Animal bonechar increases sorption and decreases leaching potential of aminocyclopyrachlor and mesotrione in a tropical soil

Abstract

While previous studies have shown the influence of various biochars on the fate and transport of herbicides in soil, little information exists on the effects of bonechar. The aim of this research was to evaluate the effect of cow bonechar amendments on the sorption-desorption and leaching of aminocyclopyrachlor and mesotrione in a tropical soil. Soil was amended with bonechar at rates of 0 (control), 1, 5, 10, and 100% (pure bonechar) (ww−1), corresponding to 0, 12, 60, 120, and 1200tha−1, respectively. Additionally, two bonechar particle size groups were compared (0.3–0.6 and 0.15–0.3mm). Aminocyclopyrachlor (pyrimidine-2-14C-aminocyclopyrachlor) and mesotrione (cyclohexane-2-14C-mesotrione) sorption-desorption was evaluated using the batch-equilibrium method and column leaching studies. Higher bonechar application rates increased the sorption of both herbicides. Aminocyclopyrachlor and mesotrione were leachable in the control soil, but the addition of bonechar reduced the depth at which both herbicides were detected. Bonechar additions to soil, regardless of the particle size, was able to statistically increase sorption, decrease desorption, and reduce the leaching potential of both herbicides in the soil.