How Does Weather Impact Soil Carbon Storage?

This article was adapted and expanded from “Voluntary Versus State-Based Compliance Carbon Markets” by David Clay et al.

The short answer: Soil carbon storage depends on plant growth, plant residue and organic matter in the soil, microbial activity, temperature, moisture, and erosion. Adverse weather and extreme climatic events can hinder storage or even release large amounts of soil carbon.

Back it up: Four practices are the big contributors to increasing soil carbon storage, including:

1. Growing plants that produce a large amount of plant material, like corn, grain sorghum, and perennials;
2. Minimizing soil disturbance;
3. Returning crop residues to the soil;
4. And planting high-carbon cover crops such as cereal or annual rye.

Weather impacts every stage of the carbon storage process. Soil organic carbon increases with more rain and lower temperatures. Rising temperatures speed up the decay of soil organic matter, releasing carbon into the atmosphere.

Wind erosion at the forefront of a derecho in eastern South Dakota in May 2022. Photo by Cheryl Reese, South Dakota State University.

Break it down: Here are other ways that weather impacts soil carbon:

1. Climate factors can reduce the amount of biomass returned to the soil following harvest.
   • For example, dry years could lead to less crop growth, and less residue left after harvest.
2. Soil carbon is lost through microbial degradation of plant materials contained within the soil.
   • Climate can also change microbial activity, increasing or decreasing carbon loss.
3. Soil carbon is lost when soil erodes due to wind or water erosion events.
   • Think derechos and floods.
4. If adverse conditions prevent planting a crop, soil carbon can be lost as the field lays bare.
5. Extreme climatic events such as enhanced warming, drought, and heavy rainfall can change how much carbon is stored in the soil.

Just as weather plays a critical role in the success of a growing season, it plays a key part in sequestering soil carbon. Considering how weather may have impacted carbon sequestration on your operation can help you make sense of carbon storage numbers over time.

Photo by Jeff Wallace.