Social networking can impact understanding of soil carbon
In a recent The Art of Range podcast, dated Sept. 27, Dr. Peter Donovan with the Soil Carbon Coalition discusses the impact of soil carbon and the importance of social networking to increase internal motivation for caring of land.
According to Donovan, the definition of soil carbon is, “the living, dead and very dead residues of living organisms, plants and living microbes.”
Soil Carbon Coalition
In 2007, Donovan helped found the Soil Carbon Coalition (SCC), a non-profit organization. The goal of the SCC is to help people ask better questions about soil carbon, as well as engage more people in asking and answering those questions, shares Donovan.
The purpose of the SCC is to raise awareness and educate others about the importance of what Donovan calls the “soil carbon sponge: living matrix that soaks up and filters water, holds landscapes in place and provides nutrients for the food chain, leading into soil’s ability to absorb and retain water.”
Donovan has spent the last eight years taking measurements of soil carbon.
“I’ve been traveling around the country,” he says. “North America, Canada and Mexico doing a lot of different base-line plots to look at range cover and water filtration, as well as some accurate measurements of soil carbon at particular points of the landscape to try to measure change.”
He continues, “The dirt’s porosity and aggregate structure are highly dependent upon carbon fractions – the knots, slimes and glues hold the mineral particles together and form a pore, which is resistant to saturation, but can still hold and transmit water when it’s saturated.”
Soil carbon measurements
The process of measuring carbon is a lot easier than measuring water, shares Donovan.
“Water changes its form minute-by-minute, hour-by-hour and day-by-day, whereas most forms of organic carbon are somewhat more stable,” he explains. “It’s easier to get a time stamp of what the change might be.”
There is research which suggests grassland and rangeland soil carbon is more stable and reliable than forest soil carbon, notes Donovan.
“Forest soil carbon is more durable but prone to loss due to wildfire,” he says. “Rangeland soil carbon can be found below ground, and therefore, is less subjectable to loss through aboveground ecosystem processes.”
Donovan uses a typical test to conduct a carbon nitrite analysis.
He explains, “A dried prepared sample is heated to about 900 degrees centigrade and the amount of carbon dioxide which evaporates can provide a good measurement of carbon.”
He goes on to mention, “Although it can be easy to focus on elemental carbon, it’s really part of a bigger picture: the capture of solar energy by the biosphere which includes water.”
Donovan uses what is called a single ring infiltration test. This process estimates the rate in which runoff will infiltrate or pass through native soil. Through his work, he found climate plays an important factor in increasing soil carbon.
“Soil carbon seems to be easier to increase in northern latitude climates with good, long winters,” shares Donovan, noting perennial grasses, diversity and long recovery periods are also key in increasing soil carbons.
Donovan shares, “The process of capturing solar energy by landscape is a combination of the carbon and water cycle in addition to nitrogen and sulfur cycles. It takes a lot of energy to desalinate sea water, move it over the land and distribute it until the soil pores; photosynthesis – a tiny percent of energy, does this.”
There is a very complex feedback relationship between water and carbon cycles, and with the management of livestock, Donovan explains there is a tremendous difference.
“If all the vegetation is grazed off and plants aren’t allowed to contribute their photosynthesis to soil microbiology in the solid food web, soil is likely to become very compact and not able to absorb water as well,” Donovan continues. “This creates a vicious cycle in terms of plant growth and will result in degraded landscapes without management of livestock.”
With better management practices it is possible to improve both water capture and photosynthesis by allowing plants to be fully expressed in addition to allowing adequate recovery periods.
Donovan notes, “We really need to improve the water cycle if we are going to make a difference in soil carbon – slowing water down will help soils better accept and hold water.”
“It’s not carbon or carbon dioxide that is highly relevant to the earth’s climate change, but it’s the factor of water vapor in terms of greenhouse gases,” Donovan continues. “We know the balance of temperature on earth is largely driven by the behavior of water and water vapor.”
As a result, this change causes longer droughts, bigger storms and greater runoff due to the water cycle intensifying, Donovan says.
Donovan notes, successful management of soil health and watershed function are internally motivated, not externally motivated.
He says, “People are motivated by their own love of the land, by their own curiosity and growing awareness of the relationship between carbon and water cycling, the way the biosphere works.
“I’ve learned most policies and programs are set up to deliver external incentive, and thus robs people from their autonomy, curiosity and entrepreneurial can-do attitudes,” he says, noting external incentives work well in a linear input/output system. “For example, if the price of corn doubles, we often see more acreage planted and more input supply, but I think a lot of the issues and concerns around soil heath, watershed function, carbon and water cycling are not as amendable to simple input and output approaches.”
Donovan says cover crops and reducing intensive tillage may help but it’s not always easy to define the outcome of every case.
“What rotational grazing means to someone might mean something different to someone over there,” explains Donovan. “Real feedback is in fact rare in most of our programs and external incentives.”
He shares feedback tends to slip into a judgement rather than active learning. “Instead of asking, ‘Is my soil type good or bad?’ a better question would be ‘How fast does it take for an inch of water or a second or third inch to infiltrate and what might the factors to encourage this?’”
“One of the things I think is very important, and this is something I’ve learned in my two dozen years of working, is that learning networks is an important way to get beyond the judgement in the external motivations that we have for soil health, water function and regenerative agriculture,” shares Donovan.
He continues, “I think local networks with people who learn, talk to others and begin to trust one another are a superpower in learning how the ecosystem works – not just this or that research – but with actual participatory observation, evidence gathering, discussion and witnessing the process of learning ourselves and with others.”
Donovan concludes, “The SCC has done a lot towards building a web application specifically designed for building networks of people who want to learn together and exchange information to share data and evidence. It’s for projects that involve local groups wanting to learn from each other and with each other.”
“Not everyone spends a majority of their time thinking and doing something about soil carbon, we don’t always have to defer to experts. We can participate, we are a part of this system,” says Donovan.
Brittany Gunn is the editor of the Wyoming Livestock Roundup. Send comments on this article to firstname.lastname@example.org.