据文献(Blair ,B. J . and Lefroy ,R. D. Soil carbon fractions based on their degree of oxidation , and the developments of a carbon management index for agricultural systems . A ust . J . A gric. Res . , 1995 , 46 :1456 - 1466.)报道, 我这么理解的: 土壤中容易被333mmol的高锰酸钾氧化的有机碳称为易氧化有机碳。