[Migration and Transformation Mechanism of Veterinary Antibiotics Based on the Returning Livestock and Poultry Manure to the Field Soil].

With the promotion of resource utilization of livestock and poultry manure， veterinary antibiotics （VAs） in manure can enter the soil environment during the process of returning to the field， posing ecological risks. Therefore， it is of great significance to accurately grasp the migration and convergence process of VAs in the soil environment for ecological risk prevention and control. However， most of the current studies focus on the distribution and removal technologies of VAs in returned soil， lacking a systematic summary of the migration and transformation mechanisms of VAs in returned soil. Therefore， this paper covers the whole process of VAs from the use of livestock and poultry farms to the final accumulation in soil environment， analyzes the migration and transformation mechanisms of VAs from ingestion by livestock and poultry to excretion， and examines the degradation mechanisms of VAs during aerobic composting and anaerobic fermentation of livestock and poultry manure. It highlights the migration and transformation mechanisms of VAs in returned soil under the influence of the properties of antibiotics and manure， and compares the cumulative levels of VAs background values in returned soil with those in domestic and international soils. It is of great significance to push forward the VAs emission threshold of the manure returned to the field， put forward a reasonable way of returning the manure to the field， and prevent and control the ecological and environmental risks.