Analysis of Soil Microbial Activity and Population in Rhizosphere Soil Exposed to Chlorpyrifos

Chlorpyrifos (CPF) is a popular organophosphorus pesticide that is widely employed in agricultural activities. However, we lack information regarding the relationship between soil microbial activity and population under CPF influence, which prohibits us from measuring CPF's actual impact on soil. In the present study, the effect of chlorpyrifos on soil microbial activity was assessed in an indoor pot experiment. The fertile soil was treated with 500 ppm of commercial-grade chlorpyrifos and paddy seedlings were transplanted. The soils treated with bacterial inoculants showed an increased microbial population on the 30th day after inoculation compared to soil receiving sole chlorpyrifos treatment. The same trend was followed on the 60th & 90th day as well. The combination of inoculants resulted in a maximum increase in the population compared to the single inoculants. As a result, there was an increase in soil enzymatic activities viz. dehydrogenase and phosphatase. Thus, inoculating the pesticide-degrading bacteria would lessen the detrimental effects of pesticides on the soil health.