Challenges and opportunities for carbon sequestration in grassland systems: a technical report on grassland management and climate mitigation
This 2010 FAO report makes a strong case for grasslands restoration as a climate mitigation strategy and “improved grazing management” as one of the most important practices for enhancing soil carbon stocks.
Soil Carbon Sequestration in Grazing Lands: Societal Benefits and Policy Implications
This paper from 2010 is a compilation of previous studies on grazing lands and carbon drawdown which themselves date from the 1990s. It shows that grazing lands/rangelands are major stores of terrestrial carbon, occupying approximately 3.6 billion hectares and accounting for about one-fourth of potential carbon (C) sequestration in world soils. Drawdown rates via grazing and on restored semi-arid savanna are reported to be as high as 2.75 tons per hectare per year.
Global Warming and Pasture-Raised Beef Production in the United States
This report evaluates the prospects for changing management practices to reduce the climate impact of the time beef cattle spend on pasture or rangeland. Improved practices are most readily applied to the finishing stage of fully pasture-raised systems—a growing alternative to CAFOs, given research showing that pasture finishing has nutritional and environmental benefits. In the long term, the use of climate-friendly best practices in the United States may lead to substantial cuts in global warming emissions if adopted in countries where beef production accounts for a greater share of those emissions.
GHG Mitigation Potential of Different Grazing Strategies in the United States Southern Great Plains
This paper demonstrates that enteric emissions (methane) from cows are not a climate impediment when the animals are managed in a way that builds soil, thus, capturing carbon. Specifically, using a life cycle assessment that weighs emissions against sequestration, it calculates a net drawdown of approximately 2 tons of carbon per hectare per year (0.8 tons per acre per year) after a conversion from heavy continuous to multi-paddock grazing.
Emerging land use practices rapidly increase soil organic matter
This paper studies three farms converted from cropland to management intensive grazing. “Farms accumulated C at 8.0 Mg ha−1 yr−1, increasing cation exchange and water holding capacity by 95% and 34%, respectively.”
Potential mitigation of midwest grass-finished beef production emissions with soil carbon sequestration in the United States of America
This partial life cycle assessment (LCA) compared two grazing management strategies: 1) a non-irrigated, lightly-stocked, high-density system (MOB) and 2) an irrigated, heavily-stocked, low-density system (IRG). Results indicated that when soil carbon sequestration (SCS) potential was included, each grazing strategy could be an overall sink, with the MOB system found to have greater SCS than the IRG system.
Impacts of soil carbon sequestration on life cycle greenhouse gas emissions in Midwestern USA beef finishing systems
This paper does a greenhouse gas life cycle analysis (LCA) comparison of two grazing finishing systems in the Upper Midwest, USA: feedlot finishing and Holistic Planned Grazing, which the authors refer to as adaptive multipaddock (AMP). It finds that AMP finishing improved soil organic carbon by 3.5 tons per hectare per year. This resulted in a net negative footprint of 6.6 kg of carbon dioxide equivalence per kg of carcass-weight.
Soil Carbon Cowboys
This short film by Peter Byck follows producers who have taken the leap from conventional to regenerative agriculture.
Adaptive multi-paddock grazing enhances soil carbon and nitrogen stocks and stabilization through mineral association in southeastern U.S. grazing lands
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. 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 role of ruminants in reducing agriculture’s carbon footprint in North America
This paper determined that properly-managed grazing, if applied on 25% of our crop and grasslands, would mitigate the entire carbon footprint of North American agriculture. Better management of cropping and grazing practices in North America could draw down and sequester in soil 1.2 gigatons of carbon annually, equivalent to about 10% of the world’s total greenhouse gas emissions.
