For the corn, I would use 100 lbs/a of 19-19-19 at planting. When the corn is about 6 inches tall, add 200-300 lbs/a (depending on how much you want to spend) of 46-0-0 (urea). Make sure you work in the urea, or apply it before a good 1/2 inch plus rain. All of the fertilizer could also be spread and worked inth the soil before planting. If the plots are small, you can use lawn fertilizer. Just buy one with a big first number, and shoot for 120-150 lbs/a of N. Do not use crab grass preventer if your corn is not emerged.

For the soybeans, consider 200 lbs/a of 5-14-42 or 9-23-30.

I would also suggest a soil test this spring or fall. It would be nice to know the pH of the soil. Soybeans do not need great fertility. You may be putting fertilizer on them that you really do not need, or under applying something that really could help.