First, the bad news: We’ve lost millions of tons of soil from croplands in the United States annually for the past 20 years due to water and wind erosion. The rate of erosion skyrockets the more soil is cultivated and left bare. Heavy tillage also destroys the soil structure and life-forms that nourish plants, meaning more fertilizer and amendments are needed later. The good news? You can help turn around these problems by practicing no-till or low-till farming techniques on your own land.
No-till farming methods (also known as “zero tillage”) can be adapted to any size of operation — backyard gardens, small market gardens, multi-acre farms, and more. The technique involves creating a deep mulch, and then planting a crop through the mulch. No-till in conjunction with cover crops can reduce erosion, boost soil nutrients and organic matter, and conserve moisture. Additionally, the thick cover-crop mulch suppresses weeds and encourages the microbes, earthworms, fungi, and other beneficial microorganisms that maintain soil structure and health.
Although no-till farming is now used on more than 35 percent of the acreage of major crops, conventional operations largely depend on herbicides and synthetic fertilizers. Organic no-till methods, however, will allow you to avoid chemicals and improve the soil structure in your plot, whatever its size. For organic farmers who need specialized equipment to make zero tillage viable, we especially recommend the following tools.
1. Roller/crimper. Organic no-till begins with a cover crop, which becomes mulch after it’s killed. You can kill your cover crop with hand tools if your plot is small enough, but larger growers do this mechanically. About 12 years ago, Jeff Moyer created the roller/crimper at Rodale Institute, a leader in organic farming methods. This implement is basically a large, heavy cylinder with long blades welded onto it in a chevron pattern (see slideshow). Rolled over a cover crop, the blades crimp the stems of the plants, killing them in place to make a weed-suppressing mulch that conserves moisture while adding organic matter to the soil as it and the cover crop’s roots degrade. “It’s the biology of the cover crop that’s doing all the work,” says Moyer, whose book, Organic No-Till Farming, describes how no-till limits tillage, reduces labor, and improves the soil without chemicals.
“The cover-crop mulch has to be fairly thick, at least 5,000 pounds of dry matter per acre — 8,000 to 10,000 pounds is much better,” says Moyer, executive director of Rodale Institute. Timing is very important, too: The cover crop is easiest to kill when it’s in bloom, but before its seeds have formed.
Gardeners and market farmers with limited power tools can make their own crimper out of simple materials: Screw a 30-inch piece of angle iron to the bottom of a 30-inch piece of 2-by-4, drill a hole into each end of the wood, thread a rope through, and knot the ends. To use a homemade crimper, Moyer explains, “You put your weight on the board and crush the stem of the plant, then pick it up by the rope and do it again.”
Kentucky-based Earth Tools has seen steady growth selling small tractors and implements to growers working 1 to 3 acres. The roller/crimper offered by Earth Tools is 30 inches wide, can be pushed or pulled by a two-wheel, walk-behind tractor, and is sized perfectly for market-garden beds.
Not all vegetables are suited to planting in a plot that’s been cover-cropped and rolled. Crops that can easily be seeded into a crimped mulch by hand or with a seeder include corn, squash, beans, cucumbers, melons, and anything that’s going to send up a strong, sturdy seedling. If the mulch is too thick, “you may have to reach down and make a little window for it to come through,” says Earth Tools’ Joel Dufour. Vegetable seedlings that can be easily transplanted by hand into a crimped mulch include tomatoes, peppers, and broccoli. Crops that come up out of the ground with small leaves, such as spinach or beets, can easily be smothered by heavy mulch. For these crops, use a flail mower or no-till slicer-planter with opening discs that lay a small strip of ground bare for the seedbed (see numbers 2 and 3).
2. Slicer-planter. For larger no-till growers, cutting through the mulch layer to direct-seed crops can be a problem. In his field trials, Moyer uses a four-wheel tractor with a 10-foot-wide roller/crimper in front, and a weighted planter with slicer attachments behind. This equipment combo kills the cover crop and instantly plants into rows cleared in the mulch.
Moyer worked with Pequea Planter to design the slicer attachment for no-till planters. Still in the early stages of development, the attachment consists of rubber tires mounted on each side of a coulter — so it looks like a round slicer resembling a big pizza cutter. The rubber tires pin down the cover-crop mulch, the slicer cuts a row in the mulch, and the planter plants a row of seeds.
3. Flail mower. Leafy, low-growing greens, such as lettuce or spinach, are best seeded into a residue-free bed to prevent pieces of old cover crop from spoiling a future salad. For this purpose, Dufour recommends a flail mower. The mower’s many pivoting blades will chop cover crops into little pieces that will then need to be tilled into the top inch or two of soil, where microbes will break them down. This type of surface cultivation still fits into a no-till farming philosophy because it doesn’t disturb the soil structure. “The flail mower is also an ace in the hole if you didn’t get your timing right with your roller/crimper,” says Dufour. Roll too early, and there may be too much energy in the plant for it to die. Hit it with the flail mower, and it’s done.
4. Broadfork. Even with organic no-till farming methods, your soil will become compacted every few years. Jean-Martin Fortier, a market farmer in Quebec, loosens soil with a broadfork. “It allows us to have the benefits of deep tillage without really tilling,” he says.
Broadforks are hand tools with vertical tines mounted to the bottom of a horizontal bar between a pair of long, straight handles. To use a broadfork, press the tines into the soil and rock the long handles back and forth to loosen the soil.
A subsoiler is another implement, like a broadfork, that might be considered “low-till.” This tractor attachment can be dragged through the soil to a depth of 11 inches to loosen up compacted beds.
5. Rotary power harrow. Fortier specializes in vegetables, annually producing thousands of pounds of mesclun — and a gross income of more than $150,000 — on 11⁄2 acres of permanent raised beds. He shreds cover crops with a flail mower, then mixes the residue into the top inch of the soil’s surface with a rotary power harrow.
Rotary power harrows stir the soil with tines and level the surface to prepare it for planting. As Fortier explains it, the tool “perfectly conditions the soil for transplants.” He adds that two-wheel tractors with reversible handlebars allow for power take-off attachments, both front and rear.
Fortier, who calls his system “minimal tillage” or “biological tillage,” will occasionally re-form raised beds with a rotary plow, an implement produced by the Berta Franco Co. to fit walk-behind tractors. But he’ll use it in early spring when the soil on his farm is still cold, so that earthworms and other soil creatures and features won’t be killed or disturbed. Fortier’s gardens — and yours, too — depend on them.
Cultivating Organic Cover Crops
Any cover crop that’s an annual or winter annual can work in a no-till or low-till system, says Jeff Moyer of Rodale Institute. “The trick is to look at your crop rotation, and figure out where there are windows of opportunity to put in cover crops, or how to rearrange your rotation to plant cover crops. Then, pick the plant that best suits your soil, environment, and rotation,” he says. Moyer recommends these cover crops.
• Small grains: wheat, rye, oats, triticale, barley, and buckwheat
• Non-perennial legumes: hairy vetch, Austrian winter peas, field peas, forage soybeans, and crimson clover or any annual clover
You should also consider these variables before deciding on a cover crop.
• How long do you want your cover-crop mulch to last? Grasses, such as cereal rye, are better for weed suppression because they take longer to break down.
• Do you want mulch that breaks down quickly? Choose buckwheat and vetch, or chop any cover crop with a flail mower.
• Want your cover-crop mulch to be in place for next spring? Plant your cover crop in summer and let winter cold kill it. Be sure it doesn’t go to seed.
• Do you want a cover that also adds nitrogen to the soil? Go with legumes, such as peas and soybeans.