Springtime has settled its luster on the virid farmlands of the Shenandoah Valley as lightly as pollen dust on the wings of angels.

But a dust-storm of controversy also rides the air. Reverential feelings for the land that have long been second nature to a local farming community that includes hundreds of Mennonite families are being challenged by the Coors brewing company.

The Colorado beer makers, known as much for their light and voguish brew as for their right-wing politics, are seeking an East Coast market. They are in the process of buying some 2,100 acres of Rockingham County earth on which to locate a brewery. What might have remained just another land-use fight in which rural values take their usual pasting has become a test of strength between religion and commerce.

In most American communities, the two get along well together, often to the point that the business of religion melds so easily with the religion of business that outsiders can't tell the difference.

But the Mennonites have not allowed their beliefs or values to be diluted, much less to be pushed around by a beer company.

That is what originally riled the Rev. Eugene Souder, a local Mennonite pastor who is cochairman of the Concerned Citizens, which is making the legal fight to preserve the valley for agriculture and a clean environment.

"It tells you something about Coors," says Souder. "Here we are Mennonites who keep away from school as part of our religious belief and tradition. And this company comes in with plans for a massive factory to market beer. Didn't they imagine that we would be offended just on that ground, not to mention what damage would be done to our land, our farming and our water?"

Perhaps, not. The common image of the Mennonites is that of a retiring, other-wordly people whose earnestness in the Christian way keeps them tied to the conservative in worship and the old-fashioned in life.

This image proved irresistible to The New York Times when it accompanied a recent story on the Coors dispute with a photograph of some joggers bouncing along a local road in worldly glee while to the rear a one-horse Mennonite buggy inched along in dark somberness.

Turning Mennonites, few of whom own buggies, into human museums is a convenient but mistaken stereotype. Unlike the Old Order Amish, Mennonites have been placing less and less emphasis in recent decades on being "pilgrims and strangers" in the passing world. In ecomonics, social attitudes and in relations to contemporary society, many Mennonites are closer to evangelical Protestantism than to their own ancestors.

In nearby Harrisonburg, the Eastern Mennonite College is a robust center of learning with a faculty intent on preserving the essentials of the church while still being intellectually progressive. Students are encouraged to enroll in work-study programs that take them outside the valley, including to Washington where the Mennonites have a center. Much of the substance of the peace demonstrations of the 1960s came when Mennonites, who are pacifists, showed up to march.

None of this is happening without a debate within the church. Some argue that capitulation to the world is the inevitable result when a separatist faith gets too close to the modern way. It is said that the church's Anabaptist heritage, going back to Menno Simons, the founder who left the Catholic priesthood in 1536, has stood for too long to be discarded or diluted now.

In a recent issue of The Forum, a church magazine, a writer said, "It saddens me to see that many Mennonites are joining the rest of society in rejecting 'simple' solutions. Modern man has come to believe that a superior way of thinking has been reached. We look 'back' on older societies and say they don't provide satisfying answers."

This is nonsense, say others. Last summer, at a seminar at Conrad Grebel College in Ontario, it was argued that accommodation to the times could be done sensibly and ethically, mennonites, said one, "are impoverished in their understanding of social systems and must begin to fashion an ethic from within the institutions of which they are a part."

As one of these fashioners, Eugene Souder feels that taking on Coors is exactly the kind of struggle he and his brethren ought to be involved in. "We have strong feelings about alcohol and drinking," he says, "and they are based on moral values. In our permissive society, it is a popular pastime to look down our noses at moral reasons.But in this case, it isn't just drinkers against nondrinkers. Respect for our way of life is an issue, too. Farming and the growing of food is fundamental to our existence. There is the question, too, of the environment. The earth is the Lord's and taking 2,000 acres of prime land to use for industry - any industry, be it a cereal factory or a church project - is wrong. Industry should locate on nontillable ground."

What is happening in this peaceable kingdom mirrors many of the economic, ecological, agricultural and moral trade-offs that arise in all parts of the country when family farmers come up against the might of industrial giants who are eager to expand their empires.

Corporate takeovers, as well as real-estate developments, highways and other pressure of the times, are quickly reducing family farmers to one of the nation's least visible minorities.

In 1940, America had nearly 7 million farms. The number is now 2.3 million. A decline of 40,000 farms occurred in 1978.

Foreigners also are in on the grab. The General Accounting Office reports that foreign investors bought 826,000 acres of farm land in a recent 18-month period, a size equal to Rhode Island. Insteand of putting money into a Swiss bank, they put it into American loam.

A loss of some 800 farms a week goes all but unnoticed in the nation's largest cities, where a generation has grown up thinking that potatoes come out of a box of flakes or that sickly pink is the natural color of a tomato. Because we were once a farming people - in 1945 1 in 5 Americans lived on a farm, against 1 in 27 today - the government has been protective of family agriculture. Subsidies, tax benefits and assistance in storing or shipping grain have been part of the political commitment given by Congress to the hearty citizens who fed the country.

But with conglomerates dominating the landscape, as well as Congress, the smaller the farmer, the smaller the protection. When Souder visited a local dairyman the other day, the latter told of how he had all he could do to protect himself from the "generosity" of Coors.

"I was offered $3,000 an acre by a Coors agent," he said. "But I told him no deal. I have teen-age boys who want to work this land. If I took the Coors money, I might be well off in being able to buy a few more things. But I'd be selling the farm out from under my kids, I'd be robbing my own family just because some strangers want to peddle their beer," he said.

Coors, which didn't figure on so organized a resistance, may still change its plans and go elsewhere. But they are owed one debt. They have stirred the holy wrath of the Shenandoah Mennonites to the point that one of the ancient truths is again visible: Pacifists aren't pushovers, especially when the force of moral conviction is at work.