Abstract: This paper deals with the dynamics of trifluralin degradation and its main affected factors in soils under field and pot experimental conditions. The results show that dealkyl -and nitro -reduced compounds are the main degradation products of trifluralin in soils, whose kind and amount depend on soil conditions. In different treatments, its t_1/2 is concentrated in 30-90 days, but more longer when organic matter content is higher or soil moisture content is ≤6％. The increase of soil moisture content and temperature can be promoted microbial activity, and is of advantage to biodegradation of trifluralin.

Key words: Trifluralin, Soil, Degradation product, Degraded rate, Microbial activity