Review of Soil Organic Carbon Measurement Protocols: A US and Brazil Comparison and Recommendation

Author(s)

Davis, Maggie R. ^[1] ; Alves, Bruno J. R. ^[2] ; Karlen, Douglas L. ^[3] ; Kline, Keith L. ^[1] ; Galdos, Marcelo ^[4] ; Abulebdeh, Dana ^[5]

Affiliation

^[1] Oak Ridge Natl Lab, Environm Sci Div, Oak Ridge, TN 37830 - USA

^[2] Brazilian Agr Res Corp, EMBRAPA Agrobiol, BR-23891000 Seropedica, RJ - Brazil

^[3] NLAE, Ames, IA 50011 - USA

^[4] Univ Estadual Campinas, Interdisciplinary Ctr Energy Planning, NIPE, BR-13083970 Campinas, SP - Brazil

^[5] Univ N Carolina, EAO, Charlotte, NC 28273 - USA

• Document type: Review article
• Source: SUSTAINABILITY; v. 10, n. 1 JAN 2018.
• Web of Science Citations: 3

Abstract

Soil organic carbon (SOC) change influences the life-cycle assessment (LCA) calculations for globally traded bio-based products. Broad agreement on the importance of SOC measurement stands in contrast with inconsistent measurement methods. This paper focuses on published SOC research on lands managed for maize (Zea mays L.) in the U.S. and sugarcane (Saccharum officinarum L.) in Brazil. A literature review found that reported SOC measurement protocols reflect different sampling strategies, measurement techniques, and laboratory analysis methods. Variability in sampling techniques (pits versus core samples), depths, increments for analysis, and analytical procedures (wet oxidation versus dry combustion) can influence reported SOC values. To improve consistency and comparability in future SOC studies, the authors recommend that: (a) the methods applied for each step in SOC studies be documented; (b) a defined protocol for soil pits or coring be applied; (c) samples be analyzed at 10 cm intervals for the full rooting depth and at 20 cm intervals below rooting until reaching 100 cm; (d) stratified sampling schemes be applied where possible to reflect variability across study sites; (e) standard laboratory techniques be used to differentiate among labile and stable SOC fractions; and (f) more long-term, diachronic approaches be used to assess SOC change. We conclude with suggestions for future research to further improve the comparability of SOC measurements across sites and nations. (AU)

• FAPESP's process: 12/06933-6 - Spatio-temporal dynamics of soil carbon stocks and nitrous oxide emissions under Sugarcane in Brazil - convergence between specific models for time and space
• Grantee: Marcelo Valadares Galdos
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Young Investigators Grants