Bowling Green Performance Standards Rating Systems

A numeric rating can be applied to each standard and grade which describe the overall quality rating for a product. For example, a basic approach could be to allocate 5 points for grade 5 down gradually decreasing to 1 point for grade 1, with no points being awarded for a value outside of the required parameters.

The overall rating could be determined from the sum of each values and could be seen as indicative of the entire surface, although this will depend on the extent of the sampling undertaken and if the sampling locations are generally representative of the surface. A significant limitation of this approach is that some standards are much easier to achieve than others included within an analysis and this can result in an overall high mark that does not represent the actual quality of the green itself.

Some of the ratings for parameters achieved within standards may also be considered conditional on other standards. For example, a fescue / bent sward can provide an excellent playing surface at, for example, a pH of 4.8 or 7.2, yet these values would actually be outside of the parameters given for the rating scheme used in the table above. If the sward density and desirable grasses were excellent, along with a playing speed, and maybe some other standards included as a contrast, then why should the rating be downgraded just because the soil pH was outside of the ‘academic’ value of 5.0 - 7.0 for an ‘elite’ bowling green. Whilst the preferred soil pH in this example is given as 5.5-6.5, as this really means is that there is a good likelihood that given this narrow soil pH there is a good chance of being able to create conditions in which all other parameters can potentially also achieve an ‘elite’ standard. In some ways this can be thought of the classic situation where a computer says ‘no’, or ‘yes’, and that is accepted as the correct answer when actually more insightful considerations need to be given to truly represent what is being assessed and evaluated. Whilst this is much more complicated than a simple rating system, it doesn’t mean that it should be discounted.

A more realistic, objective and manageable means of providing a representative picture of overall bowling green quality could focus on determining the overall quality of a suitable group of related standards and then apply a weighting to the groups to better represent the ease or difficulty of them being corrected on the ground and as a reflection of how much control a grounds manager can have over the quality of the green.

Another consideration in providing an overall quality rating for a bowling green is that of having soil nutrient indices, as well as soil pH, organic matter content, sward height, weed, pest, disease all conditional on, or significantly influenced by, other standards which a stakeholder deems as being especially important. Whatever is decided it is clear that arriving at an overall quality rating can be a lot more contentious and subjective than was originally thought when performance quality standards were conceived.

Some features, primarily the depth of topsoil/rootzone, is one standard over which a manager does not really have any routine control, because there is a significant financial input required to improve this through extensive reconstruction work. The construction of a green has a significant influence what is realistically achievable from a green regards the majority of performance standards, but so do the maintenance practices undertaken by a greenkeeper.