Here are recommendations for starter phosphorus, potassium

COLUMBUS – With potassium availability low in some areas and prices high all across the state, producers may be inclined to apply more fertilizer material this winter into early spring.
Phosphorus prices are also a little higher due to the high price of nitrogen (specifically those containing ammonium).
Depending upon soil test levels, starter materials may be an alternative to fall application.
Additional fertilizer will not be necessary for next year if soil test levels are well above the established critical levels for corn and soybeans. (For more information about these levels, see the recommendations at http://ohioline.osu.edu/e2567/.)
Additional. If soil test levels are below or near the critical level, application of additional fertilizer material is probably warranted.
Application of starter phosphorus and potassium may be a good alternative if spring broadcast applications will not fit into your operation and you have starter capability with your planter.
Research conducted in the state by Dr. Jay Johnson has revealed that application of starter does not increase yields if soil test levels are above the established critical values. (Keep this in mind if your fertility practices maintain high levels – you can get away with not applying anything without taking a yield hit.)
Starter. If you are going to apply starter next year, remember not to apply more than 100 pounds per acre of nitrogen and potassium (combined) in the band (2×2 placement) or emergence problems can occur.
While you cannot overcome serious deficiencies with starter applications (specifically for potassium), soil test levels below the critical value may benefit from application of starter fertilizer.
Make phosphorus and potassium input decisions on a field-by-field basis. Monitoring the fertility levels of your fields can really pay off – especially with the price we are paying for fertilizers.
(Robert Mullen is an Ohio State soil fertility specialist and Ed Lentz is an Ohio State agronomist.)