Fertilizing New Grass Hay Field

Planted 2 fields last fall. One in Timothy and the other in Orchard Grass. Previously land was in alfalfa hay crop. Alfalfa had died down considerably in the last 2 years. Pretty much zero alfalfa when I burned the field off late last summer. I know I need to add nitrogen, MAP, and potash. Not sure of timing. When I had alfalfa, I just put on MAP and potash after the first cutting, no nitrogen. Have 3 questions:

 

1) My fertilizer dealer wants to know if I want dry nitrogen or liquid nitrogen (urea). Is one better than the other, and when should I apply and how much/acre?

 

2) How often and how much MAP and potash needs to be added to grass hay fields? 

 

3) When should the MAP and potash be applied in grass hay?

 

I've always raised alfalfa hay in the past, so grass hay will be a new thing for me. Any help/guidance will be greatly appreciated.

Fertilizing New Grass Hay Field