Reducing nutrient runoff from golf course fairways using grass buffers of multiple heights

Because golf course fairways often border water features, the potential loss of fertilizer nutrients in surface runoff from fairways can be significant. The objective of this study was to determine if bermudagrass buffers mowed at increasingly higher heights could reduce nutrient runoff from golf course fairways better than bermudagrass buffers mowed at a single height by providing multiple physical barriers to runoff. Grass buffers, 5.5 m long by 12.2 m wide, were positioned perpendicular to 5% slopes at the bottom of six 12.2 by 18.9 m bermudagrass (Cynodon dactylon L.) fairway plots. The buffers on three plots were mowed at a consistent 51 mm height. The remaining buffers included three 1.8 m sections that were mowed at increasingly higher heights of 25, 38, and 51 mm as surface elevation decreased. Runoff from both irrigation and natural rainfall were collected at 5-min intervals for 1 hr following the initiation of runoff and tested for nutrient concentrations. Irrigation was applied 4 hr after granular urea and triple superphosphate were applied. Graduated buffers of increasing height delayed the initiation of runoff by 4 min during fairway irrigation and by 2 min during natural rainfall events. The graduated buffer resulted in 17% less N, 11% less P, and 19% less runoff volume during 60 min of natural rainfall runoff. The graduated buffer resulted in 18% less N and 14% less P during 60 min of irrigation runoff, and reduced runoff volume by 16%.