Cork - elastic element

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• Insights
• The choice of the pitch
• Fields in Natural grass
• Fields in Synthetic Turf
• Experience in the field
• FAQ - Hybrid grass
• Natural vs Synthetic
• Zeolite - mineral soil conditioner
• Cocopeat - organic soil conditioner
• Cork - elastic element
• Irrigation management
• Natural grass reinforcement
• Protection of synthetic turf
• Ground levelling
• Irrigation system
• Drainage system
• Slit-drains in the soil
• Drainage layer
• Growth medium
• Successful installation
• Renovating hybrid grass
• Gypsum calcium saves water

When developing the PowerGrass hybrid grass system we had to compare ourselves with all other existing hybrid grass systems because they were patented but also because we wanted to develop an innovative system that was ideal for professionals but accessible to everyone.

Along the way, we understood the merits but also all the limitations of the existing systems which were, as always, the starting point for further research.

In order to create a good hybrid grass system, it is not enough to use an artificial turf that allows the roots to penetrate. We have often observed that depending on the type of reinforced turf system used, the mere presence of artificial turf as well as the presence of the artificial turf can make the playing surface much more rigid for the game and therefore the demand for the use of Verti-Drain type hole punches to break up the ground increases.

THE PROBLEM

Cork grains to make the substrate soft

It is worth remembering that in stadiums, river sand is very often used almost entirely in the growth medium to increase the infiltration rate of rainwater and minimise the risk of interrupting matches in the event of heavy rainfall.

However, the sand layer tends to 'cement' due to constipation and limestone in the water and fertilisers used to maintain the natural grass. Considering that the infiltration of water into a substrate of about 15 cm of pure sand in accordance with USGA standards is about 11 mm/min equal to 660 mm/hour, it is understandable that once the substrate has been spread, compacted and covered with turf, which is further compacted by the players, it becomes hard to grow and its permeability decreases below the standard limits of 360 mm/hour, so very often there is also surface water flow, which is unable to penetrate the turf and the first layer of sand.

In fact, the maintenance staff of these fields often drill holes 1-2 times a month with Verti-Drain to loosen the soil and restore the permeability of the sand layer.

THE SOLUTION

These problems can now be overcome by mixing gentle cork with the vegetal sand layer.

The use of cork is well known as a component of the performance infill for synthetic turf and has also been used as a sand substrate conditioner in the construction of golf greens in Germany. In fact, by applying it in the innovative PowerGrass hybrid system, cork is an essential element that has raised the quality bar significantly.

Cork and sand granules

In our tests, a substrate mixed with cork, coconut and USGA sand recorded a water infiltration rate of 18.63 mm/min compared with 9.88 mm/min recorded with the same sand mixed with peat, which corresponds to a standard mixture of a USGA-compliant growing medium, which is why integrating cork into the sand substrate also significantly increases water drainage.

Another advantage is the elasticity of the cork, which remains unchanged over time. Fine cork, normally used for quality corks, with a fine grain size of 0.5-1.2 mm, very similar to the grain size of USGA sand (ø 0.25-1.00 mm - min 60% in this range) is mixed into the sand.

This characteristic offers two advantages:

• less constipation of the sand layer as it has a cushioning effect which also prevents the "cementing" of the sand by the limestone which contributes to the hardness of the sand layer,
• greater softness of the sand layer over time, since cork is a hydrophobic material that maintains its physical characteristics of elasticity over time,

which give the growth substrate characteristics of the type:

1. greater comfort for the player by offering a softer and longer-lasting playing surface which
2. improves the growing conditions of the roots, which find more space thanks to a greater number of macro-pores (the greater the infiltration of water, the greater the macro-porosity of the substrate) and develop in a softer substrate similar to natural soil, and
3. they reduce maintenance operations, which would otherwise require frequent drilling with Verti-Drain to loosen the sand, which would lead to a considerable increase in maintenance costs and stress on the turf, as well as the fact that drilling with Verti-Drain is a contraindication for hybrid turf because it makes numerous holes, approximately 225 per square metre, which would ruin the backing more quickly.