Carrying Capacity: Managing Expectations

The amount of usage and the consistent quality of provision that a sports pitch can sustain over a playing season, without resulting in unacceptable deterioration to the pitch and playing experience, is strongly related and influenced by pitch construction and the soil type. The amount and frequency of rainfall is also another key factor, and this is typically related to geographical location.

Three primary grades for football pitches were suggested for different pitch constructions in the 1990s: Basic (undrained non-constructed and pipe-drained), Standard (slit drained and sand/soil constructed), and High (sand rootzones or sand/soil constructed combined with slit drains). Adams, W.A. & Gibbs, R.J. (2000) 'Natural Turf for Sport and Amenity: Science and Practice’, pp218-223)

These primary grades would then be used to determine the likely, realistic, carrying capacity and usage capability to manage expectations for pitches maintained on these core foundations. It is important to clarify the pitch quality expectations for the pitch because changing quality expectations, especially downwards, can allow for an increase in the number of games playable, so a trade-off can be made between usage and pitch quality. For example, if a primary ‘Basic’ grade pitch (i.e. the construction feature) has a carrying capacity of 45 games at an overall performance quality standard (that which it is being consistently maintained to) of a Medium grade 2 (also called a ‘Good’ grade), the usage might be increased to about 65 games if an Entry Grade 1 (confusingly also called Basic grade in relation to performance standards) pitch quality surface was acceptable.

With the development of reinforced material to provide for even higher quality pitches the concept can be extended to at least four primary grades, with the highest potentially being termed Excellent, Outstanding, or similar.

Ensuring correctly applied maintenance activities are carried out helps to contribute to getting the most out of a pitch. However, there is a realistic ceiling to the carrying capacity for any pitch type (or primary grade of pitch) irrespective of the maintenance work that is carried out. There is a diminishing return for carrying capacity once usage is in the region of what can be sustained for the pitch construction, and only with renovation activities and rest will the pitch be able to provide for more games at a minimum desired level of quality.

Whilst the idea of making marginal gains is attractive for groundstaff at elite clubs, this is not a cost-effective or sensible approach to take for many clubs as the return on investment and inputs, being marginal (basically extremely minimal) is not worth the effort in the majority of cases.

An illustrative example might help. A football pitch is based on a sandy soil (a basic primary grade), without enhanced drainage, and has a carrying capacity (at Entry grade 1 maintenance standard) of around 65 games per season, assuming typical weather conditions for this hypothetical pitch and location. The total maintenance costs to consistently achieve the desired Entry Grade 1 standard is £9,000 per year. To provide an additional 5 games with required labour and material inputs it is estimated that for this pitch, the annual cost will be about another £6,000. At the end of the season a major renovation and pitch rest will be required to allow for it to be returned to a desirable performance quality standard for the start of the new season so it can then cope with another full season of usage. Renovation is an essential part of pitch management, but the extent of requirements will depend on many variable factors.

This simple example would indicate that the financial return for getting an extra 5 games is clearly not reasonable for the majority of clubs, so being aware of realistic carrying capacities in which pitch performance standards are embedded is essential for managing expectations. Actual figures will be different to those in the example, but the principles will be the same. There will be a relatively consistent cost to achieve the typical carrying capacity, but to exceed it will require increasing significant extra resources, which will often be difficult to justify.