Koro Field Top Maker Vs Fraise Mowing is a blog that looks at the mild differences between koro and fraise mowing, which is becoming the go to operation for many turf problems across the sports.
What is a Koro Field Top Maker
A koro is a machine that works rather like a wood plane, thatch, weeds and weed grass and soil can be planned off a few millimetres at a time, to the required depth.
As well as surface planning, scarification blades can be fitted, this is more suitable for larger sports surfaces as a tractor with a minimum horse power of 35 is required, on this pto driven machine.
Quite simply fraise mowing, is just the removal of the surface vegetation and shallow rooted weed grasses, koro is when the machine removes surface vegetation back to soil etc.
Koroing can be used to take off high areas, but they get their levels via there rollers and the rollers follow the contours, so if you want perfect levels after, you may have to look at the having the area laser levelled.
Koro (deep surface planeing)
As above used to plane back to soil of anything you don’t want in the top 50mm or so of the soil, such as thatch and weed grass or root breaks.
Removes the whole of the grass plant, meaning a full re-sowing will be required after.
Often used to plane off high spots, including raised cricket ends/saddles
Can be used to remove a soil surfaces that has a rootbreak, thick layers of thatch.Followed by some work to create a key pre topdressing the square or area can be built back up and laser levelled, if required.
Fraise mowing (shallow surface planeing)
The aim of fraise mowing is to remove vegetation within the top of the grass canopy, but not to plane into the soil. Used more to clean out the grass canopy of litter and debris from the season/s.
Removes shallow rooted weed grasses, such as Poa but leaves more desirable rye grass roots intact, meaning a lower rate of over seeding required, in comparison to koro planeing.
In my experience fraise mowing off an area to remove thatch/weed grass, can easy turn in koro work if your levels are poor and you want to get to a level below the bottom of the thatch layer. Beware of removing too much soil/rootzone, you could possibly create a low square/area which could sit like a pond.
Ideally a cricket square should sit and be maintained 25 mm above the surface of the outfield, so in theory if you’re going to remove 5mm, you may need to allow for 5mm in depth of topdressing or you could finish up with a lower in height square. Seek advice and guidance in such works, via your regional pitch advisors in summer and winter sports.
Area of usage and timings
Koro/Fraise timings are usually at the end of the season, whatever sport that maybe giving time for the new seed to grow and the soil to integrate.
Koro Field Top Makers are game changers in my experience, you can spend 4/5 years trying to remove a thatch layer that has built up, or you can raise a bit of cash and get the problem dealt with in one renovation window.
Winter Sports- It is becoming very common practice now for winter sports clubs to koro/fraise mow off yearly, this will remove the past year/s of litter, thatch and weed grass build up and enable them to fully reseed with their desired grass species.
Many clubs over the years have built up a layer of thatch (number one killer of pitch performance) or even a shallow root break. A koro can remove the offending layer in a few moves, ready for creating a key and topdressing to the required surface height. Get specialist advise on this, as l said above your need to ensure you don’t plane off to below the level of the outfield.
It’s a good option site specific for saddled end and minor level issues, but the Koro does follow the existing levels to some extent and unless you plane to lower than the deepest low, low areas can still be present. Always being mindful to planning off top much and creating a low are for water to water to pond.
Remember if you’re removing a large quantity of thatch/soil you need to factor that into your costs, specifically on larger winter sports areas where arisings cannot be left on site.
1- Planeing off too much can leave you ground low and end up sitting wet after rainfall.
2-Dont be scared of the process, just get good advise and use recommended contractors.
3- Koro/Fraise mowing is the same machine, just koroing is working to a lower depth.
Brian Sandalls on behalf of the TurfCareBlog community.
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