Depends on your irrigation. If you have rain I would suggest applying it a day early so it can soak it to the root zone. If you irrigate running it in the irrigation water would be the best way. It is easy to run with some simple dilution even if you have a thick carbohydrate source like molasses. I’d suggest that sense it is meant to be a stable N source you don’t need to time it nearly as much as you might for a salt fertilizer. Apply it before you need it, let the biology digest it, and then it will be available as needed from them on. I find it to be slow-release for that reason, which to me is the best part.