Optimizing Plant Health Through Soil Health
When it comes to plant nutrient management, the primary focus typically revolves around salt-based fertilizers which are used to promote or maintain plant quality. While these fertilizers are certainly essential for growth and development, we often fail to adequately consider soil health. Fertilizer salts typically come in pairs with a cationic component (e.g. ammonium, potassium, calcium and magnesium) being paired with an anionic component (e.g. nitrates, phosphates, sulfates and chlorides). When nutrients are not in proper balance, excess salts can negatively impact soil health. For instance, black layer is formed when sulfates or elemental sulfur are broken down in anaerobic or saturated soil conditions. High levels of hydrogen sulfide react with various metals, leading to metal sulfide deposits in soil pores. Furthermore, high concentrations of hydrogen sulfide are toxic to plants and inhibit their growth. Another example is when high levels of chlorides from salts like muriate of potash (MOP) significantly increase salinity and cause plasmolysis, or loss of cellular water in plant roots.
Even with periodic soil and tissue sampling, it can be difficult to maintain proper nutrient balance in the soil with salt-based fertilizers alone. Soil health can be improved by additions of organic acid products. These can contain various humic substances like phenolics and carboxylic acids. These substances affect organic matter decomposition and release of nutrients tied up in the organic fraction of the soil. The effect of organic matter on soil nutrient holding capacity can be measured via the cation exchange capacity (CEC). Carboxylic acids in particular are shown to increase the CEC. Furthermore, phenolics exhibit a biostimulant effect on plants, stimulating root and shoot growth. This is especially useful for stoloniferous plants, like many turf species, which can achieve greater density in response to phenolic compounds.
One of the most significant issues with several fertilizer salts is that these salts can be lost to the environment through processes like leaching, volatilization and immobilization. Organic compounds like humic and fulvic acids help soils retain these nutrients, leading to greater nutrient use efficiencies with reduced leaching or tie-up. Additionally, humic and fulvic acids have been shown to improve soil structure through increased soil particle aggregation, thus increasing soil porosity. With increased soil porosity, soils can experience improved gas exchange, limiting the negative effects associated with saturated, anaerobic soil conditions. At the same time, the overall increase in porosity associated with improved soil structure leads to better water retention.
Products like Hydra-Hume®, Resurge®, Receptor® and Essence® 6 interact with traditional fertility inputs to maximize efficiencies while promoting positive benefits to soil health. Hydra-Hume (liquid) and Resurge (granular) contain humic and fulvic acids which provide the benefits of the naturally occurring organic compounds described above. Receptor is an Advanced Nutrient Catalyst that helps you extract more value from your liquid fertilizer. It is a unique combination of three well known plant growth regulators — IBA, Gibberellic Acid and Kinetin — blended into a solution of carboxylic and polyphenolic acids. Essence 6 contains a concentrated organic acid complex that solubilizes calcium and other nutrients tied up in the soil, increasing their availability to plants. While conventional salt-based fertilizers are essential for plant growth, utilization of organic compounds can improve soil health.
Contact your local Helena representative to learn more about these products and to find the soil health solution that’s right for you.
- Josh Henry, Ph.D., Division Agronomist