Sand capping fairways seems like a “no-brainer” solution for sites with poor soils that are prone to drainage and compaction problems, but this strategy does not always produce the desired outcome. While sand capping should deliver firmer surfaces, allow for good drainage during rainy weather and help to resist compaction, I have seen sand-capped courses with widespread black layer and chronically saturated soil.
People do not always realize that sand capping must be accompanied with adequate surface drainage and subsurface drainage in low-lying areas. One golf course I visited this summer had sand capped a flat site with only a few catch basins in low depressions. Between the lack of slope, the underlying heavy clay soil, and the 6-inch sand cap, the fairways were saturated at the sand-clay interface and black layer was prevalent. Add to that irrigation water with moderate salinity and just several years after course construction the turf is dying due to very high soil salinity. There is no avenue for water and salts to exit the system.
A 12-inch sand cap with 16-18 inches in low-lying areas would have helped to dry the surface, but the costs would have been astronomical. Unfortunately, the course is now faced with installing a comprehensive subsurface drainage network to remove water from the rootzone. The cost to install the system will be around $1 million, but the investment is necessary.
Capping a golf course with sand is not necessarily the best option to address poor soils and drainage issues; sand topdressing has been shown to provide equal or even better results. Sand capping increases construction costs significantly and the difficulty to establish new grass from seed is exacerbated with a rootzone that has little moisture and nutrient retention. When considering sand capping, the importance of surface drainage to move water from primary playing areas and subsurface drainage in low-lying or flat areas cannot be overstated.
An alternative to sand capping is investing more resources in sand topdressing. If the native soil has poor water infiltration properties, implement an annual sand topdressing program to build up a rootzone that offers adequate water infiltration yet has better water and nutrient retention than a traditional sand cap. The costs for sand can be spread out over time, maintenance costs will be lower compared to a sand cap, and I would argue the playing conditions will be superior.
If you are planning a renovation or construction project and considering sand capping, please reach out to the USGA agronomists in your region more information.
West Region Agronomists:
Brian Whitlark, senior consulting agronomist – bwhitlark@usga.org
Cory Isom, agronomist – cisom@usga.org
Information on the USGA’s Course Consulting Service