Effect Of Dimethomorph Of Fungicide On Soil Enzymatic Activities And Microbial Diversity

Greenhouse as a special ecological system,has a big difference in environmental conditions and open,the environment also provides a suitable environmental conditions,diseases and pests biological cause biological blooms of diseases and pests,and pests and pathogenic microorganism mutates,resistant to pesticides,thus lead to high frequency,high dose of pesticide use.Numerous studies have confirmed that pesticide duration for far longer than normal in the facility agriculture agricultural planting.So it also gave us a problem: the facilities of pesticide in the environment of use for a long time whether impact on soil life activities.Dimethomorph for facilities in our country are widely used in agricultural fungicide,easy to produce residues in the soil,impact on soil ecological environment.Due to the frequent use,dimethomorph gradually accumulated in the soil content.Soil microbiology is one of the important indexes of soil environmental quality,it can reflect the change of the dangers of pesticides on soil ecological environment.Through indoor test and analysis,the fungicide with the frequent use of dimethomorph effect on soil microbial diversity and soil enzyme activity is in dire need of solution to the problem of science.This test is selected pesticides with dimethomorph,discusses its influence on soil enzyme and biological diversity.This research concluded the following results:(1)Dimethomorph on soil polyphenol oxidase,invertase activity has certain inhibitory effect,and the higher the content of spraying,the stronger the inhibition.Soil catalase activity presents the stimulus-inhibiting trend;No significant effect on soil urease activity;The soil phosphatase activity inhibition degree significantly stronger than the urease activity.(2)Dimethomorph significant inhibitory effect on soil respiration intensity,and the higher the content of dimethomorph,use of,the more the stronger the inhibition.Dimethomorph on soil microbial biomass carbon and nitrogen have a certain degree of inhibition,and the higher the concentration of pesticide,the more the greater the inhibition.(3)Considering comprehensive results,can be used in a soil polyphenol oxidase,sucrase soil respiration and soil microbial biomass carbon and nitrogen as a biological indicator of dimethomorph pollution.(4)Multiple use of low content(5,10 mg/kg)dimethomorph accumulated on the soil microbial community species richness and once there are varying degrees of inhibition;And the high content(25 mg/kg)dimethomorph regardless of spraying a few times,all can have a significant inhibitory effect on soil microbial community diversity.After the first application,only the high content(25 mg/kg)dimethomorph obvious effects on soil AWCD value,significant inhibitory effects on soil microbial metabolic activity;After the second and the third stage,whether low content(5,10 mg/kg),or high levels(25 mg/kg)dimethomorph processing soil AWCD value greatly reduce overall,show of its inhibitory effects on soil microbial metabolic activity significantly enhanced.Application of dimethomorph affected soil microbial carbon source utilization way and the soil microbial community structure,including soil microbes on carbohydrates carbon source utilization rate increase obviously.