No-till is a technique and tool to achieve the farmer’s objectives of reducing tillage and building soil health. It is also a whole farm system. And these techniques and tools can work equally well on all farms. The term basically describes ways to grow crops each year without disturbing the soil through tillage or plowing. A true no-till system avoids disturbing the soil with tools like chisel plows, field cultivators, disks, and plows. No-till can help your farm in a number of different ways but it is imperative that the system be implemented in a way that encourages success.
Here are just a few of the key concepts to think about:
• No-till depends on the cover crops to provide the nutrition needs of the cash crop. Of course, the nutrients from the cover crops are not available immediately. They are partially available the first year and partially available in successive years. If your soil is low in organic matter, or if you have not farmed organically before, it may take a while to build the soil. Think of it as money in the bank. You’re investing in your soil, and as time progresses you will be able to cash in on the dividends or interest from your account.
• Kill is achieved with a roller-crimper rather than synthetic herbicides. It works by rolling the cover crop plants in one direction, crushing them and crimping their stems. The roller-crimper can be front-mounted on a tractor, freeing up the rear of the tractor for a no-till planter, drill or transplanter to plant directly into the rolled cover crop. While other tools, such as a stalk chopper, rolling harrows, and mowers have been used for this purpose, the roller-crimper has several advantages over other tools.
• The rolled cover crop acts as a mulch, preventing annual weeds from growing through the entire season. To achieve adequate weed control, the cover crop should be planted at a high rate and produce approximately 3 to 4 tons to the acre of dry matter. For this reason, cover crops that yield a high amount of biomass work best for the no-till system. It’s also important to select cover crops with a carbon to nitrogen ratio higher than 20:1. The higher the ratio, the more carbon, and the more slowly the crop will break down. This will provide consistent weed management through the season.
Here are some suggestions about how to get started—without planting a single seed. The following ideas will help you become a successful no-till farmer, while managing the risks of adjusting to a new system.
Reading and learning
Find out as much as you can about which cover crops do well in your area. This might include talking to other no-till farmers, taking advantage of resources available at your local Extension office, and following up by consulting reference guides.
Assess your farm
Look at your soil types, the crops you intend to plant, the equipment and resources you have and the time you have to explore new planting systems. Like any changes on your farm, knowledge is power and understanding how new cover crop management tools will fit into your operation will be critical to your success.
Source local seed
Locally adapted cover crop seed will give you an edge, providing a crop that’s already adapted to your area. It will be less likely to winter kill and may perform better on your farm. Since it may take some time to track down a local source, you should begin early. This is especially true for organic seed since quantities may be limited.
Perhaps the biggest source of risk comes from transitioning to a new management system and a completely new technology. During the first couple of years, the learning curve may be fairly steep. It’s a good idea to start with a small, experimental area or test plot on your farm.
Cover crops are an essential part of any organic system but are especially crucial to the success of no-till in an organic operation and provide a multitude of benefits:
Increase soil organic matter
No-till is an intensive system which requires at least 3 to 4 tons of dry matter per acre to be effective. Cover crops are grown to their full potential, instead of being tilled in at an earlier growth stage. This means that, in general, the organic matter will be higher in carbon and lower in nitrogen making for long-lasting benefits as mulch for weed management.
Provide year-round cover for the soil
Covering the soil increases infiltration, reduces evaporation, stabilizes soil temperatures, provides habitat for soil life, and reduces soil crusting.
The roots of the cover crop stabilize soil and reduce runoff, while the above-ground portion of the plants protects the soil against the destructive force of raindrops. In an organic no-till system, actively growing cover crops (or, the rolled and killed cover crops) are in place during key times when erosion can occur, including spring melt, winter thaws, and summer storms.
Capture, hold and stabilize nutrients
Many cover crops (also called “catch crops”) are excellent scavengers of nitrogen and other nutrients. Rye, in particular, can scavenge 25%-100% of residual nitrogen left behind from the previous crop. As covers are rolled down and begin to decompose, this nitrogen is slowly released for use by the subsequent cash crops. Buckwheat is especially good at capturing phosphorus and releasing it for use by cash crops. Cover crop roots can also forage deeper in the soil, bringing calcium and potassium up from untapped soil layers. Unlike chemical fertilizers, organic amendments are more likely to provide a slow release of nutrients.
Increase biological activity
No-till increases diversity on the farm by providing year-round habitat and minimizing soil disturbance. Cover crops provide roots which nourish microorganisms and stabilize organic matter. Aboveground, beneficial insects find both habitat and nectar sources which may lessen the severity of pest insect problems.
Reduce field operations
In organic no-till, the yearly field operations can be as few as two: one pass to roll the cover crop and plant, and another to harvest the crop. Additional field operations may be used at other points in the rotation to establish the cover crops; however, these crops generally don’t require any cultivation to manage weeds.
According to some estimates, up to 80% of the energy used in the production of corn is conserved by converting to organic no-till. While the production system may require approved organic fertilizers, energy savings are realized through the elimination of conventional nitrogen fertilizer.
Provide non-chemical weed management
For organic farmers, weed management is ranked as the number one challenge in most surveys. No-till can help by breaking weed cycles and by providing cover through much of the growing season.
If no-till trend caught on, it could have a few big climate benefits. It would lock more carbon in the soil and curtail fossil-fuel use in farm operations. The UNEP estimates that no-tillage operations in the United States have helped avoid 241 million metric tons of carbon-dioxide since the 1970s. That’s equivalent to the annual emissions of about 50 million cars.
Croatian Center of Renewable Energy Sources (CCRES)