Contribution of High Accumulated Polyphenols to C Stabilization in Soil of Tea Gardens

摘要

To understand the effect of tea planting on soil biochemical properties,the polyphenols concentration,microbial community,microbial biomass C:N ratio and enzyme activity in top soil were compared among a native shrub,tea gardens with and without artificial managements.Our results showed that tea planting increased soil carbon contents by 14.5％ to 74.9％,as well as improving polyphenols accumulated in top soil.After long-term tea planting,soil pH value decreased 1 point in tea gardens with artificial managements and no significant change in gardens without artificial managements.The ratios of soil microbial biomass carbon to nitrogen (bio-C:N) respectively ranged from 3 to 4 in gardens without artificial managements and from 5 to 9 in the artificial tea gardens.Soil polyphenolic oxidase activity decreased and peroxidase increased with the planting ages of tea garden.Tea planting has induced the enrichment of fungi and decreased ratio of Gram positive to Gram negative bacteria.The results suggested long-term tea planting would increase soil C stock,but not induce soil acidity.Polyphenols richness in soil organic matter should be responsible for the C sequestration and stabilization in tea garden.