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ARS Home » Plains Area » Brookings, South Dakota » Integrated Cropping Systems Research » Research » Publications at this Location » Publication #283253
Title: Further modification of pressure-calcimeter method for soil inorganic carbon analysis

Author
item Stetson, Sarah
item Osborne, Shannon

Submitted to: Communications in Soil Science and Plant Analysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/8/2015
Publication Date: 7/18/2015
Citation: Stetson, S.J., Osborne, S.L. 2015. Further modification of pressure-calcimeter method for soil inorganic carbon analysis. Communications in Soil Science and Plant Analysis. DOI:10.1080/00103624.2015.1069316.

Interpretive Summary: Inorganic carbon (IC) in soil is important when considering C fluxes and processes in the environment that involve C. Here data are presented for measurement of IC in soils using the pressure calcimeter method of Sherrod et al. (2002) with modifications to decrease analysis time while preserving method accuracy. Inorganic C measured using a syringe to inject acid vs. the vial delivery method of the original method were not significantly different when using 100 ml bottles for the analysis. When using 20 ml bottles, bias was introduced in the measurement using a syringe for acid delivery, likely due to small losses of pressure from the bottle during acid delivery. There was no significant difference in IC measured on unsieved finely ground and coarsely ground soil. When quantifying IC in soils using the modified pressure calcimeter method with a 100 ml bottle, a syringe can be used to inject acid into the capped bottle rather than dropping a vial into the bottle and then capping it. This modification results in a modest reduction in cost and significant reduction in time required for analysis and cleanup.

Technical Abstract: Inorganic carbon (IC) in soil is important when considering C fluxes and processes in the environment that involve C. Here data are presented for measurement of IC in soils using the pressure calcimeter method of Sherrod et al. (2002) with modifications to decrease analysis time while preserving method accuracy. Inorganic C measured using a syringe to inject acid vs. the vial delivery method of the original method were not significantly different at the 95% confidence level when using 100 ml bottles for the analysis (R2 = 0.9946). When using 20 ml bottles, bias was introduced in the measurement using a syringe for acid delivery, likely due to small losses of pressure from the bottle during acid delivery. There was no significant difference at the 95% confidence level in IC measured on unsieved finely ground and coarsely ground soil. When quantifying IC in soils using the modified pressure calcimeter method with a 100 ml bottle, a syringe can be used to inject acid into the capped bottle rather than dropping a vial into the bottle and then capping it. This modification results in a modest reduction in cost and significant reduction in time required for analysis and cleanup.