics, the soil fertility of Pteroceltis tatarinowii and Zenia insignis plots was better than that of Cinnamomum burmanni. (2) From the perspective of decomposition rate of litter, the order of decomposition rate of different plant litter was Pteroceltis tatarinowii > Zenia insignis > Cinnamomum burmanni. (3) The organic matter content in litter had a significant positive correlation with the total phosphorus and available phosphorus content in soil, and a highly significant negative correlation with the C/P in soil. The total phosphorus content and C/P in litter were significantly positively correlated and negatively correlated with C/N in soil, respectively. There was a significant negative correlation between C/N in litter and C/P in soil. The N/P of litter was significantly positively correlated with the total nitrogen and alkaline nitrogen content in the soil, while the other measured indexes of litter were not significantly correlated with the physical and chemical indexes of soil. From this, it could be seen that the physical and chemical characteristics of litter had an important impact on soil fertility changes. Planting Zenia insignis could improve the fertility level of soil in karst areas to a certain extent through the litter. The research aims to provide theoretical support for vegetation restoration in karst areas and the protection of rare wild plants unique to China, as well as to prevent the deterioration of the ecological environment.

Key words: northwest Guangxi, karst area, Zenia insignis Chun, physical and chemical characteristics of litter, soil fertility