Abstract:

This paper studied soil nutrients, the number of microorganisms and the change of enzyme activity in rhizosphere and out-rhizosphere soil with tea trees grown of different years. The results showed that the soil pH value of the tea garden decreased as tea trees grew old .Various soil nutrients in rhizosphere soil were higher than those in out-rhizosphere soil. And tea trees grown of 20 years had the largest number of soil nutrients, followed by those of 4 years and then those of 38 years. The number of microorganisms, closely related with the pH of the soil and organic matter, was larger in rhizosphere soil than that in out- rhizosphere soil. The total number of the bacteria, actinomyces and fungi was higher in the tea garden of 20 years than that of 4 years which was higher than that of 38 years. Enzyme activity was higher in rhizosphere soil than that in out- rhizosphere soil, and as the tea grew, the enzyme activity ratio of rhizosphere soil to out-rhizosphere soil increased. So soil enzyme activity had played an indicative role in analyzing soil fertility.