The reason the grass at the World Cup stadium 'bathes' in pink light

Dallas Stadium, or AT&T, has a capacity of 94,000 people in Arlington, Texas (USA). The stadium hosted 9 matches in this year's World Cup, more than any other venue, including the match between Argentina and Jordan on the morning of June 28.

This is originally the home field of the Dallas Cowboys team of the American Professional Football League (NFL) and was renovated to serve the World Cup. According to AFP, the organizers replaced the artificial turf with natural grass, about 60 cm higher than the Dallas Cowboys' usual playing field. Rolls of grass 1.2 x 15 m have covered the yard since last month.

The meticulous effort to ensure the perfect field for the World Cup comes two years after the quality of the field in the US during the 2024 Copa America was harshly criticized. Jorge Fossati, coach of the Peru team, said at that time that the hastily laid turf at AT&T Stadium could have contributed to defender Luis Advincula's injury. "It happened suddenly. I knew this was a grass field but it wasn't normal grass," Fossati said.

This year, the organizers do not want to repeat the controversies at Copa America 2024. According to Tod Martin, Dallas stadium manager, they spent about 45,000 man-hours to spread the new field, made from a mixture of Kentucky ryegrass grown in Colorado, then transported to Texas with 24 refrigerated trucks. An irrigation system helps ensure the grass receives enough water. In addition, the field surface was reinforced with plastic fibers before the World Cup.

The Dallas stadium is equipped with a roof that can be opened and closed, but the grass underneath still cannot receive enough sunlight. Ian Craig, who oversaw turf installation at the Dallas course, said he's trying to create outdoor-like conditions. "This is an indoor stadium so there is a lack of sunlight. We need to supplement light to ensure the grass still grows," Craig explained to CBS News.

Dallas Stadium recently installed a specialized lighting system on metal bars hanging from the roof, which can be lowered close to the grass. The light rig regularly shines bright pink light on the grass to promote photosynthesis. Martin came up with this solution after visiting Wembley and Tottenham Hotspur stadiums in London, where similar turf maintenance techniques are used. "It's truly an impressive sight," Martin commented.

The specialized lighting system at Wembley is mounted on wheeled frames to push onto the field when needed, while Tottenham's system is lifted hydraulically from both sides of the touchline. Dallas Stadium uses a similar technique, but the lighting rig is pulled up and down from the roof.

According to Ewen Hodge, head of field infrastructure at FIFA, this is the first time such a light truss has been hung overhead. He told the Washington Post, usually, this system is equipped with wheels to move in and out of the yard. However, Dallas' system can be pulled up, reducing the amount of equipment that must be placed on the field. Hodge assessed Dallas' solution as "a very creative step forward".

Thu Thao compiled