Export of nitrogen and phosphorus from golf courses: A review

Mitigating the environmental impact of nonpoint source pollution from intensively managed urban and agricultural landscapes is of paramount concern to watershed managers. Golf course turfgrass systems, which receive significant fertilizer inputs, have been cited as significant sources of nutrient loading to groundwater and surface water, but a contemporary synthesis of golf course nutrient export rates is lacking. This review of nitrogen (N) and phosphorus (P) loss from golf courses and the factors affecting it aims to support watershed management efforts and decision making. We discuss previous literature reviews, examine seven golf course studies that quantify nutrient export from delineated drainage areas, and analyze the results of 40 turfgrass plot experiments. Studies were collected systematically and selected based on predetermined inclusion criteria. Combining evidence from both watershed- and plot-scale studies, typical inorganic N and P losses from golf courses via leaching and runoff are on the order of 2-12 kg ha^-1 yr^-1 and 0.1-1.0 kg ha^-1 yr^-1, respectively. Typical total N and P losses are around 2-20 kg ha^-1 yr^-1 and 1.5-5 kg ha^-1 yr^-1, respectively. However, the potential for large variation in export rates across 2-3 orders of magnitude must be emphasized. The body of turfgrass literature stresses the importance of best management practices (BMPs) related to applying fertilizer to match plant needs and reducing opportunities for its transport. Accounting for all sources of nutrients, especially soil P, in determining fertilizer application rates and avoiding excessive irrigation to prevent leaching of nutrients from the rootzone is particularly important. BMPs can also reduce nutrient leaching and runoff by controlling the movement of water across the landscape and promoting natural nutrient attenuation, such as with vegetative stream buffers.