Effect of Environmental Conditions on the Degradation of Florasulam in Typical Soils of Northern China.

The widespread use of florasulam in China makes residues from this herbicide in soil a serious concern due to their potential to pollute the soil environment and groundwater. Accelerating the degradation of these residues will reduce their pollution potential. In this study, we investigated the degradation and adsorption of florasulam in four typical soils in northern China and examined the degradation of florasulam in Inceptisols at different temperatures, soil moisture contents, and pH values, as well as the influence of microorganisms and the use of organic matter and biogas slurry as soil amendments. The half-lives of florasulam in the four soils were 13.6 d (Ultisols), 13.9 d (Vertisols), 15.1 d (Alfisols), and 19.3 d (Inceptisols), and the adsorption ability of the four soils followed the order Inceptisols > Alfisols > Vertisols > Ultisols. Florasulam degradation rates increased as temperature and soil moisture increased and as soil pH decreased (from 8.0 to 6.0). Adding a small amount of organic matter to the soil increased the florasulam degradation rates. The use of biogas slurry also increased the degradation rates. Florasulam half-life in unsterilized soil ( = 19.3 d) was significantly shorter than in sterilized soil ( = 113.4 d). These results provide agricultural producers and environmental managers useful information for reducing the environmental risk associated with florasulam use.