Effect Of Lambda-cyhalothrin On Soil Habitat Quality Of Water Conservation Forest

Using chemical pesticide as the most commonly used methods and means of inhibit diseases and pests very effective protect to normal growth and production of water conservation forests. Suppress the plant diseases and insect pests quantity, however, at the same time, there are a large number of pesticides deposited in the soil which destructed the soil environment and soil ecosystem balance. Soil chemical properties is the performance of soil environment quantify; soil microorganisms and soil enzyme are sensitive indicators of soil quality. In this paper, the water conservation forest was selected in the upper reaches of Erlongshan reservoir, we choose BIOLOG ECO microplate monitoring technology and dilution plate method, combined with soil chemical properties and soil enzyme analysis techniques to study microbial diversity and activity dynamics after spraying lambda-cyhalothrin. Purpose is evaluation of ecological toxicity and ecological security of Lambda-cyhalothrin to the water conservation forest soil environment.1.7days after the spraying of lambda-cyhalothrin, Topsoil and0-10cm depth number of bacteria that is significantly lower; number of actinomycetes were increased after spraying two days; the number of fungi showed an increasing trend after spraying.2. The variation of the average well colour development of carbon source:topsoil followed by2d>30d>21d>45d>7d>before spraying>14d;0-10cm depth followed by30d>2d>7d>before spraying>45d>14d>21d;10-20cm depth followed by30d>7d>before spraying>2d>21d>14d>45d.3. Soil phosphorus and potassium the whole quantity was no significant change after spraying lambda-cyhalothrin, but quick-impact content vary widely, and erratic. Soil organic matter and total nitrogen rise in the early sprayed, and rapid recovery.4. In addition to the uniform index E, the other microbial diversity index showed increasing tendency, but different soil layers have different response time. Two days after the spraying, topsoil was significantly increased.0-10cm and10-20cm depth was significantly higher.,which is delayed to the first7days. Analysis of variance, two days after spraying lambda-cyhalothrin and sprayed before are different significantly,45days and before spraying have no significant difference.5. The principal component analysis shows that the most significant difference in scores is topsoil. Carbon water category carbon source metabolic differences by soil microbial before and after the spraying of lambda-cyhalothrin is the most significant.6. Lambda-cyhalothrin on soil invertase enzyme, catalase enzyme activity have little impact; Urease activity was significantly activated after spraying lambda-cyhalothrin, and reaches a maximum at21days,which is3.93times before spraying. Dehydrogenase activity trend is inhibited after activation.7. The correlation analysis showed that the number of soil microorganism and soil enzyme activity was positively correlated. Except evenness index E, microbial functional diversity index and soil chemical properties were also positively correlated, and microbial diversity and organic matter, hydrolysable nitrogen, available potassium were significantly correlated.