Kinetic equations of potassium desorption and the application of equation constants.

摘要

Elovich, parabolic diffusion, power function and exponential equations were used to describe K desorption kinetics of 12 soils in a constant electric field of electroultrafiltration (EUF). Results showed that the Elovich, parabolic diffusion and power function equations described K desorption kinetics well owing to their high correlation coefficients and low standard errors; but the exponential equation was not suitable due to its relatively low correlation coefficients and relatively high standarderrors. The relationships between the constants (slope or intercept) of kinetic equations and the barley responses to K fertilizer were established in multiple-site field experiments. The K-availability of soils, Elovich constants, parabolic diffusion and power function equations were significantly correlated to the soil available K, relative yield of barley and K uptake of barley in the NP plot. It is suggested that the kinetic equation constants be used to estimate K-supplying power of soils.