Evaluation of Eximo plus Dispatch for reduction of sodium in USGA specification greens
Summary: The results show that Aquatrol's Eximo (a synthetic acid), in combination with Dispatch (a surfactant) had no impact on levels of calcium, sodium, or bicarbonate (measured using Mehlich 3 or saturated paste methods) in the soil. The test, however, was conducted on soils that were low (less than 5%) in calcium carbonate. According to Aquatrols representatives, the product's efficacy relies on the presence of calcium carbonate in the soil.
Therefore, in soils that are low in calcium carbonate, Eximo does not appear to have any positive impact on soil chemistry. The performance of this product in soils with significant calcium carbonate levels remains to be seen.
Full print version of report (113Kb)
Principal investigators: Bruce Williams, CGCS and Patty Reedy (The Los Angeles Country Club)
Cooperators: Larry Stowell and Wendy Gelernter (PACE Turfgrass Research Institute)
Posted 7/20/08
Effect of leaching greens on soil chemistry
A research study on the effects of leaching was recently conducted with the cooperation of superintendent Mike Hathaway, CGCS (a PACE advisory board member) and assistant Nathan Radwick at The Bridges at Rancho Santa Fe. The full report has been posted onto the PACE Super Journal website, and the results are summarized below.
Summary: To quantify the benefits as well as any hazards of leaching, soil chemical analyses were performed on G2 bentgrass greens that had been leached by applying 5.5 inches of water over a period of 22 hours. A parallel set of analyses were performed on greens that had not been leached. Significant benefits, as well as some lesser, but potential risks were observed, including:
- Leaching reduced salinity by 37% using saturated paste extraction (SPE) methods or 26% using 1:2 soil to water electrical conductivity evaluations (which were converted to saturated paste equivalents).
- Sodium parts per million was reduced by 30% using SPE and to 33% when evaluated using Mehlich III (M3) extraction.
- Sulfur was reduced by 46% using SPE and by 40% when evaluated using M3 extraction.
- Chloride was reduced by 50% using SPE and by 52% when evaluated using M3 extraction
- Although all of the reductions listed above are beneficial, there was also a significant loss of potassium detected in the leached samples. This indicates that applications of supplemental potassium may be needed following heavy leaching in order to replenish levels to the guideline level of 110 ppm or above (as determined by Mehlich III extraction).
Full print version of report (24Kb)
Principal investigators: Mike Hathaway, CGCS and Nathan Radwick (The Bridges at Rancho Santa Fe)
Cooperators: Larry Stowell and Wendy Gelernter (PACE Turfgrass Research Institute)
Evaluation of Captor for Management of Sodic Soils
Summary: In a replicated field trial conducted on a Bermudagrass fairway with a history of high sodium levels, the product Captor was evaluated for its ability to improve turf quality by reducing sodium levels in the soil. Key results include:
- Following three applications of Captor, no significant differences in turf quality were observed when data was analyzed at the P<0.05 level. However, using a less stringent P of <0.10, a significant improvement in turf quality was observed on the last sampling date only, for a treatment of Captor at 88 oz/1000 square feet (30 gallons per acre).
- Reduced rates of Captor (88 oz/1000 square feet for the initial application, followed by 30 oz/1000 square feet for subsequent applications) had no significant effect on turf quality when compared to the non-treated check.
- No phytotoxicity was observed, even when the rate of Captor was doubled to simulate spray overlap.
Full print version of report (77 KB)
Investigators: Wendy Gelernter, Ph.D. and Larry J. Stowell, Ph.D., CPPP, CPAg
Cooperator: Ron Nolf, Vista Valley Country Club
Sponsor: Roy Hardison, Best Sulfur Products
