Carbon sequestration in Canada's croplands: a review of multiple disciplines influencing the science–policy interface

Abstract

A widely considered climate change mitigation strategy in agriculture is enhancing soil carbon (C) sequestration—the process of capturing atmospheric carbon dioxide and storing it in the soil. By adopting natural climate solutions (NCS) such as cover crops, reduced tillage, and diverse crop rotations, farmers can increase soil C sequestration and co-benefits such as improved biodiversity. Canada is increasingly interested in better positioning farmers to adopt NCS via government cost-share programs, ecosystem marketplaces, and outreach and education initiatives. Given the policy and market-driven interest in soil C sequestration in agriculture, there is a need to advance the science–policy interface, ensuring foundational science, NCS implementation, and approaches to promote NCS are aligned. Herein, the objective is to present insights from multiple disciplines that can help build connections between soil C sequestration science and policy relevant to Canada's croplands. The method is a review of literature on soil and pedoclimate science, agricultural NCS adoption, agricultural NCS governance, and science–policy interfaces to achieve this objective. From this review, key insights underline that Canadian cropland soils do not have a homogenous history in NCS adoption and production type, nor are all regions influenced by the same contextual factors, have the same potential in C storage, or exist within the same agri-environmental conditions. Therefore, it is emphasized herein that policies that aim to enhance soil organic C in croplands should consider local context and C sequestration potential. Policies and programs implemented locally to enhance C sequestration across Canada should be complemented by nationally scalable measuring and monitoring to ensure outcomes are accounted for against climate goals. This review aims to contribute to building a common understanding of soil C sequestration in Canada's croplands and its science–policy interface. Efforts to further strengthen the science–policy interface for soil C sequestration in Canada's croplands might include greater integration and utilization of science and data from multiple disciplines, co-design and collaborative opportunities, and establishing on-the-ground test projects to explore innovation in policy and market design.