Intensive short-duration periods of grazing, interspersed with long recovery periods, are typical in natural grasslands throughout the world. These are ecosystems that co-evolved with migrations of bison, wildebeest, caribou and other herding ungulate species.
Natural grasslands, with their diversity of deep-rooted native plant species perpetuated by grazing and other periodic natural disturbance events, foster increased soil organic carbon content and enhanced water infiltration.
By emulating the migrational grazing pattern of ungulate wildlife in natural grasslands, ranchers are implementing Adaptive Multi-Paddock (AMP) grazing on their cattle ranches. These regimes are being studied by AES and its partners to determine the levels of soil carbon sequestration accrued from this strategy.
AMP grazing regimes emulate the high intensity, short-duration grazing and long recovery periods of native ungulates in natural grasslands. With this in mind, a pilot study, using peer-reviewed methods, was undertaken in Alberta, Canada, comparing AMP paddocks to heavily stocked and lightly stocked continuously grazed paddocks.
This pilot project was funded by Shell GameChanger through a grant to Arizona State University. The study is a collaborative effort between ASU, AES, Texas A&M, CarbonNation and Shell Oil Co.
In this study, scientists measured whether AMP improves: (1) soil organic carbon stored, (2) water infiltration rates, and (3) the diversity of vegetation in the paddocks – when compared to the two continuous grazing regimes.
In Alberta, as also was found in northern Texas by one of the study’s principal investigators, AMP grazing contributed statistically significant increases of soil organic carbon and increased water infiltration rates.
Throughout the world, more and more research is being devoted toward finding ways of enriching carbon-depleted soils that, in turn, builds resiliency to increased prevalence and severity of drought in rangelands.
Encouraged by the findings of this pilot study, the researchers recommend future expanded AMP grazing studies encompassing a wider diversity of soils, climates, and grazing history.