Study On The Residues Of Sulfonylurea Herbicides In Soil Remediation By Green Manure And Its Impact On Soil Environmen

Rational application of pesticides and green manure is important to prevent pests,diseases and weeds,increase crop yield and improve crop quality.However,the effect of applying green manure on the distribution and dissipation of pesticide residues when they are left in the soil is not clear,limiting the ability to provide a reasonable method for tilling green manure after applying this class of pesticides and what kind of green manure can accelerate their degradation.In this study,we simulated nine sulfonylurea herbicide residues in soil,and set up CK,chemical fertilizer and five different green manure treatments in a greenhouse experiment,and tilled the green manure in the soil for field degradation tests.The residues were determined using an improved LC-MS/MS assay.The results showed that the application of green manure had a significant effect on the half-life of rimsulfuron,so it was selected for the follow-up soil study.When no fertilizer source was used as treatment,the half-life of rimsulfuron was 28.88 days,while it was 9.00-10.66 days when chemical fertilizer and green manure were used,and 9.76 and 9.00 days in the presence of purple clover and ryegrass,respectively.In addition to this,green manure application increased the p H,SOM,AHN and AK content of the soil and the correlation analysis showed that p H,urease and phosphatase were the main factors affecting the soil microbial community.They were significantly correlated with sulfonylurea herbicide-degrading bacteria Actinobacteria,Acidobacteria,Planctomycetes and Ascomycota,which may be due to the fact that tilling of green manure changed soil properties(e.g.p H)and enriched soil microbial communities,which in turn stimulated enzyme activities(urease and phosphatase),thus further promote pesticide biodegradation.This study provides theoretical support for exploring and designing reasonable post-application green manure conversion methods.The planting and tilling of suitable green manure can effectively alleviate the harm of pesticide residues while improving the nutrient content of soil,which not only realizes the efficient use of agricultural green plant resources,but also promotes the sustainable development of agricultural production.