Comparison of permanganate-oxidizable carbon and mineralizable carbon for assessment of organic matter stabilization and mineralization

Authors: HURISSO, TUNSISA - The Ohio State University; CULMAN, STEVE - The Ohio State University; HORWATH, WILLIAM - University Of California, Davis; WADE, JORDAN - University Of California, Davis; CASS, DEANDRA - University Of California, Davis; BENISTON, JOSHUA - Santa Rosa Junior College; BOWLES, TIMOTHY - University Of California, Davis; GRANDY, STUART - University Of New Hampshire; Franzluebbers, Alan; SCHIPANSKI, MEAGAN - Colorad0 State University; LUCAS, SHAWN - Kentucky State University; UGARTE, CARMEN - University Of Illinois

Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/3/2016
Publication Date: 10/3/2016
Citation: Hurisso, T.T., Culman, S.W., Horwath, W.R., Wade, J., Cass, D., Beniston, J.W., Bowles, T.M., Grandy, S.A., Franzluebbers, A.J., Schipanski, M.E., Lucas, S.T., Ugarte, C.M. 2016. Comparison of permanganate-oxidizable carbon and mineralizable carbon for assessment of organic matter stabilization and mineralization. Soil Science Society of America Journal. 80:1352-1364.

Interpretive Summary: Soil testing procedures are needed to assess the biological component of soil. An ARS scientist from Raleigh NC collaborated with a team of scientists from Ohio State University, University of California, Santa Rosa Junior College, University of New Hampshire, Colorado State University, Kentucky State University, and University of Illinois to compare the performance of permanganate oxidizable C and short-term mineralizable C as indicators of soil biological activity. Results using the two methods across a diversity of sites were related, but influenced by management factors. Permanganate oxidizable C better reflected conservation-oriented practices expected to promote accumulation of soil organic matter, while mineralizable C better reflected practices to promote mineralization of nutrients from organic matter. Results will be valuable to scientists and practitioners of soil health management to make better interpretations of how soil health changes with management.

Technical Abstract: Permanganate-oxidizable C (POXC) and mineralizable C (as determined by short-term aerobic incubation of rewetted soil) are measures of active organic matter that may provide early indication of soil C stabilization and mineralization processes. To date, the relationship between these two promising active organic matter tests has not been comprehensively evaluated, and little is known about their functional role in the soil ecosystem. Here, we examined the relationship between POXC and mineralizable C across a wide range of soil types, management histories, and geographic locations across the United States (13 studies, 76 total sites; n = 1071) and the ability of POXC and mineralizable C to predict crop yield and total aboveground biomass. Results from this comparative analysis showed that POXC and mineralizable C are related (r2 = 0.15–0.80) but that the relationship was differentially influenced by management practices. Overall, POXC better reflected practices that promote organic matter accumulation or stabilization and therefore can be a useful indicator of long-term soil C sequestration. Conversely, mineralizable C better reflected practices that promote organic matter mineralization and therefore can be a useful indicator of short-term soil nutrient availability. Our results also show that both mineralizable C and POXC were better predictors of corn (Zea mays L.) grain yield, aboveground biomass, and tomato (Solanum lycopersicum L.) fruit yield than other soil C fractions evaluated here. Thus, the integrated use of POXC and mineralizable C can provide a complementary framework to assess the relative dynamics of soil C stabilization and nutrient mineralization functions in agroecosystems.