代森锰锌类农药对生姜种植地土壤酶活性及微生物群落结构的影响

摘要

The effect of mancozeb on activity of soil enzyme (urease, dehydrogenase, phosphatase and protease) and the diversity of microbial community in ginger fields were investigated, with treating amount of 0.48, 0.72 and 0.96 g·m-2 mancozeb in soil. The results showed that acid phosphatase activity was increased by 2.3% after treated with 0.48 g·m-2 mancozeb in vigorous growth period (VGS); 0.72 g·m-2 mancozeb inhibited soil acid phosphatase and protease activity significantly in VGS (P<0.05), with the inhibition rates 24.2% and 40.0% respectively, however, enzymes activities were partial recovered in ginger harvest season (HS). The activities of acid phosphatase and urease were markedly decreased in HS (P<0.05) by treated with 0.96 g·m-2of mancozeb, indicating that the inhibition rate is positive correlation with soil enzyme activity in certain range of treating amount (0.96 g·m-2), inhibition rate weaked when the treatment amount exceeds certain range (0.72 g·m-2). The inhibitory effects of mancozeb to soil enzyme follows a descending order in treatment amount: 0.72, 0.48, 0.96 g·m-2. Soil microbial richness and shannon wiener index of the DGGE profile exhibited that 0.48 g·m-2 was the most influential treating amount, following with 0.72 g·m-2 and 0.96 g·m-2, it is not a single linear relationship between bacterial community structure and soil enzyme activity. Cluster analysis demonstrated that the diversity of bacterial community is positively correlated with mancozeb treating amount.%研究了代森锰锌类农药克菌宝（15%）、深蓝（60%）和活根菌灭（80%）对生姜（Zingiber OfficinaleRoscoe）种植地土壤酶（脲酶、脱氢酶、磷酸酶和蛋白酶）活性和土壤微生物群落结构的影响，以期为评价代森锰锌的合理使用及环境修复提供一定的理论参考依据。结果表明，施用克菌宝的农田土壤在生姜旺盛生长期酸性磷酸酶活性提高了2.3%；深蓝能显著抑制旺盛生长期土壤酸性磷酸酶和蛋白酶活性（P<0.05），抑制率分别为24.2%和40.0%，但这两种酶的活性在生姜收获期均有所恢复；活根菌灭在收获期可显著降低土壤酸性磷酸酶和脲酶活性（P<0.05），土壤酶活性的抑制率与一定范围内（0.96 g·m-2）的农药施用量呈正相关，但当施用量超过一定阈值（0.72 g·m-2）后抑制率降低。3种农药对土壤酶活性抑制作用的强弱顺序为深蓝>活根菌灭>克菌宝；DGGE图谱的土壤微生物丰富度和Shannon-Wiener指数分析结果表明，土壤微生物的丰富度和多样性高低顺序为克菌宝>深蓝>活根菌灭，这与相应农药的土壤酶活性高低情况不一致，说明土壤细菌群落结构与土壤酶活性不是单一的线性关系。细菌16S rRNA基因的聚类分析表明细菌群落结构受到农药的影响，并与其施用量呈正相关。