MEDIA CONSTITUENTS, MICRONUTRIENT FERTILIZER SOURCE, AND CALCIUM APPLICATIONS INFLUENCE IRON, MANGANESE, AND ZINC LEACHING1*

Abstract

Sphagnum moss peat (PM), perlite (PR), pine bark (PB), sand (SN), and two media formulated from these constituents (3 PM + 1 PR and 3 PB + 1 PM + 1 SN, by volume) were used to determine the effect of individual media constituents and mixes on iron (Fe), manganese (Mn), and zinc (Zn) leaching with a granular-incorporated (GIF) or a water-soluble (WSF) micronutrient fertilizer source and calcium (Ca) surface application. Leachate electrical conductivity increased with increasing Ca application rate regardless of fertilizer source. Leachate from PR and SN contained more Fe, Mn, and Zn than leachate from other media regardless of micronutrient source. More Fe leached from SN and more Mn and Zn leached from PR than from any other medium when WSF was applied. In contrast, when GIF was the fertilizer source, more Fe leached from PR, and more Mn and Zn leached from SN than from any other medium. Perlite and SN provide aeration and stability, but should be used in combination with other media components that permit ion retention in the media. *Approved for publication by the Director, Oklahoma Agricultural Experiment Station. This research was supported by project H-2324.