Atmospheric CO2 Level and Temperature Affect Degradation of Pretilachlor and Butachlor in Indian Soil

This study was conducted at ambient (398 +/- 10 A mu mol mol(-1)), elevated (450 +/- 10 A mu mol mol(-1)) and elevated (550 +/- 10 A mu mol mol(-1)) atmospheric CO2 under three moisture regime and also three level of temperature (4, 25, and 40A degrees C) to assess the degradation of pretilachlor and butachlor. Under dry condition at 398 +/- 10 A mu mol mol(-1), T-1/2 was 28.5 and 59.4 days for pretilachlor and butachlor, respectively; slowly decreased to 18.2 and 44.5 days at 550 +/- 10 A mu mol mol(-1) indicated that elevated condition enhanced degradation than ambient condition. Under field capacity with increasing CO2 levels from ambient to elevated, T-1/2 decreased from 18.9 to 11.6 days and 39.4 to 16.2 days for of pretilachlor and butachlor, respectively. Similarly, under submerged conditions with increasing CO2 levels T-1/2 decreased 14.7-7.1 and 26.3-11.8 days for pretilachlor and butachlor, respectively. Study also revealed that both pretilachlor and butachlor dissipated faster at 40A degrees C (T-1/2, 9.7 and 19.4 days) than 25A degrees C (T-1/2, 16.2 and 36.7 days). Slower dissipation was recorded at 4A degrees C (T-1/2, 87.6 and 182.4 days).