Your Salad’s Difficulty with Sustainable Farming
No matter how organic your shopping is, when you sit down to a plate of leafy greens, chances are you are supporting farming methods that contribute to global warming. There are, however, other options.
By TODD OPPENHEIMER
Cover photo by TEXASRANCHERGIRL.COM
Italy photos courtesy of the RODALE INSTITUTE
In recent years, a growing number of grain and livestock farmers across the East and Midwest have been reporting surprising results from moving to an unusual system called “low-till” or “no-till” agriculture. The terms refer to a collection of practices that let farmers get away from conventional tilling machinery—diskers, spaders, the ubiquitous plow—all of which tear up the land. Farmers abandon tilling for a variety of reasons—soil health and future financial stability being foremost among them. But now there is an environmental rationale as well.
The struggle with no-till farming in California illuminates the central question in any attempt to master something: How do you know when you have given something enough of a chance? The answer: When you are sure you’ve tried everything possible to find a better way. And that, according to the Rodale Institute, is precisely what most California farmers have ignored.
The practice of tilling exposes the underside of the world’s land to sun and wind, which makes it dry out. As it happens, more than 50 percent of that underside consists of carbon. As the carbon dries out, it essentially burns up–in other words, it oxidizes into carbon dioxide, becoming modern civilization’s primary contribution to climate change. And climate change, the world is now learning, is causing increasingly severe droughts, particularly in the American West. Several weeks into 2015, climatologists were forecasting, for California’s lowland areas, the first dry January in the state’s history. And things only got worse as the year went on.
One would expect these developments, which have been approaching for years, to prompt some changes. After all, California grows so much of the fruit, nuts and vegetables that feed the nation, that the survival of California farmers means the survival of America. Yet most farmers in the state have by and large struggled with no-till practices. “You have to be willing to accept weeds,” says Eric Brennan, a research horticulturalist stationed in California’s Salinas Valley for the U.S. Department of Agriculture.
But wait—Gabe Brown and the other Midwestern heroes of no-till agriculture beat back their weeds without a plow. Why can’t California farmers do it too? The reasons are both simple and extremely elusive.
First, the simple explanation: When done properly, no-till agriculture begins with leaving planting “cover crops” for the winter, often straight through the unplowed leftovers of the previous season’s harvest. (Cover crops refer to the variety of grasses, beans and other plants that are grown not to eat but to protect and feed the soil during the off-season.) Before planting the next season’s food crops, in the spring, no-till farmers must find some way to knock down whatever is left in the fields, and use the dead material for mulch and compost during the approaching growing season.
This works fine in middle and eastern parts of the U.S., where winters bring in freezing temperatures that tend to suppress weed growth. In the massive farm valleys of California, however, deep freezes are a rarity (and getting rarer by the month, thanks to climate change). So the weeds—which are almost always the most aggressive members of the plant family—have a field day: wide stretches of open land, relatively warm winter months, and plenty of rain (well, usually). When that happens on California farmland, the result is often a boggy, putrid mess—a petri dish, in other words, for all manner of bacteria and disease.
This environment can kill next season’s vegetable crops—but the weeds love it. “In a no-till system in Salinas,” Brennan says, “you can get such a weed-seed bank in your soil, you never get ahead of the game.” The challenge is particularly severe for farmers who grow leafy vegetables, such as lettuce. Their seeds are tiny (“the size of sesame seeds,” as Brennan puts it), and not nearly as tough as the big, hardy corn seeds that can break through crop refuse on Midwestern fields.
It’s enough to make a farmer in California’s Central Valley throw up his hands, head to the barn, and hook up his tractor to a good, reliable plow. And many have done exactly that. “It’s not as though no one has ever thought about these ideas,” says Tim Hartz, a well-known agronomist in the department of Plant Sciences at UC Davis. “Most of this stuff has been tried and rejected over the years because it’s not cost-effective.”
But that ignores the crucial question in any attempt to master something: How do you know when you have given something enough of a chance? The answer: When you are sure you’ve tried everything possible to find a better way. This is where the answers become elusive. And, according to the Rodale Institute, the nation’s leading think-tank for organic agriculture, a determined pursuit of those answers is precisely what most California farmers have ignored.
To further no-till farming’s cause, Rodale has developed a new device that farmers can pull behind their tractors instead of a plow or spader (the common tools of tillage). The new machine, called a “roller crimper,” destroys crop leftovers by crimping them at the base of their stems, then lying them down on the field so they can decompose. While this still leaves the challenge of rotten or potentially impenetrable crop stems, Rodale reports success with the machine in a range of locales and soil types. That includes such countries as Argentina and Italy, which have climates similar to California’s.
Jeff Moyer, Rodale’s farm director, acknowledges that California cultivates many crops that some of these countries don’t—and does so on a far larger scale. But that’s no excuse in his book. The key is to develop cover crops that California’s vegetable seedlings can penetrate. “We need to do more seed breeding for cover crops,” Moyer says. “Right now, all our cover-crop seeds are just off the shelf. That’s ridiculous. No one plants off-the-shelf tomatoes.”
In fairness, there is yet another reason that California farmers are reluctant to embrace no-till practices. In contrast to tillage farming, which usually produces good yields (when there is plenty of rain), no-till methods can take a few years to pay off. In the East and Midwest, where most farmers own their own land, a shift to no-till is often seen as a worthwhile long-term investment; in California, however, where roughly half the farmers lease their land—making them the modern-day equivalent of tenant farmers—investments in the future aren’t nearly so attractive.
Whether profitable in the near-term or not, no-till farming does offer one advantage that might soon get people’s attention in the West. Over time, it typically requires lower levels of irrigation. And right now, nothing in California matters more than water. If the state’s droughts get bad enough, state officials just might see an opportunity in no-till farming for some new policies, and some financial support to back them up.