宁南山区土壤酶活性特征及其与肥力因子的关系

Characteristics of soil enzyme activities and their relationships with soil properties in southern Ningxia Loess hilly region

分析了黄土丘陵区土壤酶活性与土壤肥力因子之间的关系。相关分析结果表明,土壤有机质与全N、速效磷、速效钾等密切相关,同时与土壤几种酶活性有较好的相关性。土壤酶活性依赖于有机质,当有机质含量增加时,酶积极参与其转化分解过程,活性提高。脲酶、蔗糖酶活性与土壤N、P、K含量关系最大,土壤速效钾与蔗糖酶活性关系最大。通径分析结果表明:土壤肥力因子对脲酶活性的直接作用顺序为有机质>速效钾>速效氮>阳离子交换量>全N>速效磷>物理性黏粒>土壤pH。有机质是影响土壤脲酶活性、碱性磷酸酶活性的主要因素,速效钾是影响蔗糖酶活性的最主要因素。

The linkage between soil enzyme activities and soil properties was studied. Results show that soil organic matter has a significant relationship with soil total N, available P and available K as well as with soil enzyme activities. Soil enzyme activities are improved greatly with increase in soil organic matter due to their participatory role in the decomposition and transformation of organic matter. Urase and sucrase activities are significantly related to soil N, P, K contents. Sucras activity is especially strongly related to available K. From path analysis,the sequence of soil properties based on their direct effect on urase activity is： organic matter〉 available K〉available N〉cation exchange capacity（CEC）〉total N 〉available P〉physical clay 〉 pH, meaning that organic matter is the most important factor that affects urase activity and alkaline phosphatase and available K is the most important factor for sucrase activity.