A few years ago, Jasmine Singh started volunteering at the Queens Botanical Garden, where she first learned about composting. She became hooked.

“It’s not the sexiest hobby,” said Ms. Singh, 23, who works for a nonprofit and lives in North New Hyde Park in Queens. But “it showed me that I could be doing more on my part.”

This fall, Ms. Singh completed a Master Composter Certificate Course, offered by the New York Department of Sanitation. “I absolutely loved it,” she said.

The free program, which includes 30 hours of volunteer work, “is designed to build a citywide network of educators, advocates and community composters,” according to its website.

But now the course is on the chopping block. Initiatives like it, along with seven community programs that have partnered with the city, many for decades, to make composting a reality in New York, could be eliminated if budget cuts recently proposed by Mayor Eric Adams take effect.

The city’s new composting collection service, which is rolling out across the boroughs, aims to do much of the work that has been associated with community groups in the past. New Yorkers produce roughly eight million pounds of compostable waste per day, according to the Sanitation Department.

“Composting programs work best when they’re easy, and the programs being implemented today are for everyone, not just the truest of the true believers,” said Joshua Goodman, the department’s deputy commissioner for public affairs and customer experience.

But community composting leaders say the abrupt removal of funding could take away options that engage New Yorkers and provide a safety net for waste removal that is still very much needed.

“This is devastating to the composting network at large,” said Sandy Nurse, the councilwoman who chairs the Sanitation Committee and comes from a community composting background.

“A successful curbside organics program is dependent upon retaining a vibrant, diverse, neighborhood-based community composting network,” said Eric Goldstein, a senior attorney at the Natural Resources Defense Council.

Currently, the curbside program mostly converts waste into fuel, with some compost processing occurring at the Sanitation Department’s compost facility in Staten Island. But the initiative is still evolving, Ms. Nurse said, while community groups offer an established network for making and distributing compost.

If the cuts go forward, 198 out of 266 food-scrap drop-off sites, including those at the city’s green markets, will close, and over 100 workers will lose their jobs, Ms. Nurse said.

Mayor Eric Adams announced the cuts in November. They affect all city agencies, and are being made because of the cost of the migrant crisis, as well as slowing tax revenues and the ending of federal pandemic aid, according to a statement from the mayor’s office. Community composting efforts represent one-tenth of the $33 million in the city’s composting budget, according to the Sanitation Department.

The cuts will also affect smaller, independent composting groups, which rely on the larger, city-funded community organizations to handle their excess food waste. When Ms. Nurse first started her group, BK Rot, “the volume coming in was more than we could handle,” she said. So the group partnered with Big Reuse, one of the organizations that could lose its funding. The nonprofit picked up BK Rot’s extra food scraps for processing. “When this service stops,” Ms. Nurse said, “we will have to turn away people.”

Big Reuse’s composting project receives all of its funding from the city. Every year, its three processing sites convert over two million pounds of food and yard scraps into compost, which goes to hundreds of local groups like Socrates Sculpture Park in Queens and Randall’s Island Farm in Manhattan, said Justin Green, the executive director of the nonprofit.

“Community composting is popular because it allows for people to know and connect that their food scraps are being composted to improve the soil and green spaces of New York City,” Mr. Green said. “Large-scale systems don’t have this impact, they are set up for scale.”

Earth Matter NY on Governors Island, another city-funded group, also has a site that mass-processes food and yard waste. This year, it produced 800 tons of compost, made with 20 percent of the waste generated on the island. Finished compost is used on the island and also shipped to community gardens and city parks, said Marisa DeDominicis, the group’s executive director. “If the D.S.N.Y. funding goes away, our processing site and half of our staff positions are jeopardized,” she said, referring to the Sanitation Department.

On average, the department’s composting facility in Staten Island converts up to 150 million pounds of food and yard waste into about 42 million pounds of compost per year, giving away about 40 percent to parks and community gardens and selling the rest. But it is also undergoing an expansion that will increase its abilities twentyfold, Mr. Goodman said.

The facility’s curbside service, which unlike most community operations accepts meat and dairy waste, is operational in Brooklyn and Queens. But budget restraints have delayed its rollout in the Bronx and Staten Island by six months. Now, the two boroughs, along with Manhattan, are scheduled to receive the service next fall.

Mr. Goodman suggested that New Yorkers who had yet to receive curbside service could drop off their food scraps at the bright-orange, smart compost bins that are scattered throughout the city, which are operated by an app.

Much of the food waste collected by the Sanitation Department ends up at a treatment plant in the Greenpoint neighborhood of Brooklyn, which converts it into natural gas that is piped into homes. Between August and early November, however, there was a technical issue, which caused carbon dioxide to be flared off into the atmosphere.

“Many New Yorkers want to compost their material,” Ms. Nurse said. “They don’t want it to be turned into a greenhouse gas that is burned over Greenpoint.”

Flaring can happen when National Grid, which provides gas to 1.9 million customers in New York City and on Long Island, cannot accept the gas produced at the plant, said a spokeswoman for the Department of Environmental Protection, which oversees the facility. A spokeswoman for National Grid said that the issue has been resolved and that the system was back online.

“These big industrial systems are extremely delicate,” said Ms. Nurse, who was instrumental in developing the curbside program, and who encourages New Yorkers to use it, along with community composting. “We need resiliency in the system.”