Turf management
From Wikipedia, the free encyclopedia
Turf management or pitchcare descibes the work needed to keep a sporting pitch ready for use. This article looks at the various types of sporting pitches and the type of challenges which they present.
The skills needed vary considerably dependent upon the sport and whether or not artificial surfaces are used.
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[edit] Cricket pitches
Cricket pitches are mainly natural grass with infrequent replacement of the playing surface. Cricket pitches are unusual in that they have to last for up to 5 days of play and the way that the pitch will change over time is an essential part of the sport. The English cricket board has published a definitive paper on pitch properties and performance. The properties of an ideal cricket pitch have been identified as
- Bounce, technically measured as the vertical rebound height of a ball dropped from 3 metres.
- Pace, the degree to which a ball is slowed on hitting the pitch.
- Consistency. Consistency of bounce is reported to be the most valued characteristic of a good pitch.
- Turn. This refers to the ability of the ball to turn away from the line of trajectory. A thin grass covering has been calculated to have up to 30% less friction on a bouncing ball. However it is believed that the most significant contribution to turn comes from pitch damage as the game progresses.
Research has also identified the ideal soil as having between 27% and 33% clay. Less than this will hinder binding of the grass. More than this will make for a heavy pitch which takes longer to dry out and is more difficult to handle. There should be between 3% and 8% of organic matter in the soil.Above 8% there will be problems with water retention and soil strength.
Cricket pitches are often viewed as a long term investment. A poor year of maintenance can influence the performance of the pitch many years later.
Cricket pitches occasionally use under soil drainage .
[edit] Tennis Courts
There are two main types of tennis court, grass and clay. The clay courts can then be divided into natural clay, hard courts and fast/dry courts.
All tennis courts should ideally be a little west of true north to ensure minimum problems from sunlight.
- Grass courts. Historically very popular they are now slowly being replaced by clay courts which offer the opportunity of year round usage and lower maintenance.
The skills needed to maintain a grass court are considerable.Traditionally the court is split into the foundations and drainage, the soil or binding layer and the grass. All three must work together to provide the best playing surface. Maintenance of grass courts is typically split into the following areas
- Mowing, 6 to 8 mm
- Fertilisers.
- Scarification. Mechanically raising the surface turf to prevent compaction.
- Rolling. Usually done is springtime to correct any problems from the winter weather.
- Aeration. Winter work to remedy compaction over the summer.It will encourage deep rooting as well as assisting in drainage.
- Seeding or worn areas after the season has ended.
- Top dressing at the end of the season to maintain turf quality.
Artificial grass courts are a popular option at club level as they are weather resistant and their shock absorbing qualities help limit injuries. However they are not recommended for high skill levels and are expensive to maintain. The Lawn Tennis Association cost a basic court at £27,000 and replacement turf every 9 years, a further £11,000.
- Clay courts. Clay courts require water to keep from cracking. This limits their use in both very dry regions.At the other extreme countries like the United kingdom with very wet seasons can make a Clay court unplayable for long periods and also give rise to expensive maintenance at the start of the season.Normal maintenance is basically regular watering and rolling. This prevents the surface turning into dust. Clay courts can have both sub surface and above surface irrigation.They provide a good training surface with a medium to slow pace and consistent bounce. The Lawn Tennis Association prices the courts at between £34,000 and £60,000 to construct.
- Hard courts.Typically made from asphalt or concrete with an acrylic covering. They are also called synthetic granular courts. These courts typically provide a “fast” game which means the tennis ball will bounce with a low angle. The speed of the court can be changed by varying the amount of sand present in the covering. If a layer of cushioning material is added to a hard court then the performance increases and this is typical of an all weather court. However the cost of the cushioning can be substantial.
An interesting problem with asphalt courts arises in very hot environments. The asphalt absorbs heat very quickly, however the painted lines will reflect the heat and this differential in temperature can lead to surface cracking. These courts are generally low maintenance but they will need to be recoated every 5 to 10 years. Most maintenance involves keeping the surface clean. There is generally little movement in the surface which means added strain on ankles and knee joints. The Lawn Tennis Association costs a porous macadam court at £20,000 and it should last 10 to 12 years with low maintenance costs. An acrylic court would cost around £25,000 and is long lasting with low maintenance.
- “Fast/dry” courts.A relatively new innovation from America. These are generally made from basalt taken from the Blue Ridge Mountains of Virginia which is then finely crushed and used as the top layer over either a purpose built sub layer or just placed on top of an existing clay or asphalt. This type of surface is promoted as allowing more “sliding” by the players and therefore it helps to limit tennis injuries to the lower parts of the body.These courts are typically slower than grass.They can dry very quickly and do not have the heat relection problems of clay courts. Porosity is low and often these courts will have a slight slope to aid water run off.These courts are similar to the basic clay court described above.
[edit] Golf courses
The growth in the popularity of golf, combined with the large sums of money invested in a golf course has led to the development of turf management which is a term used to refer to the skills of maintaining a golf course.
The green, as opposed to the rough, is the principle area of concern. Many golf courses are now built in environments which would be hostile to natural grass cover and essentially the grass grows in a hydroponic or sterile environment with very fast drainage. This means that it has to be fed and watered regularly.
The key characteristics of a good green are speed and consistency. Faster greens are preferred and for tournament play the greens should be as fast as possible. To measure speed a Stimpmeter is used. The main factors influencing green speed are:-
- Mowing height. Ideally 5 to 7 mm height. Below 5 mm the grass does not have enough leaf area to survive.
- Rolling.But excessive rolling will compact the grass.
- Topdressing. Helps with consistency.
- Frequency of mowing.This helps establish a polished green.
- Scarification to remove moss and stop the collection of moisture on the green.
- Grooming to reduce the thickness of clumps.
[edit] Football (Soccer) pitches
Historically football pitches have had natural grass cover. The stresses on a pitch , combined with winter weather can often mean that the pitch has to be returfed on a regular basis. Essentially the existing turf is removed to a depth of typically 40 mm turf and 110 mm of soil. The replacement turf is ideally purpose grown to ensure consistency and freedom from weeds. A pitch can usually be returfed within 4 days and would, typically involve removing and re laying 400 cubic metres of turf and soil. The English FA recommends 4 main characteristics of a good grass pitch.
- Adequate grass coverage
- Low level of weeds
- Flat
- Good drainage
A football pitch should have undersoil drainage, up to 8 miles of pipe for a normal sized pitch. Increasingly these same pitches will have undersoil heating.
Artificial grass offers an alternative to natural grass for football stadia. There has been considerable development of this type of surface from the early days when it was very similar to tufted carpet. The performance of this surface has generally been questioned as not being truly natural. However there are definite advantages with artificial grass, particularly when a stadia has heavy or multi use requirements. Also when the environment is hostile to natural grass, for instance low sunlight or a paucity of water.
[edit] Athletics tracks
Modern athletics tracks use “polymeric surfaces”. Because of their hardwearing and porous nature they allow the facility to look attractive and well-kept at all times, although actual maintenance is low.
[edit] External links
- Lawn Tennis Association, guide to chosing a tennis court
- English Cricket Board, pitch performance
- English FA guidelines for artificial grass on Soccer pitches
- UK athletics web site on maintenance of athletic tracks
- The USGA on turf management and Golf
- Pitch care, an online magazine dedicated to Groundsmen and Greenkeepers
- Building a Tennis court - helping to understand the differences in court surfaces
- Returfing a sports arena, slide show
