I am looking to spray my food plot, about 1 acre with 28-0-0 for the fall here in northwestern Wi. I have planted a number of plants. Biologic, maxum. Rape seed, clover and turnips. Will this fertilizer keep the plants green longer? What about monoammonium phosphate?

No, I assume you are talking about uan. It only increases burn potential in your situation. If you only need N according to your soil test, try some 27-0-0 (can), or urea (46-0-0) if you have rain in the forecast. I like about 60-70 units of N/acre on brassicas.