Carbon’s Role in Soil and Crop Health

By Adam Kiel, Soil and Water Outcomes Fund Managing Director

Carbon is one of the most abundant elements on Earth, playing a critical role in both natural ecosystems and agricultural systems. From the air we breathe to the soil beneath our feet, carbon is constantly in motion, shaping our environment and fueling life. Understanding how carbon works in our soils and plants can unlock a new level of crop health and productivity while also producing environmental benefits.

Carbon: The Building Block of Crop Health
Carbon is a fundamental element that is essential to living systems. Carbon has unique bonding capabilities that allow it to combine with many other elements, forming chains and rings that serve as the building blocks of cells. The bonds in these carbon structures store considerable energy, serving as an excellent fuel source for all forms of life (Riebeek, 2011).

Residue from the previous cash crop decomposes and a radish cover crop works to increase water infiltration and capture excess nitrogen in this SWOF-enrolled field in SE Iowa.

Carbon’s role in agriculture is incredibly vast, and photosynthesis is a primary example. During this process, plants take in carbon dioxide (CO₂) from the atmosphere and use that energy to make sugars and other carbohydrates. These carbon-based molecules support all aspects of plant growth, from root to grain (Corning et al., 2016).

When plants die and decompose, some of this carbon is released back into the atmosphere while the rest enriches the soil. Soil holds the largest active reservoir of carbon on Earth, with organic soil carbon making over half of soil organic matter. As a key contributor to soil fertility and resilience, high levels of soil organic carbon are linked to:

• Improved Soil Structure: Better aggregation increases water retention and reduces erosion and nutrient loss through leaching.

• Enhanced Nutrient Cycling: Increased organic carbon content promotes beneficial microbial activity, which releases nutrients essential for robust plant growth (Corning et al., 2016).

• Greater Crop Resilience: Healthy soils help improve crop resistance to drought and extreme weather conditions, leading to more consistent yields.

All these factors lead to higher crop yields and increased farm resilience.

What Is Carbon Sequestration?
Farmers can maintain and build their soil organic carbon through conservation practices. No-till systems allow microbes to form long carbon chains, reducing the release of CO₂ into the atmosphere. Cover crops increase root volume throughout the year, providing more food for soil organisms and improving carbon storage. Because these practices help trap carbon in the soil rather than allowing it to escape into the air, they are often referred to as carbon sequestration strategies (Corning et al., 2016).

Last year’s crop residue enriches the soil and protects it from erosion here in this SWOF-enrolled field of strip-till soybeans.

Why Corporations Care
Corporations are increasingly focused on sustainability and reducing their carbon footprint. For those within the agricultural supply chain, investing in or partnering with agricultural programs that promote carbon sequestration also builds resiliency for their supply chain. Enhanced soil health means stronger, more resilient crops, which is essential for food security and consistent production. SWOF partners with these organizations to create real economic value for a farmer’s conservation efforts.

In Summary
Carbon is much more than an element—it’s a catalyst for both agricultural productivity and environmental sustainability. By understanding and enhancing soil organic carbon through effective conservation management practices, farmers can drive crop health, secure better yields, and contribute to a more sustainable future.

If you’re ready to make a practice change on your farm, such as reducing your tillage or adding a cover crop, contact us today or request an estimate. Our helpful and knowledgeable field staff are here to help you maximize the benefits of transitioning to more sustainable practices.

Adam Kiel
Managing Director

As a co-managing director, Adam Kiel works with public and private partners to support on-farm generation of ecosystem services. He has over 22 years of experience working in conservation and agriculture and has held previous roles with the National Park Service, the Iowa Department of Natural Resources, and the Iowa Soybean Association. Adam graduated from the University of Iowa with a degree in geography. In his free time, Adam enjoys watching his kids' sporting events, hunting, fishing, and backpacking.

References:

Corning, E., Sadeghpour, A., Ketterings, Q., & Czymmek, K. (2016). The Carbon Cycle and Soil Organic Carbon. Cornell University Cooperative Extension. cals.cornell.edu/cornell-cooperative-extension

Riebeek, Holli. (2011). The Carbon Cycle. NASA Earth Observatory. earthobservatory.nasa.gov/features/CarbonCycle