Twenty-three progressive extractions were performed to study individual humic acids (HAs) and humin fractions from a typical black soil (Mollisol) in Heilongjiang Province, China using elemental analysis and spectrosc...Twenty-three progressive extractions were performed to study individual humic acids (HAs) and humin fractions from a typical black soil (Mollisol) in Heilongjiang Province, China using elemental analysis and spectroscopic techniques. After 23 HA extractions the residue was separated into high and low organic carbon humin fractions. HA yield was the highest for the first extraction and then gradually decreased with further extractions. Organic carbon (OC) of the humin fractions accounted for 58% of total OC …展开更多
文摘Twenty-three progressive extractions were performed to study individual humic acids (HAs) and humin fractions from a typical black soil (Mollisol) in Heilongjiang Province, China using elemental analysis and spectroscopic techniques. After 23 HA extractions the residue was separated into high and low organic carbon humin fractions. HA yield was the highest for the first extraction and then gradually decreased with further extractions. Organic carbon (OC) of the humin fractions accounted for 58% of total OC …