(Boyoun Kim/For The Washington Post)

There’s a kind of farm that has caught the imagination of the food-conscious among us. It’s relatively small, and you know the farmer who runs it. It’s diverse, growing different kinds of crops and often incorporating livestock. It may or may not be organic, but it incorporates practices — crop rotation, minimal pesticide use, composting — that are planet-friendly. Customers are local restaurants, local markets and us: shoppers who buy into a farm share or visit the farmers market.

There’s a lot to like about that kind of farm, and advocates believe it’s the pattern for what our agriculture ought to look like. The vision of small, diversified farms feeding the world, one community at a time, is a popular one. But is it a viable one?

I talked with a passel of people who either study (agricultural economist) or live (farmer) this issue, and there were a few ideas that generated enough consensus that I’m willing to call them facts:

1. Small, diversified farms are less efficient than large ones. Which means that food grown on them is more expensive. Marc Bellemare, an assistant professor in the University of Minnesota’s department of applied economics, calls farmers market produce “luxury goods,” and Tim Griffin, director of the Agriculture, Food and Environment program at Tufts University’s Friedman School of Nutrition Science and Policy, explains the dynamic simply: economy of scale. “As the farms get larger, it’s easier to invest in labor-saving machinery, technology and specialized management, and production cost per unit goes down,” he says. It’s Econ 101.

Even John Ikerd, professor emeritus of agriculture and applied economics at the University of Missouri and an outspoken advocate of the idea that small organic farms ought to feed the world — an idea Bellemare calls “wishful thinking” — acknowledges that we’d need many more farmers to make that happen, and that food would be more expensive. How much more expensive is tough to estimate. Advocates of small-and-local tend to say not much (Ikerd guesses 6 to 8 percent), and skeptics tend to say quite a bit. It would undoubtedly vary significantly by region; areas that are densely populated, where land is expensive, or that have lousy weather, where food is hard to grow, would have higher prices.

The benefits of farm size

2. Small, diversified farms bring benefits to their communities. I’ve never talked with anyone who thinks incorporating agriculture into communities is a bad idea.  Pretty much everyone seems to believe, as I do, that there’s value in having a place where people can take kids to pull a carrot out of the ground or come face to face with a pig. Local agriculture can contribute to a sense of community and keep spaces open.  It’s a reminder to everyone that food doesn’t just appear, and that it’s only because somebody else is growing it that we’re freed up to be accountants or mechanics or scientists. Or journalists.

3. Local’s market share is small. Very small. Under 2 percent small. And the farmers market share is just a fraction of that. Although farmers’ direct sales (through markets, farm stands and community-supported agriculture programs, or CSAs) tripled from 1992 to 2007, from $404 million to $1.2 billion, they leveled off afterward, growing to only $1.3 billion from 2007 to 2012 — despite a large increase in the number of farmers markets during that time, from 4,685 in 2008 (there’s no 2007 data) to 7,864 in 2012. That’s 0.3 percent of total agricultural sales.  Expand “local” to include sales that go through channels to local restaurants and markets, and the figure is larger: $4.8 billion in 2007, the last year for which data is available, but still just over 1 percent of total farm sales. (The USDA is planning to release new data at the end of September, and I’ve seen indications that the number will increase.)   

4. Farmers selling directly to their customers aren’t making a living. The USDA defines “small” as a farm with gross sales under $50,000, and 82 percent of the farms selling directly meet that definition. But the majority — 56 percent — don’t have even $10,000 in sales. These are clearly not operations that support farmers, and perhaps not the best pattern on which to plan the future of our agriculture. 

5. Farms pollute, and large, chemical-intensive commodity farms have damaged the environment. According to the EPA, agriculture is the biggest source of pollution of lakes and rivers, and the recent shutdown of Toledo, Ohio’s, water supply because of toxins produced by bacteria is Exhibit A for agriculture’s environmental impact. That doesn’t mean that all large farms pollute, or that no small farm does, but when you have tens of thousands of acres of a two- or three-crop rotation, with chemical fertilizers and pesticides as standard operating procedure, there are bound to be problems. (There are also animal welfare issues, but I’m leaving that important topic for another day and focusing on crops.)

6. Large industrial farms grow primarily corn and soy, which consumers buy as meat and processed foods. And there’s a strong argument that those foods are making us fat and sick. But that’s not the farmers’ fault. They grow what the market demands.  If we want to fix that, and I think we should, we’d be better off talking to the government, which determines subsidies; food manufacturers, who turn crops into what we actually eat; and consumers, who vote with their wallets.

Those are the major points, and although obviously each is complicated, in aggregate, they boil down to this: Small farms are inefficient but are more likely to grow healthful foods and might be more environmentally friendly, while large farms are sometimes environmentally unfriendly but raise large amounts of food efficiently and affordably. 

The idea that we should replace the large, polluting farms with the small, diversified farms ignores what might be the best solution: Get the large farms to stop polluting.

There are some hopeful signs that it’s already happening. Cover cropping and no-till farming, which help improve soil health and reduce runoff, are on the rise. Recent droughts have underscored the importance of building up organic matter, which retains water, in soil. 

The kind of farm that doesn’t get talked about, and that may combine the best of small and large, is what economists call “the ag of the middle.” One of those farms, on 2,500 acres in southern Minnesota, has been run by Matt Eischen’s family for generations. Eischen rotates sweet corn and peas, which are contracted to become Birds Eye frozen vegetables, with field corn and soy. Growing peas, which go in early and mature in 60 days, sometimes allows him to double-crop his land.  He samples 1.5-acre parcels and adds only the fertilizer that each parcel needs to support the crop he’s intending to grow there. He practices no-till, and he plants grass strips in low-lying areas, which act as a filter for any rainwater running off the fields.  In the fall, he puts cattle out in the fields to eat the cornstalks, and he uses animal manure and crop residue to build organic matter in his soil. No, it’s not like the farmer growing 10 acres of vegetables just outside town, but neither is it the stuff of Chipotle commercials.

As a small farmer, I see both sides of small.  It’s immensely gratifying for my husband, Kevin, and me to bring people out to see our oysters, to show them the different growth stages, to describe how we bring them from pinheads to market size. Our visitors tell us that tasting an oyster right on the farm is a compelling, memorable experience. But our size means that we do many jobs in a way that is time-consuming and labor-intensive. Take tumbling, which we do to remove barnacles. Bigger operations have stainless-steel tumblers that can cost thousands of dollars. We use a ’70s-era cement mixer Kevin found on Craigslist. And, like many small farmers, we drive a truck that’s well past the first blush of youth, and an 80-mile round trip in a truck that gets 14 miles to the gallon, all to drop off 2,000 oysters at our wholesaler . . . well, you do the math.

Small and large both have benefits. Saying we need both isn’t some kind of namby-pamby, can’t-we-all-get-along compromise. It’s the optimal system, with each kind filling a different demand.

What if advocates on each side focused on getting their own house in order? If you’re in the small camp, work on efficiency. Perhaps you can reconsider organic’s natural/synthetic line in the sand, which increases costs without benefiting either customer or environment.  Down the line, think about incorporating genetically modified crop varieties that are disease- or drought-resistant. Find ways to cut back on waste. And those in the large, why not make some of the basic organic-style practices, like cover cropping and no-till, standard? Consider a target level of organic matter in the soil, to cut back on water use. How about strengthening the conservation practices required for farms to receive federal dollars, even linking them to results like runoff reductions or increased organic matter?

Ultimately, we all vote with our wallets, every day. The best way to get an environmentally sound system that grows healthful food is to buy healthful food from environmentally sound farms. And it doesn’t have to be farm stand kale. It could be frozen peas. 

Haspel farms oysters on Cape Cod and writes about food and science. On Twitter: @TamarHaspel. She will join Wednesday’s Free Range chat at noon: live.washingtonpost.com.

CORRECTION: A previous version of this article misstated the percentage of farms with gross sales under $50,000 and $10,000.