Soil Carbon Dynamics, Sequestration Potential, and Physical Characteristics Under Grazing Management in Regenerative Organic Agroecosystems

Rotational grazing and cover crops are conservation practices known to improve soil health, particularly soil organic carbon (SOC) and aggregate stability. Combining both practices may enhance these benefits more than either alone. With grazing lands covering 41% of U.S. agricultural land, adopting such methods could significantly impact the soil carbon cycle. A study near Koshkonong, Missouri, examined the effects of regenerative organic grazing with Bubalus bubalis (Linnaeus) on SOC, carbon sequestration, aggregate stability, and soil resistance. The 1620-hectare ranch tested four treatments: rotational grazing with cover crops (RGCC), grazing on native grasses (RGNCC), cover crops without grazing (NGCC), and orchards without cover crops or grazing (NGNCC). Cover crops were seeded twice yearly with diverse species. After three years, SOC increased most in NGNCC (28%), followed by RGCC (13%), NGCC (7%), and RGNCC (4%). Annual carbon gains in surface soils were highest in NGNCC (0.99 Mg ha−1 yr−1). Across all depths, NGCC led (4.88 Mg ha−1 yr−1). Aggregate stability was greatest in non-grazed systems, particularly in fine aggregates, and declined with soil disturbance. Overall, low-disturbance systems like orchards and no-grazing cover crop plots enhanced soil structure and carbon storage. Strategic management is key to improving soil function and ecosystem resilience.