Photo by Rachael Brugger
In a matter of years, you can have healthy, productive soil using the no-till gardening method.
Good soil is the foundation of every garden. In each tablespoon of healthy garden soil there are 1 billion bacteria, 1 million fungi, 100,000 protozoa, 100 beneficial nematodes and scores of other living organisms. These microscopic creatures all serve a valuable purpose. Although a few of them are likely pathogenic, most play roles in a multitude of positive actions that serve to improve crop health. They acquire nutrients from the soil, passing them along to plants in exchange for carbohydrates, suppress disease and break down soil organic matter to help build fertility. These organisms perform millions of beneficial activities in the soil every moment of every day.
However, the work soil organisms do takes place in a surprisingly fragile system. What is now commonly referred to as "the soil food web” is a delicate structure of connections among all the living organisms in our soil, each of which directly impacts the health of our plants. Because the web of life beneath the soil’s surface is so delicate, it’s important that we disturb it as little as possible. Many beneficial organisms are killed by the overuse of chemical fertilizers and herbicides, as well as by soil disturbances, such as tillage. Because of this, more and more farmers and gardeners are turning to no-till methods of farming and gardening. Leaving soil unturned means the soil food web remains intact and can function at its prime.
Weigh Your Tillage Options
Small-scale gardeners interested in utilizing no-till techniques on their homesteads should begin by investigating the pros and cons.
When no-till techniques are in place, existing weeds aren’t turned under as they are with tilling; instead, they’re smothered with mulch. Many longtime practitioners of no-till techniques discover that weeds become less and less of a problem over the years. While tilling brings viable weed seeds to the surface and enables them to germinate, the mulches no-till gardeners use bury the seeds deeper where they remain dormant.
Other positives of no-till farming include the addition of organic matter through the crop residues that remain on the garden bed and the prevention of excess carbon loss from the soil. No-till methods also offer increased protection from soil erosion and can cut down on irrigation needs because of the heavy use of mulches.
However, these methods also might mean a longer wait for organic matter to reach a plant’s root zone, increased potential for soil compaction if heavy equipment is used regularly, and the inability to expose ground-dwelling pests to predators. No-till gardening systems are unable to quickly incorporate organic matter deep into the soil. Instead they rely on the actions of soil-processing microbes to mix the organic matter into the soil—something that can take a considerable amount of time. Some crops—corn, in particular—might not respond well to no-till techniques and special equipment might be needed for planting on a large scale. Despite these potential negatives, no-till gardening methods have the ability to greatly benefit the grower, the soil and all the organisms living there.
No-till Farming Techniques
Traditional no-till farming uses large amounts of herbicides to suppress weeds. Instead of relying on chemicals, my preferred no-till technique relies on mulches to control weeds and add organic matter to the soil. For gardeners reluctant to go totally no-till, try it in just a portion of the garden for a few years before implementing the practice everywhere. I did this in my own garden: The first year, I converted 1/4 of the garden to no-till techniques, then each year, I added another portion of the garden until, within a few years, the entire garden was maintained under no-till practices. It has successfully remained no-till in the years since. The benefits of no-till techniques can take a few years to fully develop depending on the existing soil conditions and the amount of current soil life. Not surprisingly, gardeners and farmers who have been using chemical fertilizers for years might struggle with no-till techniques in the first year or two until the number of beneficial soil-dwelling organisms is rebooted and reaches a sustainable level.
To get started, decide what portion of your growing area you’re going to convert to no-till. Come spring, do not cultivate the soil. Instead, at the time you would normally till, add a 3- to 4-inch layer of organic matter across the surface of the soil. Appropriate materials include decomposed leaves (my personal favorite), finished compost, mushroom soil, year-old cow or horse manure, or any combination thereof. If none of these products are available, use a 2- to 3-inch layer of straw or untreated grass clippings instead. To really suppress the weeds, layer about 10 sheets of newspaper over the soil before spreading the organic matter on top of it. There are a number of reasons to avoid shredded-bark mulches: They are not fully decomposed and steal nitrogen from the upper layer of soil as they break down, and they take several years to decompose and add their organic matter to the soil, something we want to happen far more quickly.
Once the mulch is in place, it’s time to plant. For transplants, push aside the mulch, cut through the newspaper (if you decided to use it) and dig your planting hole. For row crops, use a hoe to push aside the mulch, slice a slit in the newspaper with a box cutter and break a strip into the soil. Sow the seeds and cover them with the soil, leaving the mulch at the side of the row.
At the end of the gardening season, you can choose to leave any non-diseased plant material intact or pull it up and toss it onto the compost pile. Then pile on another 4- to 6-inch layer of organic matter. If possible, choose a different material than you used in the spring. The goal over time is to add as many different types of organic matter as possible. Ideally, two applications of organic matter should take place each year: a 3- to 4-inch layer in the spring and a 4- to 6-inch layer in the fall.
What About Cover Crops?
If cover crops are part of your garden plan, you might think that switching to a no-till system will be a challenge. Not so! Although you’ll no longer be turning the cover crop into the soil, you can still reap all the benefits they provide. Annual cover crops, such as buckwheat, field rye and cowpeas, are the best choices for no-till gardening. They should be planted in the autumn and left in place over winter. Come spring, mow the cover crop as low as possible before it goes to seed and leave the clippings where they fall. Soon after mowing, add a 3- to 4-inch layer of organic matter. Wait three to four weeks before planting.
As the health of the soil improves, its friability will increase and it will become easier to work. It took my garden about two years of complete no-till practices to reach its full potential. Now I relish each quiet spring, void of noisy rototillers and back-breaking hand digging. Instead, I have happy plants, billions of healthy soil microbes and a beautiful, productive garden.
About the Author: Horticulturist Jessica Walliser is the author of Grow Organic: Over 250 Tips and Ideas for Growing Flowers, Veggies, Lawns, and More (St. Lynn’s Press, 2007). She is a gardening columnist for the Pittsburgh Tribune-Review and co-hosts The Organic Gardeners on KDKA radio in Pittsburgh.