I've got by spraying UAN. I think it is 11lbs/ if I remember without looking. If you spray full strength like I do 1 early app is all you need but once the grass gets going spraying it can burn down where you have overlaps. Here I pay about a buck a gallon at ag supply. Not Farm and Fleet, think seed corn dealers and huge ag sprayers. On most KBG lawns I spray 30 lbs/acre and it WORKS. So about $3/acre for N for the year. Better check your license and see what and when is allowed in your state.