SumaGrow® containing products have demonstrated the ability to increase the water holding capacity of the soil and improve water efficiency of crops. To be clear, plants grown with products containing SumaGrow® still need the same amount of water to grow; however, the water efficiency is increased sufficiently to allow crops to grow with less rain or irrigation water.
How? There are several modes of action which create better water efficiency – reduced compaction and control/reduction of salinity.
Notice the difference in the photo below of the water holding capacity of the soil in the fields treated with a product containing SumaGrow® versus the untreated fields.
Reduce Soil Compaction
The ability of soil to hold water is related to the amount of compaction of the soil – high compaction equals reduced water holding capacity. Soil compaction can easily reduce crop yields by 10 percent, and can lead to water and soil quality degradation due to increased runoff and the destruction of the soil structure. Products containing SumaGrow® alleviate this condition by reducing the compaction.
One way of measuring compaction is by using a penetrometer. Imagine a giant needle inserted into the ground. The penetrometer is designed to mimic a plant root. Root penetration decreases linearly with penetration resistance, until almost no roots penetrate into soil with a penetration resistance of 300 psi (pounds per square inch).
For example, a typical truck farm vegetable may reach a penetration resistance of 300 psi at 5-6 inches in untreated soil while the same vegetable growing in soil treated with a product containing SumaGrow® may reach a penetration resistance of 300 psi at 10-12 inches deep.
Consider the results from Holden Research’s test on cabbage in California. With only a 20 percent reduction in fertilizer and the addition of a product containing SumaGrow®, penetrometer depth increased from 6 inches to 17.8 inches.
Since topsoil dries out from the top, down, when the top 6 inches are out of moisture the grower standard crop was without water; however, the treated plot still had 11.8 (17.8 – 6) inches of soil with moisture and nutrients in it for the roots to extract.
Control/Reduction of Salinity in the Soil
Petrochemical fertilizer leaves behind salt residues. Salts in the soil can wick away moisture from the plant roots which is why soils with high salinity are more challenging. The more fertilizer applied, the more water is needed.
Microbes excrete a substance known as exo polysaccharides (EPS) which encapsulate salts, preventing the salts from absorbing moisture. This is a first step in bio remediating the soil of excess salts.
In a field trial with the City of Costa Mesa, California on sports turf, in less than three months, the treated fields achieved a 26 percent reduction in salinity, according to third party laboratory analysis. The moisture in the soil also increased by 10% and the Sodium Absorption Ratio (SAR) decreased 17 percent (lower is better). The SAR is a test of water quality, not quantity.