Here are some pictures of a ballfield I maintain with foliar applied fertilizer. This field has received two applications... May and September. It's a 10-20-10 and applied @ 1.7 oz per K. That's 1.9 acres or 83k sqf. 1.1 gallons total per app. The cost? $9.40 per gallon. It will get 1lb of N in a dry app in October and that is all the feeding it gets. I'll foliar feed all day long @ that price and the myth that it does not last is just that... a myth.