Contributions of Plant Litter Decomposition to Soil Nutrients in Ecological Tea Gardens

Plant litter decomposition and its effect on soil nutrients are important parts of the ecosystem material cycle, and understanding these processes is key for species selection and allocation to promote the effective use of litter in ecological tea gardens. In this study, the in situ litter decomposition method was used to examine the decomposition characteristics of leaf litter of Cinnamomum glanduliferum , Betula luminifera , Cunninghamia lanceolata, Pinus massoniana , and Camellia sinensis prunings in the Jiu’an ecological tea garden in Guizhou and their effects on soil nutrients. The results showed that the litter decomposition rate of broad-leaved tree species was higher than that of coniferous tree species, with a half-life of 1.11–1.75a and a turnover period of 4.79–7.57a. There are two release modes of nutrient release from litter: direct release and leaching–enrichment–release. Different litters make different contributions to soil nutrients; Betula luminifera and Cinnamomum glanduliferum litter increased the contents of soil organic carbon, soil total nitrogen, and soil hydrolyzed nitrogen. Betula luminifera litter increased the content of soil total phosphorus, soil available phosphorus, and soil available potassium, and Pinus massoniana litter increased the content of soil total potassium and soil available potassium; therefore, it is concluded that the decomposition of Betula luminifera litter had a positive effect on soil nutrient content. Thus, Betula luminifera is a good choice for inclusion in ecological tea gardens to increase their nutrient return capacity, maintain fertility, and generally promote the ecological development of tea gardens.