Characterizing gas diffusivity, air permeability, and extracellular enzyme activity in an early‐stage comparison of conventional and regenerative pasture

Regenerative pasture is an emerging agricultural framework characterized by high forage diversity, adaptive grazing, and reduced external inputs. However, early‐stage soil structural transitions and associated microbial activities remain unclear, particularly given the higher spatial variability expected in these systems. We compared regenerative and conventional pastures after 3 years of management at an experimental site in Canterbury, New Zealand, evaluating soil‐water retention, diffusion‐controlled aeration, and macropore‐dependent properties, alongside extracellular enzyme activities as an early biological indicator. Twenty undisturbed cores were analyzed for soil‐water retention (−1 to −1500 kPa), soil‐gas diffusivity ( D p / D o ) and air permeability ( k a ) (−1 to −10 kPa), bulk density ( ρ b), and saturated hydraulic conductivity ( K s ). Additional cores were used to measure eight hydrolytic and oxidative enzyme activities and compare spatial heterogeneity. Regenerative soils showed modestly lower ρ b (1.29 g cm − 3 ) than conventional soils (1.33 g cm − 3 ) and consistently higher water retention, giving 9.8% more plant‐available water. Derived pore‐size distributions indicated emerging micropore connectivity despite minimal change in total porosity. The D p / D o slope coefficient ( A ) was ∼30% higher in regenerative soils, allowing well‐aerated conditions ( D p / D o > 0.01) at field capacity, whereas conventional soils remained largely hypoxic. In contrast, macropore‐sensitive indicators ( k a and K s ) were highly variable and lower in regenerative soils, suggesting early reorganization favors functional macropore connectivity rather than increased pore volume. Mean enzyme activities did not differ between systems, but within‐plot variability was higher in regenerative plots. Functionally meaningful responses are therefore not yet clearly evident, and longer term monitoring is required to detect statistically distinguishable outcomes.