UAN dealer. Sugar is the carbon source. I'm betting you know the N cycle better than most here-yes? I don't but if I read about it I get something from it. I'll look for something from my extension about that for you Ted. Thanks for asking. I've been doing it for years if that helps you. 46-0-0 fades quickly when spread dry. I know because I just bought a spreader this Spring and started doing it dry and it is fine for about 3 weeks then it fizzles out and now those places don't even look like they had any N to begin with. It's do or die time I'm guessing now with the heat coming close to 90 next week. I'm afraid of burning if I go out and spread now, or it won't rain for 3 weeks if I do and then what? I always throw some sugar with UAN as well. That was the first source of N I ever used on my own lawn. It's still my favorite but not when it's above 75* or it's crispy tire tracks everywhere. Or worse where the overlap gets heavy. I'm told ammonia is what burns the grass not the N- I'm talking immediately post app. Like 2 days after. Sugar really helps to stop that light burn before a good rain hits it. Sorry to ramble. I bow down to Ted Putnam any day.