Smithsonian World: `The Promise of the Land' PBS, tonight, 8-9 p.m., check local listings for premi`eres and repeats. Narrated by David McCulloch. You know something's going to be a little different when a documentary on American farming begins in a fancy restaurant with chamber music in the background and a bird's-eye view of Pittsburgh.
And there is a difference: the insight and breadth of view offered by ``Smithsonian World'' as it probes its subject - in this case the alarming destruction of farmland through modern, chemical-dependent, ``miracle-working'' agricultural methods.
Host David McCulloch - looking very much at home in this civilized setting - is telling how the meal before him represents the marvels of modern farming. Then in a flash he's seen in a field, grabbing a fistful of earth and saying ``...our health, our sustenance, comes down to this - the soil.''
``The Promise of the Land'' puts its material together so thoughtfully, so reasonably, yet with such cumulative urgency, that it leaves you thinking about ancient and modern parallels - like the loss of soil down the rivers of America's heartland, which the show says is worse than the dust-bowl calamity of the '30s, only not as dramatic, because you can't see it.
You recall things like the brief but telling study of California's central valley. There the magic elixir, water, has turned dry land into a multibillion-dollar farming empire, but through evaporation it could turn into a giant salt flat. And you'll reflect on the agrarian vision of an American society of small, independent farmers held by that lover of the land, Thomas Jefferson, who corresponded with George Washington and others about the latest agricultural techniques.
The Jeffersonian vision may have turned to dust during the '30s, but Mr. McCulloch suggests there are commercially viable ways to avoid such disasters. One example is an 860-acre Kansas farm - untouched by chemicals for some 100 years - where three generations of Vogelsbergs have been farming in harmony with nature and against the prevailing techniques.
``My father didn't consider it organic farming,'' says John Vogel, now the patriarch. ``It was good farming practice.'' After World War II, John and his brother tried working a nearby farm with standard methods, thinking they'd show the old man a thing or two. But the older man's system did better and survived during periods when other farms were going under.
Segments like this illustrate how nicely ``Smithsonian World'' puts together its varied elements - human, historical, and scientific. The Vogel-family interview lets you see what inheriting a farm means in the relationship of man to land, and why people should be willing to avoid overtaxing the soil - even at the expense of maximum profit - for the sake of posterity. Mr. Vogel talks about planting a tree on his farm. He won't enjoy its shade, but he sees a time his grandchildren may sit beneath it and say, ``That's one that Grandpa left.''