Depends on the soil. You might be able to estimate what type of fertilizer to use with a soil map, but without a test, it's hard to say.
Oats like Nitrogen, 15-15-15 would be standard. 1st number is Nitrogen. If you're anywhere near my part of TN you're probably going to need a lot of lime to neutralize the acid in the soil. Otherwise, fertilizer won't work.
