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本文用恒温改变电压电超滤、恒温恒电压电超滤及生物(黑麦草)耗竭试验等动态方法对江苏省几种不同土壤K素供应状况进行了研究。结果表明:(1)恒温恒电压电超滤连续解吸60分钟的K的释放可以用二级反应方程K_=K_0t/(t+1/kK_0)来描述,K_0与土壤K供应的数量有关,K素的释放速度受K_0的影响较大;(2)在耗竭试验中,生物吸收来自缓效性K量(第一部分非交换性K量)可达总吸K量的15％～47％。随着收割次数的增加,交换性K可降至一个最低值,该值可以用来反映第一部分非交换性K的释放速率。同时,缓效性K也会降至一个最低值,该值可用来反映第二部分非交换性K的释放速率。上述研究结果都表明:淤土、小粉浆土、勤泥土和鸭屎土的供K特性良好;沙土,两合土次之;乌底白土较差;黄白土、淀浆白土和黄泥土最差。
This paper studied the status of K supply in several soils of Jiangsu Province by dynamic methods such as constant temperature changing ultrafiltration, constant temperature constant voltage ultrafiltration and biological (ryegrass) depletion test. The results showed that: (1) The K release after 60 minutes continuous desorption by constant temperature and constant voltage can be described by the second-order reaction equation K_ = K_0t / (t + 1 / kK_0) (2) In the depletion test, the bioabsorption is from the slow-acting K (the first part of non-exchangeable K) reaches 15% -47% of the total K uptake. As the number of harvests increases, the exchangeable K can be reduced to a minimum value that can be used to reflect the release rate of the first fraction of non-exchangeable K. At the same time, K will also be reduced to a minimum value, which can be used to reflect the second part of the non-exchangeable K release rate. The results of the above studies indicate that the K characteristics of silt soil, small silty soil, silt soil and duck feces soil are good; sandy soil and two-lobed soil are inferior; the black bottom white soil is poor; difference.