There’s a lot of discussion about No Till farming.
Everyone may be talking about different things.
No Till Farming is a term of aspiration with plenty of history, currently having a strong resurgence as part of climate challenge mentality and a deepening understanding of soil health, foodwebs, and carbon sequestration. One of my first farming reads in 1980 was Plowman’s Folly (1943) by Edward Faulkner, an agricultural agent from northern Ohio who observed the degradation of soil caused by recurrent use of the moldboard plow. He observed and reasoned what we now know by a thousand measures; turning the soil repeatedly oxidizes humus and buries fresh organic matter that should be protecting and feeding the soil surface. His solution was revolutionary at the time, the common disc. It chops and stirs the soil surface, incorporating fresh organic matter into the topsoil without inverting or stirring up anything deeper than a few inches. Plowman’s Folly was met with disparaging skepticism from the agronomist community. Deeper is better was the motto of the day. Of course, a certain number of farmers embraced Faulkner’s concept, deeply.
And then there were many mulchers over the decades, starting with Ruth Stout and her “no work method” of deep mulching with straw, leaves, weeds or anything at hand. The permaculturists laid down cardboard and newspapers by the carload, and buried them with woodchips. Avant market gardeners covered acres with round-baled straw and hay. Cover crop crimpers were invented, intending to lay down and kill standing cover crop. Then came the silage tarps and occultation, a dark term that raises eyebrows.
But of course, the most widely employed No Till method relies on herbicide to kill everything except the crop. Seed and fertilizer is inserted through undisturbed stubble into the soil using highly engineered no-till planters. The seed may have been engineered as well, to tolerate the herbicides. No Till includes a wide spectrum of practices and practitioners.
I have employed all of these methods, except the last, to one degree or another, and all have a place. But none of them really get the whole farm planted in a narrow weather window, under the wide range of preconditions that a seed farm finds itself in. The glory of plowing or tillage is its erasure of complexity and discontinuity across the landscape. Stubble, weeds, cover crops, failed crops, trouble spots, burrows, nests--all disappear with a few passages of the tillage machine, leaving behind a blank canvas of a soft dark medium, ready to accept sown seeds or transplants with ease and without competition. For about a week. Then come the first weedlings. Tillage also works for them, bringing buried seed to the surface, providing the light signal that breaks dormancy, eliminating the overstory and competition of established roots. Every benefit to the farmer in terms of uniformity, fertility application, effortless crop establishment, abounding seedling growth; these also benefit the undesirable explosion of weeds that will occupy the farmer’s attention and resources for too much of the year.
Within the disturbed soil there are comparable explosions of life as bacteria respond to a surfeit of oxygen, consuming organic material of all sorts (fresh and humic), releasing nutrients in a shock wave of availability, some of which may leach away quickly as dissolved nutrients or reach for the sky as ammonia or nitrogen oxides. Fungal mycelium that might have captured nutrients and turned them toward plant roots are destroyed by tillage, and require time and established plant communities to rebuild their networks. Earthworms, burrowing arthropods, and microcritters that create soil aggregates, pores, and channels suffer the same fate as creatures and plants of the surface, complete homogenization, community dissociation, and death by chaos. Repeated tillage of a pounding nature degrades soil structure and aggregation, creating problems for water and air infiltration that results in surface crusting, and increased bulk density as air spaces become ever smaller. With clay soil, you make bricks. With sandy soil you make a sandbox. With loess, you make dust. Such problems are not evident immediately after tillage, they come with time in the form of “soil problems” like compaction, tillage pans, crusting, erosion, and the like. It takes reflection to see these as tillage problems, not soil problems.
No Till farming attempts to address the many consequences of tillage by eliminating or minimizing soil disturbance. The most recent calls for reduced tillage emphasize the need to capture and secure atmospheric carbon, visualizing “carbon-sink” agriculture as a solution to climate chaos, and, conversely, tillage as a source of greenhouse gas pollution. There are many takes on how to do this, all variations on the discing/mulching/crimping/tarping themes. Scale, location, crops, and equipment are big factors in the variations at hand. A No Till family garden is one thing, a 300 acre mixed vegetable-grain operation is something else. Vermont is one place, California completely another. It is one thing in a humid climate where rain during summer moves decomposing matter into the soil, and another in a dry climate where summer aridity sucks water and nutrients out of the earth. Irrigated land is different from dryland, overhead irrigation is different from drip. Creating soil fertility with cover crops requires a different system than one laying nutrients down as concentrate powders and compost. Growing vegetables for market is one situation, growing seeds on contract is another.
Some farms have a system that works great for them (already right now!), whereas other farmers with great skill, knowledge, and experience cannot attain the same yields in organic no till systems as they do with tillage. My understanding is that yields drop by half in California grain and vegetable no-till trials where fertility is based on cover crops and their timely decay. Not so in the same climate on a smaller scale where fertility is based on compost and mineral powders with overhead summer irrigation, and fresh market vegetables are cycling through beds many times a year. The dynamics (and scale) of these systems are completely different, and in essence, incomparable. It isn’t possible to up-scale a 3 acre system to 300 acres without up-scaling the number of workers by the same factor. As much as I wish this wasn’t true, there are not 100 times more farm workers out there ready to get their hands dirty raising food if only they could do it No Till organic. This isn’t to criticize one scale for being unable to be another scale, systems are just built to scale. There is virtue and humility to be found at every size.
At this point in our understanding, it seems every farm system is destined to find their own path to No Till farming. The individuality of these efforts begins with location, crop, and scale, but more subtly, it begins with what individuals mean by No Till. How many No Till videos have I seen where the process involves a “tilther” to mix surface applied compost and nutrients, and a broadfork to loosen soil deeply? A lot of people see tilthing and broadforking as soil disturbance, and so, “that ain’t No Till” is a common response. But it ain’t tilling or plowing either. It is referred to as “minimal tillage” by most of us, a catch-all term for systems that fail the undisturbed test, but pass the test of good intentions. Surely a broadfork disrupts mycelial networks. Can we say that’s a bad thing, done occasionally? Does the benefit of quickly breaking up pans and compaction outweigh the momentary disruption of soil food webs?
Like other path choices in life, the decision to go No Till can take on strictures that can become a bit zealous. I can relate to that. Fervor provides the commitment to do something new and hard and prone to failure. It can also make us judgy of those who aren’t sharing our zeal, or who haven’t taken our word to do as we have done. In the organic community, there is a lot of farming by philosophy. Done it my whole life. I’m hoping we can share a lot of information and grace as we practice toward No/Lo/Minimal tillage.
I’ve done all manner of tillage in 42 years. I was initiated into market gardening as a Jeavons-inspired double digger. I double dug three farms in their beginnings, and in each case moved toward minimal tillage after the third year. We are now on the fourth farm, following the same trajectory, but without the double digging. In the beginning, a moldboard plow turned under a pasture of 40 years. A disc smoothed it out, half for production, half for cover crop. Permanent beds were established with a BCS walk-behind tiller. Eight tons of compost were applied per acre, once or twice per year. But by summer of year three, one could see the soil aggregates breaking down, crusting following irrigation. No surprise, really. From cake to cracker in three cycles. The question was, What’s the No Till approach to this farm and these crops?
If you go looking into productive No Till agriculture, you run straight into Singing Frogs Farm. Elizabeth and Paul Kaiser have created an unparalleled specimen of a successful small scale No Till intensive vegetable farm in Sebastopol, CA, 3 acres of year round production with over $100,000 in returns per acre. By every measure this is an ecologically beneficial farm, that is optimally productive, a treasure of its community, that maintains high levels of fertility, and it doesn’t “leak.” The fertility stays on the farm. Water leaving the property is cleaner than water entering the property. This is accomplished by shear biology, by the constant presence of living roots at all depths with all the attendant fungi, bacteria, worms, insects, and microlife. The Kaiser’s have orchestrated a dynamic ecosystem that never seems to rest, that founts food and employment and education and income ceaselessly. The permanent beds are maintained with applications of compost and are soft enough to transplant with bare hands. Most crops are transplanted rather than direct seeded, so beds may have 3-7 replantings per year. An overriding principle here is keeping the soil covered by growing leaves and filled with growing roots at all times. This keeps many hands productively at work with good pay doing pleasant work; planting, tending, harvesting, marketing, teaching. Ceaselessly.
As appropriate as Singing Frogs Farm is to its location, crops, and mission, it isn’t the right model for us, though our “human scale” is the same. Our crops are long term, one per location per year. And they are tended by two or three people, not ten. We use winter cover crops. Those differences change everything.
Oregon winters are cold and wet, rain pounds down, and the ground needs cover. Our land comes into planting season in a variety of ways. Some is in cover crops of grains and legumes. Some is covered in plants we have no use for (weeds), some is in chickweed (for April harvest), some has a canopy of dead-standing late seed crop (strawflower, etc.) left in place for the birds. Much of the ground, especially pathways, will be clumped with annual bluegrass (Poa annua), bittercress, Persian veronica, and sow thistle. Some of the ground may be under silage tarps, and the plant community beneath it completely devoured by voles, worms, beetles, fungi, and microbes by time planting day comes around. Atop the silage tarps are death pools where worms, slugs, beetles, flies, millipedes, and moths ferment after drowning. A disgusting brew.
Our climate grows grass and broadleaf weeds all winter, and only occultation with lightproof tarps will leave us a clean slate to begin a completely No Till season. I like the results of occultation, but I don’t like working with large wet tarps stinking to high hell from rotten invertebrates. I also question turning off the lights from the earth for 6-10 weeks, as it seems to go against the principle of gathering maximum light to fix maximum carbon for the soil. There’s a limit to the scale of the process, as well. I wouldn’t want more than a quarter of my cultivated area under a water impermeable layer through the winter. In my experience, permeable landscape fabric doesn’t kill grass in the necessary time frame. Even the uniform death by occultation leaves the irregularities of molehills, undecomposed grass clumps, and rodent tunnels. If you place a transplant into any of these irregularities, it won’t thrive.
When I think about a minimal tillage system for our farm, it needs to accommodate all of these preconditions, from oat crowns to Poa zombies to vole-riddled occultations. It also has to suit the geography, which is sloped, the geology, which is clay, and the climate, wet in spring, dry in summer. And suit the crop (seeds), which has one planting per year. So how do we begin a minimal till planting season with most of the land growing plants of some kind?
My compromise between No Till and standard tilling is what I call “skim tillage.” Just as it sounds, skim tillage aims to remove the top 1-2 inches of soil and the crowns of living plants. This is more challenging and delicate than it sounds, and would best be done with a power harrow (which has good depth control) rather than a tiller. But a tiller is lighter weight, and it’s what I have, and at this stage of life I’m into making use of what I already own. New equipment leaves big carbon footprints to be atoned.
Skimming off the soil surface without deeper disturbance has a number of desirable outcomes, including a coarse, fibrous surface layer above and intact soil biota with all its natural channels and interconnections below. The process begins with a close mowing, shredding green and dead plant materials into lengths that will mix with loosened soil to create an organic-rich surface layer. Without their crowns, the roots of most farm and garden plant species will die and rot in place, food for the soil that leaves vertical channels with mycelial connections. Canada thistle, field morning glory, dandelion, and dock are the common species that don’t die from beheading, and remain a challenge in (I think) All Tillage systems throughout the season. (I choose to think of these as deep nutrient recyclers, imposing an involuntary cover crop regime.)
Skimming can begin earlier than standard tillage, after just enough fair weather to make the mowed surface friable. The strategy is to go slow, perhaps a single pass, or one pass in each direction to begin. This starts drying the soil, wilting down the green parts, and beating soil from the roots of Poa, which can be hard to kill before it reroots, flowers and reseeds. The first or second pass will not finish the job. There are always skips where tines bounced over grass crowns or didn’t cut deep enough to prevent resprouting. After green tissues have wilted and clumps have dried a little the process is repeated to eliminate skips and again rattle the persistent grass root balls from their clinging dirt. The number of skimming repetitions will depend on the kind and density of plant cover being converted into the surface soil layer. Broadleaf plants wilt and rot quickly, grains and grasses are more resistant and prone to regrowth. I do the pathways first, the beds the next day, and keep this pattern going until the bed surface looks like a coarse mulch of dead plants and soil. Doing the paths first is a way to define the space, and doing the work on alternate days keeps the pathways and beds distinct as they are being prepared. At this point, the tiller is done: organic matter is dead on the surface, worms and beetles are rising through undisturbed passages to feed on the surface debris, pulling it down deeply into the earth, dying roots are creating new passages, feeding fungi and the microherds.
Wheel hoes are a brilliant invention, hula-hoe action on a wheel that can sweep down pathways or cut surgically close to the row long after crops outgrow tractor cultivation. They can slice precisely beneath the crowns of weeds big and small with either a pushing or pulling motion, leaving a crumbed surface strewn with wilting soil food. I really love the Oak Valley wheel hoe, which has a long list of attachments and blade-width options that can be switched in seconds without a tool. The stirrup blade is the perfect complement to skim tillage, maintaining the loose breathing surface layer where weedlings are easily undercut, and capillary action can’t draw water to the surface, an arid west issue.
Once the skim tillage layer has wilted, the furrow attachment is used to draw rows the length of the bed (2 rows 24” apart, or 3 rows 16” apart). The furrower lightly scrapes over the untilled soil, pushing the tilled matrix to the side, leaving undisturbed soil exposed. Soil amendments are applied to the rows using a low to moderate application rate, then the 8” stirrup blade lightly stirs them in and a light application of compost covers the row. After watering and resting overnight, the bed is ready to receive transplants. If the bed is to be direct seeded, this would happen before compost is added between the rows (to avoid burying the seed).
We transplant with a soil knife (hori-hori), placing the roots into the undisturbed soil, using loose soil to snug the seedling in place. I think this is the key step in our process, forcing the seedling to root into firm soil rather than stirred soil. In the untilled ground, seedling roots find and follow worm channels, beetle burrows, and rotted root traces downward toward moisture. I’ve noted that the mature transplants often have roots that remind me of teeth, with 3 or 4 strong roots going straight down from the seedling root tangle. Direct seeded plants have strong taproots with little branching near the surface.
In contrast, transplants placed into soft fertile soil put roots out in all directions from the root ball, and grow really fast, but not really deep. The roots look like bottle brushes, and they may flatten out where soft soil meets undisturbed soil. This is fine for crops in quick rotation that don’t get very tall, but seed plants and other tall, top-heavy crops are more likely to lodge (fall over) if growing in tilled soil. For our kind of crop, in our windy location, the difference in lodging alone is enough to justify the change from standard till to skim till. The deep roots also reduce water stress, and we use less water overall, perhaps by a quarter last year. Reduced water use is a primary goal for sustainable farming.
This process seems straightforward, even obvious, in my 30 second description to visitors who ask about tillage. “We do a shallow ‘skim till’ one or two inches deep to terminate surface vegetation. Then we make shallow row furrows to expose undisturbed soil, add amendments, and scratch these into the row with a stirrup blade. We transplant (or direct seed) into the furrow, placing roots into the untilled zone. The furrow is closed with loose soil as the transplants are set in place, or left open if direct seeded. The tilled surface is the cultivation medium, a movable layer for undercutting or burying weeds and moving soil around for hilling up around crops that benefit from that. The loose layer acts like an organically enriched dust mulch, breaking soil capillarity, keeping moisture in the ground.” Obvious, right? Sure it is, after trying many other ways that didn’t work at all. Our instincts can lead us astray, especially when they are based on bias.
We have a deep instinct that plants need loose soil to thrive. After indoctrination into double digging it is hard to imagine otherwise. How many times have I heard bragging about “beds so soft you can put your arms in up to your elbows.” I made beds like that, and I was always confused when volunteers in the pathway did as well as transplants on the bed. Better even, when water was short, or the crop was tall and top heavy. I learned quickly on coarse soil that double digging was counterproductive (farms #1 and 2), and less quickly that raised beds make no sense in an arid summer climate (farm #3), even on clay soil. A visiting mentor made the point 25 years ago, pointing to the dry bed and the verdant pathway; “This method makes no sense; you are planting on the Mountain, and weeding to death the Valley.” I have never forgotten this. I leveled my Mountains, and formed Valleys there for planting. Fertility always moves from Mountain to Valley. Duh.
But even then, I was a sucker for softness. But plants really are not. Fluffy soil contains too much air. Roots need steady moisture and good soil contact. Being rooted means having a firm grip on the earth, not a tenuous grasp on movable dirt. My earlier versions of minimal till provided a soft zone to receive transplant roots with undisturbed soil just beneath. Too often the roots went for the soft fertile watered layer at the surface, without forming a downward tap root, the roots apparently diffusing their energies in all directions. By midsummer, these plants were prone to wilting without frequent watering, and by harvest, many would lodge. The root systems seemed to push themselves out of the earth, or the earth settled from around them, exposing their crowns and roots that had that bottle brush structure, and they pulled easily from the ground. When the transplant roots are set into the firm but life-channeled earth, they grow down into it, holding strong, resisting wind throw, and even pulling.
This is not a finished puzzle, it’s an ongoing one. The soil is changing yearly, and the practice varies some depending on initial conditions. As it is, the skim till process allows for the use of cover crops and the presence of overwintered stubble, and does not require the import of large amounts of compost or mulching materials (something I’ve chosen to avoid), or labor. I can see evidence of deeper rooting in crops, volunteers, and weeds, but don’t really know if there is an effect on seed yields, which can vary for many reasons. I don’t yet know the impact on soil organic matter and fertility, or whether I should be testing fertility at a deeper depth. I think the plants grow more slowly in the beginning, compared with tilled soil, but they seem very sturdy as they mature. I didn’t expect root crops to do very well, but have been pleasantly surprised by the best carrots ever, prodigious beets, and parsnips with roots to hell (I now include parsnips in cover crop mixes). This is not a prescription for any other farm or garden, just a progress report from ours, as we try to farm a little better every time.
Originally published in the 2023 Wild Garden Seed Catalog.