Originally published in Permaculture Magazine by SETH ITZKAN, KARL THIDEMANN, AND STEVEN KELETI
“A lot of farmers are being educated about the capacity of soil to sequester carbon. It gets them excited to think that they can contribute to a reversal of climate change.”
– Kate Duesterberg, Farm Manager, Cedar Circle Farm, Vermont
A new and growing movement is inspiring farmers to produce food in a manner that can mitigate and even help reverse global warming. We call this “climate farming, the agriculture of hope.”
At the core of this movement is the understanding that soil health and climate stability are closely linked. The condition of one impacts the other. In the atmosphere, carbon exists as carbon dioxide (CO2), a greenhouse gas warming the planet. But in plants, carbon forms a sugary liquid (like maple sap) that is exuded through the roots and gobbled up by microscopic critters at the foundation of what soil scientist Dr. Elaine Ingham calls the “Soil Food Web.” This infusion of carbon and the microbial activity it supports gives structure to soil, improves the nutrient density of food, and, perhaps most importantly, increases soil’s capacity to hold water.
Working to put more carbon into the soil, the climate farmer is thereby enhancing the productivity of soil while contributing to the long- term welfare of the planet. Regenerative farmer Jesse McDougall, of Studio Hill Farm in Shaftsbury, Vermont, shares, “Carbon is the world’s best fertilizer. Our goal in farming is to pass on to the next generation land that is outrageously fertile.”
Photosynthesis is nature’s invention for pulling carbon out of the atmosphere and giving it to plants and soils. Respiration and decay then return the carbon to the air. In a natural state, this exchange is in balance. However, as soil is degraded through industrial farming practices, including plowing and the use of fossil fuel- intensive fertilizers, more carbon is released to the air than is absorbed in the soil. Fortunately, this process can be reversed. Soil can be a carbon sink. There are many methods to achieve soil carbon sequestration.
Courageous climate farmers are at the forefront of experimentation. Cover crops and no-till farming are recognized as core methodologies for improving soil health, and thus, improving carbon content. Organic farmer Kate Duesterberg states, “We have a pretty hard- and-fast rule to never allow bare soil after harvest. To the extent possible, we always have a cover crop. We are also experimenting with no-till farming.”
For grazing operations, mixed species, bunched herding, and well-timed animal movement are helpful approaches to aid in carbon sequestration. According to McDougall, “We chose to raise animals here for their amazing natural ability to revitalize the soil under their feet. The chickens, turkeys, and sheep that move through our rolling pastures every day are the central component of our regenerative farming practices. The animals, when allowed to act naturally in nature, restart the downward swing of the carbon cycle.” Improving the soil enables the grass to sequester more carbon, explains McDougall, who concludes, “It’s a food-producing, carbon-sequestering, positive- feedback loop.”
A difficult challenge of the climate farmer is weed control. In a grazing operation, weeds are less of a concern because animals graze on the weeds. In an organic, annual row crop operation, however, weeds can wreak havoc. As no toxic chemical applications are permitted with organic farming, tilling has been the standard approach. However, like pesticides, tilling degrades soil health in part by harming the soil biota. So, the staff at Cedar Circle Farm are experimenting with a solarizer – a thin sheet of clear plastic laid over the cover crop that heats the area underneath the plastic sufficiently to kill off the weeds, while not harming soil life under the matt of the flattened cover crops (typically rye). The solarizer is moved daily, depending on the weather, and weeds are killed with no chemicals and no tilling.
Nicholas Cook, research and development manager at Cedar Circle Farm, explains it this way: “We are trying to take a systematic approach to solving one challenge at a time. So, the first challenge that we decided to overcome with an organic, no-till system was making sure that we can have effective weed control for our cash crops.”
The Rodale Institute is promoting a new piece of machinery, a High Residue Cultivator, for managing weeds in a rotational, no-till system. It slices weeds both above and below ground without turning the soil or disturbing the desired crop or the fragile soil food web.