How do public policies and private initiatives influence carbon stocks in agricultural and livestock production: a systematic review protocol
Protocolo
Carbon stocks in agricultural and livestock systems play a relevant role in linking productivity, resilience, and climate change mitigation objectives. Higher levels of carbon stored in soils and biomass are associated with improved soil fertility, greater water retention capacity, and increased resilience to climate variability, while contributing to atmospheric carbon sequestration. Although agricultural practices such as conservation tillage, cover cropping, crop rotation, agroforestry, and improved grazing management can enhance carbon accumulation, their adoption remains uneven and is often constrained by technical, economic, and institutional barriers. Public policies and private initiatives, including economic incentives, regulatory instruments, technical assistance programs, carbon markets, payments for environmental services, and sustainability standards, among others, have been implemented to promote the adoption of these practices. However, evidence on the effectiveness of these interventions in increasing carbon stocks remains fragmented across contexts and production systems. As part of the Avanzar2030 initiative, this systematic review aims to synthesize the available evidence on how public policies and private initiatives influence carbon stocks in tropical and temperate agricultural and livestock systems, assess their associated environmental, social, and economic outcomes, and identify key enabling factors and implementation barriers. The review is intended to support evidence-informed policy design and implementation in the Mercosur countries: Argentina, Brazil, Paraguay, and Uruguay. Methods: A systematic literature search will be conducted in Web of Science, Scopus, CAB Abstracts, CAB Global Health, ProQuest Dissertations & Theses, Agricola, LILACS, and grey literature sources accessed through the Agricultural Information and Documentation Service of the Americas (SIDALC). Searches will be performed in English, Spanish, and Portuguese. Eligible studies will examine agricultural or livestock systems exposed to a public policy or private initiative intended to increase carbon stocks and will report measured carbon stock outcomes. Included study designs comprise before-after (BA), control intervention (CI), and BACI studies. Screening, data extraction, and risk-of-bias assessment will be conducted according to predefined protocols, with consistency checks among reviewers. Data extracted will include characteristics of interventions, study contexts, measurement approaches, and reported environmental, social, and economic outcomes, as well as factors identified as enabling or constraining the implementation and effectiveness of interventions.
