Jack Kitteridge, policy director of Northeast Organic Farming Association/Massachusetts, works hard to keep carbon in the soil on his New England farm.
He was a panel speaker at the NOFA-NJ Winter Conference in late January. His expertise in the field was illustrated by a monograph on carbon sequestration in 2015. He is also working on the NOFA/Mass soil carbon survey which includes questions about the growing practices of anyone who manages land: farmers, gardeners, homeowners and professionals. The questions center around practices, learning and interests.
In addition to developing the survey, NOFA/Mass recruited participants for a trial to research the most effective methods of capturing carbon in the soil. Practices include low till, no till, mulching with organic matter, use of fungal/microbial inoculants, ending synthetic chemical use or integrating livestock into cropping.
Storing carbon in the soil is important because it is returning the carbon where it belongs, according to Kitteridge in his essay, “Soil Carbon Restoration: Can Biology do the Job?”.
Kitteridge points out in his writings that land clearing and cultivation release massive amounts of carbon from the soil. The microbes in the soil return carbon but must be helped along for optimum soil conditions.
Since there is too much carbon, in the form of carbon monoxide in the atmosphere, farmers and researchers started about 20 years ago to work out methods of removing it from the air and returning it to the soil.
Kitteridge emphasized the importance of understanding the role of agriculture in drawing out carbon and sequestering it in the soil. “A lot of people want to tax carbon and pay farmers to sequester it,” but carbon is not easily measured in the soil, especially stable carbon, he explained. This has led him to an effort to create a new system of testing for carbon. Measuring the vitality of the soil helps to demonstrate the carbon amount. And, he pointed out, experienced farmers can tell good soil by looking at it.
The color is evidence of good carbon, he said, and there is an active carbon test with potassium permanganate. The number of microbes in the soil is also a good indication. A refractometer can be used to measure dissolved solids in a fluid, which in the case of plant sap is sugar.
Studies continue, but Kitteridge and others have found perennial growing systems restore more carbon than most other systems.
During the panel discussion, member Nathan Kleinman, who farms in Elmer and runs a non-profit seed-sharing initiative, the Experimental Farm Network, said perennials require less tilling and less water. He cites asparagus and rhubarb as two examples of these perennials.
Since there are challenges to growing perennials in temperate climates, the Land Institute of Kansas is attempting to overcome these challengers, Kleinman said.
Another panelist, Joseph Heckman from Rutgers University’s agricultural school, explained that trees and pasture both contribute carbon to the soil. “Pasture is a great kind of no-till farming.” Kitteridge says organic, no-till practices paired with adding sufficient organic matter to the soil seem to be best at restoring carbon. However this carbon stabilization may only impact the first few inches of soil, but studies have indicated there may be a slow deepening of organic matter in the soil.
Soils with more humus maintain carbon most easily. Its complex molecules are not easily broken down by microbial life in the soil.
Kitteridge’s research reveals the importance of cover crops. Bare soil, even over winter, oxidizes carbon. He believes there is a need for more research into methods for fighting weeds without disturbing the soil so much carbon is released. There are currently systems and devices in the design stage that may reduce tillage requirements which should be effective, according to his writings.
Kleinman explained the Badgersett Research Corp in Minnesota develops plans for carbon sequestration. Much of their research is in nut trees, an area also the subject of Rutgers research.
Kleinman’s network collaborates with other non-profits on plant breeding and other agricultural research, he said. “We create thousands of crosses but can’t plant all of them. Our idea is to get volunteers energized and interested in perennial crops.” He said they have 250 volunteers in 45 states.
Bryan O’Hara of Tobacco Road Farm in Connecticut was also on the panel. He says the talent of farming is in handling the carbon/nitrogen cycle. He makes considerable compost and grows cover crops to help with carbon sequestration. “We seek to keep the soil surface covered with vegetables as much as possible.”
O’Hara practices no-till on his farm which was not managed well when he took it over. There was a lack of forest cover and pollinator die outs. He said that isn’t unusual in the Northeast which he called “the land of innovation.”
Kitteridge said he is concerned about the schemes that blow carbon into mines. “It will blow back out again,” he said.