USDA Agricultural Research Service scientists in St. Paul, Minn., and their partners at the University of Minnesota are helping protect waterways by identifying strategies for minimizing runoff from the nation’s golf courses. Photo by Pamela Rice
More than 20 million people play golf on the estimated 14,000 golf courses in the United States. As Americans head for the links this year, golf course managers and superintendents know it’s not only important to maintain the greens and fairways, but to minimize the risk of pesticides and fertilizers flowing into nearby ponds, streams or lakes.
Pamela Rice, a chemist with the USDA’s Agricultural Research Service (ARS) in St. Paul, Minn., and her colleagues at the University of Minnesota (UMN) are offering clear recommendations to golf course managers and superintendents on how to do exactly that.
The work was partially funded by the United States Golf Association (USGA), the sport’s governing body and sponsor of the U.S. Open and other major championships.
“Golf courses can be surrounded by hundreds or even thousands of people living right alongside them, so it’s important to us that they’re managed in an environmentally friendly way, and that they are not polluting the air or the water,” says Michael P. Kenna, who oversees the USGA’s turfgrass and environmental research.
Rice and Brian Horgan, Ph.D., a UMN turfgrass expert, compared the effects of two turf management practices on controlling pesticide runoff by simulating rainstorms at a research site on the UMN campus in St. Paul. The site is equipped with sprinklers and gutters that channel runoff into a flume, with instruments that allow researchers to control precipitation, measure runoff and collect samples for pesticide analysis.
Two management practices were evaluated: hollow-tine core cultivation (HTCC) and verticutting. HTCC involves punching holes that are dime-sized or a bit smaller into the turf with hollow tubes to aerate it, giving it a Swiss cheese look. You pull up the soil cores, let them dry out, brush the soil back into the holes, and blow away the stray grass so that the turf is aerated, less compacted and better able to absorb water.
Verticutting involves running a mower with vertical blades into the turf to lightly penetrate the soil, opening it up for air and water to filter through. Both practices are common for controlling thatch and loosening up the soil to increase infiltration of rainwater, but they are also labor-intensive, and golf course managers need to know whether they have any deleterious or beneficial effects on pesticides or fertilizers applied.
The researchers measured concentrations of five different pesticides in the runoff and found that HTCC absorbed more runoff than verticutting did, and it was even superior to the combination of verticutting and HTCC, possibly because verticutting can compact the soil at points where the mower blades cut into it. The message is clear: If you are concerned about pesticide runoff at your golf course, go with hollow-tine core cultivation.
The results were published in Science of the Total Environment, and the USGA will disseminate the findings to golf course managers around the country, Kenna says. The findings may also apply to any of the 32,000 golf courses around the world, as well as to athletic fields and other facilities that use managed turfgrasses, Rice says.
Dennis O’Brien is a public affairs specialist with the USDA Agricultural Research Service.