A look at European methods for maintaining a perfect pitch
The Koro FTM removes surface organic matter and plant material, while leaving behind a graded seedbed.
PHOTOS COURTESY OF PAM SHERRATT AND KARL DANNEBERGER UNLESS OTHERWISE NOTED.
There are 50 countries in the European continent, stretching from the U.K. to Russia and from Scandinavia to the Mediterranean Sea. Most European countries are positioned at more northern latitudes compared to the U.S., resulting in cooler weather and fewer daylight hours during the winter and more daylight hours during the summer. As an example, Madrid in southern Spain is on the same latitude as Columbus, Ohio, and Manchester in England is on the same latitude as Calgary in Alberta Canada, so daylight hours and light quality at those locations are fairly similar.
Rainfall and local climate conditions in European countries vary greatly, as they do across the U.S., but as a rule of thumb, southern European countries like Spain, Italy and Turkey are considered “warm season,” and more northern countries like England are considered “cool season.” Because there is so much diversity it is hard to make broad statements about sports turf management in Europe, but there are some general trends.
Sand slits are commonly used to improve the drainage capabilities of native soil fields.
Most of the science, technology and advances in sports turf management have been developed in Western Europe at places like The Sports Turf Research Institute (STRI, est. 1929) in Bingley and The Institute of Groundsmanship (IOG, est. 1953). Technological advances in sports turf maintenance techniques, equipment and products typically come out of countries like the U.K., the Netherlands, Germany, France and Spain.
The most popular sport in Europe is football, with more than 50 leagues. Other popular sports in Europe include cricket, rugby and tennis, but for the sake of keeping it brief the focus of this article is football.
Probably the most recognized football leagues are The English Premier League, the German Bundesliga and the Spanish La Liga. These leagues run from August to May. The timing of those leagues, over the winter months, causes challenges for the groundsman in regard to light quantity and quality. Some of the Scandinavian leagues, like the Norwegian league, are scheduled March to November because of the inclement weather and lack of sunlight during winter.
Most of the premiership clubs have training academies with several pitches built and maintained exactly like the match pitches. Arsenal football club would be a good example, and their training academy is first class.
At Denmark’s national stadium pedestrian reel mowers are commonly used.
PHOTO COURTESY OF CHRIS HAGUE.
Sports governing bodies like the Football Association (FA), the Union of European Football Associations (UEFA), and the Federation of International Football Association (FIFA) play an active role in the condition and preparation of match pitches. They have guidelines for boundaries and pitch playability (hardness, ball bounce, ball roll, etc.) In addition to the sports governing bodies taking an active role, professional associations like the Institute of Groundsmanship (IOG) and the European Stadium & Safety Management Association (ESSMA) offer professionals training and recognition and bring respect to the craft, much like The Sports Turf Managers Association (STMA) does in the states.
As in the U.S., there are generally two types of sports pitches in Europe: native soil and sand-based. Native soil pitches are constructed with either basic pipe-drainage systems or more highly managed with sand topdressing programs and sand slits installed.
Sand slitting is a common practice on soil pitches in Europe, especially in regions that receive considerable rain. Sand bands, or slits, are created and then backfilled with sand that is compatible with the topdressing material that will be used thereafter. They are sometimes referred to as “bypass” systems, as they allow water to drain through and bypass the poor native soil. They need to be kept at the surface with regular sand topdressing, and they should ideally tie in to an underlying gravel blanket or drain tile system so water can flow unrestricted from surface to drain tile. Sand topdressing and sand slits are the main method used to improve drainage on soil pitches, rather than elevated crowns or turtle-back grades, which would not be conducive to the game of football.
In Europe, sand-based pitches are constructed as they are in the U.S., with underlying drainpipe, a gravel blanket, and rootzone sand that meets specific criteria. The rootzone sand for sports pitches tends to be a medium-fine sand rather than a medium-coarse sand like the United States Golf Association (USGA) spec. The use of finer materials addresses the issue of stability in many situations, but an alternative solution is to add a stabilizer. The sand stability challenge is addressed in Europe (particularly the U.K.) by the use of stabilizers like Fibresand (a fiber-like material mixed into the rootzone sand) or a vertical hybrid system like DD Grassmaster (Desso), where thousands of fibers are sown vertically into the rootzone.
Half of the Premiership pitches in England, and many of the professional pitches in Europe, are stabilized with the Desso system. The company has been around for 20 years, and will be installing its 500th pitch this year. Manchester United football club and Everton football club are both scheduled for renovation with a Desso system.
Pitch renovations and lights
One of the challenges with any sand-based pitch is to keep organic matter accumulation to a minimum in order to prevent poor surface conditions developing, not just for the turf, but also for athletes. Innovations in equipment that removes or controls organic matter has been coming out of Europe for about 15 years. In particular, the Koro range of equipment, like the Field TopMaker (FTM), has somewhat revolutionized the industry. The Koro FTM can strip organic material off the surface to leave a graded bare soil seedbed or to leave crowns, stolons and rhizomes of the desirable grass. This latter practice is referred to as fraize mowing.
Prague’s national stadium pitch with underground heating; snow is still visible around the edges.
There have been some demonstrations of fraize mowing on overseeded bermudagrass pitches at Maryland SoccerPlex and FC Dallas this year. In both instances, the Koro FTM was used to strip out the perennial ryegrass and Poa annua to leave behind rhizomes and stolons of bermudagrass that could then be encouraged to come in with a good fertilizer and irrigation program.
In Europe, the equipment (and others like it) is used to selectively remove Poa annua and other organic material from ryegrass pitches during renovation, because there is no selective control of Poa annua. The theory is that the perennial ryegrass will then grow back from the crown. There have also been innovations in heavy-duty scarifiers that do not damage the Desso system, as well as rapidly moving verti-drains and topdressers and recycle dressers that pull cores and then pulverize and recycle them back as a topdressing. Many of the sand-based pitches will have additional technology like underground heating pipes, SubAir systems, and sensors to control pumps or irrigation heads.
Arsenal football club’s Emirates Stadium.
Renovations on both match and training academy pitches typically take place between late May and late July, with renovation starting immediately following the last match of the season in May. Renovations typically include complete removal of turf and organic matter from the playing surface. The renovation process involves removal of the surface, followed by spiking/deep-tining, fertilizing, seeding, topdressing, rolling and irrigating. The process is done as quickly as possible so the perennial ryegrass has the maximum time to mature before the playing season starts in August. Seed rates for perennial ryegrass are universal at 6 to 8 pounds per 1,000 square feet (35 grams per square meter) The seed may also be coated with a seaweed or nutritional coating to enhance germination and establishment.
Turfing (sodding) is not as prolific in the U.K. as it is in the U.S. Turfing is done if there is an emergency (pitch failure), or if there is not enough time between playing seasons because of concerts or corporate events. The great thing about ryegrass is that it can produce a playable surface in just a few weeks, which is probably one of the reasons why turfing is not a common practice.
A recent innovation on European pitches is the use of supplemental light racks to promote grass growth year-round. The reason for supplemental light racks is three-fold:
1. The stadiums have roofs and thus have major shade issues.
2. Some stadiums are land-locked and have increased in height over time, limiting light getting onto the pitch; an example of this would be Manchester United’s stadium.
3. The sport is played over the winter months, when there are fewer daylight hours and light quality is poor.
The Wheel-to-Wheel line marker is a popular piece of equipment that provides clean, crisp lines.
Groundsmen have adopted management practices like regular spiking, fans, minimal irrigation and fertilizer use, choosing shade-tolerant species, and using plant growth regulators like trinexapac-ethyl (Primo Maxx) to combat the impact of shade and lack of air movement. The light racks are used to provide the turf with the right spectrum of light (or as near to it as possible with bulbs) to keep grass growing over the winter period. The introduction of light racks has also spurred related technologies, like LED lights and remote-controlled growing environments. Pedestrian, self-propelled sprayers have been developed that can be used under the light racks and leave a minimal footprint (for example, the Techneat SPPS 120).
The predominant sports turf grasses in Europe are perennial ryegrass, bermudagrass, Kentucky bluegrass and tall fescue. Perennial ryegrass is by far the most popular, and is used on most pitches as a blend of several cultivars or mixed with Kentucky bluegrass. Where bermudagrass is used, perennial ryegrass is used as a winter overseeding. Perennial ryegrass is adapted to a short height of cut (1 inch), is quick to establish, produces little thatch, is tolerant to wear, and produces both an aesthetical and functional playing surface. Stoloniferous/creeping ryegrasses are becoming more popular. Ryegrass/Kentucky bluegrass mixes are more commonly installed as sod because Kentucky bluegrass is generally too slow to be established by seed. Tall fescues and bermudagrass are used in the warmer areas of Europe (Spain, Portugal, Turkey, etc.)
A major difference between the U.S. and Europe is that groundsmen in Europe prefer to do many of their operations with pedestrian (walk-behind) equipment, to keep their footprint and traffic to a minimum. In particular, pedestrian mowers are commonly used on sand-based pitches in stadiums and training grounds, and the clippings are collected.
To minimize surface organic accumulation there is a mixed approach to mowing. For example, a pedestrian rotary mower is used after a match to pick up any surface debris and to stand the grass back up, and a pedestrian reel mower is used prior to the match to create mowing patterns and a smooth playing surface. Between matches a ride-on mower might be used because it is quicker and more efficient. Other pedestrian approaches to management include line markers; the “wheel-to-wheel” line marker is still used at many facilities.
Fertilizer applications are generally the same as the U.S., with a mixture of granular and liquid feed applications made on a biweekly or monthly schedule, applied at a rate of 1 pound of nitrogen per 1,000 square feet (50 kilograms per hectare). Conditioners, biostimulants and seaweed products are also used.
Problems & pesticides
European pesticide restrictions vary from country to country. Generally speaking, the more northern countries have tighter restrictions (and sometimes bans) compared to southern Europe. In the U.K., there are minimal restrictions. Just as restrictions in the U.S. tend to originate from the coastal states, the restrictions in Europe tend to originate from the northern countries. Some professional pitch managers are using seaweed products and/or bacterial products in the hope of reducing chemical inputs and becoming “chemical-free” in the near future.
The major pest problems in Europe are grassy and broadleaf weeds. Poa annua is the most widespread. Rough bluegrass (Poa trivialis) and Yorkshire fog (Holcus lanatus) are also common. Broadleaf weeds are the same usual suspects found in the U.S.: dandelion, plantains, clover, knotweed, purslane, chickweed and ground ivy. Two weeds that were prevalent in the U.K. that I have not seen in the U.S. are creeping buttercup (Ranunculus repens) and lawndaisy (Bellis perennis).
Insect pests that cause problems are typically larvae/grubs that damage roots. These would include leatherjackets (European crane fly larvae), and masked and European chafer grubs. Earthworm and mole activity can cause some surface problems on native soil pitches, and nematodes are a problem on sand-based pitches.
The use of pedestrian equipment and light racks is common in Europe’s stadiums.
Other problems include algae and restricted root growth (in shaded stadiums) and diseases like leaf spot, rust and Microdochium (fusarium) patch. Diseases are particularly a problem on cool-season grasses grown in the warm-season area, such as gray leaf spot on ryegrass grown in Spain. Generally speaking (as someone from a northern European country), turfgrass disease pressure is not as great in Europe as it is the U.S. For example, in the U.K. perennial ryegrass grown on sports pitches may be susceptible to three diseases, while in Ohio (high temperatures plus high humidity) perennial ryegrass is susceptible to 12 diseases, and can get every one of them if not covered by a preventative fungicide program.
Pam Sherratt is a sports turf specialist at Ohio State University and served on the STMA board of directors from 2010-2011.Dr. Karl Danneberger has been a turfgrass professor at OSU since 1983.