冬枣果园土壤非交换态钾的释放动力学

Release Kinetics of Nonexchangeable Potassium in an Orchard Soil of Winter Jujube

为了研究长期施肥条件下冬枣果园土壤非交换态钾的释放特征,以Ca Cl2和柠檬酸溶液为浸提剂,采用连续提取的方法对枣园土壤的非交换态钾释放动力学进行研究。结果表明,枣园土壤非交换态钾在释放过程中表现出快速释放和缓慢释放2个连续的阶段。快速释放阶段（〈188 h）的累积释放量占到总释放量的53.6%-59.2%,而在缓慢释放阶段（188-1244 h）的释放量不及总量的一半。在相同时间内,使用柠檬酸溶液浸提时,非交换态钾的释放量明显高于使用Ca Cl2溶液时的释放量。相比之下,冬枣果园土壤非交换态钾的释放量明显高于对照土壤。在5种动力学方程中,幂函数方程是描述冬枣果园土壤非交换态钾释放的最优模型。

In order to explore release characteristics of nonexchangeable potassium（K） in winter jujubeorchard（WJO） soil, the release kinetics of nonexchangeable potassium by Ca Cl2 and citric solution werestudied by using a successive extraction method. The results showed that the soil nonexchangeable K releasewas comprised of two processes： rapid and slow ones. In the rapid release process（〈188 h）, accumulative Krelease amount occupied 53.6%-59.2% of the total amount, but only less than 50% in slow release process（188-1244 h）. The K release amount in citric solution was higher than that in Ca Cl2 solution at the same time.By comparison, the K release amount of WJO was higher compared with the control. The power functionequation was the best model for describing nonexchangeable K release in WJO soil.