陕西土壤脲酶与土壤肥力关系研究──Ⅱ.土壤脲酶的动力学特征

STUDY ON RELATION BETWEEN UREASE AND FERTILITY OF SOILS IN SHAANXI Ⅱ.SOIL UREASE KINETIC CHARACTERISTICS

土壤脲酶动力学特征研究，国内少见报道。本文通过对陕西七种主要土壤十六个土样脲酶动力学参数的测定，揭示出：动力学参数（V0、Km、Vmax、Vmax／Km、K）和活化能Ea从各个角度表征了处于不同生态环境中土壤脲酶的活性特征；高、低肥土样间也有明显差别，除水稻土外，各高肥土壤脲酶的V0、Vmax、K、Vmax／Km均大于低肥，相关和主成分分析表明，动力学参数Vmax、Vmax／Km可作为土壤肥力的指标；Ea平均值大小顺序也显示出高、低肥土样脲酶在酶促反应中作用机理上的差异。

The parametrs of urease kinehcs were studied using sixteen samples collected from seven main soils in Shaanxi Province.The kineti parameters (V0, Km' Vmax,Vmax /Km and K) and the active energy Ea could be used to express the characteristics of urease activity under different conditions of ecology,and there were apparent differences between the soil samples of high and low fertility.Except for the paddy soil, the V0, Vmax, K and Vmax /Km of urease in the high fertility soils are all greater than those in the low fenility soils. By means of correlation and principal component analysis, the kinetic parameters Vmax and Vmax /Km could act as the indexes of soil drility; The equence of average values of Ea showed a differnece of enzyme reation mechanism between high and low fertility soil samples.