Not to stretch a point, but global hunger pangs could have their beginnings on farms like Charlie True's little place out here in the corrugated hillsides of west Tennessee.

The rich American farm topsoil that feeds much of the world is washing away, and you have only to saunter into True's private textbook disaster zone in Obion County to grasp what is happening.

As farms go, True's 103-acre croft is not much, but it offers a perfect microcosm of the American crisis of the soil. It nearly washed away because he planted it the wrong way with the wrong crop. In many parts of the country, in similar ways, the land is being abused and overused, pushed beyond its limits.

The Department of Agriculture says that the topsoil is washing and blowing away at intolerable rates on 143 million acres similar to True's, more than a third of the U.S. cropland. The erosion rate is reaching critical levels on millions of acres more, raising new questions about farmers' ability to maintain their high productivity. Despite massive federal spending, erosion remains a major farming problem.

Since the Dust Bowl days of the 1930s, the government has spent more than $15 billion on three dozen special erosion-control schemes which, in the view of many critics, have been little more than another dipper out of Uncle Sam's pork barrel.

There are signs that the crisis of the soil is worsening, endangering the last major productive edge that the United States holds over the rest of the world. The recently passed 1981 farm bill continues most of the old programs; the Reagan administration, pleading lack of money, is burnishing a soil-protection policy that contains no dramatic new strategies.

But concern grows. Listen to J. B. Napier, a farmer from Columbia, Tenn., who heads the Tennessee Association of Conservation Districts: "Most people in the nation don't realize we are in a critical situation. It is going to take millions and millions of dollars to correct just Tennessee's problems . . . or someday we are going to wake up without food.

"A lot of Tennessee land goes out of the mouth of the Mississippi River every day. But soil conservation has come second to the farmer who has notes on his land and machinery. We've got to get farm prices up so we can get conservation programs going."

Erosion rates in western Tennessee and northern Mississippi are among the highest in the country, but the critical list also includes parts of the Iowa-Illinois Corn Belt, the hilly Palouse region of the Northwest, upper Maine's potato kingdom, southeastern Idaho and the Blackland Prairie of Texas.

Soil technicians calculate that a topsoil loss rate of five tons or less per acre each year is normal and acceptable. That translates to a loss of about an inch of soil in 30 years. But some west Tennessee farms routinely lose as much as 100 tons of topsoil per acre annually. Sections of the fragile Palouse in Washington, Oregon and Idaho lose between 50 and 100 tons per acre.

Depressed farm prices, most experts agree with Napier, play an important part in putting new stress on the land. Farmers plow up more pasture, chop down trees that form windbreaks and push more marginal land into production in an effort to cover their costs with higher volume. As a result, record crops in 1979 and 1981 helped keep prices low.

The Land Miners

But this is just one element of a madcap tableau that has converted many farmers into what some agriculturalists call "land miners," who milk the soil for all it is worth without resting it or regenerating it. Some other elements:

* Pressure to grow more grains for export. Since the Soviet entry into the U.S. market in 1972, American overseas sales have increased dramatically. About one of every three acres now produces food for export, bringing home more than $40 billion. Some critics, such as Iowa Gov. Robert D. Ray, contend that the export emphasis strains the land further.

* Government policies that promote overuse of land. In the eyes of many, federal price-support loans and target price payments (direct subsidies) reduce a farmer's risk and encourage him to overproduce, particularly on marginal land. At the same time, the argument goes, a conservation policy that abets production on fragile land makes Uncle Sam an accomplice in soil erosion.

* Oversized farm equipment. The trend to larger implements, suitable for speedy cultivation and harvest of long, straight rows of soybeans and corn, is viewed as a deterrent to erosion control. In the government-spurred push for production, fences have been knocked down and protective timber and grass strips torn out to accommodate big machines that are not economical to use on smaller tracts. Heavy machines are often driven over old conservation terraces, ruining their erosion protection and crushing underground tile conduits used to divert excess surface water.

* Improper cultivation practices. Change is coming, in part because of high costs of fuel and fertilizer, but farmers in many sections of the country continue a habit of fall plowing, which riles the soil and exposes cropland to harsh and erosive winter wind and moisture. "I wish I could find these guys another hobby in the fall," said a federal soil conservationist in Iowa.

* Shifting land-ownership patterns. In one community after another, particularly in the South, farmers and bankers say that a surge of absentee ownership by nonfarming investors, speculators and heirs has diminished the conservation ethic. Absentees often insist on a quick and high return from their land. In turn, farmers renting land, usually year to year, are under more pressure to meet lease payments than to protect soil.

Farmers' changing attitudes toward their work. A move toward farms that emphasize a single crop, in part promoted by the demand for more exports, gives farmers more free time and discourages the sophisticated management practices conservation requires. "Corn, beans and Florida--our major crops," said an Iowa farmer who doesn't go south for the winter.

Norman A. Berg, head of the USDA's Soil Conservation Service (SCS), agrees that these factors are causing "a very serious soil loss in areas where we didn't have soil loss a decade ago." But he disputed farmers' claims that a shaky economy is deterring soil protection. "We also lost conservation systems when farm prices were high . . . ," he noted.

"When we disposed of our farm surpluses beginning about 1973 and went into a push for production, with fence-row-to-fence-row planting, there is no question but what we lost some of our conservation systems . . . . The rotations were gone and we were into a cash-crop philosophy," Berg said. "People who came into farming paid more for land and machinery. West Tennessee is a good example of this."

Enter the Soybean

Throughout west Tennessee, Mississippi and other portions of the lower Mississippi Valley, SCS says average annual topsoil losses reach as much as 20 tons per acre, four times the "tolerable" level. But on many of the area's more degraded farms, the annual loss rate is as high as 100 tons per acre.

Farmers and conservationists in this area agree with the analysis of the SCS offered by Berg. Attracted by higher prices, farmers abandoned livestock, plowed under their moisture- and soil-preserving pasture lands and switched to soybean planting on a massive scale in the 1970s.

The American Soybean Association, predictably, takes broad exception, but the soybean is widely identified as a major culprit. Agriculture Secretary John R. Block, also a soybean grower, recently called it one of the most erosive crops grown in this country. The plant enhances the soil's nitrogen content, but its shallow root structure breaks up the soil crust and makes it vulnerable to movement by wind and water.

Here in the valley, where the soil is a fertile, deep silt loam so fine it feels like sugar, the soybean appears to be a plant made to cause trouble. The soybean's damage potential rises radically when farmers plant it in long, straight rows instead of on a contour or when they put it on sharply sloping hillsides, both common practices in this area.

The advent of huge new fuel-guzzling farm implements is another factor. Tractors and combines run more efficiently along straight lines than with the natural lateral roll of a hill. To keep operating costs down, many farmers have abandoned time-honored contour-planting practices and have put their rows up and down the slopes.

Berg and others say crop yields in some parts of the country appear to be leveling off because of topsoil losses, although some dispute that point. Intensive fertilization of the soil to make up for its loss of natural nutrients becomes increasingly costly and counterproductive.

Another and equally controversial factor in the erosion equation was noted recently by Bill Headden, an SCS resource conservationist based in Nashville. Headden, like many farmers, says he believes that a zest for easy living has had a devastating effect on agricultural work habits and conservation practices.

"The glib answer is economics, but I'm convinced it is more a social thing," Headden said. "We American people like a life style that gives us a lot of free time. Row-cropping does that. Part of the row-crop land, maybe 15 percent of it, should never be used because it is on slopes."

The same theory applies to livestock farming, although Headden noted that "beef hasn't been profitable for the last several years."

Cattle, he said, have to be fed year-round. "A cattleman can't take trips to Florida or Montana for elk hunting. The farmer will opt for more free time, so in a few years we have gone from a labor-intensive kind of farming to an easy system of farming. Row-cropping.

"With all the technological improvements--seeds, chemicals, machines--and with 20 years of benevolent weather, our yields went up. People thought it was because we were so smart. But then we had the 1980 drought, and it helped to make our conservation arguments credible. We had an eight-bushel-per-acre yield loss on beans from 1979. Too much of the land here lies bare too long during the year."

Here in west Tennessee, on farms like the one Charlie True operates, Headden's theory has a ring of authenticity. It is not uncommon to see vast acreages of soybeans on slopes of 30 to 35 degrees, angles that most agronomists say are too acute for this crop. The slightest bit of rainfall slices gullies and ravines into the fields and sends tons of topsoil into ditches, streams and lakes.

Expensive SCS reclamation projects are under way, but the streams of western Tennessee and northern Mississippi are clogged with silt from the eroding farmland. Siltation is rapidly filling scenic Reelfoot Lake, created by an earthquake in 1810, and has cut at least a dozen miles from its shoreline. Arkabutla Reservoir in Mississippi is experiencing similar problems.

In west Tennessee, with more than 6 million acres of productive farmland, major rehabilitation work is going on under the auspices of the SCS and the Tennessee Valley Authority. Newly developed and less expensive cultivation practices, generally called "conservation tillage," are being promoted avidly by SCS technicians and the state association of soil conservation districts.

But technicians like Bruce Calhoun in Obion County and Curtis Haynes in Gibson County complain that farmers' requests for aid in various federal cost-sharing programs far outstrip the USDA's ability to provide money. "We have 300 to 400 requests for help in building terraces and taking other conservation measures," said Haynes. "We'll never catch up."

Calhoun, pointing to sloping fields of soybeans where the soil loss is 100 tons per acre, says that many farmers are beginning to use better practices. But old habits die slowly, and Calhoun and other conservationists say they worry that erosion is outrunning reclamation.

Change, and Disaster

The USDA predicts that conservation tillage practices will become commonplace over the next three decades. In northern Mississippi last year 95,500 acres of minimum tillage crops were planted--double the 1980 figure--but there is concern that the change is occurring only with difficulty.

"We have had more no-till here in 1981," said Dorris L. Johnson, SCS area conservationist at New Albany, Miss. "But we have had some failures, and that has been a setback. Our publicity has stimulated more interest in no-till, but many farmers won't go for no-till because around here the yields have been less and the cost savings have not been that great."

Farmer True alit from his old pickup on a recent morning to show where his personal disaster occurred: a patchwork of collapsed 30-degree hillsides, rutted land and lost topsoil. He has joined a federal SCS cost-sharing program, and the farm is slowly coming back. True abandoned soybeans, put in water-restraining basins and planted wheat and fescue to hold the soil in place.

"I had beans here and I lost a lot of soil. I should have, but I didn't, take erosion precautions. In the first two years I had good bean yields, then I started to lose the yield. This is good soil, but there's no way to hold it without grass or trees," True said. "I'm going to put cattle on this in a year or two."

Additional strain on the land has come in the past decade, as more and more area farmers turn to winter wheat for extra income. Wheat makes valuable ground cover between bean crops, but the additional tillage involved means that the earth is churned up more and its erosion potential heightened. In Mississippi, wheat production is rising dramatically. A record 750,000 acres (up from 600,000 in 1981) was planted last fall.

A Vicious Circle

Some farmers, such as Milton Jones, a lean and friendly man who raises soybeans, cotton and cattle on about 1,500 acres near Hernando, Miss., confess that they aren't proud of what they're doing, but say they see no way out of the vicious circle.

"With the six-row equipment [planters and harvesters] we have, contour farming is almost out of the question. I try to keep my hill land in cover crop, but I'm the first to admit that I'm growing cotton on land where grass and cattle should be. But cattle won't pay the way. We need a fair and stable price for commodities," Jones said.

Bill Davis, an official of the Production Credit Association in northern Mississippi, said, "They are farming too much marginal land--anything with flat to it will be farmed. My grandfather would turn over in his grave if he saw some of these mounds they plant beans on. Soybeans and hills just don't go together."

Riley Brooks, an SCS conservationist in Tate County, Miss., noted that in 1970 farmers there grew 25,000 acres of soybeans. "By 1976, it had climbed to 55,000 acres," Brooks said, "and most of that was added on marginal lands that had been pasture or timber. There was a desperate effort to make up for low prices, and the planting around here has remained at about 55,000 acres of soybeans."

Average cropland erosion in Tate County, not far from the Tennessee border, is 28.6 tons per acre annually, according to the SCS. Neighboring DeSoto County, with 65,000 acres of soybeans, is losing soil at an average rate of 23.8 tons per year. The state average is 10.9 tons, double the national average.

Brooks and Tate County farmer and cattle breeder M.P. Moore, echoing an opinion widely held in this area, contend that the growing amount of absentee land ownership is a key in a slackening of the conservation ethic and land stewardship.

"This is the most astounding factor we have," Brooks said. "It is simply an economic factor--a farmer who rents on a one-year lease can't afford the conservation. The leasing prohibits conservation practices."

Moore added: "These guys who rent land, some of them don't even know how to spell 'farm,' they take these big machines, then they mine the land for three years and they leave it barren. There are strains on the land to get more volume. We see them plowing up 25 percent more land."

DeSoto County farmer M.C. Sparks Jr., who works about 3,000 acres and preaches conservation, said, "The real crisis is that there is not sufficient return on our investment to allow the average farmer to establish erosion-control practices. We have a tremendously fertile land, but we are headed down the same row as other countries that have misused their land resources."