Skip to main content
ARS Home » Plains Area » Miles City, Montana » Livestock and Range Research Laboratory » Research » Publications at this Location » Publication #425666
Research Project: Precision Technologies and Management for Northern Plains Rangeland

Location: Livestock and Range Research Laboratory

Title: Soil carbon-enzyme relationships persist despite neutral long-term grazing effects in the northern Great Plains

Author
item Reinhart, Kurt
item TOSSOU, FRIMENCE - University Of Parakou
item Rinella, Matthew
item EBERLY, JED - Montana State University
item Waterman, Richard
item WOROGO, HILAIRE - University Of Parakou
item McGranahan, Devan
item Vermeire, Lance

Submitted to: Agriculture, Ecosystems & Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/25/2026
Publication Date: 4/7/2026
Citation: Reinhart, K.O., Tossou, F., Rinella, M.J., Eberly, J.O., Waterman, R.C., Worogo, H., McGranahan, D.A., Vermeire, L.T. 2026. Soil carbon-enzyme relationships persist despite neutral long-term grazing effects in the northern Great Plains. Agriculture, Ecosystems & Environment. 406. Article 110404. https://doi.org/10.1016/j.agee.2026.110404.
DOI: https://doi.org/10.1016/j.agee.2026.110404

Interpretive Summary: Problem - Effects of grazing management on soil carbon accrual are difficult to predict and known to vary by place and time. We used a long-term grazing experiment to test for grazing effects on soil carbon and the potential activity of soil enzymes associated with the break down of organic matter. Our aim was to uncover whether soil carbon accrual was mechanistically linked with variation in soil enzyme activity. Accomplishment - After applying five grazing treatments for 10 years, we observed no appreciable effect of treatments on topsoil soil organic carbon and potential activity of numerous enzymes involved in breaking down organic matter and the cycling of carbon, nitrogen, and phosphorus. We found that final soil carbon was explained more by baseline (pretreatment) soil carbon levels than grazing treatments. This detail indicates the importance of having pretreatment soil carbon measurements when attempting to quantify change in soil carbon. Despite the lack of treatment effects we observed some correlations between soil organic carbon and enzyme activity suggesting a possible link between enzymes and soil carbon accrual in semi-arid grazed systems.

Technical Abstract: Livestock grazing is a dominant land use in dryland ecosystems around the world, and grazing often impacts soil carbon dynamics and microbial activity. Interactions between soil organic carbon (SOC) levels and extracellular enzyme activity (EEA) are varied, and the response of each to grazing management is poorly understood. We measured SOC and EEA of eight enzymes in the top 10 cm of soil in a 10-year study of five bovine grazing treatments in semi-arid prairie in eastern Montana, USA. We observed no effect of grazing on topsoil SOC and EEA, but final SOC and total cellulase activity were positively correlated. Furthermore, change in topsoil SOC over the study was positively correlated with the ratio of carbon- to nitrogen-dissolving hydrolytic enzymes. While we found no impact of grazing management on topsoil carbon and soil microbe dynamics, we detected complex relationships between SOC and enzyme activities demonstrating the need for further investigation.