Organic No-Till

May 15, 2013

NOTE: Images in this archived article have been removed.

Here are two more 2% Solutions that I wrote, one about farming and one about an olive ranch:

Organic No-Till Farming

Rodale Institute, north of Philadelphia, PA.

Many farmers consider organic no-till the ‘holy grail’ of regenerative agriculture because it combines the best of both worlds: reduced soil disturbance and no chemicals. Its development, however, came about as innovations so often do: by accident.

Conventionally, a modern farm requires a tractor and a plow in order to turn over the soil and furrow the land in preparation for seeding and fertilizing. In a no-till system, however, a farmer plants the seed directly into the soil, usually with a mechanical drill pulled behind a tractor. A thin slice is made in the soil by the drill as it moves along, but nothing resembling a furrow. The soil is not turned over and whatever is growing on the surface is largely left undisturbed. In fact, many no-till farmers plant a cover crop, usually in the fall, so that the soil will be kept cool, moist, and protected from the elements as the cash crop emerges from the ground in the spring or early summer.

One of the major disadvantages of no-till, however, is its lack of weed control. Without a plow, the weeds say ‘thank you very much’ for all that undisturbed soil and start growing vigorously, sometimes elbowing out the cash crop. To check weeds in a no-till system, many farmers apply synthetic herbicides to their fields. They’ll also spray pesticides to keep the bugs in check. Additionally, many conventional no-till farmers will use genetically-modified seeds, often in combination with chemical herbicides. All of this is verboten in an organic farming system, of course.

This is where the happy accident comes in.

One day, Jeff Moyer, the long-time Farm Director at the Rodale Institute, noticed that as he drove in and out of a field on his tractor, the wheels had crushed and killed a plant called hairy vetch along the field’s edges. Vetch is a winter-tolerant legume that organic farmers often plant as a cover crop in their fields. Seeing that the vetch was still alive where he had not driven over it, Moyer realized he had ‘crimped’ the plants with the tractor’s wheels, causing them to die without causing them to detach from the soil, as cutting or harvesting would do. This intrigued Moyer because by remaining attached the dead vetch became a type of ‘in situ’ mulch for the soil. Normally, cover crops are harvested, composted, and returned later to the field as mulch. Moyer’s accidental discovery changed this equation dramatically: he could now crimp the cover crop instead!

However, no mechanical piece of equipment existed to do this job. Jeff took the initiative and after lots of trial-and-error, he and a colleague, John Brubaker, settled on a design for what they call a roller-crimper – a hollow metal cylinder to which shallow metal ribs have been welded in a chevron design (like tractor tires). The roller-crimper is mounted in front of a tractor and as it rolls along through a field it crimps the cover crop, breaking the plant stalks and killing it. The weight of the crimper can be adjusted by adding or subtracting water into the cylinder in order to achieve the desired effect.

As developed by Moyer and others, there are four basic steps to organic no-till: (1) to protect the soil and keep down the weeds, a winter-hardy cover crop is planted in the fall, such as vetch, barley, wheat, or rye; (2) when the cover crop reaches maturity in the spring, the farmer knocks it down with a roller-crimper; (3) the farmer plants a cash crop into the crimped cover crop with a no-till drill or planter, usually at the same time (crimper in front of the tractor, drill pulled behind), and then the cash crop grows up through the crimped cover crop; (4) after harvest in the fall, the organic residue of both crops can be disked into the soil, if the farmer wants, as next year’s cover crop is planted. All together, the use of a cover crop and a roller crimper creates a dense mat of organic material on the soil surface that smothers weeds while providing nutrients, shade, and moisture to the cash crop.

Voila, the holy grail!

The many benefits include: soil is built by the decomposing cover crop; erosion is reduced substantially; nearly all annual weeds are smothered; cover crop roots increase nutrient cycling in the soil, including carbon and nitrogen; biodiversity is increased; greenhouse gas emissions are reduced; costs are low; and the roller-crimper is easy to use and maintain. Better yet, if the tractor is run on farm-produced biodiesel or pulled by horses, it eliminates dependence on fossil fuels, creating a positive energy balance.

There are downsides: cover crops are extra work and an extra cost; they require water, sometimes a lot of it (which makes the practice problematic in arid environments); perennial weeds can be a nuisance; choosing the correct cover crop for your land and matching it to the needs of the cash crop can require a lot of experimentation; rolling the crimper too early in the season can be a costly mistake if the cover crop doesn’t die completely; and like anything new, success requires lots of patience.

The advantages far outweigh the downsides, however, which is why the practice is spreading rapidly. According to Moyer, there are now hundreds of roller-crimpers at work on hundreds of farms and research stations across the nation.

There’s one more benefit: research at Rodale shows that plowing releases large amounts of stored carbon into the atmosphere, adding to the planet’s greenhouse gas problem. When soil is turned over, the sudden access to oxygen speeds up the biological decomposition process, by which microbes eat up organic matter and ‘burp’ carbon dioxide into the air. In contrast, organic methods sequester carbon by improving biological life in the soil. When combined with no-till, according to data, the system has the potential to sequester 1000-2000 lbs of carbon per acre per year – pulled directly from the atmosphere.

That’s a holy grail that we can all appreciate!

Here’s a photo of a roller-crimper in action (Jeff Moyer driving):

 

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What’s in a Olive?

McEvoy Olive Ranch, near Petaluma, northern California

Can the carbon content of soil be doubled in less than ten years? It has on McEvoy Ranch, a 500-acre organic olive Ranch, with benefits including increased soil fertility, water holding capacity, and carbon sequestration.

Settled in the mid 1800’s by Swiss Italian immigrants, the native hardwood rangelands that defined the area were well suited to small-scale dairying. In the early years, many of the abundant oaks and bays were harvested for firewood to help meet the growing demand for fuel in nearby San Francisco, and for the needs of the farm itself. Very little of the farm was actually tilled, due to the predominantly steep terrain, though hay and other field crops were grown on the more level meadow areas.

When Mrs. Nan T. McEvoy purchased the farm in 1991, the infrastructure of the dairy was rundown, but the land itself was in good shape. Abundant water, extensive stands of native perennial grasses and mature woodlands that characterize the landscape were in good condition. With a love of Italian cuisine, Mrs. McEvoy soon decided that rather than continue with livestock production, her goal would be to produce one of the finest olive oils in the world. With a commitment to not to remove any of the trees on the property, she began to plant olives on about 80 acres on the less-steep areas of the ranch.

Dr. Jeffrey Creque came to the project in 1997 to address the question of what to do with the waste products from the ranch’s new olive oil mill. With a Ph.D. in rangeland ecology and decades of experience as an organic farmer, Jeff set out to help Mrs. McEvoy accomplish her goal with a goal of his own: raise the carbon content of the soil from less than 2% to 4%.

Creque and his co-workers embarked on a soil- building strategy that included: (1) applying lots of compost, made on-farm from olive mill waste + livestock manures + landscaping debris harvested on the ranch; (2) avoidance of tillage via the maintenance of a permanent cover-crop beneath the olive trees; (3) seasonal rotational grazing of sheep through the orchard; and (4) riparian area restoration, to address downcutting gullies on the property.

Only 15-20% of an olive is oil, Jeff said, the rest is water and solids. Historically in the Mediterranean region, this organic material would accumulate at the milling site or be dumped into a nearby river or the sea – until the practice was banned in the 1970s. Today, handling and disposition of olive mill waste remains a challenge for olive oil producers. Jeff’s idea at McEvoy was simple: compost all of that material and return it to the soil of the olive orchards, increasing their fertility. In this way, a problem became a benefit.

“Olive oil is like butter,” Jeff said, “meaning it is produced from the current season’s photosynthetically-derived carbon. If the farm exports only oil, it essentially removes nothing permanently from the soil. By avoiding tillage and returning all residuals to the land, the olive oil agroecosystem takes in more carbon from the atmosphere than it emits. Done well, olive oil production can be an essentially permanent, regenerative form of agriculture.”

Data backs him up. Dozens of soil samples are taken every year from all over the farm and sent to a laboratory for analysis. While results have shown year-to-year fluctuations in the organic matter content of the soil, due to weather and sampling variables mostly, the trend has been clear: upward. In fact, after ten years the carbon content of the soil began hovering around 4%. This means the farm is sequestering more CO2 than it did back in 1997, it’s more productive and it’s holding more water in the soil.

Jeff doesn’t want to stop there. With the restoration of the ranch’s riparian areas, a new challenge – and carbon sequestration opportunity – has emerged: managing surplus riparian vegetation (especially willows) for compost production. As the overall productivity of the ranch has increased, the volume of carbon sequestered in standing biomass and soils, and potentially available for composting, has also increased.

“There’s no reason to think that we can’t increase soil carbon in our agricultural systems to levels above those that would occur without management,” Jeff told me. “Besides, there are no downsides to trying and lots of upsides, especially for agricultural productivity, sustainability and climate change mitigation. If we can manage our soils to store more carbon, we’ll also enable them to store more water, while reducing the volume of CO2 in the atmosphere. That’s a BIG upside.”

Jeff notes that millions of tons of organic waste – food, grass clippings, branches, manures, – go into landfills every year across the nation. Why not compost them instead and divert them to farms and rangelands where they could provide multiple benefits? There’s a cost to hauling this material around, of course, but it could be offset by increased ecological productivity + potential carbon credits, not to mention benefits to the Earth’s climate system.

McEvoy also employs renewable wind and solar thermal energy on the farm. However, accomplishing energy self-sufficiency has proven to be more difficult to achieve than the carbon work. “Increasing soil carbon,” Jeff said, “is relatively easy. Overcoming the bureaucratic challenges to installing sustainable energy systems has proven much more difficult.

As for the economics of it all, McEvoy olive oil and associated products (including a body care line) are high-end goods that have established themselves in the marketplace.

What’s in a little olive? A lot.

Here’s a photo of Jeff Creque and a compost pile:

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Courtney White

A former archaeologist and Sierra Club activist, Courtney dropped out of the 'conflict industry' in 1997 to co-found The Quivira Coalition, a nonprofit dedicated to building bridges between ranchers, conservationists, public land managers, scientists and others around the idea of land health. Today, his work concentrates on building economic and ecological resilience on working landscapes, with a special emphasis on carbon ranching and the new agrarian movement. His writing has appeared in numerous publications, including Farming, Acres Magazine, Rangelands, and the Natural Resources Journal. His essay The Working Wilderness: a Call for a Land Health Movement" was published by Wendell Berry in 2005 in his collection of essays titled The Way of Ignorance. In 2008, Island Press published Courtney's book Revolution on the Range: the Rise of a New Ranch in the American West. He co-edited, with Dr. Rick Knight, Conservation for a New Generation, also published by Island Press in 2008. He lives in Santa Fe, New Mexico, with his family and a backyard full of chickens.

Tags: carbon sequestration, organic no-till