It doesn't need mowing. It doesn't get muddy. And it's always ready for play.

Little wonder, then, that more and more high schools and colleges across America are opting for artificial turf over Mother Nature's fickle, high-maintenance grass for their athletic fields.

"It's a lot safer," says David Barbera, president of Artificial Turf Supply, a nationwide supplier based in Dalton, Ga. "It's more of a consistent surface, a softer field to play on, so they're seeing a lot less injuries."

Further, fake grass lasts a lot longer than the real thing, which needs constant watering, pesticide application and upkeep.

"Well-conditioned natural grass can only take 50 events a year," says Richard Kryztof, project manager at A-Turf Inc., a supplier of artificial turf in Cheektowaga, N.Y., near Buffalo.

That was too much for nearby Amherst High School, where students play football, lacrosse, soccer and field hockey to the tune of some 350 athletic events per year. The school purchased fake fields from A-Turf, which means it now saves a lot on sod.

• Click here to visit FOXNews.com's Natural Science Center.

Artificial turf can be a superior playing field to traditional grass. Proponents say the $700,000 a football field it can cost may be worth it, because the surface is level, a ball can move better and the players can move a little faster. And regardless of rain or snow, the field stays playable.

But many environmentalists aren't buying it. They don't like that the fake turf is composed of polyethylene fibers made to look like grass, which are in turn anchored by rubber pellets made from chopped-up automotive tires.

"We are talking about large tracts of land, football field-sized pieces of land," says Patricia Wood, executive director at Grassroots Environmental Education, a non-profit group based in Port Washington, N.Y., near New York City. "When you add them up, you are talking about a significant loss of natural turf."

Because natural grass can sequester carbon dioxide, replacing it with plastic doesn't help the fight against global warming, Wood adds.

She also points out that because artificial turf is prone to heating up — some estimates figure it can hit 160 degrees Fahrenheit on a hot day — and raises the temperature of the entire playing area, it could make scrapes and bruises even worse.

Environmentalists say that heat also may unlock a lot of nasty fumes from the ground-up tires underneath, which would be inhaled wholesale by hard-breathing athletes.

Nonsense, says Kryztof, who says study after study has failed to prove anything dangerous about the installation of, or playing on, artificial fields — which, he claims, help reduce pollution.

"Any way you slice it, you have all these tires and what do you do with them?" he asks. "You either put them in a landfill or you keep them going as long as you can."

The debate's not limited, of course, to between self-appointed "greens" and, um, "plastics."

Over the past four decades, professional sports teams have embraced early versions of artificial turf, then backed away from them, and then popularized them again as quality improved.

Giants Stadium in East Rutherford, N.J., provides a good example. Originally laid with an early version of Astroturf in 1976, real grass was installed in the stadium in 2000.

But that natural surface wore out quickly during each football season — the stadium does double duty as the home field of both the New York Giants and the New York Jets — and a newer, more resilient kind of artificial sod, FieldTurf, was installed in 2003.

By 2006, 13 NFL teams played in home stadiums with artificial fields.

But that may not make players happy. According to a 2007 report by the NFL Players Association, 61 percent of 1,511 players polled had negative reviews of artificial surfaces, with many believing artificial surfaces were more likely to cause injury and shorten players' careers.

There may be something to that. A 2005 New England Journal of Medicine study found a high rate of methicillin-resistant staphylococcus, or MRSA, bacterial infection in artificial-turf scrapes among St. Louis Rams players, though it blamed the transmission of the bacteria on sloppy hygiene rather than the turf itself.

There's also "turf toe," a common athletic injury to the big toe made more likely by hard surfaces, such as older forms of artificial turf.

Then there's the problem of cleaning the stuff. Blood, sweat and spit are easily absorbed by natural soil, but on artificial turf they've got to be swabbed down with disinfectants and detergents, then mopped up.

Perhaps the biggest environmental hazard from artificial turf is in its disposal, Wood says.

Synthetic turf on school athletic fields needs to be completely replaced after eight to 12 years, but the old turf will never disintegrate, she points out, adding that it's already been banned by some landfills.

Still, Wood admits that fake grass is the right choice for certain locations, such as indoor or domed fields and urban playgrounds that have blacktop or concrete lying beneath.

Both artificial-turf proponents and environmentalists agree on one thing: It's still early in the game for a firm conclusion on its impact on health and the immediate surroundings.

"There's a lot of pressure [to come up with a solid answer]," says Neil Lewis, executive director at Neighborhood Network, a non-profit environmental organization on New York's suburban Long Island. "And we are doing this without a lot of information, which I think is a mistake."