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【目的】研究黄土丘陵沟壑区不同弃耕年限草地土壤酶活性的特征与演变趋势,为正确评价土壤质量提供科学依据。【方法】在陕西安塞县纸坊沟流域,采集不同年限(1,2,3,4,5,6,7,8,9,13,15,20,25,30年)弃耕地0~20,20~40和40~60 cm土层土样,测定土壤理化性质及脲酶、蔗糖酶和碱性磷酸酶活性。【结果】随着弃耕时间的延长,土壤容重、pH值、有机质、CEC、全N、有效N等理化特性得到不同程度的改善,土壤脲酶、蔗糖酶与碱性磷酸酶活性均逐渐增强,土壤脲酶活性随土层深度的增加而大幅度递减;相关性分析表明,以上3种酶活性与土壤有机质、CEC、全N等理化性质显著正相关,与土壤pH等呈显著负相关,而3种酶之间的相关性也达极显著水平。【结论】在植被恢复过程中,脲酶、蔗糖酶与碱性磷酸酶活性逐步增强,土壤酶活性与植被的恢复是一个互动过程。
【Objective】 The objective of this study was to investigate the characteristics and evolution trend of soil enzyme activities in grasslands with different abandonment ages in the hilly and gully regions of the Loess Plateau and provide a scientific basis for the correct evaluation of soil quality. 【Method】 In the area of Zhifanggou watershed in Ansai County, Shaanxi Province, 0 ~ 30 years of abandoned farmland with different years (1,2, 3, 4, 5, 6, 7, 8, 9, 13, Soil samples of 20, 20-40, and 40-60 cm soil layers were collected for determination of soil physical and chemical properties and urease, invertase and alkaline phosphatase activities. 【Result】 With the extension of abandonment time, physicochemical properties such as soil bulk density, pH value, organic matter, CEC, total N and available N were all improved to some extent. The activities of soil urease, invertase and alkaline phosphatase increased gradually, Soil urease activity decreased with soil depth increasing. Correlation analysis showed that the above three enzyme activities were significantly and positively correlated with soil organic matter, CEC, N and other physical and chemical properties, but negatively correlated with soil pH, and 3 The correlation between the kinds of enzymes also reached a significant level. 【Conclusion】 During the process of vegetation restoration, the activity of urease, invertase and alkaline phosphatase gradually increased. The interaction between soil enzyme activity and vegetation restoration was an interactive process.