土壤脲酶活性与底物浓度定量关系研究

通过对陕西 7种类型 1 9个土样脲酶活性与底物浓度关系的研究 ,表明 Y=a× b×x/ ( 1 b×x)模型能较好地表征二者的关系 ,并得到了最大表观脲酶活性 Umax,同时揭示出酶促反应存在着吸附机制 ;除水稻土和黄褐土外 ,其余土样的 Umax值均呈现高肥力大于低肥力的规律性变化 ,相关分析发现在不同生态区中土壤脲酶特征截然不同 ,其 Umax值有明显差异 ,故在分析时需区分开来 ;只有同一生态区中土壤脲酶的 Umax与肥力密切相关 ,可作为土壤肥力指标之一。

The Study on Quantitative Relationship between Soil Urease Activity and Substrate Concentration

The relationship was studied between soil urease activity and urea concentrations in nineteen samples of seven soil types in Shaanxi Province. It shows as follows:The model Y=a×b×x/(1+b×x) can be better expressed their relationship because the equation is the most significant correlation, acquired the maximum apparent urease activity Umax when urea concentration is infinity, there is a adsorption mechanism in enzyme reaction; The urease Umax of higher fertility samples are greater than that of lower fertility except paddy soil and Yellow cinnamon soils, It must be distinguished to analyses because soil urease has apparent polarity characteristics under different ecology environments, urease Umax can be an index of soil fertility because it is remarkable correlation with soil fertility level by correlation analyses in the same ecology.