Case Study: Chemically Remediating, Flushing Greens
September 27, 2021
Green #3 Lab ID: 21080020
The Legends’ greens had been evaluated for their chemical and physical conditions in the Fall, 2020 by Robert Oppold of ISTRC and Dr. York of Tournament Turf Laboratories (hereafter: “TTL”). Water quality was reported as poor by the experts. The soil testing incorporated the improved methods using the York-Oppold Legacy Testing Package through Tournament Turf Laboratories, and exhibited that Fe, Ca, and other metals (Al) were extremely high, significantly more then conventional exchangeable methods (AA, DTPA and Mehlich III) portrayed. The greens were found to have extreme hardpan midway through the soil profiles.
The physical properties testing through ISTRC confirmed poor infiltration/percolation through the root zone profiles, low air porosity, and high water retention properties (water porosity and water holding). The greens were excellent candidates for treating the water and soils with HCT’s Curative and BC products. Rather than handling Curative and BC in their concentrated condition, HCT’s pHix product was chosen. pHix is Curative and BC blended in a solution that is easier, more user friendly, and compatible with most topically applied products.
At ISTRC and TTL recommendations, a commercially available HCl product for comparison purposes of the urea buffered acid products available in the marketplace (hereafter: “Product B” unless stated otherwise).
I. RESEARCH QUERIES
No. 1. How much product can turfgrass tolerate? This is a practical question because of the hypothesis that the rate directly impacts the amount of time required to remediate soil chemistry issues below the surface. In addition, the rate has a direct impact on the amount of nutrients that can be liberated within a given time frame.
The more nutrients that can be liberated and sequestered within a given time frame should equate to more rapid removal of those liberated and sequestered nutrients through plant uptake and leaching.
No. 2. Is it possible to change soil chemistry and soil physics within a 12 day testing window that was reduced from the original 30 days? Given the limited 12 day testing period available, the expectation was that there should be a measurable change in chemistry but changes to the physical properties were predicted to be “minimal, at best”.
No. 3. Would there be a measurable difference between pHix and the urea buffered HCl product? pHix is a combination of the Curative product – HCl based, and BC which consists of Hydrogen Peroxide, both contain an ammonium acetate and other proprietary ingredients. [NOTE: Product B was chosen because HCl is a stronger acid than sulfuric acid.]
Conclusion #1. The turf was able to tolerate solutions of 500 ppm of the pHix and the Product B. No yellowing or adverse reactions were observed. Our conclusion, that the turf could tolerate substantially higher concentrations except that Product B caused a flush of leaf tissue growth and drops of raw product burned the turf. Likewise, Product B, the grass became puffy and soft. We attribute the flush of growth to the urea. The Product B was rated as 17-0-0. The flush of growth limits its use to remediate soils in that no fertilizer was applied during the 12 day testing period. A similar flush of growth was not observed with the pHix.
Conclusion #2. There were measurable changes in soil chemistry with both the pHix and Product B. There were also measurable improvements in the physical properties particularly in the 8-to-12-inch strata (3rd tier), which was contrary to expectations.
These tests were the first time we were able to directly attribute high bulk densities to contaminants in a sand-based root zone. In the 3rd tiers, the pHix and Product B lowered bulk density and increased both air porosity and water infiltration/percolation.
Conclusion #3. The pHix is a solution consisting of 20% active ingredients - Curative (HCL) and BC (peroxide and acetic acid) - and 80% water. Product B is approximately 60% buffered HCl and 40% water. There were measurable differences between the two products. Product B, for instance, produced a larger change in water infiltration/percolation and a larger change in the porosity properties in the 3rd tier; however, the pHix was able to produce a substantially lower bulk density with almost one-third less active product.
Both products were effective with the carbonates and bicarbonates and both mobilized Fe. The pHix’s lower bulk density, however, indicates that it was more effective in dissolving hard crystalline structures and flushing the residual.
Conclusion #4. Physical and chemical changes occurred over a short period of time. The flush of growth associated with the Product B was attributed to the urea N. There was insufficient time to measure the ability of the grass to uptake the liberated nutrients thereby reducing fertilizer costs. Additionally, there was insufficient time to improve the physical properties of the top 4 inches. There was a black layer that extended from the surface to about the 5th inch.
The layer did not have the rotten egg smell that is typically associated with hydrogen sulfide produced black layer. The blackened root zone mix was more likely caused by an anaerobic induced reduction reaction involving Fe & Mn. On the 12th day, it was observed that the black soil in the pHix 500 ppm test plot appeared to have lightened.
The testing indicated that the pHix moved more Fe & Mn than Product B; however, the more likely explanation for the lightening of the soil was the impact of the peroxide and O2 or a combination of the acid/peroxide/HAA of the pHix.
III. TESTING PROCEDURES
Test plots for the pHix and Product B were marked with paint. The size of each plot was 3 ft. x 5 ft. There were three sets of two plots: 50 ppm, 250 ppm, and 500 ppm. The picture on Page 3 is an accurate depiction of the set up. In the photo, the nearest squares are the 50 ppm for pHix and Product B. The next two squares are the 250 ppm applications. The furthest two squares are the 500 ppm applications.