Soil Microbiological Properties and Enzyme Activities in Ginkgo-Tea Agroforestry Compared to Monoculture

Studies on enzyme activities and microbiological properties in the soil were very important as they may give indications of the potential of the soil to support biochemical processes which were essential for maintaining soil fertility. The objective of this study was to investigate the difference of soil quality parameters, including organic carbon and nitrogen in the soil, microbial biomass, basal respiration, and the activities of soil enzymes (Catalase, polyphenoloxidase, dehydrogenase, urease, protease and invertase), between monoculture system and agroforestry system. Three management treatments were studied in this work: pure tea system (G0), intercropped with grafted ginkgo seedlings (G1 and G2), which were in a twenty years old tea orchard. Three kinds of depths of soil (0-10 cm, 10-20 cm and 20-30 cm) were used for all treatments. All the parameters except polyphenoloxidase in soil surface in the agroforestry system showed significantly higher values as compared to those in G0. The contents of soil organic C, total N, microbial biomass and the activities of enzymes were higher in the surface soil as compared to the soil from middle and lower layers. The activities of soil enzymes, such as catalase, dehydrogenase, urease, protease and invertase, and soil organic carbon, total nitrogen were significantly positively correlated. The results of this study suggested that growing teas in combination with ginkgo could be considered as a good forest management practice, which would enhance organic matter accumulation in the soil and improve the activities of soil enzymes, furthermore, could maintain soil productivity and sustainability.