[Effect of planting white clover on nutrients and biological properties of soils in persimmon orchard of Weibei, Shaanxi Province, China].

Leguminous crop planting is one of the most important managements in sustainable agriculture, which has the potential to improve soil quality and environmental health by increasing N input and facilitating soil and water conservation. In this study, effects of white clover planting on soil nutrients and biological properties in persimmon orchard was investigated to understand its potential effects on improvement of soil fertility and economic performance. Soil samples were collected on September 14th, 2017 at 0-10 cm, 10-20 cm, 20-30 cm and 30-40 cm soil depth in two treatments (i.e. ploughing with no grass and planting white clover) in persimmon orchard, and were analyzed for soil available nitrogen, organic matter, microbial biomass carbon and nitrogen, and enzyme activity. Compared to the control, soil available nitrogen, organic matter, microbial biomass carbon and nitrogen, and the activities of urease, sucrase, catalase and alkaline phosphatase all increased in grass treatment. Specifically, in grass planting treatment, soil organic matter and microbial biomass carbon were significantly increased at 0-10 cm soil, and increased soil avai-lable nitrogen was found at 10-20 cm soil. For enzyme activity, significantly elevated urease activity exhibited at surface depth (0-20 cm), while catalase, sucrase activity and geometric mean (GME) of enzyme activity were higher within entire tested soil profile (0-40 cm). Overall, our results indicated white clover planting in orchard could not only facilitate soil fertility, but also reduce chemical fertilizer input and improve economic benefit, which could be considered as a good orchard cultivation mode.