Impact of insecticides acetamiprid and carbofuran on soil protease activity

The purpose of this study was to evaluate the effect of commonly used pesticides carbofuran and acetamiprid on protease enzyme activity in soils. Two types of soils with previous pesticide history, were amended with low to high concentrations (1.0, 2.5, 5.0, 7.5, 10.0 kg ha-1) of pesticides and incubated in the laboratory at 37oC for 40 days. Protease activity was measured during the incubation at 10, 20, 30 and 40 days interval. Acetamiprid and carbofuran stimulated the protease activity at lower concentrations at 10-days interval. Striking stimulation in soil enzyme activities was noticed at 2.5 to 5.0 kg ha-1, persists for 20-days in both soils. Overall, higher concentrations (7.5 - 10.0 kg ha-1) of acetamiprid and carbofuran were toxic or innocuous to protease activity.