non native COOL season grasses do well because of favorable temps and abundant moisture.
thin growing turf,disease,weeds taking hold are all reasons to make sure your lawn is fed properly because the alternative more often then not is MORE environmentally harmful curative applications needed to fix issues do to poor turf growth. no spring N at all is bad advice, site specific issue.
use less at any one time, 50%-100% slow release N urea based products.
the AS is very cheap to use but best to go light to prevent surge growth and possible leaching do to excessive rain