The fertilizer used at Duxbury Beach to aid the growth of beach grass is an essential part of the preservation process, according to Conservation Commissioner Joseph Grady.

The town has been using the fertilizer, with the approval of the conservation commission and state environmental agencies, for over 35 years, Grady said.

“We fertilize the beach with a product used on golf courses that has a slow-release nitrogen,” said Grady. “We usually do it before March 15, before the piping plovers arrive.”

The planting of beach grass on Duxbury Beach is an annual event.

The annual beach grass planting at Duxbury Beach has become a popular event in the early spring with local families coming out to help plant the grass.

Some residents, however, question the need for the fertilizer and wonder why the town can’t use pesticide and nitrogen-free fertilizers at the beach.

Anne Fenwick noted that the town of Marblehead recently passed a bylaw that does away with the use of pesticides and chemicals on all town-owned land and promotes organic pest management.

Organic pest management is a strategy that promotes a natural, organic approach to turf grass and landscape management without the use of toxic pesticides, according to the Marblehead regulations. It mandates the use of organic practices to promote healthy soils.

Fenwick said Duxbury should also move forward with an organic pest management program, especially given the role the town has played in the history of environmental awareness. A letter written by Duxbury resident Olga Huckins to the Boston Herald about the impact of pesticides played a part in Rachel Carson’s writing of “Silent Spring.”

According to Grady, the fertilizer plays an essential role in protecting the beach.

“We’re always conscious of what we put out there,” he said. “The reason we do what we do is that we’re trying to hold the sand there.”

Without the beach grass and vegetation, large storms could wreak havoc on the beach, Grady said.

Since a large storm in the early 1990s, one million stalks of beach grass and over 35,000 shrubs have been planted.

“The program encourages vegetation to grow,” said Grady. “We also work hard to keep vehicles and people out of the vegetation.”

The beach grass and shrubbery plantings are at the heart of the conservation efforts at the beach, he said.

The nitrogen levels in the fertilizer used on the beach are also well below what is used on the typical lawn, Grady said.

“It’s a small level, about 30 pounds per acre,” said Grady. “That’s a fraction of what is used on the typical lawn. On a lawn, you can use up to 100 pounds per acre for a season.”

The special blend of fertilizer used on Duxbury Beach encourages root growth in the sandy soil, Grady said.

The New Jersey nursery that has supplied the dune beach grass for years was so impressed with the mix used in Duxbury that they have marketed the fertilizer blend for use in other seaside communities, according to Grady.

“We’re quite proud of our program,” said Grady. “We’re always looking at the situation and asking people to provide input.”

He said the Duxbury Beach Committee is constantly analyzing its program to make sure it is done in the most environmentally-conscious manner.

“It is fertilizer, and it is a sensitive area, so we are very cautious and everything we do is reviewed by a number of individuals and agencies,” Grady said.

Fenwick countered that there are organic methods that can be used on the beach that are more environmentally friendly than the current fertilizer mixture.