TRAVERSE CITY, Michigan—Art McManus slowly threads his 2001 white GMC pickup through a rolling grove of cherry trees, their limbs heavy with crimson fruit. Eyeing his 25-year-old grandson working with a crew of farmhands, he stops to watch them attach a mechanical shaker that grips a tree and violently rocks its cherries into a canvas catch frame and conveyor.

"Each one of those trees is like a child—when a limb breaks, it bothers me," says McManus, who planted this orchard of maraschino cocktail cherries more than a decade ago. "It took all this time to get it to this point, and I'd like to keep it going."

But the 73-year-old owner of the 150-acre Southview Orchards isn't sure he can make that happen. None of McManus's three grown children wants to take over the tart cherry farm. (Read "The Next Green Revolution" in National Geographic magazine.)

His son makes good money as a lineman for the local power company. A daughter works as a physical therapist. Another is a stay-at-home mom who isn't interested in farming.

And so McManus remains a reluctant poster boy for the dramatic graying of the American farmer.

The latest U.S. Department of Agriculture farm census, released in May, showed the average age of principal farm operators is now 58 years old. That's seven and a half years older than the average age of a farmer in the early 1980s.

View Images There are fewer U.S. farmers than there were 30 years ago, and as a group, they’re getting older. In 2012 (the most recent data), 62 percent of all U.S. farmers were 55 years and older, a change of 20 percent from 1982. The average age of farmers increased as well, to 58.3 years old in 2012, from 50.5 in 1982. NG GRAPHIC; SOURCE: USDA

The aging of farmers presents challenges that transcend simple nostalgia for a more agrarian past. With the world population expected to bulge to nine billion by 2050—up from just over seven billion today—there are real concerns about having enough farmers to feed the future planet, agricultural experts say. (Read "A Five-Step Plan to Feed the World" in National Geographic magazine).

And with the trickle of new farmers slowing the adoption of innovative, sustainable farming methods—and hastening the consolidation and industrialization of American agriculture—some family farm advocates say that more than a way of life is at stake. Critics of agricultural corporatization say the trend has torn at the social fabric of communities and degraded the quality of water, soil, and air in rural America. (Related: "Family Farmers Hold Keys to Agriculture in a Warming World.")

"Farmers not retiring is a big drawback for beginning farmers because if the older generation doesn't step aside, there isn't much room for the newer generation," says Mike Duffy, an economics professor emeritus at Iowa State University, in Ames. "The new, beginning farmers of today have to look for niches or attributes so they can generate an income on less acres."

Today, the nation's farmers are 17 years older than the average American worker, with the ranks of farmers who are 75 years and up outnumbering those in their prime working years of 35 to 44.

One big reason U.S. farmers are going gray: spiraling costs. Five years ago, McManus had two prospective buyers approach him, but both backed out when he tallied expenses: Around $7,000 for an acre of land. Another $300,000 for equipment. And then there's taxes, crop insurance, fuel, and supplies, which shave the profit margin even more.

McManus's grandson, Dan Worm—the one behind the mechanical shaker—is enthusiastic about a farming life, but the 25-year-old is a decade or more away from being able to buy his granddad out and pay taxes before he can take over the farm. In the meantime, Worm is likely to continue working two jobs while taking accounting classes and buying a little bit of land and equipment at a time.

"Younger farmers can't afford to buy in," says Judy McManus, Art's wife. "Everything is sky-high."

View Images Jess Piskor does much of the work in the fields of Bare Knuckle Farm. Photograph by Fritz Hoffmann, National Geographic

High Prices in the Cherry Capital

More than 70 percent of the nation's tart cherries for pies, yogurt, preserves, juice, and dried fruit are grown in and around Michigan's Lower Peninsula, specifically in the "pinkie" of the mitten-shaped state. The sandy soil, rolling hills, and Lake Michigan breezes are ideal for cherry trees.

And ever since celebrity chef Mario Batali started summering in this part of Michigan, home of the National Cherry Festival, agri-tourists and well-heeled retirees have helped turn local farmland into shopping malls and subdivisions. The development pressures have squeezed land prices higher and higher.

When fourth-generation cherry and apple grower Gene Garthe, 66, bought land near the peninsula town of Northport in the 1980s, the price was about $2,000 an acre. Then a great-uncle sold off what had become known as "the Garthe bluffs," and second homes sprouted on the scenic cliffs between Gene Garthe's cherry groves and Lake Michigan. Today, the going rate for farmland here is between $6,500 and $10,000 an acre—more if it's suitable to grow grapes for the area's burgeoning wine industry.

"These inflated land prices will determine what a person can do," says Garthe, who has no children and isn't sure what will become of his farm when he retires.

View Images Gene Garthe grows cherries, apples, and pears on the Northport farm homesteaded in 1872 by his great-grandfather, a Norwegian immigrant. With no heirs to take over the farm, he worries about its future. Photograph by Fritz Hoffmann, National Geographic

The cost of increasingly scarce farmland has spiked in many parts of the country, following the national real estate market.

Agricultural economists Ani Katchova of the University of Kentucky, in Lexington, and Mary Ahearn of the U.S. Department of Agriculture have studied the effects of the land price boom on aspiring farmers. "Most young and beginning farmers do not inherit their land, and, instead, purchase or lease farmland to start their businesses and grow over time," they wrote in an academic paper earlier this year.

"In today's record-breaking high land value and farmland rental markets, this is doubly challenging."

The mechanization that took much of the backbreaking labor out of farming and allows senior citizens to keep plowing is another barrier to entry for beginner farmers. One mechanical cherry harvester can cost $200,000 or more.

Between 2007 and 2012, Michigan saw a 21.5 percent drop in the number of new farmers. Nationwide, the decrease was about the same, at nearly 20 percent.

View Images Gene Garthe drives a loader to lift bins of cherries onto his truck. Photograph by Fritz Hoffmann, National Geographic

Toll on Family Farms

Here in cherry country, a number of small growers in recent years have been bought out by larger growers such as Redpath Orchards, one of Michigan's largest fruit farms.

Redpath's Chris Alpers, 31, a third-generation grower who works with his father, David, 55, worries that the dearth of young farmers will lead to more family farms being bought out by bigger farms like his and by even larger agribusinesses.

"If you're my age, you have no chance to get into farming [on this scale] if it's not in your family," says Alpers, who carries a walkie-talkie to connect with field hands. "It's impossible—you can't have ten acres and make a career of it."

While 96 percent of farms are run by families, there's no question that U.S. agriculture is corporatizing. In 2007, the size of an average farm was 418 acres. By 2012, that had grown to 430 acres.

As farms get bigger, says Bob Young, chief economist for the American Farm Bureau Federation, "you don't need as many folks involved in direct production."

Lindsey Lusher Shute, executive director of the National Young Farmers Coalition, says that more corporate farmers, and fewer family operations, means fewer young farmers.

"As farm families have struggled over the last century under the effects of globalization, farmland speculation, industrialization, and competing land uses, many discouraged their children from staying on the farm and the generational farm transition was broken," she says, warning that "barriers to new farmers are barriers to national food security."

Few of Chris Alpers's friends are clamoring to work in a dirty, risky business that's increasingly affected by climate change. Two years ago, an unusually early spring followed by a late freeze wiped out Michigan's fruit crop, the second "once in a lifetime" loss in just over a decade.

"Today I got up at 4 a.m. and won't leave until dark," says Alpers, sitting in his home office. "None of my friends who I went to college with think that's smart."

View Images Nic and Jen Welty, with their 6-week-old son Levi, stand by one of the fields where they grow vegetables as a cash crop. The couple also owns a bakery and a restaurant where they cook what they grow. Photograph by Fritz Hoffmann, National Geographic

Farming Like It's 1948

"See how ergonomic, how light this is?"

Jess Piskor shows off his handmade hoe, which looks like an oversize razorblade on a stick. Nearby is a hand-push seeder from the 1930s. Out back sits a refurbished 1948 Allis-Chalmers G tractor, which was cutting-edge technology back when most farmers tilled fewer than a hundred acres.

There's no big or expensive equipment at Bare Knuckle Farm, the four-acre operation where Piskor and co-owner Abra Berens, both 32, grow vegetables and raise free-range pigs. Set in a valley between two cherry groves on Michigan's Lower Peninsula, their vegetable plot is "not a 'cute' farm," says Berens.

"This is a new model," she says, with "the idea of going back to some of the old-school ways."

Piskor, who first turned soil on his grandfather's land in 2009, and Berens, who grew up on a southern Michigan pickle farm, insist that they're not niche farmers. Like many locavores their age, they are passionate about growing fresh, healthy food for their community and about reconnecting people to the land that sustains them.

Bare Knuckle Farm sells food to a local children's center where the 4- to 7-year-olds "know me as their farmer," Piskor says. "I like getting kids to eat their vegetables."

Yet the duo are typical of beginner farmers who must be creative to make ends meet on a small bit of land. Berens, who cooks professionally at a suburban Chicago restaurant in the winter, stages monthly summer farm dinners in their tool shed to earn more from what they grow. They also sell direct to consumers at local farmers markets and through community supported agriculture (CSA) so that they can keep more of what they earn.

Piskor, who leases land from his grandfather, hopes to buy his own farm someday, but that will require a lot more capital than he has at the moment. He hopes to pay himself a salary of $30,000 this year after working without pay for the past two years.

"There are more people who want to do this than land available" Piskor says. "I wish I had more peers my age because it would be fun to sit down and talk shop together."

View Images David Alpers (at left) and his son Chris pause during cherry harvest at the family farm, Redpath Orchards, on the Leelanau Peninsula. Chris plans to someday take over the farm from his father. Photograph by Fritz Hoffmann, National Geographic

Economies of Scale

Small-scale farmers like Piskor and Berens thrive by catering to local customers and well-heeled tourists.

"But not in a way that's going to feed nine billion people," says Nikki Rothwell, district horticulturist and coordinator at the Northwest Michigan Horticultural Research Station. "We're not going to feed even Leelanau County on pea shoots."

Let alone Detroit. While younger niche farmers have found an eager market in some rural upscale regions like northern Michigan, many city dwellers with more limited means live in food deserts with little access to fresh food. And they can't afford $9 beet salads and $4 radishes.

To produce and distribute large quantities of affordably priced food, Rothwell and others say, larger farm operations are needed.

Those operations include Redpath Orchards, where Chris and David Alpers work. It isn't huge by row crop standards, but its 920 acres of westward sloping hills overlooking Lake Michigan is a capital-intensive operation that uses the latest technology and profits from economies of scale.

The Alperses' inventory includes three mechanical cherry harvesters, a precise GPS to evenly plant and space trees, and an electric-eye sprayer that shuts off over empty patches. Redpath is also experimenting with high-density apples, a new way to plant that increases the number of trees per acre from 200 to 2,000 to produce more and higher quality fruit.

"A lot of farmers who don't have that next generation coming up, they're not open to new technology," says David Alpers, who frequently talks over new methods and equipment with his son.

Carl Zulauf, an agricultural economist at Ohio State University, in Columbus, says that when it comes to upgrading to newer technology, "people who adopt something new tend to be younger."

And when it comes to trying new seed varieties or introducing more sustainable cultivation practices, "that's where we see the most gap between younger and older," Zulauf says, "with older producers saying, 'I've farmed this way, it's been successful for me, I'm still farming, and I'm going to continue doing what I'm doing."

View Images A mechanical shaker harvests cherries from a tree at Gene Garthe's farms in Northport. Photograph by Fritz Hoffmann, National Geographic

More Than Just a Farmer

Nic Welty looks down at a plot of fennel and does the math. At $2 a bulb, this square will bring $34 at the local farmers market. But if he serves them in salads at his chic restaurant in Suttons Bay on the Lower Peninsula, he'll make triple that.

"I find the best market," says Welty, 32, "or I build it."

A torn-shirt entrepreneur with dirt beneath his fingernails, Welty majored in economics and has a master's degree in developmental biology and genetics. He grows vegetables on eight acres, including in hoop houses—greenhouses that trap heat from the sun to lengthen the growing year by several months.

But, he says, he makes a living only because "I own every step along the way," from seedling to plate.

Besides the 9 Bean Rows restaurant in Suttons Bay, he and his wife Jen own a bakery and farm stand. They feed 35 families through their CSA and sell at local farmers markets. Welty is also working with 15 other small-scale farmers to share marketing and distribution costs for a food hub that would sell their produce to local schools, hospitals, and supermarkets.

Welty dreams of franchising his business model to break soil for thousands of five-acre farms across the country. But like other young farmers, including many already deep in college debt, access to capital and credit remains a stumbling block. When he's not farming, Welty teaches financial management classes to local farmers and works through local nonprofits to convince local bankers they should invest in the next generation of farmers.

It's hard work, and sometimes, he says, he wishes he didn't have to do so much selling.