No-Till: Parking the Plow for Soil Health
“The nation that destroys its soil, destroys itself.” …..Franklin D. Roosevelt
FDR wrote those words in 1937 in conjunction with the recently launched effort to create soil conservation districts. By that time, about 35 million acres of farmland in the Southern Great Plains had been decimated by an extended drought and windstorms that blew topsoil away and devastated the lives of rural people. Farming practices, specifically the plow, greatly exacerbated the impact of the environmental catastrophe of the Dust Bowl era.
Some of the most fertile soil in the world developed in the Great Plains as a result of the co-evolution of enormous herds of bison and deep-rooted perennial native grasses that built a resilient soil structure and provided a protective armor over the topsoil, preventing erosion.
Plowing the grasslands to farm left the ground bare and destroyed the ecosystem’s ability to endure weather extremes. We now know that plowing or tilling also releases carbon into the atmosphere and is a very real contributor to climate change.
The Problem with Tillage
Regenerative farmer Elizabeth Kaiser of Singing Frogs Farm has parked the plow and is using a no till system on her’s and her husband Paul’s 8-acre farm (2.5 acres under cultivation), “Tillage is when you take a tractor, when you take a rototiller, or when you take a horse and plow and you turn up the soil. You take the soil aggregates from larger sizes down to smaller sizes. There are two negative things that will happen. One is chemical and one is biological.
“The chemical part is that as the soil aggregates are broken up into smaller and smaller pieces, the surface area is increased compared to the volume. Tilling also brings oxygen into the system so more oxygen is in contact with the soil, which volatilizes a lot of compounds. Carbon becomes carbon dioxide, nitrogen becomes nitrous oxide, and there are also certain processes that can create methane. Those are the three most potent greenhouse gases. As farmers and ranchers, carbon and nitrogen are the things that we need most in our soil. So, the act of taking them out of the soil and putting them where we need it the least – in the atmosphere – makes no sense.
“The second thing that happens is biological. As the aggregates are broken up, the tilling creates total ecological destruction for the organisms that are in the soil. ‘Tilling the soil is the equivalent of an earthquake, hurricane, tornado and forest fire occurring simultaneously to the world of soil organisms. Simply stated tillage is bad for the soil.’ That quote is from the USDA. This is not some West Coast leftie idea. We know that tillage is bad for the soil, and we need to figure out how to farm and sustain ourselves on this planet in a way that doesn’t do so much damage.”
If plowing destroys soil health, what alternatives do farmers have? That depends on the scale of the operation. Kaiser describes a few options for the small-scale farm down to the backyard garden.
“There are a lot of options when starting a no-till field depending on what your resources are, what your soil type is, what you’re going to be growing, and how much space you are going to be utilizing.
“If you’re already tilling, till one more time, create beds, put compost on top and never till it again. That’s how most of our beds were formed because we were already doing tillage.
“A second way is using occultation, which is more time intensive. Leave whatever is there – the grass, the weeds, or whatever– to decompose in place until you have a clean slate, and then create your beds. To start, we put down landscape fabric over an entire area where there was pretty strong grass and left it for six months. Then we did a slight inoculation with some compost teas to make sure the soil biology was high. We covered the whole thing in straw, and we then pulled up the straw and created beds. We spread a bit of compost on the beds, but not very much and then we were ready to plant.
“The last way is resource intensive. If you have a smaller space or if you want to get going quick, or you have the resources, I highly recommend this. Put down cardboard, build your beds out of two inches of compost, put straw flakes down for pathways, and go. If you’re just doing two beds in your backyard where you have lawn, this is what I recommend.”
No-Till for Larger Farms
But these recommendations, although highly effective, are not practical for larger farming operations. No-till farming systems have been used on medium size and larger farms since the 1940’s and are increasing in favor. According to the 2017 USDA Agricultural Census, over 100 million acres of cropland in the US are no-till. The caveat, however, is conventional no-till farmers use toxic herbicides like Round-Up to kill the cover crop and weeds. Conventional farmers who till also use similar chemicals, but they have the option to use a disc or plow to control weeds. So, no-till does not decrease chemical use and, in some cases, may even increase it.
Organic farmers are highly dependent on tilling because they are not able to use herbicides. The need for herbicides eliminated no-till as an option for organic farmers until the Rodale Institute designed the roller-crimper and made the design available free to farmers in 2006.
Designed for use after a cover crop has matured, the roller-crimper mechanically kills the cover crop by rolling over and crimping the stem to break the water flow from root to stem. The timing of this is critical; if done too early, the plant may not die back sufficiently, if done too late there will be too much seed produced and left in the field. The optimum time to pass over the field with a roller-crimper is when the cover crop reaches anthesis – the time when the flower opens when the plant goes from the vegetative stage to the reproductive stage. Once the roller-crimper passes through the field a thick, protective, weed-suppressing mulch is formed, which can be planted through. As that mulch breaks down it feeds soil life and deposits carbon in the soil. Iowa State organic specialist Kathleen Delate’s research shows no statistical difference between the yields of no-till and plowed plots of organic soybeans.
Mowing the cover crop is also an option, but that doesn’t result in the same level of weed suppression as the roller-crimper mower and, in some cases, doesn’t kill the cover crop allowing it to regrow.
The Benefits of No Till
No-till has proven agricultural benefits: less erosion, lower fuel cost due to less tractor use, less soil compaction, better soil moisture, and better soil health. Of course, there is a learning curve to adapt the practice to a specific farm crop and soil and some initial start-up costs, but the past has shown the terrible ecological and economic costs of tilling.
People in the 1930’s who lived through the trauma of, what was at the time, the greatest ecological disaster in the US history, learned the value of soil the hard way. Today topsoil is being lost at an alarming rate threatening global food security. At the same time, we face an even greater ecological crisis – the disruption of the climate due to anthropogenic causes. No-till can help address both of those problems.
Will we make the same mistakes over again or can humanity make the necessary changes to protect life on the planet? Agriculture, a key contributor to climate change, has the potential to be a leader in mitigating the climate crisis. Adopting no-till farming, one of a number of Regenerative Agricultural practices, is a readily available tool to help turn things in the right direction.