Hibernians FC - Tony Bezzina Stadium

The Project of the hybrid pitch - Why POWERgrass system?

Uniform grass emergence of Bermudagrass

The project provides for the requalification of the main pitch area and the training area next to it. The actual surface is based on natural grass which is necessary to be upgrated by using the innovative hybrid grass system to increase the number of playing hours the pitch is available for the club members.

The project provides a resilient hybrid surface for about 1000 hours of play per year on really reinforced natural grass with regular maintenance and, last but not least, will provide a safe playing surface even in case natural grass cultivation fails, thus "eliminating" the risk of costly extraordinary maintenance interventions to restore or replace the worn areas. 

Hybrid grass systems are not new; they are basically reinforcing the root zone with fibres injected deep in the soil or hybrid carpets with low amount of fibres. In some cases the fibres are weak, in other cases the fibres are not well bound on the backing, not to mention those with hard and not uniform permeable backing that instead of reinforcing will provide additional stress to the grass cultivation and will increase the budget for the maintenance. Meanwhile there are many standards on the artificial turf industry promoted by FIFA and national Federations, very little knowledge is public on hybrid grass systems with the exception of POWERgrass that is offering free knowledge on its website.

POWERgrass provides a new definition of the "HYBRID FIELD".

Implementation and inauguration of POWERgrass hybrid pitch 

POWERgrass sets an new meaning of “hybrid grass systems” that defer from the "reinforced natural systems" we know so far. Hybrid grass systems must deliver a surface where the natural grass can thrive inside the system and resist for at least 20 hours of play per week during the growing season. At the same time, must provide enough fibres protruding on the surface to play also without grass, because in the winter the plant leaves may be damaged. This result is only possible with on site installation as natural or reinforced grass sods are simply laid down and cannot be sewn just as the hybrid carpet rolls. This type of installation make a huge difference for the lifespan of the hybrid grass system and the warranty itself.

Hybrid carpet systems can be also provided in big slabs but we cannot anymore consider this any more "hybrid field" but simply reiforced. For the sake of good understanding POWERgrass can deliver a hybrid pitch when it is installed directly on site or a reinforced natural pitch when the installation is made in slabs that include the hybrid carpet even if it is the same.

Hybrid grass systems are in fact an alternative to the synthetic pitch and not something in between as the “reinforced natural system” because the game activity never stop during the playing season.

Those who love to play on natural grass and wish to provide a high performing pitch that will reduce the maintenance and overall costs, select the POWERgrass system and contribute on the dissemination of new ecologic methods to operate based on the circular economy guide lines. 

The features of the hybrid grass system

Uniform emergence inside the carpet

The hybrid pitch is capable of hosting numerous professional events with significant savings in maintenance costs compared to a natural grass course because, first and foremost, no divots are formed. The system is innovative because has fully integrated natural grass into a patented synthetic turf. This synthetic grass reinforces natural grass in a way that is invisible and imperceptible to the player. Natural grass grows better and uniform in the system because it finds a better water/air balance and its roots are protected against thermal stress (hot/cold). In a short time, natural grass becomes predominant occupying over 97% of the surface, offering sports performance designed for the most demanding professionals. At the same time, the hybrid system is easy to maintain and guarantees a field that is always playable.

The hybrid system provides a sand based background because it allows the grass to breathe, does not form mud and offers the possibility to play in the rain. The hybrid pitch is much more resistant to foot traffic, which is the main cause of compaction that suffocates the roots in fields made on agricultural land.

Soon after installation it is possible to play on the synthetic fibres but, to get the best comfort that only natural grass can provide, wait until 4-5 weeks for cool season grasses or 6-8 weeks for warm season grasses to establish. Cool season grasses grow ideally in the range of temperature 15-25°C meanwhile warm season grasses 24-32°C therefore, if possible, adjust the intensity of your training program during the day with those temperatures to provide more comfort to players and less damage to the grass. If the pitch is overused off the growing period, you may expect to loose part of the grass density until growth conditions are suitable for the type of grass selected, and new buds sprout from the crowns of the plants, thus, within a few weeks, the field is transformed back into natural grass in the same way as it is in nature.

In hybrid system POWERgrass is much easier to apply an ecologic maintenance with positive environmental impact, in line with Circular Economy principles:

• Providing a system with over 20 years of lifespan is a much longer duration compared to any other type of pitch because the synthetic fibres are protected by natural grass from exposure to UV rays from the sun, which causes the plastic to age prematurely, therefore also the warranty is 50% longer than a fully synthetic pitch.
• Optimising thus the resources over the time but also by the usage of renewable and recycled materials like cork, compost and natural organic fertilisers.
• There is no waste production if the grass clippings are left over the soil or are collected for compost and the whole system is either reusable for less intensive usage or recyclable on the same pitch area milling the synthetic grass at the of its life cycle to reinforce also the sand based background.
• Reducing the water usage for irrigation because the evaporation is lower and the water field capacity is higher below the support. The system mitigates also heat and frost stress preserving the roots and the soil biology. Under the support the water efficiency is higher and the cooling ability of the plant is more effective because it helps maintaining the leaf temperature below 25,5°C for cool season grasses and below 30°C for the warm season grasses that is the critical point to better support heat stress.
• There is significant carbon sequestration in the soil because it is known that lawns are able to sequester anywhere from 25,4 to 204,3 g C/sq.mt./year (Zirkle et al., 2011) and this hybrid system is optimising the photosynthesis potential for higher carbon sequestration with the teaching of the regenerative agriculture. Our goal is that within two years, the system benefits of its own soil biology and we can reduce the inputs.
• Providing circular job opportunities for specialised ecologic maintenance, acquiring extended knowledge and principles to be used for regenerative agriculture producing also healthier food.

Training goalkeepers in Derby County Academy

The hybrid system POWERgrass reduce the risk due to unexpected climate changes, costly extraordinary maintenance and has nearly no expiring date.

1. Compared to a natural field the risk of erosion from floods is limited because the hybrid carpet is binding the soil all over the pitch surface. Any human error, biotic or abiotic stress on the natural grass can be recovered with a few maintenance interventions within a few weeks and therefore, does not involve sudden risk that requires costly maintenance interventions.

2. Compared to a synthetic field, it does not require the reintegration of the infill or the peremptory replacement of the field within 8/10 years. The hybrid system is always renewable, even when the synthetic fibres are consumed because, over time, it becomes progressively simply more natural with less reinforcement from the synthetic fibres.

The characteristics of the hybrid system

Unique features world wide 

The POWERgrass hybrid carpet comprises 75600 strong and resilient synthetic monofilaments per square metre. The synthetic fibres are heat-bonded with force >30N, to a uniform mesh support with 320,000 three-dimensional and interconnected holes per square metre which guarantees gas exchange and acts as an anchorage element for the roots. The backing also includes a lightweight non-woven fabric that reduces water evaporation under the substrate and, in addition, offers an insulating effect to the underlying roots.

After installation, the synthetic fibres protrude 20-25 mm on the surface to protect the plant crowns from intensive play. During germination, the synthetic fibres shade the surface against the UV rays of the sun, thus preventing the sprouts from drying out. The roots penetrate the support from the first period of growth, find a balanced moisture content and are therefore protected against drying and temperature changes in summer and winter.

The design of the hybrid system gives a new meaning to the word "hybrid field" where it is necessary to use it immediately by playing on synthetic turf because the fibres all protrude to the surface or playing on reinforced natural grass that grows vigorously right between the fibres of the synthetic turf with numerous mutual benefits.

The design hybrid system combines the comfort of natural grass with the strength of synthetic turf, offering more play, more safety and a 12-year warranty.

Low maintenance with positive environmental impact

Aerate often to relief the surface

During the lockdown for the Covid-19 we raised the quality bar of the POWERgrass hybrid grass system by integrating the HEALgreen maintenance method. A method that adheres to the Circular Economy with the strategic objective of promoting specialized employment for maintenance with a positive environmental impact. The method is based on the teachings of regenerative agriculture for turf care. The method brings considerable benefits because it involves the most appropriate use of mineral nutrients and biological bio-stimulants and the reduction of the use of pesticides, until their complete elimination. The growth of the turf for sports use, has as its main limit the intensive foot-traffic because it compresses the porosity by altering the physical properties of the soil, binding the gas exchange between the soil and the air. However, aerating the surface and releasing the soil regularly ensures the gaseous exchange (CO₂ ⇄ O₂) necessary for biological processes. In the well aerated, draining substrate, microorganisms proliferate and mineralise forms of nutrients inaccessible to plants, both among those present in the soil and those supplied with fertilizers. On sunny days, by frequently mowing the natural grass and letting the clippings settle on the soil, some of the nutrients are returned to the circle through biological activity.

From an environmental point of view, there are many reasons to use the HEALgreen method, which can be summarised as follows:

1. capturing the fine dust and thus purifying the air,
2. sequester carbon from the air while it emits more oxygen,
3. reduce the air temperature through more efficient cooling,
4. prevent pollution of the underground water table by filtering rainwater,
5. reduce mosquitoes during the summer months,
6. reduce the use of chemical fertilizers and eliminate pesticides or herbicides,
7. reduce the overall cost of a healthier city life.

Only through soil regeneration can we have a positive environmental impact. The maintenance of all green spaces with regenerative agriculture is the only way to combat pollution in our cities. It is everyone's responsibility, and it pays off in health by offering a prestigious aesthetic appearance.

In the POWERgrass hybrid grass system it is easier to maintain natural grass in an environmentally friendly way by cooling the air temperature, purifying the air we breathe and filtering the water we drink.