Nitrogen utilisation efficiency in different golf green constructions of Creeping Bentgrass golf greens.

There is still quite limited experience of how to maintain golf greens to minimize environmental impacts. A study was set up at Fullerö GK near Västerås in central Sweden, to investigate the fate of nitrogen in a golf green. Measurements were made of nitrogen leaching, nitrogen removal with the grass clippings and nitrogen stored in the soil, and nitrogen balances and nitrogen use efficiency (NUE; nitrogen in grass clippings as a percentage of added N through fertilisation) were calculated. Sampling was carried out during three 14-day fertilisation cycles in 2001, 2002 and 2003. Nitrogen removal with the grass clippings was generally the most important measured flow of nitrogen (Fig. 1). Large nitrogen losses and low nitrogen use efficiencies were found early and late in the season when the potential biomass production was limited by sub-optimal temperature and light conditions in spring and autumn (Fig. 1). NUE varied between 15 and 102 % during the study period. Leaching losses of mineral N were equivalent to between 0.3 and 15% of the fertilisation. As a result of this study, recommendations for N fertilisation have been modified to better match the potential biomass production resulting from the climatic conditions.