'Closeup' on the plight of US farms - and a chat with Buffalo Bill

Are we seeing the end of rural America as we have known it for the past 200 years? The answer is Yes, unless we do something quickly, according to a thoughtful and insightful ''ABC Closeup'' documentary, The Vanishing America (ABC, Sunday, 7-8 p.m., check local listings). By choosing the Sunday at 7 p.m. hour, ABC is bucking TV's most popular newsmagazine series, ''60 Minutes.'' It's a courageous - and possibly fruitless - try.

Radiantly dazzling cinema photography by John Else, Dean Gaskill, and Ron Van Nostrand tends to compound the viewer's realization of the potential loss to the nation. This sad story is told most effectively in the faces of the farmers as they look out over their land, their crops, their livestock.

Correspondent Marshall Frady informs viewers that not very long ago, 1 of every 15 Americans was a farmer. Today, it's 1 of every 200. And he reminds us that there are fewer and fewer small farmers, since it has proved to be more economical to farm a few thousand acres than a few hundred. The large family-run farms in tandem with the huge corporate farms have increased productivity to the point where they are providing the country with the cheapest food in the world.

But according to ''The Vanishing America,'' this very efficiency has resulted in a monetary crisis for America's farmers - the more they produce, the lower the prices. And in the recent period of inflating costs, increasing interest rates, record harvests, and world recession, many farmers have overextended themselves to the point where their creditors are poised to take over their property. In 1982, around 34,000 family-run farms were lost.

This beautifully photographed film tells the story of the nation's farm emergency mostly through talks with the farmers themselves (although there are few small farmers included), and the government officials who are trying to find solutions, interspersed with some breathtakingly gorgeous shots of rural America. John Korty and Pamela Hill shared the function of executive producer; John Else and Karyn Taylor produced and directed.

The United States secretary of agriculture, Mr. Frady informs us, has now called for a summit meeting of America's agricultural leaders to seek some radically new solution to the farmers' enduring problems.

''We were born and largely molded as a nation of farmers,'' Mr. Frady says in conclusion. ''It's a hard reality that what we could lose is an indispensable asset to America's world position - a simple capacity to grow food unequaled among nations, one of this country's great national strengths.''

Are we prepared to do something about it? This challenging documentary poses the question in a bold effort to stimulate an answer. TV's blowhard role

For a while after CBS announced it was dropping Archie Bunker from the air, it looked as if J.R. of ''Dallas'' would be the only ''man you love to hate'' left in series television. But now NBC has come to the rescue with its own new insufferable blowhard. It's Buffalo Bill Bittinger in Buffalo Bill (NBC, Wednesdays, 9:30-10 p.m.).

I found that the show evokes a unique kind of ambivalence - I often found myself feeling slightly guilty because I was laughing. On one level it is slyly sophisticated and on another level it is broad and outrageous. Quite a bit like the straight-faced way-out humor of the star, Dabney Coleman, himself.

Obnoxious as he is in character, chances are TV audiences may find Coleman as funny as they found him in ''Mary Hartman, Mary Hartman'' and the ''Forever Fernwood'' series. You may also remember him from the movies ''9 to 5,'' ''On Golden Pond,'' and ''Tootsie.'' And this week he is opening in a ''straight'' obnoxious role in the movie ''War Games.''

I've seen a couple of episodes of ''Buffalo Bill'' and there is no question but that the character played by Coleman is insincere, nasty, boorish, hypercritical, overambitious - but, somehow, despite it all, annoyingly lovable. Or, as Dabney Coleman himself puts it, ''vulnerable.''

"My character is definitely an antihero,'' he told me the other day on a visit to New York after completing 13 episodes of the series, which will run through August - thereafter probably to be continued if audience reaction is positive enough. ''However, although he is a bad guy, he usually doesn't hurt anybody but himself. He manages to be both a male chauvinist and a romantic, but relatively harmless to society. And I am hoping it is his vulnerability which will have people pulling for him. That's a lot to have going for you.''

''Buffalo Bill'' has a lot going for him, mainly the series creators Tom Patchett and Jay Tarses, who emerged from the ''Mary Tyler Moore'' menage. The character is a talk-show host (in Buffalo), so the series is able to poke fun at blowhards in television.

''But the overambitious character I play is no more typical of TV people than any other group in our society. I'm from Texas and you can find Buffalo Bills in the oil, insurance, and banking businesses there. They are all over.''

But are they funny?

''Look, TV usually plays things so safe and pat and watered down that it's all vanilla. The good guys are usually all good and the bad guys all bad. This show is an attempt to dip into characterization.''

Isn't he a bit like the Ted Baxter character in the old 'Mary Tyler Moore' show?

''Ted's character was a whole lot broader, bigger than life. My character is a bit more sophisticated, a believable human being.''

Is it planned to have the series make some social comment?

Mr. Coleman shakes his head and shrugs his shoulders simultaneously. ''What could be more of a criticism of our culture than the fact that a mildly different show like this is considered to be taking a great risk? There's such a fear of offending anybody. 'All in the Family' opened the door to the antihero series. Maybe we're just bridging the gap between the hard-edge comedy of 'Family' and the traditional soft-edge sitcom.''

''Don't forget,'' he says as he prepares to leave, ''Buffalo Bill is never a complete villain - he pushes people to the absolute limit but then backs off because he always has some vague misgivings. And when the problems are solved, they are most often solved through charming misunderstanding or hilarious accident. Most of his faults are due to his insecurity. And, since he is not really a man of great stature, he never seems to learn very much from those experiences. However, that doesn't mean that the TV audience can't learn from his mistakes . . . while they are laughing, I hope.'' '1984' vs today

It's Uncle Walter vs. Big Brother!

When George Orwell wrote ''1984'' some 35 years ago, little did he know that ''Uncle Walter'' Cronkite would be comparing the fictional world of ''Big Brother'' with the real world of 1983.

In the CBS News Special ''1984'' Revisited (CBS, Tuesday, 8-9 p.m. check local listings), special correspondent Cronkite (retired only from ''The CBS Evening News,'' he insists) tracks Orwell's political vision from the pages of the book to today's computer invasions of privacy. Too much of what Orwell predicted - from widespread torture to doublethink and doublespeak - have come to pass in contemporary society, with even more on the horizon.

Cronkite talks to Orwell's friends and biographers in a journey into the science fiction that has become reality. The special is an absolute ''must'' for Orwell fans and a fascinating adventure into the relevance of literature for everybody.

''How far is fact from fiction?'' Walter Cronkite asks in conclusion. ''Not so far that you can't recognize it from here,'' TV's own Big Brother concludes. France's superman

Almost every French schoolboy is as familiar with Fantomas as American schoolboys are familiar with Superman. And just as in this country Superman has been adopted by the intellectuals, so in France Fantomas has become the darling of the Surrealists and the cultists.

Based upon a potboiler novel by Pierre Souvestre and Marcel Allain, this Superman-type outlaw who flits in and out of society was used into a popular serial in the silent-film era. Now it has been revived in a stylish four-part French series called Fantomas (Monday, TeleFrance, check local listings), starring Helmut Berger and Gayle Hunnicut. Episodes 1 and 4 were directed by Claude Chabrol and Episodes 2 and 3 by Luis Bunuel's son Juan-Luis.

For most viewers it will take some searching to find, since it is being aired by the free cable service, TeleFrance USA, which airs at different times depending on the cable system. But despite its disconcerting subtitles, it is definitely worth the trouble of calling your local cable system for information. Officially, it is scheduled to premiere on Monday at 11 p.m. But there will be many repeats.