Fig. 2.
13C-CPMAS–NMR spectra of humic acids: HA-H oxidized coal; HA-I silver fir and beech forest soil; HA-L peat soil; HA-M vermicompost; HA-N Hungarian lignite
Fig. 2. | Chemical and Biological Technologies in Agriculture
13C-CPMAS–NMR spectra of humic acids: HA-H oxidized coal; HA-I silver fir and beech forest soil; HA-L peat soil; HA-M vermicompost; HA-N Hungarian lignite