Volatilization and mineralization of 14C-labelled pesticides on lysimeter surfaces

The volatilization and mineralization of 14C-labelled chemicals applied on soil surfaces in lysimeters was determined continuously with a new developed test-system. 14C-Terbuthylazine and 14C-Pendimethalin were applied on two different types of soil, one typical for a sandy agricultural soil and the second one simulating a soil of an adjoining forest ecosystem. Volatilization of terbuthylazine within 32 – 36 days was 0.26 – 0.65% of the amount initially applied, that of pendimethalin 1.24 – 2.78 within 28 days. Mineralization was 1.02 – 7.41% for terbuthylazine and 2.79 – 5.39% for pendimethalin within 28 – 36 days.