羊草草原土壤酶活性对土壤肥力的指示作用

Function of Soil Enzyme Activities in Indicating Soil Fertility in Leyluse Chinensis Steppe

采用现场采样及室内测试方法,研究了在锡林河流域羊草草原围栏封育与放牧退化状况下,7种主要土壤酶的活性与土壤肥力的关系。结果表明,土壤肥力水平接近则土壤酶的活性相似,土壤蛋白酶、脲酶、多酚氧化酶的活性与土壤有机碳、全氮呈显著相关关系;蛋白酶、脲酶、多酚氧化酶的活性降低是土壤退化的重要标志之一。土壤酶活性可以反映土壤肥力水平高低,由此得出可以用土壤酶活性总体指示土壤肥力状况。通过判别分析还发现围栏封育保护有利于提高土壤肥力。

Finding a reasonable index to indicate the degree of soil degeneration and recovering in steppes is very important for improving soil fertility in grazing degeneration steppes. In this paper, seven enzyme activities of fencing protection and grazing degeneration in Leymus chinensis steppe in Xilin river basin were determined and analyzed by using statistical methods. The results of ANOVA and cluster analysis showed that the soil enzyme activities were similar in different kinds of soils with the same soil fertility. Through correlation analysis, we found that soil protease activities, urease activities and polyphenoloxidase activities had significant positive correlations with soil organic carbon and total nitrogen. The results of principal component analysis indicated that soil enzyme activities could reflect the soil fertility, and through discriminate analysis, we found that the decrease of protease, urease and polyphenoloxidase activities was one of the most important signs of soil degeneration. Hence, we concluded that soil enzyme could indicate the soil fertility and fencing protection had great advantages in raising soil fertility.