Influence of Humic Substances on Soil and Plant Health.

The International Food Policy Research Institute reports that each year an estimated 10 million hectares of cropland are lost due to erosion and diminished soil health. Restoring soil health and learning efficient ways to utilize water should be the number one mission for farmers and the agricultural industry. For almost 30 years, I have been researching the effects of humic substances (HS) on soil health and water quality, using different humate products in various field conditions. 

The biology and chemistry of humic substances in the soil are exceedingly complex.  Humic substances as soil amendments are new management tools for the agronomist and land manager.  My applied research has been focused on determining the management situations where HS are most useful as well as finding and implementing the most effective management techniques. 

In 2014, field trials were conducted on potato and sugarbeet crops, in Glenns Ferry and Hammett, Idaho. We did four replications of each treatment (1X, 2X, 3X & Control) Our objectives were to evaluate the influence of liquid humic and nutrients on soil health, fertilizer and water-use efficiency, how these nutrients affected soil compaction and to evaluate crop yield and quality. Our data showed that the potatoes from row 1X had a 26.8% difference in yield compared to the control rows. The sugarbeet harvest showed a 19.6% difference in yield between 2X and control.

We observed that the crop response could have been affected by the rate of humic acids used in relation to other soil macro/micronutrient availability. In our experiments, humate product efficacy is responsive for P, N, potash, and K fertilization. With calcareous soil, we documented that it solubilizes Ca and doesn’t allow P to precipitate with Ca.  This is important for creating better consistency to standardize humic analyses methods, as well as establishing a good scientific baseline for different products and rates/hectare in various soils.