The knowns, known unknowns and unknowns of sequestration of soil organic carbon

• Published in: Agriculture, ecosystems & environment ecosystems & environment, 2013-01, Vol.164 (1), p.80-99
• Main Authors: Stockmann, Uta, Adams, Mark A., Crawford, John W., Field, Damien J., Henakaarchchi, Nilusha, Jenkins, Meaghan, Minasny, Budiman, McBratney, Alex B., Courcelles, Vivien de Remy de, Singh, Kanika, Wheeler, Ichsani, Abbott, Lynette, Angers, Denis A., Baldock, Jeffrey, Bird, Michael, Brookes, Philip C., Chenu, Claire, Jastrow, Julie D., Lal, Rattan, Lehmann, Johannes, O’Donnell, Anthony G., Parton, William J., Whitehead, David, Zimmermann, Michael
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Atmospherics; Biological and medical sciences; Carbon; Carbon capture and storage; carbon dioxide; carbon sequestration; carbon sinks; climate change; Decisions; environmental management; Environmental Sciences; Fluxes; food shortages; Foods; Fundamental and applied biological sciences. Psychology; General agroecology; General agroecology. Agricultural and farming systems. Agricultural development. Rural area planning. Landscaping; General agronomy. Plant production; Generalities. Agricultural and farming systems. Agricultural development; Global Changes; hosts; Pools; risk reduction; scientists; soil; Soil (material); Soil carbon modelling; Soil carbon pools; Soil carbon sequestration; soil organic carbon; soil quality; soil resources
• ISSN: 0167-8809; 1873-2305; 0167-8809
• DOI: 10.1016/j.agee.2012.10.001

[Display omitted] ► Soil has great potential to become a managed sink for CO2 in agroecosystems. ► Increasing the SOC pool is also beneficial to secure soil fertility. ► This review discusses perspectives and practices to sequester more soil carbon. ►It also highlights methods and models used to estimate soil carbon pools. ► This knowledge and technology underpins decisions to protect the soil resource. Soil contains approximately 2344Gt (1 gigaton=1 billion tonnes) of organic carbon globally and is the largest terrestrial pool of organic carbon. Small changes in the soil organic carbon stock could result in significant impacts on the atmospheric carbon concentration. The fluxes of soil organic carbon vary in response to a host of potential environmental and anthropogenic driving factors. Scientists worldwide are contemplating questions such as: ‘What is the average net change in soil organic carbon due to environmental conditions or management practices?’, ‘How can soil organic carbon sequestration be enhanced to achieve some mitigation of atmospheric carbon dioxide?’ and ‘Will this secure soil quality?’. These questions are far reaching, because maintaining and improving the world's soil resource is imperative to providing sufficient food and fibre to a growing population. Additional challenges are expected through climate change and its potential to increase food shortages. This review highlights knowledge of the amount of carbon stored in soils globally, and the potential for carbon sequestration in soil. It also discusses successful methods and models used to determine and estimate carbon pools and fluxes. This knowledge and technology underpins decisions to protect the soil resource.