茶园土壤钾素容量／强度关系及施用钾镁肥的影响

对我国主要茶区茶园土壤分析结果表明，土壤钾素含量大都处于中等水平以下，且呈地带性分布，即缓效钾的含量由北而南下降，速效钾占缓效钾的比例由北而南增加。对土壤钾素容量／强度（Ｑ／Ｉ）分析表明，茶园土壤钾素的ＡＲｋｅ（强度指标）通常都小于０．０１（ｍｏｌ／ｌ）－１２。施用钾肥能显著提高供钾强度指标ＡＲｋｅ和ΔＫ０（容量指标）。施镁能增加ＡＲｋｅ，但对ΔＫ０和ＰＢＣｋ（缓冲能力）无明显影响。不施钾处理土壤的ＡＲｋｅ和ΔＫ０均趋于下降

Potassium Quantity Intensity Relationship(Q/I)in Tea Soils and the Influence of Potassium and Magnesium Application on It

The Potassium Quantity Intensity relationship(Q/I)in tea soils of China and the influence of K and Mg application on it were investigated.The K availability status were rather low with the available and slowly available K in 16 samples out of the total 18 tested ranging from the medium to the very low levels.The contents of slowly available K decreased,but the percentage of available K content in the slowly available K increased from the northern to the southern tea geowing areas,showing an obvious zoned characteristic in distribution.A majority of soil samples had the equilibrium potassium activity ratios AR k e below 0 01(mol/l) -1/2 ,indicating that the K + was primarily held at edge positions.With K addition,the AR k e value increased from below0 01 to above 0 01,suggesting an increased K + intensity.The △ K 0 became more negative with K addition,showing a greater K + release into soil solution,resulting in a greater labile K pool.Applying Mg increased AR k e value markedly but indefinitely influenced the △ K 0 and PBC k values.The △ K 0 and AR k e values in the control treatment without K and Mg applications tended to decrease.