The new INFiNiSystemTM30” & 34” brings new flexibility and performance to sports stadiums.
Modern sports pitches are often constructed with stabilized sand. The stabilizer is normally either polypropylene/polyethylene fibers that are randomly distributed throughout the matrix of the sand rootzone (example Fibresand/Fibreturf) or polypropylene/polyethylene fibers that are uniformly “stitched in to the pitch vertically to a depth of approx. 150mm (example SIS Grass). Apart from the obvious benefit that stabilized pitches offer with respect to lateral sheer strength, the advantage of being able to use sands with a high uniformity of particle sizes permits a growing medium that has a high level of porosity. This porosity confers rapid drainage rates and it is therefore unlikely that anaerobic conditions develop. However, the flip side of this type of construction is that pitches with extremely high percolation rates display high nutrient leaching properties. The ensuing inert nature of the rootzones also make them prone to symbiotic imbalances between bacteria, algae, fungi, nematodes etc. and when conditions are inclined to favor the proliferation of any one then problems can rapidly cultivate.
One can therefore deduce that modern pitch construction ethos is highly prejudiced towards the provision of a mechanical solution rather than a functioning soil medium per se. This is understandable as on an ongoing basis agronomic management can be manipulated on a frequent basis whereas soil physical properties cannot.
For the reasons cited above, very high sand content rootzones require a high level of agronomic skill to gain the best from them. Small variations in management can result in disproportionately high differences in plant health.
MOWING
The most frequent day-to-day management of a pitch is normally the mowing procedure. Mowing may appear simple in its application but it can have either positive or negative consequences for plant health dependent on mower performance. Due to the frequency with which pitches are cut the effect can be pronounced. The main factors determining the attainment of the correct cutting performance when used on sports pitches are:
- Sharpness of cut
- Relationship of the bedknife/cutting reel geometry (Attitude Angle)
- The Behind Centre Distance (BCD) of the bedknife
- Frequency of Clip
- Weight distribution
SHARPNESS OF CUT
Dull or poorly sharpened mowers tear and shred grass blades rather than cut them cleanly. This is particularly relevant when cutting perennial ryegrass due to the very tough leaf of this variety. Ripped or “ragged” grass blades increases the plants vulnerability to disease. The damaged leaf also increases the loss of sap and increases the demand for water and nutrients. One of the reasons for a dull cut can be the use of a mower that does not maintain cut quality for an acceptable length of time. This is normally due to either:
- A poorly designed bedknife to reel adjusting mechanism resulting in “drifting” of the bedknife away from the reel during use.
- An imbalanced reel causing premature wear.
- A poorly designed cutting unit that “oscillates” during rotation also causing premature wear. Sound design of the cutting unit is therefore paramount in achieving a consistent quality of cut. ATTITUDE ANGLE/BCD The cutting unit attitude is the angle between the bottom of the bedknife and the ground plane under the cutting unit. Attitude angle and behind center distance (BCD) are interlinked and an improper set-up of both of these features will not only change after-cut appearance but can affect the overall health of the plant. The greater the BCD, the more aggressive the cut because the grass blade will be “dragged” prior to it being trapped between the bedknife and reel. An aggressive cut means the cut is shorter because the leaf blade is lifted “up and back” prior to shearing. For a less aggressive cut the bedknife is positioned much less far back than the bottom most part of the reel. When too aggressive an attitude angle or BCD is employed it can lead to up-rooting of the plant especially if rooting is shallow to begin with. This can be particularly problematic when establishing new grass on a renovated pitch. The ability therefore to alter attitude angle and BCD is extremely useful in maintaining pitches at optimum levels. FREQUENCY OF CLIP (FOC) Frequency of clip is the distance between mower shear points and is affected by the number of reel blades, the reel rotational speed and the forward speed of the mower. FOC is important in ensuring the correct cut quality is attained for the specific height of cut. Moisture content of the leaf is also important when considering FOC as too high a clip rate on grass that is less rigid can end up mulching the plant. Reel diameter is also worth considering when looking at FOC as a reel with a larger diameter will exhibit more of a fan effect and blow the plant down and away from the shear point during cutting. Conversely, a smaller diameter reel can accommodate a faster rotational speed before encountering this issue. The ability to alter FOC is advantageous in ensuring the best quality of cut possible during different types of plant conditions. WEIGHT DISTRIBUTION Using stabilized sands increases sheer strength but it comes at the price of a less compliant surface. Most maintenance practices therefore should be geared to at least not make matters worse – particularly mowing as it is performed so regularly. The less the surface needs to be “moved” to attain a softer surface (e.g, solid tining) then the less chance of uprooting the plant which can lead to general plant stress and a reduction in plant health. Continual rolling with heavy equipment is not recommended and so mowers should be used with low ground pressure where possible that minimize compaction. The use of a mower with a cutting unit independent of the traction unit (normally termed floating head) will decrease ground pressure as the combined weight of the mower is spread between both elements – traction unit and cutting unit. Less ground pressure also means less chance of rolling the fibers in to the turf canopy and “losing them” which can compromise pitch performance.
In addition, it is beneficial if the grass bucket is attached to the traction unit rather than the cutting head itself. This helps with excess weight being progressively placed on the cutting unit as the bucket fills with more clippings. As the bucket becomes continually heavier it presses the unit more heavily in to the turf and results in a closer height of cut at the end of a cutting pass than at the start. This is unavoidable on fixed head mowers and can cause stress on the turf as well as an uneven playing surface. The nature of the design of floating head mowers offers some scope to move most of the weight of the bucket on to the traction unit thereby achieving a more consistent cut from start to finish regardless how much the bucket is filling with clippings.
The new 30” and 34” InfInISystem from ATT meets all of the above criteria and more. It has been designed to allow Groundsmen to calibrate the machine exactly how they deem suitable for their particular situation. Every pitch is different with its own individual makeup and microclimate and therefore without the ability to change the machines operating parameters, mowers without this ability are mostly working less than optimally for a given situation. With today’s highly technical approach to pitch construction and maintenance a mower that can complement this modern approach seems both logical and necessary.
KEY POINTS
Much more functionality than any other pitch mower
- Reduced Ground pressure is kinder to turf without affecting striping
- Set bedknife B.C.D. and attitude angle for an unsurpassed level of cut quality
- Programmable variable clip rate putting you in control
- Easy end of line turning
- Grass basket weight is transferred to the traction unit ensuring consistent H.O.C. regardless of how much grass is in the basket
- In Field ability to swap power source from engine/generator to battery
- Can accommodate a range of different cassettes (sarel roller/rotary brush etc.) John Coleman Advanced Turf Technology Ltd