Pitch Quality – a case of fine tuning

Pitch Quality - a case of fine tuning

By Marke Jennings-Temple

Managing natural turf winter sports pitches is a challenge and one that many Groundsmen around the UK rise to every day. As the emphasis on a science-based approach increases, and the solutions that are put into use become ever more complex, there is a need to ensure that research is directly linked to something that will aid the Groundsman (or woman) in their battle to produce a pitch that looks good, can support play throughout the wet winter months but is also safe.

Marke Jennings-Temple, a student at Cranfield University at Silsoe is developing a model that will allow Groundsmen to make some simple measurements to reach an immediate assessment of pitch quality. He outlines his research here.

In most work places around the world, employers are faced with a duty of care to ensure they provide safe facilities that are not hazardous to health. In an increasingly litigious society, football clubs and the grounds care industry must accept the need for quality and performance measures relating to the surface. Furthermore, the British Government is focussing on increased sports participation as a means of combating the rising rates of obesity, coronary disease and diabetes. If the rise in participation rates is not to be mirrored by a rise in lower limb injuries, the playing quality of the pitch must be monitored and quantified in order to ensure management is specifically targeted towards improving quality.

Performance Quality Standards (PQS) already exist, but absent is any obvious link between the soil physical conditions (which can be managed) and the results of tests. If these tests are to be meaningful and accepted industry wide, Groundsmen must be able to manage their pitch, or pitches, in a way they know will directly impact on the measures of quality in use. It is the aim of this research to begin to understand this link so that a model can be produced. This model will provide an immediate measure of pitch quality. This will ensure that;

• Problem areas can be dealt with immediately and the correct tool can be chosen to bring those areas back up to the right standard.
• By knowing the physical condition of the soil, certain techniques that would be detrimental to the quality of the surface can be delayed until the soil conditions improve.
• Action can be taken to ensure that games are not delayed or cancelled because the pitch is not of the desired standard,

In order to produce this model, the research has taken a multi-stage approach.

The first phase looked at drainage. Water left behind in the soil after the rest has drained away contributes to the strength of the soil by pulling the soil particles together. In order to determine how much this contributes we need to know the relative saturation of the soil (its moisture content now, compared to the moisture content at saturation) and the amount of tension that the water is under. These two things combine and result in the concept of effective stress. Laboratory tests were conducted to investigate whether a relationship existed between this effective stress concept and a measure of soil strength.

The results indicated that a significant relationship exists between the concept of effective stress and the strength of the soil, enabling the strength of the soil to be predicted from a measure of the water status of the soil and importantly that the strength of the soil increases significantly when there is good grass cover. Although there is much more research required before a useable model can be produced, these results are important for a number of reasons. Of particular importance are the following:

• Grass not only regulates the water content of the soil but its roots add strength. If bulk density remains relatively constant throughout a playing season, the only way to achieve more soil strength (and so traction) is through the addition of grass roots.
• Good drainage and the provision of an irrigation capability can allow the fine tuning of a turf pitch as long as the soil system is understood.
• Areas repaired using loose sand (such as larger divot holes, or damage in goal mouths) will be inherently weaker than the surrounding soil as the loose sand will be both lower in density and not have the benefit of grass roots. This leads to an inconsistent playing surface in terms of hardness and amount of traction available and for a player running across this surface, the risk of injuries become greater.

My testing kit on the pitch at Hearts Football Club, Edinburgh.

This research and the potential output will provide Groundsman with a powerful tool to ensure that the quality of a pitch can be determined at any time and the selection of management tools will stem from an exact knowledge of the current pitch conditions. Measures of pitch quality will become more necessary in time, particularly in terms of sport insurance and liability. The grounds care industry must embrace the notion of pitch quality and measurement, before it is forced upon us.

For further information, please contact Marke Jennings-Temple on m.a.jennings-temple.s01@cranfield.ac.uk