HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (19) Citing Articles via Google Scholar Google Scholar Articles by Catlett, K. M. Articles by Ebinger, M. H. Search for Related Content PubMed Articles by Catlett, K. M. Articles by Ebinger, M. H. GeoRef GeoRef Citation Agricola Articles by Catlett, K. M. Articles by Ebinger, M. H. Related Collections Soil Chemistry

DIVISION S-2—SOIL CHEMISTRY

Soil Chemical Properties Controlling Zinc²⁺ Activity in 18 Colorado Soils

^a Neptune and Company, 1505B 15th Street, Los Alamos, NM 87544
^b Dep. of Soil & Crop Sciences, Colorado State Univ., Fort Collins, CO 80523
^c 205 Woodside Drive, Provo, UT 89604
^d MS J495, Los Alamos National Lab., Los Alamos, NM 87545

* Corresponding author (kcatlett{at}neptuneandco.com)

Zinc is a heavy metal of much interest since it is a plant micronutrient as well as a potential contaminant in soils. In soil solution, the speciation of Zn, and thus the free Zn activity, determines the plant availability of Zn as a micronutrient and its characteristics as a heavy metal contaminant. A better understanding of the mechanisms that control free Zn activity could improve soil treatments of Zn deficiency or toxicity. Possible controlling mechanisms for Zn activity include adsorption or precipitation. In our study, Zn²⁺ activity was measured by chelation and was related to soil properties for 18 alkaline soils from three farms in eastern Colorado. Soil organic C (OC) and pH were statistically significant parameters in a multiple regression with log Zn²⁺ activity. The significance of OC may suggest that adsorption onto organic matter controls Zn solubility in some of our soils. Log Zn²⁺ activities plotted with pH fell near the soil-Zn solubility line. However, the slope of the regression line was -1 rather than an expected -2, which indicates that another mechanism besides precipitation and dissolution of soil Zn may occur. Another possibility is that there are two different regions of solubility, one below pH 8.4 and one above pH 8.4. It is suggested that free Zn ions may adsorb on organic matter in a region of low pH and may precipitate as franklinite or other minerals, such as a Zn-containing kerolite, at high pH.

Abbreviations: CEC, cation-exchange capacity • EC, electrical conductivity • EDTA, ethylenediaminetetraacetic acid • IC, inorganic C • ICP-AES, inductively-coupled plasma-atomic emission spectroscopy • IS, ionic strength • ISE, ion-selective electrode • MF, mole fraction • OC, organic C • XAFS, X-ray absorption fine structure spectroscopy • XRD, X-ray diffraction

This article has been cited by other articles:

				W. E. Riedell, J. L. Pikul Jr., A. A. Jaradat, and T. E. Schumacher Crop Rotation and Nitrogen Input Effects on Soil Fertility, Maize Mineral Nutrition, Yield, and Seed Composition Agron. J., July 7, 2009; 101(4): 870 - 879. [Abstract] [Full Text] [PDF]

				J. J. Wang and D. L. Harrell Effect of Ammonium, Potassium, and Sodium Cations and Phosphate, Nitrate, and Chloride Anions on Zinc Sorption and Lability in Selected Acid and Calcareous Soils Soil Sci. Soc. Am. J., June 2, 2005; 69(4): 1036 - 1046. [Abstract] [Full Text] [PDF]

				M. H. Ebinger, M. L. Norfleet, D. D. Breshears, D. A. Cremers, M. J. Ferris, P. J. Unkefer, M. S. Lamb, K. L. Goddard, and C. W. Meyer Extending the Applicability of Laser-Induced Breakdown Spectroscopy for Total Soil Carbon Measurement Soil Sci. Soc. Am. J., September 1, 2003; 67(5): 1616 - 1619. [Abstract] [Full Text] [PDF]