Effect of biochar amendment on the bioavailability of pesticide chlorantraniliprole in soil to earthworm.

To evaluate the effect of biochar amendment on the bioavailability of chlorantraniliprole (CAP) in soils with different physico-chemical properties, the uptake of CAP from various soils by earthworms was studied. It was observed that the biochar amendment of the soils affected the sorption of CAP, but the magnitude of the sorption enhancement by biochar amendment among the soils was varied, presumably due to the attenuation of the sorptivity of the biochar when amended in the soil. The amendment with biochars leads to a decrease in the bioavailability of CAP in the soils to earthworms, and more prominent for biochar BC850 amendment. In the soil with a CAP concentration of 10 mg kg(-1), the residue of CAP in the earthworm tissues was found to be 9.65 mg kg(-1), in comparison with that the CAP residue was 4.05 mg kg(-1) in BC450 amended soil and 0.59 mg kg(-1) in BC850, respectively. The degree of bioavailability reduction by same level of biochar amendment was different among soils with different properties. The results demonstrate that the properties of soils are important to performance of biochar in soil.