Getting your Sports Pitch ready for Winter is easy with our Groundsmen - Technical Guide from The Grass People
Winter Sports Pitches
FOOTBALL AND RUGBY PITCHES
The amount of wear on grasses used in both football and rugby pitches can be extreme. With playing seasons often extended due to poor weather conditions, the off-season window for repairs is often very short. Using quality amenity grasses of high germination and purity is very important if rapid repair is to be achieved.
PREPARATION AND DRAINAGE
Specifications for drainage vary widely depending on the individual site conditions, but whatever the design, it should be capable of removing any excess of water either by natural rainfall or irrigation.
A typical system might have main drains, formed on a grid type system at a depth of 450-900mm deep (to avoid machinery damage). The distance between drains will vary from 2.5m on heavy soils to 12.5m on sands. A fall of 100-200mm is considered ideal.
An open, well-textured topsoil will help to remove surface water. A mixture ratio of three parts sand to one part topsoil (with the option of adding peat at 5% if necessary) is ideal.
Slit drains at 300-600mm centres, back-filled with sand, to a depth to suit underlying soil layers will give rapid movement of surface water. Slit drains should run at right angles to the existing drainage system.
Benefits gained are:
- Better playing conditions
- Improved traction, quality and durability of the turf
- Better aeration
- Quick drying of the soil improves soil temperatures
- Improved root development
- Better soil structure
- Early growth
Management during the playing season
The main problem associated with winter sport is the level of compaction which leads to a loss of surface drainage. To relieve compaction, frequent spiking or slitting is necessary. It is important to take care with these operations as the machinery used can cause surface damage if operated in poor ground conditions.
In smaller areas, a pedestrian machine can be used. A hand fork, although time-consuming, can also work well. The use of a roller often leads to the depression of hollows, compaction and problems with drainage. If a roller is used, spiking or slitting should be carried out immediately afterwards to re-open the surface.
Closed season renovation
Immediately after the last game of the season, renovation work should start with spiking to improve aeration, root development and drainage. Hollows, scrum damaged areas and goal mouths should be levelled with loam or sand. It may be necessary to top dress the whole pitch with sand, brushed into the surface to restore levels. A fertiliser application will help grass plant recovery from winter damage and help encourage newly sown grasses. A slow release fertiliser with a high nitrogen content should be applied.
Over-seeding can be carried out by hand onto a soil tilth or by using one of the specialised seeding machines. These machines place the seed in the ground with minimum disturbance to existing grasses. It will be necessary to carry out two to three passes in different directions, where the turf has become really badly worn, such as in goal mouth areas, and down the centre of the soccer pitch.
Regular mowing encourages strong tillering and produces a dense sward which should be topped at a height of 25-35mm. As the playing season approaches, the turf can be left to grow to approximately 75mm.
Ideally, cuttings should be boxed, but in most cases this is not practical. Where the collection of cuttings is not possible care should be taken to ensure that the dead material does not smother the grasses beneath.
The recommended amounts of fertiliser for a football or rugby pitch per hectare / per annum are:
Soil based pitch:
- Nitrogen 160Kg
- Phosphorus 0-20kg
- Potassium 120-150kg
Sand based pitch:
- Nitrogen 250kg
- Phosphorus 50kg
- Potassium 120-150kg
Golfers like to approach a well manicured green that is smooth, fine and even textured.
Good drainage is important on a green and consists of well laid clay tiles or plastic pipes usually placed in a herringbone pattern in trenches with adequate falls conforming to a recognised design.
The trenches should be backfilled with an approved gravel or stone carpet to a depth of 100mm and a binding layer of sand to a depth of 50mm spread evenly over the stone. Finally, a good root zone mix that has been laboratory tested should be applied to 250/300mm depth and a good fine tilth obtained.
Soil compaction and the loss of soil porosity leads to a lack of oxygen and moisture in the vital root zone area. This will quickly cause the grasses to die back and thin or bare areas will appear particularly on greens and tees. The surface should be spiked using hollow coring, slitting or solid tines.
Solid tines are useful when the ground is very hard and difficult to penetrate. Slitting tines break up the surface thatch as well as allowing the entry of moisture and air into the soil. Where there is serious compaction on a golf green or tee, the greatest effect will probably be achieved by a hollow tining to a depth of at least 100mm. There are spikers on the market that will give an even greater penetration of up to 225mm. The holes should be filled in with sand of a uniform rounded profile or a good open compost to ameliorate the soil.
It is essential that a golf course is regularly mown. A putting green should be mown down to 5mm through the summer months. Very close mowing must be avoided as this will only weaken the fescues and bents which in turn will allow annual meadow grass and possibly moss to invade the green.
During the winter months, the grass can be left a little longer at 8mm which will help to protect the sward. Grass clippings should always be removed to prevent any build up of dead material in the base of the turf as this can help the spread of fungal diseases.
On golf tees, the sward should be kept to a height of around 12mm and on fairways at 15-24mm. Grasses should never be allowed to grow too long as this will weaken their base when they are eventually mown again. Even through a normal winter, grasses will never stop growing completely and the occasional topping when the conditions are dry is beneficial to the turf.
Dead thatch on the surface of a green should be avoided as this can quickly build up over a season’s close mowing to create a soft spongy surface. This can affect both drainage and irrigation. Moss will retain moisture leaving a soft surface which is susceptible to fungal disease. However, when dry, the fibre can act as a water repellent hindering the penetration of moisture to the soil. Under these conditions annual meadow grass may colonise weaker areas when moisture becomes available.
Deep thatch should be tackled carefully before any overseeding programme can be carried out. Deep coring or verticutting following by topdressing with coarse grain sand is required to punch through and remove the thatch layer and improve the structure of the underlying soil over a period of time. This should be combined with regular light scarifications throughout the year.
All fine turf areas benefit from a top dressing which will help to preserve a true and level putting surface and reduce the build of thatch. Normally an application of 2 kg/m2 is applied two or three times a year during the summer season, although it is important on thin swards not to smother the grasses otherwise die back will occur.
The type of top dressing to be applied will depend on the original root zone mixture as a similar material should be used so as to maintain a continuity of profile. On well established courses, where the greens were built on local soil, it may well be necessary to apply a top dressing containing high quality sand, particularly when applied after hollow coring.
Grasses should be fed during the growing season to encourage natural growth but not to force or stimulate unnecessary growth especially early in the year. Too much fertiliser will tend to stimulate top growth to the detriment of the roots and overfeeding of nitrogen in the autumn period should be avoided as this will only encourage fungal diseases such as Corticium and Fusarium.
It is also important to control the levels of phosphate used as this tends to encourage Poa annua. At the beginning of the season the greens and tees should receive a well balanced Slow release Spring/Summer Fertiliser which should be applied evenly at 35g/m2. This dressing can be obtained in the form of a slow release fertiliser which will stimulate root growth and help to thicken the sward without promoting a flush of growth.
During the summer months as conditions demand, it will be necessary to apply either the same fertiliser at a rate of 35g/m2 or apply a spring summer liquid feed. In the autumn an autumn winter turf hardener is recommended.
Overseeding is part of a general autumn maintenance of the greens in September when soil temperatures are still high enough for good uniform germination but the playing calendar allows time to get on the greens. It can however be carried out whenever soil temperature are favourable which is between May and late September.
The green should be thoroughly scarified before it is either hollow tined or verticut. The core holes or striations left behind should be filled to within 10mm 12mm of the surface with a suitable topdressing of coarse grain sand. Seed should then be applied either by mixing with the remaining topdressing and brushing into place or alternatively if the greens have been verticut by following the resulting striations with a dropseeder and then top dressing over the top afterwards.
Keeping a tee in good condition requires constant maintenance which can result in excessive wear. Therefore, the larger the tee, the less the effect of wear will be.
Regular scarification and aeration is important, as too is the application of fertiliser during the summer to ensure strong growth during this period. While mowing should be carried out regularly, care should be taken not to cut below about 12mm, leaving as much cover as possible on the tee to assist with wear. Weekly repair work should be carried out to restore the surface and to reintroduce the desirable grasses.
A good slow release fertiliser should be applied in March/April. With further applications of spring summer granular or liquid feed applied in the summer depending upon requirements.
Regular mowing should be carried out on the fairways especially during the summer months. Fortunately, modern short-growing varieties can be selected to keep mowing to a minimum. On busy courses it is important to relieve compaction by using tractor mounted slitting tines which offer a good soil penetration. In the spring, a good harrowing of the fairways will help loosen the thatch to assist in restoring the turf’s vigour and stimulate tillering.