Comparison of co-granulated fertilziers to equivalent blends of phosphorus, sulfur, and zinc in a corn-soybean rotation

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] High yielding corn and soybean production systems in Missouri have renewed an interest in micronutrient management such as sulfur (S) which is essential for protein formation and zinc (Zn) which is important for enzymes and metabolic reactions. Soil tests in 2010 indicated that over 60% of the samples in upstate Missouri had low ([less than or equal to]0.6 ppm) to medium (0.7 to 1.0 ppm) soil test Zn (Nathan, unpublished). Similarly, over 70% of the soil test samples were very low to medium for Bray 1P. Fertilizer manufacturing has progressed to accommodate more uniform distribution of nutrients in an individual fertilizer granule. Co-granulated fertilizers, where S and Zn are added in layers to the monoammonium phosphate (MAP) prill, allows for a more uniform distribution of fertilizer. Mosaic has formulated MicroEssential[copyright] Sulfur 10 (MES10[trademark]) (12-40-0-10S) and MicroEssential Sulfur and Zinc (MESZ[trademark]) (12-40-0-10S-1Zn) with two forms of sulfur (50% sulfate and 50% elemental S). The overall objectives of this research were to 1) evaluate P amounts of MES10and MESZ formulations to equivalent blends of MAP, Zn, and S; and2) evaluate Zn amounts in a blend with MAP or diammonium phosphate (DAP) compared to MES10 and MESZ formulations on grain yields and uptake of nutrients in a corn-soybean rotation. In objective 1: Phosphorus amount or addition of S or Zn did not have a consistent effect on corn grain yield with only three of the six site-years showing any significance yield increase over the non-treated control. However, relative corn yields showed P treatments at 123 kg P ha[superscript -1] increased corn yields 13 to 20% compared to the non-treated control. In objective 2: The amount of Zn fertilizer (2.2 vs. 5.6 kg Zn ha[superscript -1]), Zn source (SuperZn vs. ZnSO[subscript 4]), or P source (DAP vs. MAP) showed no significant effect on yield. The addition of P, S, and Zn were generally observed in greater post corn harvest soil samples.--From public.pdf