By Georgine Yorgey
When you work at a land grant university, people sometimes reach out to you with questions. I love this aspect of my job, as it often gives me a chance to bridge the divide between research and the real world. In 2019, one of the questions I got most often was “How much additional carbon could cropland soils store through improved management?”
Over the years, we had already worked to gather the available evidence from across the Pacific Northwest region and help managers interpret that evidence. But these questions provided us an excuse to re-visit the question. Working with colleagues from Washington State University’s Center for Sustaining Agriculture and Natural Resources and the Department of Biological Systems Engineering, we prepared a white paper summarizing the existing experimental and modeling evidence relating to the carbon sequestration potential of cropland soils in the Pacific Northwest. We review regional research on a number of strategies that could lead to increases in soil organic carbon, including intensifying crop production, tillage, perennial crops, soil amendments, cover crops, crop rotation, reduced burning, and reduced erosion. Check out our summary, which suggests that a number of practices can provide real contributions to carbon sequestration, with the likelihood of substantial co-benefits in the form of soil conservation, improved water quality and soil water storage, increased microbial activity, and sustaining our soil’s ability to grow food over future generations. Within cropland agriculture, the opportunities to build soil organic carbon are greater in annually cropped systems with higher productivity, though the benefits of particular management practices are variable and depend on multiple environmental and physical conditions.
What we hope is that over time, consideration of the environmental and production contexts surrounding Pacific Northwest agriculture, combined with targeted research to establish credible estimates of how carbon moves into and out of the plants and soils in Northwest agricultural systems, could lead to the development of strategies that can realize the potential for Pacific Northwest croplands to contribute to climate change mitigation efforts, and for producers to reap the co-benefits.
Yorgey, G.G., S.A. Hall, K.M. Hills, C.E. Kruger, and C.O. Stockle. 2019. White Paper: Carbon Sequestration Potential in Cropland Soils in the Pacific Northwest: Knowledge and Gaps. (Undergoing review as a Pacific Northwest Extension Publication). Center for Sustaining Agriculture and Natural Resources, Puyallup, WA.