Main content area

Permanganate Oxidizable Carbon Reflects a Processed Soil Fraction that is Sensitive to Management

Culman, Steven W., Snapp, Sieglinde S., Freeman, Mark A., Schipanski, Meagan E., Beniston, Josh, Lal, Rattan, Drinkwater, Laurie E., Franzluebbers, Alan J., Glover, Jerry D., Grandy, A. Stuart, Lee, Juhwan, Six, Johan, Maul, Jude E., Mirksy, Steven B., Spargo, John T., Wander, Michelle M.
Soil Science Society of America journal 2012 v.76 no.2 pp. 494
Geographical Locations, carbon, ecosystems, environmental management, microbial biomass, new methods, permanganates, soil organic carbon, soil types
Permanganate oxidizable C (POXC; i.e., active C) is a relatively new method that can quantify labile soil C rapidly and inexpensively. Despite limited reports of positive correlations with particulate organic C (POC), microbial biomass C (MBC), and other soil C fractions, little is known about what soil fractions POXC most closely reflects. We measured POXC across a wide range of soil types, ecosystems, and geographic areas (12 studies, 53 total sites, = 1379) to: (i) determine the relationship between POXC and POC, MBC and soil organic C (SOC) fractions, and (ii) determine the relative sensitivity of POXC as a labile soil C metric across a range of environmental and management conditions. Permanganate oxidizable C was significantly related to POC, MBC, and SOC, and these relationships were strongest when data were analyzed by individual studies. Permanganate oxidizable C was more closely related to smaller-sized (53–250 μm) than larger POC fractions (250–2000 μm), and more closely related to heavier (>1.7 g cm) than lighter POC fractions, indicating that it reflects a relatively processed pool of labile soil C. Compared with POC, MBC, or SOC, POXC demonstrated greater sensitivity to changes in management or environmental variation in 42% of the significant experimental factors examined across the 12 studies. Our analysis demonstrates the usefulness of POXC in quickly and inexpensively assessing changes in the labile soil C pool.