Objective Correlation between the microbial community and the nutrients in rhizosphere soils of varied years of tea-planting was studied to improve soil conditions and productivity at tea plantations.
Method Microbial specimens collected from the rhizosphere soils at areas where tea bushes had been planted for 5, 10 and 15 years in Wuyishan city were cultured in the lab using standard dilution-plating method. A correlation analysis was conducted between the microbial count and soil fertility at corresponding sampling spots.
Result The microbial population in soil layers decreased with the depth. The counts in different soil layers at areas of different planting ages did not show a consistent pattern. The 10-year-old planting area had the highest microbial count in the rhizosphere. Acidification of the rhizosphere soils was serious showing a pH ranging from 3.14 to 3.36. The fertility indices on soils of different planting ages differed. The contents of total P and total K in the 0−15 cm soil decreased with planting age, while those of total and available N in the 15−30 cm layer increased with years of planting. Other fertility indices either peaked or bottomed out when consecutively cultivated for 5 or 10-years. The redundancy analysis on the data revealed that the bacterial plate count was mainly affected by the contents of available K and total P in soil, while the fungal count by total and available N.
Conclusion There was a significant correlation between the microbial population and fertility indices (e.g., available K, available P, total N, and available N ) in the rhizosphere soils of varying years of tea cultivation at the plantations.
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