Around 73,000 supporters attended the final at the stadium

Cardiff University researchers analysed the habits of supporters to calculate the event's "ecological footprint".

They estimated the match had the footprint of 3,051 football pitches, mainly because most fans came by car.

The figure represents how much land would have to be cultivated to provide the energy consumed on the day.

Around 73,000 fans watched Manchester United beat Millwall last May.

Researchers interviewed supporters during the weekend, and added up how much energy they used by travelling to and from Cardiff, by the food and drink they consumed and the waste they produced during their stay.

Dr Andrea Collins, from the Centre for Business Relationships, Accountability, Sustainability and Society (Brass), said changes to travel arrangements could have made a big difference to the figures.

Food and drink consumption (per average 10 fans) 41 pints of lager 30 cans of soft drink 12 measures of spirits 10 sit-down meals Nine bottles of alcopops Nine pints of beer Five pies or pasties Five pints of cider Four sandwiches Four teas or coffees Three portions of chips

"If match-day travel by car could be replaced by coach travel, there would be 6,500 fewer cars on the road - and an additional 424 coaches," she said.

"The environmental impact could be reduced by as much as 24%, the equivalent of 399 football pitches."

The team also found that the fans had created 59 tonnes of waste, most of it glass and food, which works out as the equivalent of 146 football pitches.

"The environmental impact of the waste could be minimised by recycling or reducing the amount of waste produced in the first instance," said Dr Andrew Flynn, also from the Brass centre.

"Recycling food and drink packaging alone could reduce the footprint of waste by as much as 14%."

Olympic bid

However, the stadium itself is seen as very efficient in terms of its footprint.

Despite being made from concrete and steel, its long lifespan and its large number of users mean that, for every event it holds, it has a footprint equivalent to about one tenth of a football pitch.

The figures are being used by experts putting together London's bid to host the 2012 Olympics.

Last month, WWF Cymru hosted a conference in which the impact of the entire Welsh population on the planet was discussed.

They calculated that, if everyone in the world lived like the average person in Wales, we would need almost three planets to support our lifestyles.