Effects of soil organic matter and oxidoreductase on adsorption and desorption of herbicide oxadiazon in soils

제초제 oxadiazon의 토양 흡탈착에 미치는 유기물의 함량과 산화환원효소의 영향

  • Lee, Wan-Seok (Department of Agricultural Chemistry, College of Agriculture, Kyungpook National University) ;
  • Kim, Jang-Eok (Department of Agricultural Chemistry, College of Agriculture, Kyungpook National University)
  • 이완석 (경북대학교 농과대학 농화학과) ;
  • 김장억 (경북대학교 농과대학 농화학과)
  • Published : 1998.12.30

Abstract

Dissipation, adsorption and desorption of oxadiazon were examined in two soils containing different amounts of soil organic matter. In addition, reactivity of oxadiazon with humic monomers was searched to clarify binding mechanism of oxadiazon to soil organic matter in the presence of a laccase of Myceliophthera thermophila. Half lives of oxadiazon were 38 days in Soil I and 45 days in Soil II. Freundlich constant, k values of fresh soils were higher than those of oxidized soils. Adsorption rates of oxadiazon were increased 17.1% in Soil I and 9.3% in Soil II in the presence of a laccase but no significant increase was observed in oxidized soils. Desorption rates of oxadiazon in fresh soils were lower than those in oxidized soils. Desorption rates of adsorbed oxadiazon in soils addes with the enzyme were not changed in oxidized soils but decreased in fresh soils. The herbicide oxadiazon alone underwent no transformation by a laccase but in the presence of catechol, guaiacol and gallic acid as humic monomer, transformation rates of it were from 20% to 24%.