不同银杏复合经营模式土壤酶活性及综合评价

The activities and integrated evaluation of soil enzymes of different agroforestry patterns of Ginkgo biloba L.

为了解银杏复合经营对土壤酶活性的影响,选择江苏泰兴3种传统的银杏复合经营模式,即银杏+桑树(G+M),银杏+小麦+黄豆(G+W+S)和银杏+油菜+黄豆(G+R+S),以纯种桑树(M)和油菜+黄豆(R+S)为对照,连续种植3a后,对这5种经营模式下土壤部分酶活性进行了比较分析,并采用改进层次分析法,对土壤酶活性进行综合评价。结果表明,不同经营模式土壤中及同一模式不同深度土壤中的过氧化氢酶、多酚氧化酶、蔗糖酶、脲酶、脱氢酶、磷酸酶和蛋白酶等的活性均存在着显著差异。随着土层深度的增加,5种经营模式土壤过氧化氢酶和多酚氧化酶的活性逐渐增加,而蔗糖酶、脲酶、脱氢酶、磷酸酶和蛋白酶等的活性则逐渐下降。各种银杏复合经营和纯种桑树模式土壤中酶活性除过氧化氢酶外,其他酶活性均比纯种农作物(R+S)模式的高。5种经营模式土壤酶活性综合评价指数从大到小依次为G+M(0.870)、G+W+S(0.820)、G+R+S(0.500)、M(0.281)、R+S(0.127)。因此,银杏复合经营可明显改善土酶活性,增加土壤的肥力。

Ginkgo biloba L.is a traditional economic tree species in China, and it is a common plant cultivated in agroforestry system. In order to understand the effects of different agroforestry patterns of G.biloba L.on the activities of soil enzymes, three agroforestry patterns were studied, including G.biloba L.＋Wheat＋Soybean （G＋W＋S）, G.biloba L.＋Mulberry （G＋M） and G.biloba L.＋Rape＋Soybean （G＋R＋S）. The other two planting patterns Mulberry （M） and Rape＋Soybean （R＋S） were used as control. The activities of soil enzymes of the five managing patterns were determined after planting three years, and their integrated activity were evaluated by using the improved Analytic Hierarchy Process （AHP）. The results showed that the activities of catalase, sucrase, urease, dehydrogenase, phosphatase, polyphenol oxidase and protease in soil of the five patterns were different remarkably, and these enzymes varied significantly in different soil layer. The activities of sucrase, urease, dehydrogenase, phosphatase and protease of soil of five patterns decreased with an increase in soil layer. However, the activity of catalase and polyphenol oxidase increased, and the activities of these enzymes were the lowest among five patterns except catalase of R＋S pattern. The results of integrated evaluation of soil enzyme activity showed that the integrated evaluation indicators were different significantly for the activity of soil enzymes among the five agroforestry systems. They were ordered in G＋M（0.870）, G＋W＋S（0.820）, G＋R＋S （0.500）, M（0.281）, R＋S （0.127）. Therefore, ginkgo agroforestry could increase the activities of soil enzymes, and improve soil fertility.