甘肃省盐碱草地主要植物群落土壤酶活性研究

Soil Enzyme Activities Under Main Plant Communities of Saline-alkalied Badlands in Gansu Province

对甘肃省盐碱地主要植物群落土壤脲酶、过氧化氢酶、碱性磷酸酶、脱氢酶及硝酸还原酶活性的季节动态进行研究。结果表明,5种土壤酶活性季节变化趋势不同,脲酶、过氧化氢酶及碱性磷酸酶活性均在夏季达到最高,硝酸还原酶在秋季最高,脱氢酶在春季最高;不同植物群落土壤酶活性变化趋势不同,脲酶、碱性磷酸酶、过氧化氢酶活性在狗尾草群落(Setaria viridis)具最大活性,硝酸还原酶、脱氢酶活性在芦苇群落(Phragmites australis)均最高,5种酶活性在盐爪爪群落(Kalidium foliatum)均最低;各植物群落的土壤酶活性多表现为随着土壤深度的加深呈递减趋势,在表层0—5cm土层,土壤酶活性最强。对5种酶之间的相关性进行分析,研究发现碱性磷酸酶与脲酶、过氧化氢酶间呈极显著相关,脲酶与过氧化氢酶、硝酸还原酶与脱氢酶间呈显著相关。

This study investigated seasonal dynamics of soil urease,catalase,alkaline phosphatase,nitrate reductase and dehydrogenase activities under main plant communities of saline-alkalied badlands in Gansu province.The plant communities of Haloxylon ammodendron,Kalidium foliatum,Agropyron cristatum,Glycyrrhiza uralensis,Setaria viridis,Alhagi sparsifolia,Phragmites australis,Karelinia caspia and Nitraria sibirica were selected in this study.The results showed that activities of 5soil enzymes showed different seasonal change trends.The activities of urease,catalase and alkaline phosphatase were the highest in the summer,while nitrate reductase activity was the highest in the autumn,and dehydrogenase activity was the highest in the spring.Soil enzyme activities varied under different plant communities.Urease,catalase and alkaline phosphatase activities were the highest under Setaria viridis community,while nitrate reductase and dehydrogenase activities were the highest under Phragmites australis community,and the activities of 5kinds of soil enzymes were the lowest under Kalidium foliatum community.Under different plant communities,the activities of soil enzymes all decreased with the increase of soil depth,which were the highest in the 0—5cm soil layer.It was found that alkaline phosphatase activity was extremely significant correlated with urease and catalase activities,while urease activity was significantly correlated with catalase,nitrate reductase and dehydrogenase activities.