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Abstract
This study evaluates ion chromatography (IC) as an alternative to atomic absorption (AA) and inductively-coupled plasma spectromctry (ICP) for analysis of potassium (K), magnesium (Mg), and calcium (Ca), and and as an alternative to antimonylmolybdate colorimetry and ICP for analysis of phosphorus (P) macro-nutrients in Mehlich 1 extracts. Soils typical of pine forests in the southeastern United States were tested. IC correlates well with AA and ICP for K and Ca, but not for Mg, unless conditions are chosen that resolve Mg from manganese (Mn). IC does not correlate very well with colorimetry for P at extract levels below 2 mg kg
-1 or in extracts with high levels of dissolved organic matter complexes of aluminum (Al) and iron (Fe). ICP results for P exceed both IC and colorimetry by 3-5 mg kg
-1 for all soils tested. The merits of IC relative to AA, ICP, and colorimetry for forest soil testing are discussed.
Keywords
Ion chromatography,
Soil,
Forest,
Analysis,
Mehlich 1,
K,
Ca,
Mg,
P,
Colorimetry,
ICP,
Atomic absorption,
Macro-nutrients
Citation
Fischer, Joseph B.; Miller, James H. 2004. Ion Chromatography as an Alternative to Standard Methods for Analysis of Macro-nutrients in Mehlich 1 Extracts of Unfertilized Forest Soils. Communications in Soil Science and Plant Analysis, Vol. 35, Nos. 15 & 16, pp. 2191-2208, 2004
