Abstract: The investigation on two tea garden soils (continue planting tea for 30 and 50 years, respectively) and their neighboring natural soil in Yongchuan Experimental Tea Garden were conducted to characterize the effects of continue planting on physical, chemical and microbial changes of the soil properties. Results showed that the physical properties of tea garden soils, including bulk density, porosity, water-stable aggregate, water capacity, moisture and three-phase fraction, improved markedly and continuously along with planting ages of the tea garden. Besides, the cation exchangeable capacities (CEC) enlarged and soil acidification strengthened progressively (soil pH declined, exchangeable acidity increased). Investigation showed that the soil organic matter, available NPK and total NP increased in large scale after 30 years planting. However they had no more increase when planting time lengthened from 30 years to 50 years. Available Ca and Mg decreased steadily with planting years and available K also decreased slightly in the old tea garden soil. Total Mn, Zn, Cu, Cd, Pb, As, Hg, Cr showed no accumulation or reduction in soil after 50 years planting, while available Mn, Cu, Zn increased and available Hg decreased significantly. The amount of bacteria, fungi and actinomyces rised significantly in planting soil of 30 years, but no further rised in planting soil of 50 years.

Key words: tea garden, yellow soil, soil characteristics, continue planting