Golf Greens Fertiliser Application

Fertiliser application will be minimal for most golf greens if a firm surface is to be produced with the desirable grasses of red fescue and browntop bents. Do not worry about creating a lush green coloured sward as this will result in a slow game, an increase in undesirable annual meadow which will further increase thatch depth and reduce the quality of the playing surface. A fertiliser based on a traditional 8:0:0, or similar, is an ideal starting point.

The quantity of nutrient inputs to different green constructions can vary significantly. The highest quantities of Nitrogen are required on pure sand constructions with typically a minimum input of 25g/N per m² being required per annum. The ratio of Nitrogen to Phosphate should be less than 4:1 in these situations, whilst that of Nitrogen to Potash of 4:3 would appear to be adequate. (Lawson, D.M. (1987), 'The fertiliser requirement of Agrostis castellana-Festuca rubra turf growing on pure sand', The Journal of the Sports Turf Research Institute, Vol.63, 28-36)

The actual nutrient inputs to golf greens in the UK can vary quite significantly.

A 1995 survey found that most “greens received between 75-250 kg ha^-1 of nitrogen”, which is within an expected range. Sand greens often had the higher inputs, including rates up to 350 kg ha-1 of nitrogen. For phosphate applications, many greens didn’t apply any, whilst those that did the application rate was less than 10kg per hectare during the year, with few greens having more than this. Soil analysis indicated that adequate residual phosphate was still present within the vast majority of greens. A similar situation was identified for applied potash, with about one-third not applying any, and another third applying less than 10kg per hectare during the year. Soil analysis indicated that residual potash might be limiting in many greens, inferring underapplication may have been occurring, although more recent practices have typically seen more emphasis placed on potash within fertilisers applied to sandy soils to aid sward development and this would correspond with the earlier research which indicated a Nitrogen: Potash ratio of 4:3 might be required in golf greens.

• Hind, P.D., Baker, S.W., Lodge, T.A., Hunt, J.A. & Binns, D.J. (1995), ‘A survey of golf greens in Great Britain I. Soil properties’, The Journal of the Sports Turf Research Institute, Vol.71, 9-22.
• Baker, S.W., Hind, P.D., Lodge, T.A., Hunt, J.A. & Binns, D.J. (1995), ‘A survey of golf greens in Great Britain II. Sward characteristics, The Journal of the Sports Turf Research Institute, Vol.71, 23-30.
• Baker, S.W., Hind, P.D., Lodge, T.A., Hunt, J.A. & Binns, D.J. (1995), ‘A survey of golf greens in Great Britain III. Questionnaire data on the performance and maintenance of greens’, The Journal of the Sports Turf Research Institute, Vol.71, 31-41.

If the greens are continually performing well and have good sward characteristics which maintain a positive trend, then in the majority of cases continuing with the same fertiliser programme would probably be a sensible option. Changing a successful programme, where positive outcomes are the evidence of success, should not be taken lightly, even if advocated by a greens committee member, supplier, or even agronomist.

Gather the evidence as to why a suggested change might be made to make an informed decision, without being unduly influenced by others.

Reflect on data gathered from soil testing and current vegetation analysis, previous applications and the effectiveness of these, the range of other activities undertaken, and other materials applied and any other data which will be of use.

At the end of the day, it is the head greenkeeper’s job and employment requirement to manage the entire course, being accountable for the end results, unlike many who will offer advice, often ill-informed, freely and also often with a conflict of interest somewhere in the mix.

A ‘typical’ fertiliser programme could be as follows:

Soil-based green:

• March (often classed as a ‘false spring’): Sulphate of ammonia (21%%N) @ 9 g/m², providing 19 kg/N/ha.

• April/May: 8.0.6 @ 35 g/m², providing 28 kg/N/ha.

• June: 8:0:6 @ 35 g/m², providing 28 kg/N/ha.

• August: 8:0:0 @ 35 g/m², providing 28 kg/N/ha.

This will provide an annual Nitrogen input of 93 kg/N/ha, which is within the suggested range for soil rootzones of 80-200 kg/N/ha.

For sand-dominated rootzones the suggested quantity is 240-300 kg/N/ha, (Lawson, D.M (1996) ‘Fertilisers for Turf’, STRI, p.34).
The majority, with at least 60%, of Nitrogen is typically applied before mid-June, and no controlled slow-release, particularly if based on IBDU, after this time as well. The main reason being that autumn growth will be softer, nitrate leaching potential can increase, and the green will be more susceptible to disease, especially fusarium patch. (Adams, W.A. & Gibbs, R.J. (1994) ‘Natural Turf for Sport and Amenity: Science and Practice’, p287).

The use of one or more liquid feeds, instead of using a mini-granular feed, during the playing season is often considered. This is primarily to reduce the potential of the fertiliser not being adequately watered into the green, to reduce the potential impact some mini-granular fertilisers might have on the roll of a ball on a green, and also to accommodate programmes where a regular spoon-feeding approach is undertaken.

The phosphorus and potassium inputs for any fertiliser programme will be strongly influenced by findings from both a soil and sward analysis.