The request for hybrid grass is increasing so it is good to provide a clear definition and differentiate hybrid grass systems from reinforced rootzone systems in natural grass.
It is understood that for reinforced rootzone natural systems in natural grass mean: "the set of methods that use synthetic products to reinforce the rootzone of natural grass".
According to FIFA there four different types of natural grass pitch reinforcements:
Filled carpet systems, Fibre systems and Net-based systems have in common that the synthetic reinforcement is buried in the rootzone meanwhile in Hybrid systems the synthetic fibres protrude on the surface where the grass is grown between. All of them increase the stability but have also some drawbacks as for example higher maintenance and renovation costs.
Analysing the etymology of the word “hybrid”, from the agronomic point of view, this term is improper because otherwise there had to be a genetic fusion and this is impossible. However, taking a cue from the automotive industry, it is conventionally accepted the term "hybrid car" for a car powered by two different energy sources such as gasoline and electricity. Taking a parallelism in the sports industry we can define a "hybrid grass" a mixed grass, natural and synthetic, where is possible to play either with or without the natural grass.
According also to FIFA the reinforcements that can improve stability of the pitch even without grass cover are recommended and in that direction has been developed POWERgrass hybrid grass system using a Filled carpet Hybrid system with high density of synthetic fibres protruding on the surface to grant an always playable pitch.
This also coincides with the market demand and it is the concern of many who make an extreme use of the pitch. In little substance, setting a new market standard we can define a Filled carpet Hybrid system: carpet backing with fibres where the natural grass is grown between the synthetic fibres. The system should provide proper growth conditions for natural grass from the very beginning and playable pitch without grass in those cases, for any reason (extreme use, weather conditions or human mistake), the natural grass is possibly damaged.
PowerGrass hybrid turf has also additional innovative features and offers better playing experience and better growth conditions than any other system of natural grass, reinforced or hybrid grass.
The grasses for sports are often cultivated on sand based growth mediums. Those mediums are preferred because they drain easily in case of heavy rainfall during the game and provide 45-55% of porosity with greater amount of meso- and macro-porous where roots, water and biochemical processes are present. The roots provide a support to natural grass plant meanwhile absorb water and nutrients present in the soil water. The nutrients are often applied is salt forms by fertilisation and need to be broken in simple forms that the plants can absorb. To perform their function both roots and useful bacteria (to mineralize the nutrients), need nutrients, water, oxygen and ideal temperature.
In Filled carpet systems, there is backing at 4-5 cm depth and the soil arranged above the backing is not sufficient to develop healthy root growth therefore the roots have to grow also through the backing anchoring also to it, in search of water and nutrients. For that reason it is not possible to use the classic backing in PP to tuft the fibres, then coated with latex or PU, to fasten the fibres to the backing.
Mind that excess of moisture in the soil may occur because of the presence of the wrong backing or because of bad water management. In some cases the excess of moisture associated with a rich biological activity consumes oxygen (O2) in the soil, giving rise to an anaerobic activity that consumes the little oxygen left from the water (H2O) and oxides of sulphur (SO2 and SO3) thereby releasing hydrogen (H) and elemental sulphur (S). Those two elements form a very powerful acid, a toxic poison, the hydrogen sulphide (H2S) with a characteristic smell of rotten eggs. The persistence of these conditions results in a fatal poisoning of the grass that becomes red, rootless and dies.
Apply only resilient synthetic fibres to make sure they maintain the upright position during installation and that are also easy to raise during the maintenance operations.
It’s necessary to apply an open backing and bind the fibre-tufts on the backing by different methods like woven grass, light coating, finger coating or hot melt without clogging the backing porosity. The backing has to remain open and soft to prevent surface hardness.
Another important issue regards the selection of the proper growth medium above the below the backing. The sand offers a high porosity growth medium where roots can grow easily, but after a certain number of hours of play, the surface becomes hard and requires decompaction. With the introduction of synthetic fibres in the sand to increase stability, after the first period, the surface becomes even harder and requires decompaction more frequently. The presence of the backing soon or later will contribute to provide surface hardness therefore without proper maintenance the natural grass tends to thin out.
Last but not least the way the system is installed is essential to avoid hardness and reduce future maintenance.
All details have been subject of reflection and a long study to understand the ideal characteristics of synthetic turf, the growth medium and the system as whole.
Following a long study and direct experience in the field that characterizes the partners involved in PowerGrass group we realized that it is crucial to develop an indivisible set of essential features to provide the ideal Filled carpet Hybrid system by:
All of these features provide the ideal fabric for an excellent hybrid system, quite unique in the world, protected by 3 international patents and one recent application.
An excellent hybrid grass system also requires an ideal sand-based growth medium to optimize sports performance and natural grass growing conditions and the development of the roots above and below the backing.
ZOEsand® is the result of a long reflection and intuition thanks to a deep knowledge of both worlds: that of natural grass and artificial turf.
ZOEsand® increases the porosity and moisture content of the sand-based growth medium, provides its isolation proprieties to reduce temperatures variations during hot summers and winter frost, attributes a cushioning effect to the playing surface and reduces soil compaction and the bulk density of the substrate.
The soil conditioner ZOEsand®, contains coco peat, zeolite sand
and finally gentle fine cork. Integrate in the growth medium ZOEsand® is just as important to enhance performance, resistance, duration, reducing dramatically maintenance costs.
PowerGrass hybrid turf with natural grass
Natural grass in full growth on PowerGrass hybrid turf system covers the synthetic turf from UV sun rays.
Observe a direct comparison and the limits of another hybrid turf system: the fastening of synthetic fibers to the horizontal support is inadequate: when the natural grass gives away, even synthetic fibers are removed away from the player; moreover, if the fibers are "buried" in the sand based rootzone, do not offer protection to the grass crowns.
The synthetic fibers used on direct soil injected system (left) are of 100 microns, compared to hybrid turf PowerGrass (right) of 365 micron
Only elastic fibers (on the right) maintain an upright position and protect the crowns of the plants of natural grass. Actually, PowerGrass hybrid turf is provided with 365 micron of synthetic fibers to ensure resilience and resistance to natural grass maintenance interventions.
Not breathable backing from the very beginning in this hybrid grass has no roots bellow the backing after several weeks from installation
A strong limit of another old hybrid turf system: the roots do not penetrate the backing until the partial degradation of the backing takes place. When this happens, it affects approximately 1/3 of the surface of the support as the remaining 2/3 is waterproofed from the "finger coating" over the backing that welds the fibers in alternate rows to it. A strong limitation when only 8-10 weeks are available for the development of natural grass and even after as rooting affects only 1/3 of the surface, that may result limited from the water barrier.
Poor growth conditions of an hybrid grass not suitable, compared to natural grass
The synthetic turf should not prevent the growth of natural grass: in most of the older systems, we observed that the soil becomes very hard and suffocating the growth of natural grass.
Instead PowerGrass hybrid grass will provide better growth conditions and resist more compared to natural grass
In PowerGrass the synthetic turf assists the growth of natural grass: the synthetic fibers provides shadow to grass shoots against the summer heat meanwhile the support of synthetic turf provides water content and preserve the heat in the growth medium against the winter cold.
The soil conditioner ZOEsand is the result of a long experimentation
After a long trial of all available organic amendments we came to the special blend of ZOEsand containing cork, coconut and zeolite.
All fields are required!
POWERgrass hybrid turf field
Synthetic turf field