The important characteristics of soil organic matter affecting 2,4-dichlorophenoxyacetic acid sorption along a catenary sequence.

摘要: Variations in the characteristics of soil organic matter (SOM) at field-scale are largely unknown, particularly relation to observed variations herbicide sorption. For 2,4-D [2,4-dichlorophenoxyacetic acid], we found that its carbon-normalized sorption coefficient, Koc, varied by four-fold, from 76 315 L kg−1, Ap-horizon along a slope transect an undulating agricultural field Manitoba, Canada. In order explain relatively large in-field variation Koc values, techniques ranging conventional chemical fractionation methods solid state Cross Polarization and Magic-Angle Spinning 13C-Nuclear Magnetic Resonance applied on whole soils, were used derive SOM chemical, physical structural parameters for correlation analyses with measured values soils. Out 15 considered, was significantly positively correlated 1) carbon (C) content sodium hydroxide-extracted humic acids (r ...