If earth could talk or water could lobby, Lue Walters is sure he would keep his job with the federal government.

But Walters, a district conservationist in Fairfax County, says the work he and others like him do suffers from a "visibility problem," and that he must consider the possibility that President Reagan's proposed cuts in soil conservation spending might mean an end to his job.

"If two years from now we find that the Chesapeake Bay has no life in it and there's a two-foot-deep gutter down the middle of the main street of Washington, then people will ask, 'Where are the people who can get us out of this?' " said Walters, 33, who provides technical assistance to institutions, farmers and developers in Fairfax and Prince William counties.

The Reagan administration's budget proposals for fiscal 1986 would slash spending for the Soil Conservation Service and other related soil-conservation programs at the Agriculture Department from the current $814 million to $454 million. The proposed cut, expected to meet strong congressional resistance, would wipe out most conservation service programs and eliminate an estimated 9,000 jobs.

Walters, who has no way of knowing whether his job will be eliminated, said he is more concerned about the future of the water and the land than about his job with the conservation service, an arm of the USDA created in the wake of the erosion-plagued dust bowl years of the 1930s.

In Fairfax, where he works with one other USDA conservationist and two Virginia soil conservationists, Walters mostly advises commercial developers, providing information on matters such as building drainage systems and preventing soil erosion. In Prince William County, he works with farmers, whom he attempts to persuade to switch to soil-conserving practices such as reduced plowing. Walters surveys land, evaluates erosion problems, designs conservation projects and helps supervise construction to correct the problems.

While area government officials are not sure what effect the president's proposed cuts will have on conservation programs, the proposal does call for killing many of the programs in which the federal government shares the cost of conservation projects with farmers and municipalities. Walters provides technical assistance in many such programs.

"Conservation, to me, is not a luxury, but it is one of those things you do if you have the money," said Walters, who joined the Soil Conservation Service 10 years ago, two weeks after he graduated from Alcorn State University in Lorman, Miss.

"If you take away free technical assistance, farmers, developers and homeowners will have to hire engineers, and the cost of doing that will probably stop them," he said.

"Farmers are most worried about the soil conservation programs that help with putting in ponds, water lines and drainage," said Kite Roseberry, a Manassas farmer who used the cost-sharing watershed program to install water lines for livestock.

"There is a cutoff to the burden that farmers can bear," said Harley Kleine, a farmer and director of the Prince William County Soil and Water Conservation District, which distributes federal dollars for local conservation programs. "If the EPA puts pressure on a farmer for pollution . . . and the government won't share the cost of correcting the problem, well that might be the coup de grace for farmers. With the high cost of machinery and everything else, something has to go."

Municipalities have benefited from cost-sharing programs, too. Fairfax County shared with the federal government the cost of building dams to control flooding in the Pohick watershed, which runs from Fairfax City southeast to the Potomac. In Montgomery County, the Soil Conservation Service is working with farmers to protect a county-built lake reservoir in Boyds.

"In Culpeper, the whole town water supply came from the conservation service," said Walters. "The town had wells, and the water system's growth had peaked. We provided technical assistance . . . and now they have a water system with unlimited growth potential."

Last year his agency saved more than 35,000 tons of soil and served about 600 people, Walters said, noting, "That soil would have eroded, gone into pipes or into the Chesapeake Bay. There are nutrients, fertilizers and other organic materials in that soil that would create unlivable conditions for fish and life along the bay. Farmers use all kinds of chemicals now that can be harmful to our health," he said.

"Environmental programs suffer with a visibility problem," he said. "Most people -- when they buy a house -- use us to see if the site floods, but they don't know it. Most people have soil survey maps in their offices and they don't know it. Then when budget-cutting time comes, they think we haven't done anything.

"But we're losing prime farm land at a tremendous rate to commercial development . . . " he said, adding, "I've always felt, he who controls the land controls the world."