Still a lot of shade in the Sunbelt

For three and a half centuries we in the South have paid a heavy cost for a history of exploitation, slavery, segregation, and disenfranchisement. It was more than a question of human suffering by those who lived through those times. For those things were so linked with restraints on economic innovation, and so linked with sectional conflict that they left the South impoverished and politically isolated for more than a century.

Now, in the 37 years since World War II, the region has gone through what historian Charles P. Roland calls an ''improbable era'' of new things: the decline and fall of Jim Crow, the reentry of the South into the orbit of national politics, and an approach to economic parity. It seems to be more than a coincidence that when change came, it came on with a rush. The racial, economic, and political constraints all began to loosen at once.

It is not, I hasten to add, that we have reached the millennium -- that's nearly 20 years off -- and we had better not buy the success myth too soon. The growing image of a prosperous ''Sunbelt'' rolling in riches is surely premature when only one state in the region (Texas) has a per capita income above the national average - and that only $24 above, according to figures for 1980.

And the advance has been less sudden than it seems. In the aftermath of the Civil War, apostles of a New South preached the gospel of industry. The defeat of the Confederacy, they reasoned, came from too much reliance on King Cotton. In the future the South must industrialize like the North. It must also have a more diversified and efficient agriculture, better education (especially vocational training) as a passport to success, and sectional peace as a requirement for stability. But not until the mid-20th century did the South begin to reach the goal set forth in Henry Grady's classic speech, ''The New South,'' in 1886: ''a diversified industry that meets the complex need of this complex age.''

The South has surmounted a host of problems, to be sure, but one of the ironies of history is that in surmounting old problems we invent new problems. Nobody who has fought his way through the shabby strips that lead to Southern cities can be ignorant of the pitfalls into which we have already stumbled. An even more desperate result of the change that had led to better life for many is the plight of those multitudes left stranded in the backwaters, those people without the skills or even the simple literacy that the modern economy demands. There is still a lot of shade in the Sunbelt.

The supreme problem, but also the supreme opportunity, now facing this region is how to reconcile economic development with the ''good life.'' We have yet to see whether Southerners can avoid the kind of progress that will turn one of nature's masterpieces, the South, into a modern wasteland.

A little over 10 years ago former North Carolina Gov. Terry Sanford urged Southern governors to address this dilemma by setting up an interstate agency to monitor the burgeoning growth of the South and recommend ways in which the South could avoid repeating the mistakes of the North in a Southern setting, as he put it. The response was quick and just 10 years ago an interstate compact was drawn up and the Southern Growth Policies Board set up shop in the Research Triangle Park in North Carolina. In 1975 the board issued its first report on the future of the South, which spoke in large measure to the question of how to plan for orderly growth without spoiling the environment.

But a new sectional conflict over formulas for federal grants-in-aid transformed the board suddenly into what Alabama editor Brandt Ayers called the ''Dixie Defense League,'' with an office in Washington which supplied Southern congressmen with computer-processed ammunition with which to battle a Northeast-Midwest Coalition, a sort of ''Yankee Defense League'' formed in 1976 by congressmen from 16 states of the ''Frostbelt.''

Last year, however, in accordance with its original charter, the Southern Growth Policies Board went back to formulating a second statement on the future of the South, which it is called upon to do every six years. Much of the report, however, departed from Governor Sanford's original admonition that the board's function was not to promote growth but to help the South cope with growth. ''There is need for more growth in the 1980s,'' the report says. ''Continuing growth is needed to provide more and better jobs for Southerners so that the region's legacy of poverty finally can be overcome.''

One is hard put to quarrel with the point. But one hardly needs to promote it , either, for Southerners were long since converted by Henry Grady and his disciples to the New South Creed of economic growth. It is less certain that the dangers to the environment come readily to mind, or the costs in the added demand for public services.

There have been signs recently that the Southern Growth Policies Board may be called back to its original mission. The Washington office, devoted to working with Southern congressmen, has now been turned over to a new congressional ''Sunbelt Coalition.'' And under its new chairman, Gov. William Winter of Mississippi, the board is turning back to the cause of trying to avoid repeating the mistakes of the North in a Southern setting. It will be interesting to see if such a cause can arouse a durable political constituency, or whether we shall end up with the kind of shortsightedness that makes long-term decisions for short-term reasons, in the interest of the fast buck. If experience (which is history) is any guide, I'm afraid we shall have to make the same mistakes all over again.