In Ann Arbor, Michigan, the grass stops growing in October, so any damage done to a natural-grass football field will stay that way for the remainder of the season, and that includes any holes, gaps and crevices.

That's part of the reason the University of Michigan installed a synthetic surface on its football field this summer .

"The real advantage of this infill is that you have a consistent surface all season long," said Michael Stevenson, Michigan's executive associate athletics director. "Here in Michigan, in the upper Midwest, your grass goes dormant about the 15th of October, so any damage that's done doesn't recover. Everybody has a much better field and much truer field in early September than they do in November when the championships are played."

Michigan is one of about 40 Division I-A schools that use synthetic turf on its football field. While there still are significantly more schools playing on natural fields, the number of synthetic fields is now at its highest percentage since 1997, according to the 2003 NCAA Football Records book.

The trends in football field technology go back and forth through the decades. Years ago, schools switched from natural grass to AstroTurf, then went back to natural grass. Now, some are moving on to the second generation of synthetic fields that have more give and feel more like natural grass than the first generation of these products.

"There's no one right answer," said Suz Trusty, communications director of the Iowa-based Sports Turf Managers Association (STMA). "We're seeing both things happening."

Trusty, and other sports turf experts, say that there are pros and cons to both types of fields. The decision to go with one or the other often depends on a school's specific needs.

Grant Teaff, executive director of the American Football Coaches Association, said he hasn't seen a recent trend toward one or the other.

"I think it has to do with institutional desires," he said. "A lot depends on the football coach, but then the rest of it has to do with cost and maintenance and all the things that go into the overall budget."

Mike Andresen, the athletics turf manager at Iowa State University and secretary of the STMA, said his school uses a natural turf but has a synthetic field for practice. He, too, stressed the notion that both fields have value.

At a recent STMA trade show, he said, some attendees were upset that synthetic turf providers attended, but more and more people are realizing that they can learn something from those vendors.

Besides, Andresen added, synthetic turfs require maintenance, too.

"The new synthetic fields definitely have a place," said Bob Campbell, president of the STMA and sports turf manager at the University of Tennessee, Knoxville. "If a field gets too much use, you can't grow grass and they are a good alternative."

But, he added, "Some people look at the synthetic as a threat to their job. Everybody who's a groundskeeper or a sports turf manager, I think, likes to grow grass. It's kind of in your blood."

Tennessee has had a natural field since 1993. Before that, Campbell said, the school had artificial turf from 1968 to 1992. Tennessee broke in its artificial turn in 1968 with a 17-17 tie against the University of Georgia, two years after the first major-college game on artificial turf was played at the Astrodome between the University of Houston and Washington State University.

"In the 1990s, everybody was going back to grass. It was a preference of the coaches and a preference of the players," said Campbell. "The reason we did it was because it's just a better surface -- everyone else was doing it and it would have become a recruiting problem (not to change)."

But it was for some of the other reasons that Campbell mentioned, such as a field getting too much use, that the University of California, Berkeley, switched to a synthetic field this summer. The school had played on a natural field since 1995, when it switched from Astroturf.

"The coach really wanted to have a facility he could use 365 days a year and not have the playing conditions go from optimal to marginal with that heavy use," said Bob Milano Jr., assistant athletics director at California. "The field looks remarkably like natural grass. It has a longer fiber and it has some variation in color and texture. It's not perfectly uniform like the old nylon products."

Milano said California is short on space and doesn't have a lot of practice fields. The fields they do have are used for several sports, not just football, so the synthetic field in the stadium solved some of the problems associated with heavy use.

"In terms of value, it's very cost-effective if you have limited space," he said.

State of the industry

One of the perceptions of artificial turf is that more injuries occur on a synthetic field than on a natural field, and while most experts say this is really a myth with no evidence to support it, others say that perception alone is reason enough to use a natural field.

"Even though there's no scientific proof that (synthetic turf) creates more injuries, the perception is there, and again when you go back to a recruiting standpoint, perception is reality," said John Lewandowski, assistant athletics director for communications at Michigan State University. "There's no question that the players prefer natural grass."

Lewandowski said his school had an artificial surface until last year when it switched to natural grass. He said that while the new generation of artificial turf appears much different from the turf the school formerly used, he did not believe there was enough information on its long-term use to support taking a chance.

But those who make the new generation of turf say most people couldn't tell the difference between natural fields and the second-generation of synthetic fields.

John Gilman, CEO of FieldTurf, attributes much of his company's success to a story that former University of Nebraska, Lincoln, coach Tom Osborne did not know he was walking on a FieldTurf-created field, rather than a natural turf field.

Gilman said about five years ago Osborne flew to Pittsburgh to meet Gilman, along with a group from a Nebraska high school that was looking into installing FieldTurf on its football field. Gilman said when Osborne walked across the high-school field to introduce himself, Osborne asked Gilman where the synthetic field was.

Gilman said he pointed down at his toes, and soon after Nebraska had a FieldTurf field.

"The man coached for 25 years...and didn't realize he had walked across an artificial field," said Gilman, who called supplying Nebraska with its field a "seminal event."

Gilman said his company has grown exponentially since 1996 when it did about $1 million in business. This year, he said, the company stands to hit about $75 million.

Mark Nicholls, president of Sportexe, said his company does about $34 million a year in sales and counts California as the company's first Division I-A client. He estimates Sportexe is third or fourth in the industry.

But Nicholls said he is worried about the state of his industry. He says there's not enough testing done on products or research done to improve products. Also, he said, there is a glut of companies.

Colleges, and other entities, need to do more research before choosing a synthetic field, he said, noting that too many schools just go with the biggest name because they may be inundated with bids from companies claiming to sell the best product.

Nicholls said there are nearly 80 companies in the sports-surfacing industry, and that's up from about 34 last December. He recalled receiving a press release last year from a company in Colorado that was moving from Web-hosting into sports surfacing.

"That's a perfect example of what's wrong with our industry," Nicholls said.