Zinc (Zn) and Sulfur (S) are state-specific. For example, some states do not see a yield increase to fertilizer sulfur applications, while other states do.
For these recommendations consult:
Kansas State: http://www.oznet.ksu.edu/library/crpsl2/mf2586.pdf
Michigan State: http://www.css.msu.edu/SPNL-SoilTestReport.cfm
Mississippi State: http://msucares.com/crops/soils/index.html
North Carolina State: http://www.ces.ncsu.edu/plymouth/cropsci/cornguide/Chapter3.html
Penn State: http://www.aasl.psu.edu/SOILRecHdbks.HTM
Virginia Tech: http://www.soiltest.vt.edu/
For more information on this or other topics related to corn production, contact your state extension corn specialist or your local extension educator/agent.
The following is the link to the corn extension specialists: state extension corn specialist