How about both?
April 22 is earth day, and per Earth Day tradition, many folks will feel inspired to plant a tree, and they should. In a time of drastically changing climate, planting trees is one way of combating the excess of greenhouse gases trapping heat in the atmosphere. Through photosynthesis, trees and other plants pull carbon dioxide from the atmosphere and convert it into sugar, cellulose, and other carbon-containing carbohydrates that they use for nourishment and growth. This natural process is called carbon sequestration.
Although trees are famous for their carbon sequestering abilities, it is actually soil that is the largest terrestrial reservoir of carbon. Soils contain approximately 3/4 of the carbon pool on land — three times more than the amount stored in living plants and animals. This is great news, but, how does carbon come to be stored in soil? The answer: through plant roots. When plants convert CO2 into food for themselves, they are also creating food for microorganisms in the soil through their root exudate. These microorganisms eat and defecate, directly adding organic carbon to the soil and increasing its organic matter.
Trees are impressive exemplars of biomass, many of which grow taller and older than any human. However, in reality the greatest amount of carbon is sequestered in the soil of grazing lands. While trees store most of their carbon in vegetation that eventually dies and rots (re-releasing the carbon), carbon sequestered by grazing lands is more readily transferred into the soil itself, where it can be permanently stored (1). Among the types of agricultural land, grazing land has the highest ability to sequester carbon, partly because its soil is left intact as it is used. Although many crop farms now use practices to keep soil covered, carbon is lost to the atmosphere every time cropland soil is disturbed via tilling and in some cases harvesting. Our soils have lost more than half their carbon over the last 200 years due to common crop farming practices.
There is a long-held misconception that pasturing livestock only results in overgrazing and desertification of grasslands. However, if done with proper management, the use of grazing lands with domestic livestock can play a significant role in mitigating climate change. Researchers have estimated that it is possible for 29.5-110 million metric tons of carbon to be sequestered annually in the grazing lands in the United States (2).
Grass has evolved to be grazed. When grass is grazed by an herbivore, it stimulates the plant to begin a phase of rapid biomass production. This means more photosynthesis and thus more carbon sequestrated into the soil. In the absence of grazing, or well timed mechanical harvesting, grass merely grows to a certain maturity, becomes senescent and dies. Dead grass will decompose, but the amount of carbon it adds to soil is nowhere near the amount the cycle of grazing and regrowth can sequester. Nothing can mimic the natural interaction between plants and grazing animals.
When overgrazing occurs, the grass does not have enough time to regrow, so it drains the energy reserves in its roots. This results in shorter and shorter roots that are unable to hold the soil together or feed the resident microorganisms. Proper grazing management allows grass to recuperate after a calculated grazing period on a specific area by a certain number of animals. The livestock are moved rotationally around the pasture in paddocks, and may not re-visit a previous paddock for weeks at a time. This management is very healthy for the soils, and it is beneficial for the animals subsisting on them. There are several different types of management strategies that take a pasture’s rest and regrowth into consideration such as Management Intensive Rotational Grazing, Mob Grazing, and Holistic Grazing Management, to name a few. Well managed grazing land could rival the intensity of passive soil carbon accumulation of native ecosystems.
As a triple-bottom-line business that equally weights Environment, Community, and Profit in our operation, we at Kriemhild take great interest in the grazing management of our producers. We believe that grazing is important nutritionally for livestock animals and the food they produce, but it also has the ability to affect profound and far-reaching positive environmental impact. If all of the countries on earth committed to increasing their soil carbon by just 0.4% each year, the global community could store 75% of our annual industrial greenhouse emissions. The way that farmers choose to use and manage agricultural grazing lands, and the practices consumers support thru our purchases, can and do shape our global environment thru local ecology.
So, don’t hesitate to plant your tree on earth day. Just remember this as well: when you choose purchase our Meadow Butter or Crème Fraîche, you are choosing to support over 1500 acres of active soil carbon sequestration; and that’s one more way you can influence global change thru small, local action.
(1) Schuman, G.E., D.R. LeCain, J.D. Reeder, and J.A. Morgan. 2001. “Carbon Dynamics and Sequestration of a Mixed-Grass Prairie as Influenced by Grazing.” In Soil Carbon Sequestration and the Greenhouse Effect, special publication no. 57, edited by R. Lal, 67-75. Madison, WI: Soil Science Society of America.
(2) Follett, R.F., J.M. Kimble, and R. Lal. 2001. The Potential of U.S. Grazing Lands to Sequester Carbon and Mitigate the Greenhouse Effect. Boca Raton, FL: Lewis Publishers
As the Butter Churns
Author: Ellen Fagan
Farm and Outreach Coordinator