New research from Food Systems Research Center postdoctoral researcher Serge Wiltshire adds to a growing body of evidence showing how regenerative agricultural practices can reduce the impacts of climate change. , shows that farmers can play an important role in sequestering atmospheric carbon in the soil through different land use and management practices.
The release of carbon dioxide emissions into the atmosphere is the primary driving factor of climate change. Typically, we discuss carbon generated from burning fossil fuels, but soil also holds large amounts of carbon that, when disturbed, can be released. However, it is also possible to change land management practices in ways that sequester carbon from the atmosphere back into the soil.
While climate change research has largely has focused on slowing or stopping greenhouse gas emissions, Wiltshire, a postdoctoral researcher with the ̽̽ Food Systems Research Center, and his mentor Brian Beckage, professor in the Department of Plant Biology, aimed to observe how farmland management in Vermont could remove excess atmospheric carbon. Their research question is built on existing data showing how altering land use can sequester carbon and play a role in reducing the impacts of climate change.
“Basically, as a human species we have released a lot of carbon into the atmosphere. This carbon mostly began underground, but was oxidized and entered the atmosphere either through soil disturbance or burning fossil fuels,” said Wiltshire. “At the end of the day, the only viable way to reduce atmospheric carbon is to store it back in the ground, where it started. There are several proposed methods to do this, but tweaking farmland management is probably the easiest and most effective of the currently understood strategies.”
The researchers utilized a model that considered various strategies for land management, such as regenerative farming practices like cover cropping, crop rotation, and rotational grazing, along with conversion to forests. In all their scenarios except maintaining current practices (dubbed business-as-usual), carbon was sequestered in the soil.
The most dramatic sequestration of carbon occurred when transitioning all agricultural land to old growth forest, or forests that have attained age without much disturbance, which would be a highly unlikely scenario in the real world. However, farmers adopting intensive rotational grazing, and to a lesser extent regenerative cropping practices, showed significant carbon sequestration, meaning these approaches can make a difference in addressing the impacts of climate change.
Although their data suggest that farmland soil carbon sequestration shows promise as a greenhouse gas mitigation strategy, the researchers pointed out how the soil carbon storage rate diminished over time in these models, meaning that this strategy represents a potent, albeit short-term part of the overall solution. In the long term, carbon emissions from the burning of fossil fuels will still need to be a critical part of any climate change mitigation strategies and policies. Also, because only 12% of Vermont’s land is used for agriculture, contributions of regenerative agricultural practices are important, but not as significant as in states with more farmland, such as the mid-west, where large amounts of land are dedicated to farming. Nevertheless, seeking methods to increase soil carbon was found to be an effective transitional strategy to mitigate climate change.
Wiltshire and Beckage also noted it is imperative we find ways to produce enough food to feed the world, while also caring for the land and the planet.
“We have to balance food production and farms’ economic viability with carbon reduction goals. This might mean that it’s better to farm intensively on a smaller land base in the state, while letting some of the more marginal land progress to forests. We’re continuing to look into these types of trade-offs,” said Wiltshire.
The researchers conclude that in all scenarios, farmers could aid in sequestering atmospheric carbon through regenerative agricultural practices like rotational grazing, cover cropping and crop rotation whenever possible, especially as these practices produce co-benefits like building soil health and reducing harmful runoff.
