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Abstract
Pastures and rangelands are a dominant portion of global agricultural land and have the potential to sequester carbon (C) in soils, mitigating climate change. Management intensive grazing (MIG), or high density grazing with rotations through paddocks with long rest periods, has been highlighted as a method of enhancing soil C in pastures by increasing forage production. However, few studies have examined the soil C storage potential of pastures under MIG in the northeastern United States, where the dairy industry comprises a large portion of agricultural use and the regional agricultural economy. Here we present a 12-year study conducted in this region using a combination of field data and the denitrification and decomposition (DNDCv9.5) model to analyze changes in soil C and nitrogen (N) over time, and the climate impacts as they relate to soil carbon dioxide (CO2) and nitrous oxide (N2O) fluxes. Field measurements showed: (1) increases in soil C in grazed fields under MIG (P = 0.03) with no significant increase in hayed fields (P = 0.55); and (2) that the change in soil C was negatively correlated to initial soil C content (P = 0.006). Modeled simulations also showed fields that started with relatively less soil C had significant gains in C over the course of the study, with no significant change in fields with higher initial levels of soil C. Sensitivity analyses showed the physiochemical status of soils (i.e., soil C and clay content) had greater influence over C storage than the intensity of grazing. More extensive grazing methods showed very little change in soil C storage or CO2 and N2O fluxes with modeled continuous grazing trending towards declines in soil C. Our study highlights the importance of considering both initial system conditions as well as management when analyzing the potential for long-term soil C storage.
Department
Open Access Fund; Soil Biogeochemistry and Microbial Ecology
Publication Date
2-25-2022
Journal Title
Science of The Total Environment
Publisher
Elsevier
Document Type
Article
Recommended Citation
Kyle A. Arndt, Eleanor E. Campbell, Chris D. Dorich, A. Stuart Grandy, Timothy S. Griffin, Peter Ingraham, Apryl Perry, Ruth K. Varner, Alexandra R. Contosta, Initial soil conditions outweigh management in a cool-season dairy farm's carbon sequestration potential, Science of The Total Environment, Volume 809, 2022, 152195, ISSN 0048-9697, https://doi.org/10.1016/j.scitotenv.2021.152195.
Rights
© 2021 The Authors.
Comments
This is an open access article published by Elsevier in Science of The Total Environment in 2022, available online: https://dx.doi.org/10.1016/j.scitotenv.2021.152195