ON ACIDIFICATION OF TEA GARDEN SOILS IN CHONGQING

In Chongqing, soil pH of approximately 80% of tea garden soils was found to fall in the category unsuitable to teat growth. In various pH ranges, soil acidification manifested distinct characteristic features. When soil pH dropped to 4.5, the buffering capacity of the soil to the process of acidification weakened significantly and exchangeable base Ca~(+2) desaturation decreased together with soil pH. When soil pH ranged from 4.5 to 5.0, the buffering capacity increased markedly, and the correlation between base desaturation and the changes in soil pH was non-significant. When soil pH was higher than 5.0, the bases Ca~(+2) and Mg~(+2) and base saturation increased with soil pH.