Golf course turf

The grass is usually maintained by a greenskeeper to control weeds, insects with pesticides, plant fungal diseases with fungicides and to introduce nutrients such as nitrogen fertilization.

[2] The quality and color of turf can increase[clarification needed] depending on nitrogen application amount.

[3] In another study, nitrogen applied after 15 September (of a northern-hemisphere autumn) caused relatively little plant growth, resulting in increased NO−3 - N concentration in percolate water.

A highly soluble fertilizer, containing nitrogen in its nitrate form, such as ammonium nitrate, can create leaching three to seven times greater than United States Environmental Protection Agency (EPA) limits of (10 ppm) NO3-N during a time of ten to twenty-five days following nitrogen application.

For example, greater water percolate concentrations of NO3 - N resulted from a late autumn application programme during a New England experiment.