Lawrence, Kansas, United States: Golf courses in the United States decreased the use of nitrogen, phosphorous and potassium in 2021, compared with usage in 2006, according to recently released survey data from the Golf Course Superintendents Association of America (GCSAA).

The 2022 Nutrient Use and Pest Management Survey was conducted by the GCSAA and funded by the GCSAA Foundation as part of its Golf Course Environmental Profile programme, which began in 2005.

The report found that the use of nitrogen (N) decreased by 41%; the use of applied phosphorus (P2O5) decreased by 59%; and the use of applied potassium (K2O) decreased by 54% in 2021, compared with usage in 2006.

The reduction of applied N, P2O5, and K2O since 2006 is likely a result of reduced application rates and fertilised acres. The reduction in fertilised acres occurred as a result of acre reductions at operational facilities and facility closures.

The survey results from more than 1,400 GCSAA member and non-member golf course superintendents were collected and independently analysed by scientists Travis Shaddox, PhD, Bluegrass Art and Science LLC, and J. Bryan Unruh, PhD, University of Florida, and the National Golf Foundation (NGF), which published the findings for peer review before making the information public.

The most significant nutrient reduction occurred with applied P2O5. This reduction appears to be at least partially a result of mandated phosphorous restrictions, which was the most common restriction reported by facilities.

Whether voluntary or mandated, this recommendation appears to be followed by more facilities year-over-year as evidenced by the finding that more facilities did not apply any P2O5 in 2021 than in both 2014 and 2006.

The study also provides data on average nutrient use in the seven different agronomic regions of the country. Acres fertilised with N, P2O5, and K2O declined within each agronomic region, and fewer nutrients were applied across the regions in conjunction with reduced fertilised acres.

The median N application rate declined in the North Central, Southeast, Southwest, Transition, and Upper West/Mountain regions, while the median N application rate remained unchanged in the Northeast and Pacific since 2006.

P2O5 application rates declined within each region with the greatest reduction reported in the North Central. K2O application rates declined within each agronomic region except the Pacific.

“The latest national survey results continue to demonstrate golf course superintendents’ dedication to being responsible environmental stewards,” said Rhett Evans, CEO of GCSAA.

“Through their work and focus on the environment, superintendents are more perspicacious with their use of nutrients, enabling healthier green spaces today and for the future,” he added.

As part of the third series of its Golf Course Environmental Profile programme, GCSAA will publish the Pest Management Practices on US Golf Courses report and results of the Property Profile and Environmental Stewardship Practices Survey separately in 2023.

To learn more and to see the complete survey report, read the January 2023 issue of GCSAA’s GCM magazine at www.gcmonline.com