Abstract: Soil excessive acidification is one of the main problems affecting the sustainable and healthy development of tea industry. To understand the long-term impact of organic management on soil pH of tea gardens, this study selected both soil samples from organic and conventional tea gardens in 84 tea producing counties of 18 provinces in China. The organic tea garden was managed organically from 1 to 21 years. The results show that the mean soil pH in organic tea gardens was significantly increased by 0.36, compared to the conventional tea gardens. With the increase of the years under organic management, the overall pH of tea garden soil shows a significant rise, and then a stable trend. The soil pH under organic management for 1-5, 6-10, 11-15 and 16-21 a significantly increased by 0.48, 0.23, 0.28 and 0.30, respectively compared to those in conventional tea gardens. The organic management also helped the soil pH towards the direction for most suitable growth and development of tea plants, the proportion of soils with pH 4.5-5.5 was only 41.9% in conventional tea gardens, it was increased to 53.1%、48.9%、58.7% and 66.7% in tea gardens under organic management for 1-5, 6-10, 11-15 and 16-21 a, respectively. These results indicate that organic management could not only overcome soil over acidification, but towards to the direction of the most suitable soil pH for the growth and development of tea plants.

Key words: organic management, tea garden, soil, pH