Perennializing Grain Crop Agriculture: A Pathway for Climate Change Mitigation & Adaption
Response to a 2019 Request For Information from the U.S. House Select Committee on the Climate Crisis
The Land Institute was one of a handful of organizations asked in to submit a white paper in December 2019 to the Bipartisan Policy Center to assist in informing the House Select Committee on the Climate Crisis on the science of carbon sequestration in forests and soils. The Center was working to develop policy options related to this topic for its report, Solving the Climate Crisis, published in June 2020. This opportunity allowed TLI to share its vision of the benefits of transitioning from annual to perennial agriculture with policy makers at a high level. The paper argues that an actionable level of scientific knowledge exists right now to say that converting annual agriculture to perennial agriculture is the single most promising route to sequestering carbon in the soil, and that developing perennial grain crops is a critical and urgent step to enable fully perennializing the landscape.
EXECUTIVE SUMMARY
- Soil carbon sequestration is the most beneficial source of negative emissions for the global climate change mitigation portfolio, and current grain crop production acreage is the prime candidate for major sequestration opportunities.
- Global grain crop agriculture is based on crops that are shallow-rooted annual plants grown in low-diversity monocultures that have lost the majority of the soil carbon that existed pre-settlement. The native grasslands that sequestered that carbon to start with were composed of deep-rooted perennial plants growing in high-diversity mixtures of multiple species.
- While discussions of soil carbon sequestration often emphasize uncertainty, it is unambiguous in the scientific literature that the highest levels of carbon sequestration achievable occur when lands previously planted to annual crops are converted to continuous perennial vegetation.
- In other words, we now have actionable knowledge that perennializing the agricultural landscape is the single most effective thing we can do for carbon sequestration.
- Perennial grain crops produced in high biodiversity have now emerged as a pathway for simultaneously abundantly provisioning both food and ecosystem services.
- In addition to providing a major carbon sequestration opportunity, perennial polyculture grain cropping systems have the potential to substantially reduce emissions of the potent greenhouse gas (GHG) nitrous oxide from agricultural soils, and to reduce carbon dioxide emissions from farm equipment operations and the synthesis of inputs, especially nitrogen fertilizers.
- In addition to their climate change mitigation benefits, perennial grain crops can also make major contributions to increasing agriculture’s adaptation to climate change, as well as reducing soil degradation, reducing negative water quality impacts, and reducing agricultural pesticide use.
- The Land Institute and its network of global research collaborators have recently achieved proof of concept with their perennial grain crops research efforts. The world’s first two perennial grain crops are now in pilot scale commercial production: Kernza® perennial grain and perennial rice. Other perennial grain crops are under development.
- Results achieved to date demonstrate that a suite of perennial grain crops can be developed to replace the bulk of current global grain crop production, resulting in transformational increases in carbon sequestration – but at current levels of investment, full deployment is decades away.
- Decisive action by funders is now warranted to accelerate perennial grain crop research and development while hastening adoption of perennial crops that already exist. A detailed strategy to this end is presented on page 8.