Conservation of Agricultural Soil Using Entomopathogenic Fungi: An Agent With Insecticides Degradation Potential

A major current focus in agricultural soil conservation is to ensure a pest control program is sustainable, and therefore, entomopathogenic fungi have been considered and extensively studied as biopesticides. However, the ecological role of entomopathogenic fungi in degrading insecticides in soil is not well understood. In this study, the potential of entomopathogenic fungi Metarhizium anisopliae (Met.) in degrading two common agricultural insecticides, chlorpyrifos and cypermethrin was investigated by introducing M. anisopliae into autoclaved soils artificially contaminated with 500 ppm of chlorpyrifos, and cypermethrin. The concentration of chlorpyrifos and cypermethrin were determined after 21 days using UPLC/PDA detector. The residues, rate, and percentage of degradation between insecticides treated and control soil were compared using an independent t-test (SPSS 20.0). The degradation of both insecticides in Met. treated soil (>80%) was significantly higher than control soil (47-61%). The residues for chlorpyrifos and cypermethrin residue in Met. treated soils were 19.39±0.10 ppm and 19.68±0.36 ppm, respectively, significantly lower than control (residues of chlorpyrifos-262.6±7.6 ppm and cypermethrin-194.4±4.3 ppm, at p<0.05). The results suggested M. anisopliae may play a role in the bioremediation of soil.