A brief outline of the Basic Principles of Greenkeeping & the Acid Theory
“The game of golf is played on grass; firmer grass and soils are best for golf; a firmer, drier golf course may be a more sustainable golf course; and a green, lush golf course is not necessarily a great golf course.” (Zontek, 2010)
Reflecting on and reinforcing the application of the ‘Basic Principles of Greenkeeping’ certainly puts greenkeepers on the path to sustainability; we only need see this on many fine courses, but why not all courses or bowling greens? So, what actually are the basic principles?
It relates to the traditional grass species in a golf, as well as bowling, green of red fescue and browntop bentgrass, and not newer species which are sometimes used in the UK, such as creeping bentgrass, although this is different in the USA.
The basic principles emphasise the following:
- Apply fertiliser which encourages the long-term survival of the desired grass species:
- Nitrogen is the most important nutrient and the source should be acid reacting, such as ammonium sulphate;
- The created acid soil conditions are favoured by the desirable red fescue and browntop bent grasses; these conditions would also discourage most weed species.
- Phosphorus and Potassium should not be applied as a routine matter, but only if there is a deficiency. This seems to be the area which is most problematic, i.e. in determining what is actually defined or expressed as deficient and how this is represented in practice and the impact it might actually have on the condition of a fine turfgrass sward.
- Do not apply lime, except for extremely rare cases;
- Regular aeration to encourage deeper rooting of grasses;
- Mowing at correct heights of cut and not shaving the turf;
- Mechanical vertical actions – at the time this would have been raking (scarification), but modern practices would also include verti-cutting and grooming within this section;
- Irrigation to keep the grass alive but not to create a lush green surface. The aim being to produce dry firm greens;
- Regular top-dressings to maintain good surface evenness and also to act as a supply of nutrients which would be slowly available to the grass plant.
Directly related to this is what is called the‘Acid Theory’. This was a greenkeeping practice which was carried out during the 1920s and early 1930s and which was based on the routine application of ammonium sulphate and sulphate of iron to golf and bowling greens.
It had been established earlier in the 1900s that turf fertilisers for a fescue and bentgrass sward should provide an adequate amount of acid soil reacting nitrogen, with a very limited supplies of phosphates and potash: This approach underlies one significant element of the Basic Principles of Greenkeeping.
Excessive application of these acidifying fertilisers,
- without consideration being given to the impact this would have on a fine turf sward,
- without adjustments being made to prevent extreme acidity arising,
- combined with not carrying out other appropriate maintenance practices,
resulted in the practice being effectively abandoned by many greenkeepers. This was, arguably, primarily due to poor education and training at the time.
Correct application of what is termed the acid theory has been shown to be the most appropriate regime in many situations, however, this must not be taken as being the only approach to take and will depend upon soil and construction type, as well as the predominant desirable grass species. For example, if creeping bentgrass is to be maintained on a golf green then less acidic soil conditions will be desired, and a different fertiliser and maintenance programme will be required.
Monitoring and assessment of any turf grass situation provides useful, if not essential, information on which a turf manager is better informed so as to make the necessary and correct adjustments to any fertiliser and maintenance programme. Starting off with the basic principles of greenkeeping is an ideal place to begin if a sustainable turf is to be achieved.
References and further reading:
Beale, R. (1924) ‘Lawns for Sport’
Clouston, D. (1939) 2ndEdn, ‘The Acid Theory or the Effect of Sulphate of Ammonia on Turf’, in The establishment and care of fine turf for Lawns and Sports Grounds, pp31-34
Levy, E.B. (1949), ‘Theory and Practice underlying the establishment and maintenance of greens’, in Construction, renovation and care of the bowling green, (New Zealand Greenkeeping Research Committee), pp10 -35
Sutton, M.A.F. (1950), 2ndEdn. ‘Golf Courses: Design, Construction and Upkeep’
Dawson, R.B. (1959) ‘Fertilizers and their Practical use’, in Practical Lawn Craft and Management of Sports Turf, 5thEdn, pp111-124
Goss, R.L., Brauen, S.E. & Orton, S.P. (1975) ‘The effects of N,P,K and S on Poa annua L. in Bentgrass Putting Green Turf’, in The Journal of the Sports Turf Research Institute, 1975, Vol. 51, 74-82.
Radko,A. M. (1977) ‘Green is not great’ USGA Golf Journal. 30(7) :34-37, accessed at an external site
Isaac, S.P. & Canaway, P.M. (1987) ‘The mineral nutrition of Festuca-Agrostis golf greens: a review’, in The Journal of the Sports Turf Research Institute, 1987, Vol.63, 9- 27.
Lawson, D.M. (1999) ‘Phosphate and potassium nutrition of Agrostis spp. And Festuca spp. Turf growing on sandy loam. I. Turf ground cover and Poa annua ingress’, in The Journal of Turfgrass Science (incorporating the Journal of the Sports Turf Research Institute) Vol.75 (1999), 45-54.
Lawson, D.M. (1999) ‘Phosphate and potassium nutrition of Agrostis spp. And Festuca spp. Turf growing on sandy loam. II. Leaf and soil phosphorus and potassium content’, in The Journal of Turfgrass Science (incorporating the Journal of the Sports Turf Research Institute) Vol.75 (1999), 55-65.
Lawson, D.M. (2000) ‘The effect of nitrogen source, lime application and phosphate application on the quality of Festuca rubra-Agrostis tenuis turf growing on a sand-dominated rootzone’, in The Journal of Turfgrass Science (incorporating the Journal of the Sports Turf Research Institute) Vol.76 (2000), 12-23.
Arthur, J. (2003), 2ndedn, ‘Basic Principles of Greenkeeping’in Practical Greenkeeping, pp34-47,
Zontek, S.J. (2010) “Understanding and Appreciating Firmness: Our mentors taught us that firm is good. Now we have to spread the word.” USGA Green Section Record Vol. 48 (22) November 5, 2010
Chris Gray, 10th November 2018