Persistence and effects of fenamiphos on native algal populations and enzymatic activities in soil

Fenamiphos is a commonly and widely used nematicide and insecticide in agriculture but information on its effects on microorganisms in soil is scarce. The microbial role in the persistence of fenamiphos in soil was determined by comparing the relative rate of its degradation in autoclaved and unautoclaved soil. Nearly 80% of added fenamiphos disappeared in unautoclaved soil during a 20-day incubation. In autoclaved soil incubated under similar conditions the recovery of fenamiphos was about 91%. This indicates the involvement of microorganisms in the degradation of this compound. Fenamiphos in general was not toxic to the soil algal community and soil enzymes (dehydrogenase, phosphatase and β-glucosidase). Therefore fenamiphos at field application rates may not endanger non-target microorganisms and their activities in soil.