Effects Of Herbicides And Seed Coating Agents On The Structure And Function Of Soil Microbial Community In Plantations

With the increasingly serious pesticides pollution,forest ecosystem is facing greater and greater risks.This study took the plantation soil of Harbin urban forestry demonstration base as the research object,Seven test groups were set up: Control group without seed coating agent and herbicide(CK),add acetochlor atrazine herbicide with mass fraction of 5 mg/kg(AA1),add acetochlor atrazine herbicide with mass fraction of 10mg/kg(AA2),add 0.5 mg/kg of metalaxyl-fludioxonil seed coating agent(SCA1),add 1.0 mg/kg metalaxyl-fludioxonil seed coating agent(SCA2),acetochlor atrazine with a mass fraction of 5 mg/kg and metalaxylfludioxonil with a mass fraction of 0.5 mg/kg were added for mixed application(M1),acetochlor atrazine with a mass fraction of 10 mg/kg and metalaxyl-fludioxonil with a mass fraction of 1.0 mg/kg were added for mixed application(M2),sprayed according to the corresponding concentration,measured the physical and chemical properties of soil,enzyme activity,functional diversity of soil microorganisms and genetic diversity of soil microorganisms.The results showed that:1.The application of herbicides and seed coating agents changed the soil physical and chemical properties and soil enzyme activities of plantation,and changed the significant correlation between soil physical and chemical properties and soil enzyme activities.2.The application of herbicides and seed coating agents significantly changed the carbon source utilization and diversity index of soil microorganisms in plantation,and changed the functional diversity of soil microorganisms in plantation.3.The application of herbicides and seed coating agents significantly changed the dominant phyla,species and relative abundance of soil bacteria,fungi and AMF,the diversity index of soil bacteria,fungi and AMF,the correlation between soil physical and chemical properties and soil enzyme activity and soil bacteria,fungi and AMF,and significantly reduced the correlation between soil microorganisms.This study is expected to provide a certain scientific basis for the scientific use and risk management of herbicides and seed coating agents,and also provide theoretical support for the protection and restoration of forest soil.At the same time,it has positive significance for revitalizing northeast forestry economy,giving full play to forest ecological function,maintaining forest ecological health and promoting ecosystem balance.