Impacts of the Application of Enrofloxacin-containing Poultry Manure on the Soil Microbial Activities

Through natural decomposition, organic materials are transformed into a nutrient-rich soil amendment during controlled composting which was identified as a highly advantageous way to alleviate the detrimental effects of antibiotics in manure. The purpose of this investigation was to determine the effect of enrofloxacin (ENR) on the breakdown of chicken manure under aerobic and anaerobic circumstances, as well as the effect of this combination on the population of soil microorganisms. ENR was mixed with poultry manure at three different concentrations, i.e., 0, 10, and 50 mg kg(- 1), and composted for 40 days under aerobic and anaerobic conditions. Then, the fresh and described composted poultry manures were introduced to the soil to examine their effects on the population of microorganisms. The results showed that the final concentration of ENR under anaerobic conditions was approximately 50% lower than aerobic composting. Besides, ENR had negative effects on the organic carbon decomposition, total nitrogen, and organic matter loss. Under aerobic conditions, ENR reduced the cellulase and protease activities at the beginning of the composting process, while protease activity moderately increased by the degradation of ENR. The population of fungus and the application of ENR did not vary significantly. Finally, treating soil with the poultry manure and ENR reduced the population of the soil bacteria, and as a result it has negative effects on composting process. The application of poultry manure with ENR had a substantial adverse effect on soil bacterial population, but manure without ENR positively affected the microbial populations.