Humic acids are colloids and behave somewhat like clays, even though the nomenclature suggests that they are acids and form true salts. When the cation exchange sites on the humic molecule are filled predominantly with hydrogen ions, the material is considered to be an acid and is named accordingly. However, it has no great effect on pH because the acid is insoluble in water. When the predominant cation on the exchange sites is other then hydrogen, the material is called humate. The humates of monovalent alkali metals are soluble in water, but the humates of multivalent metals are insoluble. Apart from their effect on the solubility of the materials and their absorption by clays, the different cations have little effect on the humic molecules.

The manifold effect of humic substances on the plant, shown both in the external medium and in the biochemical processes occurring in the plant, has been well demonstrated.

There is a growing interest in the use of organic materials as fertilizers or soil amendments. This may be attributed to: 1) an interest in the reduction of the use of chemical fertilizers; 2) public concern for the potential polluting effects of chemicals in the environment; and 3) a pressing need for energy conservation. The research reported herein was conducted in an effort to explore humate material as one of the organic natural resources with the potential for meeting some of these needs.

Reference: Senn, T. L. and Alta R. Kingman, 1973, A review of Humus and Humic Acids. Research Series No. 145, S. C. Agricultural Experiment Station, Clemson, South Carolina.

This study showed significant increases in yield on potatoes, soybeans and algae cultures on test plots near Grand Forks, North Dakota. Other tests in North Dakota documented yield increases in barley with or without applied mineral fertilizer (Agvise Inc., 1977-1979). Tests done by commercial farms have consistently resulted in a significant reduction in irrigation water usage on plots treated with humates, as well as better seed germination, leaf petiole growth and crop yields.

Interest in humates and their value in agriculture is increasing rapidly. There are numerous universities and commercial concerns engaged in testing / documenting the benefits of humates used in fertilizers, animal feed and environmental remediation.