DOKUCHAEV IDEAS AND THE PROBLEMS OF ORGANIC-MATTER

The diversity of organic and organo-mineral substances in soil account s for its individual and unique character. Trends in terrestrial organ ic residue transformations underwent considerable changes over the geo logical time scale: coal formation was replaced by mineralization and humus formation in accordance with the sequence of geological periods. The state and composition of soil organic matter as a function of fiv e soil-forming factors may be followed both in historical and geograph ical aspects. Soil organic matter is a sensitive indicator of undue in teractions between human beings and nature.