Artificial turf was the foe yesterday as about 100 Brooklyn residents, war veterans, and park advocates descended on Cadman Plaza Park, chanting, “What do we want? Real grass!”

They were protesting the Parks Department’s plan to replace the field in front of Brooklyn’s World War II memorial with the turf. The fight is reminiscent of the opposition to the department’s ongoing renovations of Riverside Park, where baseball fields worn to dust are being replaced with artificial turf.

In its current state, the historic field at the park is a large oval of dirt with grass receding along its edges. The chief of staff of Brooklyn Parks, Martin Maher, said the situation requires a permanent change.

“The area right now is essentially a dust or a mud bowl, depending on the weather,” Mr. Maher said. “Turf is the best solution for this particular place.”

Local schools often use the field for sports activities, he said. Although it is not officially a playing field – no city permit designates it as such – it is a “de facto playing field,” Mr. Maher said. He said the project was supported by the community board and funded by the City Council. The year-long construction schedule is already under way.

The turf is the same kind used by the local professional football teams, he said. The material is made of recycled crumb rubber that comes from old tires.

Some residents and park advocates yesterday said artificial turf couldn’t be a worse solution to the park’s woes. Residents and park advocates said the park’s ecosystem would be disrupted, that the “plastic grass” would be a blight on the memorial, and they even claim it would affect the developmental psychology of children in the neighborhood. They advocated for the re-seeding of the field and for the department to allocate more funds for its upkeep.

“Children need contact with nature. They practically yearn for it,” a developmental psychologist, Bill Crain, said. Mr. Crain was active in the campaign against artificial turf at Riverside Park. “We lost that fight, let’s not lose this one,” he said.

The World War II memorial at the park is one of the city’s largest. The names of about 7,500 Brooklyn residents who died during the war are inscribed on the ceiling inside the 24-foot structure. Its stone facade with its two giant statues faces the field slated for artificial turf.

“Would you put astroturf in Arlington Cemetery?” the commandant of the Marine Corps League, Tony Ibelli, said. “We agree the lawn needs to be fixed, but not destroyed.”

The protesters lashed out at Council Member David Yassky and the parks commissioner, Adrian Benepe, for their roles in the project. Mr. Yassky helped acquire the money to pay for the project from the council. One of the chants was: “Hey, Mr.Yassky, no fake grassky.”

Mr. Yassky’s spokesman, Evan Thies, said the council member saw two choices: Either replace the field with artificial turf or seed it for grass and watch it return to dust after a year’s worth of sports activity.

“We don’t have the money to keep replacing the grass,” Mr. Thies said. “We understand both sides of the argument, but it’s simply better if we have turf there permanently rather than have grass temporarily.”

Mr. Maher said the protesters did not represent the sentiments of the neighborhoods surrounding the park or all war veterans. “There has never been more public review of a project in my 31 years working here,” Mr. Maher, who is a veteran of the Persian Gulf war, said. The process included seven public meetings and three community board hearings, he said. The American Legion and United Veterans of Brooklyn support the plan, he said.

The anti-turf groups are hoping for an intercession from above. They sent Mayor Bloomberg a letter yesterday, calling on him to restore the natural grass lawn, stop the installation of the artificial turf, and keep the flagpoles in their current locations.

“This war memorial is the entranceway to Brooklyn,” a local resident, Richard French, said. “To have an unnatural environment greeting locals and guests of Brooklyn, it’s an outrage.”