The chemical composition of soil organic matter in classical humic compound fractions and in bulk samples — a review

In the present paper new findings in soil organic matter (SOM) research were reviewed with regard to non-aromatic species in order to make evident the recent conception about the chemical nature of humic matter structure. The main purpose of this paper was to unravel the manifold information of SOM investigations in order to characterize the classical humic matter fractions (fulvic acids, humic acids, humins) and bulk soil samples. Such common state-of-the-art information is missing in current SOM literature. In addition we focus on improvements in SOM research due to the application of the new instrumental methods such as NMR and pyrolysis-MS and its problems of analysis.