Movement of Potassium in the Soil During Its Development From Quaternary Red Clay and the Diagnosis of Potassium Deficiency in Tea Gardens of Low-hilly Red-earth Areas
Wu Xun(Tea Rescorch Institute,Chinesc Academy of Agricultural Sciences,Hangzhou 310008 )
The accumulation of aluminum and the serious acidification in the soil during its development from qua-ternary red clay stimulated the potassium leaching and decreased the total potassium content in the soil.Theavailable potassium in the soils sampled from tea growing areas in China was zonedly characterized and thecontent declined from the north to the south.The soil samples whose available potassium content was below50 mg/kg accounted to 1/3 of the total samples and they mostly came from the southern tea growing areas inChina. The available potassium accumulated in the upper horizon of the soil due to the biological cycling ofmaterials in tea gardens during the process of the soil development. Preventing the soil from acidification anderosion is considered important to maintain the‘potassium bank’in the soil.Potassium fertilizers ought to befirstly recommended to tea gardens located on laterite and lateritic red earth in southern China.