Abstract
The purpose of this study was to evaluate the effect of commonly used pesticides such as Pendimethaline, Trifluralin, Glyphosphate, 2, 4-D, and MCPA (Chwastox) on microbial activities in soil. Two types of clean soils were amended with recommended level of pesticides and incubated in the laboratory at 35 degrees C for 15 days. Microbial activities in the form of CO2 production were measured during incubation at 1, 2, 3, 4, 5, 7, 9, 11, and 15 day intervals. CO2 production was not affected substantially by any of the applied doses of pesticides. However, the total amount of CO2 produced during 15 days was suppressed by all pesticides, except MCPA (Chwastox). The effect of pesticides on microbial activities varied greatly with the type of pesticides used. The MCPA Chwastox did not exert any inhibitory effect on the respiratory rate of microbes, while other selected pesticides showed highly toxic effect on soil microbial activity.