Influence of Humic Products On Soil Health and Crop Production in Idaho.

Since 1900, soil organic matter in farmlands worldwide has declined drastically as a result of carbon turnover and cropping systems. Humic substances, major constituents of soil organic matter, have long been known important properties including chelation, mineralization, buffer effect, clay mineral-organic interaction, and cation exchange. Since 1990, we have evaluated commercial humic acid products derived from lignite and leonardite in different cropping systems.    Research trials were established from 1990 through 2007 to evaluate the efficacy of different humates products in potatoes, sugar beets and alfalfa in Western Idaho. Data from humic acids trials showed that different cropping systems responded differently to different products in relation to yield and quality. Important qualifying factors included: source; concentration; processing; chelating or complexing capacity of the humic acid products; functional groups (Carboxyl -CO2H; Phenol -Ohp; Hydroxyl -Oha; Ketone -C=O; Ester O=C-O-R; Ether –C-O-C-; Amine –NH₂,-NH,-N); rotation and soil quality factors; consistency of the product in enhancing yield and quality of crops; mineralization effect; and influence on fertilizer use efficiency. Humate increases phosphorus availability by complexing ions into stable compounds, allowing the phosphorus ion to remain exchangeable for plants’ uptake. Collectively, the consistent use of good quality products in our replicated research plots in different years resulted in a yield increase from 11.4 percent to the maximum of 22.3 percent. Humic acid products enhanced nitrogen mineralization in early season by an average of 9.6 percent. Alfalfa research plots had yield increases from a minimum of 8.2 percent to the maximum of 20.9 percent.  Over the past decade, there has been a major increase in the quality of research and development of organic and humic acids by some well-established manufacturers. Our experimentations with these commercial products showed an increase in the yield and quality of crops.