A holistic assessment of climate smart agricultural practices at a long-term research site in the U.S. Corn Belt

Authors: Schreiner-Mcgraw, Adam; WOOD, JEFFREY - University Of Missouri; Ransom, Curtis; Sudduth, Kenneth - Ken; Veum, Kristen; Abendroth, Lori

Submitted to: American Geophysical Union Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/4/2023
Publication Date: 12/15/2023
Citation: Schreiner-McGraw, A.P., Wood, J.D., Ransom, C.J., Sudduth, K.A., Veum, K.S., Abendroth, L.J. 2023. A holistic assessment of climate smart agricultural practices at a long-term research site in the U.S. Corn Belt [abstract]. American Geophysical Union Meeting Abstract. Paper 1391354.

Interpretive Summary:

Technical Abstract: Climate change presents many challenges for sustained agricultural production including an increased frequency of heat waves and droughts. Climate smart agricultural practices have been proposed to both increase carbon sequestration in soils and to build agro-ecosystems that are resilient to climate changes. Despite the enthusiasm for climate smart practices, there is limited evidence they are more effective at removing carbon from the atmosphere and storing it in the soil than current practices. Additionally, it is uncommon for climate smart practices to be evaluated holistically for their ability to both mitigate and adapt to climate change. Here, we present evidence that a field with alternative (ALT) practices (i.e., no-till corn-soybean-wheat-hay rotation with cover crops) accumulates more soil organic carbon (SOC) versus a conventional (CON) field (i.e., conventional-tillage, corn-soybean-soybean rotation). We also demonstrate that the ALT field is more resilient to sub-optimal environmental conditions, including air temperature and soil moisture. We used deep soil cores (1 m) to assess changes in soil organic carbon ('SOC) between 2016 and 2022 for the two fields and compare with estimates based on eddy covariance calculation of 'SOC. We found that the ALT field had 'SOC that was positive, and larger than the CON field. Both the soil sample method ('SOCSS) and the eddy covariance method ('SOCEC) agreed on this point, but the magnitude of 'SOC was much larger when estimated with soil samples ('SOCSS was 1.9 ± 1.7 % yr-1 and -0.7 ± 1.3 % yr-1 at ALT and CON, respectively) than with eddy covariance ('SOCEC was 0.80 ± 0.09 % yr-1 and 0.12 ± 0.06 % yr-1 at ALT and CON respectively). We use eddy covariance measurements to assess the resilience of plant growth to heat waves and soil moisture drought and find that the ALT field continues carbon uptake (i.e., plant growth) for a wider range of conditions than the CON field. Results from this study illustrate the value of conservation practices in a changing climate and the value of eddy covariance measurements for assessing climate smart practices.