The relation between the molecular structure of humic acids and their biological activity

The relation was established between the physicochemical properties of the humic acids separated from peat of the high and low types and of brown coal of a high rank and also of the humic acids modified by hydrolytic and oxidizing destruction and their biological activity. It is shown that humic acids with a higher content of functional groups, a high degree of aromatization and level of paramagnetism have the strongest biological action on the growth processes of plants.