干湿交替过程对黄土高原几种主要土壤钾有效性的影响

室内模拟试验研究不同温度条件下干湿交替对黄土高原区四种土壤有效钾的影响,结果表明:(1)土壤钾有效性受干湿交替过程影响较大,干湿交替次数与有效钾含量间具有y=a+blogx函数关系;(2)温度升高,增强了干湿交替的剧烈程度,提高土壤钾的固定量,显著降低了土壤钾的有效性;(3)建立了反映干湿交替次数、土壤物理性粘粒和粘粒含量比值、以及钾固定量三者之间的关系方程。

Effect of Alternation of Drying and Wetting on K-fixation Capacity of Soils in Loess plateau

Experiments about the potassium fixation capacity of four types of soils in the loess plateau were studied, with different drying and wetting cycle and temperature. The results showed in the following: (1)With applying K of 200mg/kg,the potassium fixation quantities of four soils were very different,capacities of fixing potassium in turns were: Hei lu soil>Lou soil>Loessial soil>Aeolian sandy soil. (2) The first time of drying and wetting cycle gave the largest influence on total quantity of fixed potassium, and with increasing cycles, it's influence became weaker. (3) The effects of temperature on potassium fixation capacity varied among four types of soils.