Morphological structure and chemical composition of soil organic matter in different humus forms of forest soils in Schleswig-Holstein

The morphology and chemistry of the soil organic matter (SOM) can be used to estimate its functions in soil and its ecological significane with regard to SOM transformation processes. Typical humus profiles of forest soils in Schleswig-Holstein were characterized morphologically using the current German mapping instructions. Problems in its application for Soils in Northwest-Germany were discussed with specific examples in order to develop modification proposals. The SOM of these profiles was investigated by means of wet chemistry. The humus forms: mull, moder and rawhumus are characterized by typical depth profiles of organic SOM compounds. The amount of lipids increase from mull to rawhumus whereas the importance of polysacchrides decrease. The C/N ratio should be used only in connection with soil texture as a organic chemical indicator of the recent humus form.