top dressing - Bourne Amenity

top dressing
A COMPLETE GUIDE
Top Dressing
What is a Top Dressing
and where should it be used?
What Does Top Dressing Mean?
The term Top Dressing is used to describe the surface
application to turf of sand, soil, organic matter or any
combination of the three. When added to the surface,
over a period of years the Top Dressing becomes part
of the rootzone and will alter or sustain the physical
and biological properties of the rootzones.
Why Are Top Dressing Necessary?
The long term maintenance of any sports surface is
difficult. It’s not just a matter of getting good
grass cover but helping hold the character of the
surface and rootzone. It is often used to level off any
undulations in the playing surface whilst giving good
response in rain, allowing the water to permeate
through the soil profile at a controlled rate,
which will not only help to reduce surface water, but
will also allow the roots to get the necessary natural
feed it requires.
BEFORE
Composition and Physical Properties
of Top Dressing
Top Dressing becomes part of the Rootzone, so
AFTER
logically they should have compositions and properties
similar to the rootzone you already have. This being
said, changing the sand grading to course sand on poorly draining surfaces can dramatically improve game
playability. In all cases, the sand in the Top Dressing should be of a uniform size. Cheap Top Dressings are
often comprised of sands with a wide range of particle sizes even when the amount of fine particles is small.
When compressed they have a smaller total pore space than uniform sands and are therefore inferior.
Choice of Top Dressing
Fine Turf:
Winter Games Pitches:
For areas cut to below 5mm e.g. golf greens and
bowling greens.
For longer grass than fine turf e.g. football and rugby
pitches.
• Fine Turf Dressing: A blend of sand and organic • Design Rootzone: A blend of sand and organic
amendment that has been kiln dried and finely amendment to your soil profile requirements screened (3mm maximum) to produce a
and screened (8mm maximum).
sterilized and free flowing material.
• Sports Sand: A washed and graded moist silica
• Dried Sports Sand: Kiln dried and screened to 2mm. sand available in various gradings.
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Outfields:
Golf fairways and cricket outfields.
• Design Rootzone: A blend of sand and organic amendment to your soil profile requirements
and screened (5mm maximum).
• Sports Sand: A washed and graded moist silica
sand available in various gradings.
Synthetic Pitches:
Any synthetic surface pitch.
• Silica Sand: Double washed and kiln dried for a free flowing material and screened
(3mm maximum).
Summer Games
Cricket wicket and tennis courts.
• Clay Loam: A blend of clay, silt and sand to give
a Motty strength which provides the required
bounce during game play and screened (5mm maximum).
Understanding Top Dressing
What are the benefits of using
Dressings?
two products must be compatible i.e. have
similar composition and properties.
• Helps to maintain a smooth, true running surface.
• Improves mowing efficiency.
• Helps prevent the build-up of thatch.
• Enables control of organic matter content, water
infiltration and aeration.
• Essential in the maintenance of rootzone depth.
• Improves germination in over-seeded areas
• A quality Top Dressing supplier will want you to
test your greens before selling you the right
product for your particular application.
How to choose the right Dressing:
• Firstly, there is no such thing as a universally
‘good’ Top Dressing.
• Test and establish the existing soil profile of the
green before selecting a Top Dressing.
Over time a Top Dressing will add to and
become part of the Rootzone, therefore the • Samples should be taken from the greens and
tested to determine particle size distribution,
pH and organic matter content.
• This information is used to identify a suitable
Top Dressing that is compatible with the
existing rootzone.
All topdressings should contain the rounded silica
sand and never sharp or building sand.
This will, over a matter of time, cause the soil profile
to bind together and reduce the drainage capabilities
resulting in any rain water sitting on the surface and
puddling.
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This will cause playing conditions to deteriorate
dramatically, so getting the cheapest product
for the sake of cutting your budgets could end up
costing vast sums to resolve in later years.
Application
Typical rates of Top Dressing range from 2-5kgm².
Single application rates should be around 5kg/m²
as any more is often difficult to integrate into the
existing Rootzone at any one time.
The results of using a miss-matches
Dressing:
Frequent, light applications are recommended for the
• Layering problems – layers of different pore size systems within shallow depths of the rootzone.
• Water retention.
• Reduction in porosity.
• Problems with the air/water balance causing
anaerobic soil.
• Rooting depth can be affected.
following reasons:
• Promotes fast integration.
• Prevents layering.
• Avoids smothering grass when growth is slow
(Spring and Autumn).
• Avoids significant disruption to play.
• Cancellation of games causing loss of revenue.
Over the years it can build up a depth of high
quality Rootzone on top of inferior material used in
By the time the problems become apparent they may
the original construction.
be impossible to rectify and you may be better starting
from scratch!
The 70/30 Myth
The use of generic terms such as 70/30 and 80/20
are common in the natural turf industry but
actually mean very little. Knowing the ratio of
sand/soil does not tell the user about the quality
of either the sand or the organic amendment that
has been used.
A purchaser should request a precise analysis of the
Top Dressing in terms of:
• Grading of silica sand.
• Silt and Clay content.
• Percentage of Organic matter.
Handling Tips
What should also be highlighted is the actual and
content to any topdressing.
Incorrect handling of the Top Dressing will have a
detrimental effect on product performance.
Although a 70/30 is 70% Sand and 30% organic
mendment, people tend to forget that topsoil
is made up of 50-80% sand in its self.
This would cause the analysis to give a greater sand
content then you may have expected.
To assist, the following Handling Tips are recommended but are not all encompassing:
• Site surface onto which the Top Dressing is
discharged should be as hard, clean and as dry
as possible.
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• Top Dressing should be handled as little as possible.
• Top Dressing should be stored in a way which
minimises the risks of contamination.
• Top Dressing should not be stored for prolonged
periods.
• The Top Dressing should not be over-compacted
e.g. by heavy plant and equipment.
• Installation during excessively wet conditions
should be avoided.
The formation of the British Rootzone & Top
Dressing Manufacturers Association (BRTMA) in
2000 by a group of specialist manufacturers
within the industry, of which Bourne Amenity Ltd
are founder members, was an important
development in ensuring the supply of materials
to high standards of specification and quality control
for the varied applications on natural turf areas.
All member companies of the BRTMA offer
consistent, repeatable and quality controlled
products for the construction and maintenance of
natural turf areas.
The BRTMA is managed by an
Executive Committee made up
of elected members, representing
manufacturers of Rootzones and/or
Top Dressings.
All materials must conform to a
standard approved by the Association’s
appointed Testing House i.e. USGA or UK
guidelines.
The Sports Turf Research Institute (STRI) has
been appointed as the official Test House for
the BRTMA, ensuring independent assessment of
rootzones and top dressings.
All Bourne Amenity Ltd Fine Turf Dressings are heat treated to
200°C and then passed through a 2mm screen to ensure a
weedfree, easy flowing product.
All Bourne Amenity Ltd Top Dressing Rootzones are shovel
mixed and then screened through a 5mm screen directly
into the delivery vehicle to avoid contamination.
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Bourne Amenity Ltd
The Wharf
Newenden
Cranbrook
Kent
TN18 5QG
Tel: 01797 252299
Fax: 01797 253115
Email: enquiries@bourneamenity.co.uk
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