ifoam'96 Book of Abstracts 11th IFOAM Scientific Conference 11-15 August 1996, Copenhagen, Denmark

ECOWEB FRONT PAGE SUBJECT INDEX AUTHOR INDEX

Posters

The Benefits of Humus (Humates) in Agriculture. P2; 20

Hawaii Bio-Organic Grower's Association Honaunau, Hawaii 96726

The use of humic acid derivatives produced in the Western U.S. is expanding throughout the world. The history of the last 25 years of humate use in the U.S. and the latest humate research answers many questions about humic acids: the economic and ecological benefits of humus use in modern agriculture and organic/biological agriculture systems; the use of humates for soil reclamation; how humates work to increase crop yields and insect resistance; and the use and benefits of humates in fertilizer formulation and livestock feeding.
Humic acids include a group of complex organic compounds that are the end product of the decomposition of organic matter under specific conditions. Low molecular weight humic substances are the most active fraction. Humates (the salts of the humic acids) are geologically concentrated organic matter that is many millions of years old and sometimes referred to as lignite humus because it is found in association with shallow coal deposits capped with sandstone. Humates from the Western part of the U.S. are the most concentrated sources of humic/fulvic acids. The geology and age determinesthe biologically active components that stimulate cell division by making the cell walls more permeable. The high weight humic substances that are closer to coal than humus tend to accumulate at the cell wall but not penetrate. The most valuable from a cellular standpoint are the low molecular weight humics that are younger and come from freshwater deposits; the more northern deposits have higher weight humics and are less valuable in biological effects even though the total humic acids contained may actually be slightly more. The best way to determine effectiveness of humic acids is at the cellular level, hence biological assays are more reliable criteria than strictly a simple humic acid analysis.

Lee, Y.S. & Bartlett, R. J. (1976): Stimulation of Plant Growth by Humic Substances. Soil Science Society of America Journal, 40 (6), 876-79.

Senn, T.L. & Kingman, A. R. (1973): A Review of Humus and Humic Acids. Research Series No. 145, South Carolina Agricultural Experimental Station.

Valdrighi, M.M.; Pera, A; Scatena, S.; Agnolucci, M. & Vallini, G. (1995): Effects of Humic Acids Extracted from Mined Lignite or Composted Vegetable Residues on Plant Growth and Soil Microbial Populations. Compost Science & Utilization, 3 (1), 30-38.