Quantifying golf course nitrogen use efficiency

Background

Previous studies have surveyed golf courses to determine nitrogen (N) fertilizer application rates on golf courses, but no previous studies have attempted to quantify how efficiently golf courses use nitrogen.

Methods

This study tests the ability of the growth potential (GP) N Requirement model as a benchmarking tool to predict a target level of N use on 76 golf courses in 5 regions of the US (Midwest, Northeast, East Texas, Florida, Northwest) and 3 countries in Europe (Denmark, Norway, UK).

Results

The ratio of the golf course-wide N application rate to the GP N requirement prediction (termed the nitrogen efficiency score or NES) was 0.27, indicating that golf courses used 73% less N than predicted by the model. As such, the GP N Requirement model needs to be recalibrated to predict N use on golf courses. This was achieved by adjusting the N_max coefficient in the model. N rates on golf courses were widely variable both within and across regions. All regions had a coefficient of variation in N rates of 0.46 or greater.

Conclusions

The high variation in N rates, which is largely unexplained by climate, economic factors, grass type, and soil type, may be indicative of inefficient N use in golf course management.