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The Distribution of Micronutrient Cations in Soil Under Conditions of Varying Redox Potential and pH
Author(s) -
Sims J. L.,
Patrick W. H.
Publication year - 1978
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1978.03615995004200020010x
Subject(s) - chemistry , organic matter , dissolution , redox , loam , oxalate , inorganic chemistry , micronutrient , environmental chemistry , pyrophosphate , soil water , organic chemistry , soil science , environmental science , enzyme
A laboratory study was conducted to determine the influence of redox potential and soil pH on the distribution of Fe, Mn, Zn, and Cu in Mhoon silty clay loam soil (Typic Fluvaquents) and to provide insight into factors affecting micronutrient dissolution and mobility in soil. Generally, greater amounts of Fe, Mn, Zn, and Cu were found in the Na acetate (exchangeable) and pyrophosphate (organic) extractions at low pH and Eh than at high pH or Eh. In contrast, the amounts (except Mn) in the water‐soluble, NH 2 OH·HCl, and oxalate fractions were greater at high pH or Eh. Although the micronutrients were brought into solution at low pH and Eh, much of the soluble cations soon associated with the exchangeable and organic fractions. After reduction, mobilized Fe associated about equally with the exchangeable, organic, and NH 2 OH·HCl fractions; mobilized Mn with the exchangeable and water‐soluble fractions; mobilized Zn with the organic fraction; and the mobilized Cu with the organic and water‐soluble fractions. Separation of the water‐soluble fraction into free ions and those complexed by soluble organic matter indicated that micronutrient cations were complexed by organic matter to a greater extent in reduced soil.