Adaptive multi-paddock grazing enhances soil carbon and nitrogen stocks and stabilization through mineral association in southeastern U.S. grazing lands

Full paper: https://doi.org/10.1016/j.jenvman.2021.112409

Summary: This paper conducted a large-scale on-farm study on five “across the fence” pairs of Holistic Planned Grazing, referred to by the authors as adaptive multi-paddock (AMP) grazing, and conventional grazing (CG) grasslands covering a spectrum of southeast United States grazing lands. They quantified soil C and nitrogen (N) stocks, their isotopic and Fourier-transform infrared spectroscopy signatures as well as their distribution among soil organic matter (SOM) physical fractions characterized by contrasting mechanisms of formation and persistence in soils. Findings showed that the AMP grazing sites had on average 13% (i.e., 9 Mg C ha⁻¹) more soil C and 9% (i.e., 1 Mg N ha⁻¹) more soil N compared to the CG sites over a 1 m depth. Additionally, the stocks’ difference was mostly in the mineral-associated organic matter fraction in the A-horizon, suggesting long-term persistence of soil C in AMP grazing farms. The higher N stocks and lower ¹⁵N abundance of AMP soils also point to higher N retention in these systems. These findings provide evidence that AMP grazing is a management strategy to sequester C in the soil and retain N in the system, thus contributing to climate change mitigation.

Citation: Mosier S, Apfelbaum S, Byck P, Calderon F, Teague R, Thompson R, Cotrufo MF. Adaptive multi-paddock grazing enhances soil carbon and nitrogen stocks and stabilization through mineral association in southeastern U.S. grazing lands. J Environ Manage. 2021 Apr 7;288:112409. doi: 10.1016/j.jenvman.2021.112409.