Unraveling edaphic, environmental, and management drivers of soil microbial communities via ester-linked fatty acid methyl esters using a multilocation agroecosystem study

Authors: Roper Iii, Wayne; Acosta Martinez, Veronica; Veum, Kristen; Burgess, Christopher; Moore, Jennifer; Manter, Daniel; Stewart, Catherine; Emmett, Bryan; Liebig, Mark; Fischel, Matthew; Lehman, Richard; Franco Jr, Jose; Johnson, Jane; Weyers, Sharon; Mikha, Maysoon; Trippe, Kristin; Maul, Jude; Dungan, Robert; Gollany, Hero; Ducey, Thomas; Hale, Lauren; Jin, Virginia; CAVADINI, JASON - University Of Wisconsin; Reardon, Catherine

Submitted to: Geoderma
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/22/2024
Publication Date: 1/2/2025
Citation: Roper III, W.R., Acosta Martinez, V., Veum, K.S., Burgess, C.J., Moore, J.M., Manter, D.K., Stewart, C.E., Emmett, B.D., Liebig, M.A., Fischel, M.H., Lehman, R.M., Franco Jr, J.G., Johnson, J.M., Weyers, S.L., Mikha, M.M., Trippe, K.M., Maul, J.E., Dungan, R.S., Gollany, H.T., Ducey, T.F., Hale, L.E., Jin, V.L., Cavadini, J., Reardon, C.L. 2025. Unraveling edaphic, environmental, and management drivers of soil microbial communities via ester-linked fatty acid methyl esters using a multilocation agroecosystem study. Geoderma. 453. Article 117158. https://doi.org/10.1016/j.geoderma.2024.117158.
DOI: https://doi.org/10.1016/j.geoderma.2024.117158

Interpretive Summary: Soil microbial communities can be valuable indicators of soil health, or the capacity of soil to provide many essential functions that benefits crop production. Thus, they are sensitivity to management practices and can help producers understand how their decisions are affecting soil health. However, site-specific characteristics impart a strong influence on microbial communities and challenge our ability to make broad inferences about the impact of management across regions. Coordinated, multi-location soil health assessments can overcome these limitations by harmonizing measurements to provide insight into the complex interactions of the biological component with climate, soil conditions and management practices. The USDA-ARS in Lubbock, TX led a multi-location effort with 15 locations and their scientists to represent a wide range in climate and edaphic characteristics across the United States. Agricultural management related to reduced tillage, cover cropping, crop diversity, and manure applications was considered for effects on soil microbial community composition via their fatty acids. Total fatty acids had a stronger relationship to the soil organic carbon of the soils than to soil pH or their soil texture. Fatty acid abundance was more sensitive to all management practices than soil organic carbon. Fatty acids markers for fungi were more sensitive to management than markers for bacteria, which implies management can effect microbial community composition. Our multi-location effort will continue to evaluate other characteristics of soil microbial communities to identify key microbes impacted by management across regions and how their presence could affect soil productivity.

Technical Abstract: Soil microbial communities are responsible for essential functions and provide information about management effects on soil health. Understanding the interactions between agricultural management and soil biological properties is an important step toward sustainability; however, broadscale inferences on these interactions are challenged by differences in site-specific characteristics. To identify the effects of conservation management on soil communities, we conducted a multilocation study of 15 sites across the United States, which varied in crop management strategies and climate and edaphic characteristics. Microbial community composition was assessed by ester-linked fatty acid methyl esters (EL-FAME) with biomarkers for gram-negative bacteria, gram-positive bacteria, actinobacteria, saprotrophic fungi, and arbuscular mycorrhizal fungi. Among the edaphic characteristics considered in this study, soil organic C (SOC) was more correlated with FAMEs than pH, and clay content. Reduced tillage, cover cropping, and manure increased total EL-FAME and SOC, whereas crop diversity had no significant effect. Abundance of bacterial fatty acid biomarkers had stronger relationships to SOC (r2 = 0.64–0.65) than fungal biomarkers (r2 < 0.23), but fungi exhibited more sensitivity to management than bacteria. Though some fatty acids were sensitive to management across locations, manure had the overall largest effect on EL-FAMEs. This study revealed a strong response of the microbial community to conservation management practices regardless of location, but the magnitude differed across locations. Additionally, SOC and moisture deficit were key drivers of site-specific responses. Our multilocation study supports the utility of EL-FAMEs as an important soil health indicator that should be considered in national soil health assessments.