第四纪低丘红壤茶园钾的成土迁移和丰缺诊断

第四纪红粘土发育的低丘红壤茶园，由于土壤不断富铝化，酸度大，增强了钾的淋失，全钾含量趋向贫化。有效钾的抽样调查表明，其含量由北而南逐渐减少，表现出明显的地带性特证，其中：低于５０ｍｇ／ｋｇ以下的茶园约占１／３，且多数分布在南部茶区。在成土过程中，由于受茶树的生物物质循环的影响，使土壤表层的有效钾富集起来。防止该类茶园土壤的进一步酸化和表土层侵蚀，是保护土壤“钾库”的重要措施之一。在钾肥施用上，应首先考虑赤红土和砖红壤大叶茶地区的茶园。

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

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.