Factors Affecting Iron and Manganese Contents of Tea leaves and Plantation Soil in Central Fujian

From a field survey at 25 plantations in Datian County, the iron and manganese contents in layers of soil and one-bud-2-leaves from the bushes grown on same sampling spots were determined. The distribution and factors affecting the variations on the mineral contents were analyzed.The average contents of total iron, available iron, total manganese and available manganese in the soil were 61.08 g·kg^-1, 144.42 mg·kg^-1, 258.97 mg·kg^-1 and 33.72 mg·kg^-1, respectively. The soil in the region were relatively rich in total and available iron, but low in those of total and available manganese.Nearly half of the soils sampled in the region was considered deficient in manganese. There was no significant difference in total iron in the 0-60 cm layer but richly accumulated in 20-40 cm.The available iron as well as the total and available manganese in soil decreased with depth below the surface.In the soil, the organic matters, pH, total and rapidly available phosphorus were important factors affecting the iron content; whereas, the total and available manganese closely related to the organic matters and pH. The average iron and manganese contents in the tea leaves were 164.52 mg·kg^-1 and 849.73 mg·kg^-1, respectively, and the accumulation coefficient of manganese was much higher than that of iron. The iron content in the tea leaves significantly correlated with the available iron in soil, while the manganese content with the total and available manganese in soil. The iron and manganese accumulation coefficient in the leaves decreased with increasing mineral contents inthe soil.