Minutes after a Virginia Senate committee approved for the first time a bill requiring mandatory deposits on soda and beer bottles on Monday, industry lobbyists were at their telephones--talking not to lawmakers but to a statewide network of members that had been waiting for a decade to swing into action.

Garry G. DeBruhl, a former state legislator who now heads the Virginia Soft Drink Association, called about 15 district coordinators, who in turn called bottlers, distributors and retailers in every senator's district. By Tuesday, the unusually intense lobbying campaign had come full circle, with grocers like Comar Shields, owner of Blairs Minit Market in a one-street town north of Danville, telephoning their senators and urging them to defeat the bill when it comes up for debate Thursday.

"This is the perfect example of grass-roots lobbying," said John DeMoss, executive director of the Virginia Food Dealers Association, which reported spending $22,000 on political candidates in 1981 and $31,000 last year. "There's no mystique about lobbying. It's just hard work."

But the campaign against the bottle bill, which had been killed in committee every year since 1972, did not depend solely on the grass-roots network of mom-and-pop grocery stores like that of Comar Shields.

Representatives of Virginia giants like Anheuser-Busch in Williamsburg, Reynolds Metals Co. in Richmond, Giant Food in Northern Virginia and politically active beer distributors around the state sent telegrams, visited their senators, and by this morning were confident they could get the bill killed.

"Listen, these people contribute to campaigns, and they contribute heavily," said Northern Virginia Sen. Charles L. Waddell, a longtime proponent of the bottle bill. "A lot of clout on the other side is an understatement."

The bottle bill, backed by environmentalists and farm groups, would require beer and soda distributors to buy back empty bottles and cans for 10 cents each. The bill is intended to decrease litter and waste and spur recycling, but industry officials say it would burden them unfairly and put people out of work.

The Senate Agriculture Committee had killed the bill in previous years, and the panel's 8-to-7 favorable vote Monday dismayed some senators caught between the monied interests of their districts and the garden clubs, farm bureaus and activist voters at home.

"What good is a committee if it can't kill a controversial bill like this?" one senator joked unhappily.

Industry officials did everything they could to make the choice easy. Sen. W. Onico Barker, a funeral director from Danville, heard over the telephone from more than 30 employes of the Brockway Glass Co. in his district. They warned above the background din of bottles on the assembly line that the deposit bill might cost them their jobs.

Lobbyist William G. Thomas, Alexandria lawyer and confidant of Gov. Charles S. Robb, stood discreetly outside Senate hearing rooms, explaining the complex issues raised by the bill to passing senators on behalf of his clients, the beer wholesalers.

Other lobbyists were more direct. "Either the legislators are for us or against us," said W. Edward Gregory, public relations director of Pepsi-Cola Bottlers of Washington. "Certainly if a legislator is doing something that is economically wrong and would harm his district, I would like to see him out of office."

Fairfax Sen. Joseph V. Gartlan said he was being lobbied from both sides, by beer wholesaler Joseph Guiffre on the one hand and Fairfax Democratic treasurer LaVerne Taylor, a bottle bill supporter, on the other.

"Joe Guiffre has been a friend for a long time, and he's a supporter," Gartlan said. "But in the way Guiffre influences me, LaVerne Taylor influences me, too. I sure don't want to go before that whole Democratic county committee with LaVerne howling after me because I voted the wrong way."