Degradation capacities of chlorotoluron and simazine in subsoil horizons

The degradation capacity of the two herbicides chlorotoluron and simazine was investigated using different soils and the different horizons of these soils. The results revealed excellent correlations for DT50 values and biomass for an individual soil and its different horizons. The correlation is not valid for the comparison of different topsoils. These results were confirmed by the fact that within one soil identical metabolism patterns for the different horizons were observed. Consequently, the easily determinable parameter biomass can be used to assess depth-dependent DT50 values on the basis of one experimental result. This is of great importance for generating input data of sufficient accurracy for simulation models such as PELMO (pesticide leaching model).