Influence of Humic Products On Potato Production and Soil Health.

Soil organic matter (SOM) in farmlands has declined drastically over the past century due to carbon turnover and cropping systems. As a result, today levels of SOM in arable lands worldwide are critically low. Humic substances, major constituents of SOM, possess dynamic properties of chelation, mineralization, buffer effect, clay mineral-organic interaction, and cation exchange. Over the past 18 years, research trials were established in southwestern Idaho to evaluate the efficacy of different commercial humates products derived from lignite and leonardite in potato crop production. Data from these humic acid (HA) 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 potato crops; mineralization effect; and influence on fertilizer use efficiency. Humates increase 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. Over the past decade, there has been a major increase in the quality of research and development of organic and humic acid products by some well-established manufacturers. Our experimentations with these commercial products showed an increase in yield and quality of crops.