I'm using soluble fertilize on St. Augustine and Centipede (Warm Season Turf). However, irrigation is a MUST!!! Watering in prevents burn as Riggs pointed out. The use of soluble and adding the weed herbicides to the mix cuts one application. Also, since mixing the correct amount of Nitrogen and Potassium is different for each of these, the mix is customized for the variety and the particular lawn. Stressed lawns can be spoon fed at a two (2) week interval if needed with other nutrients and iron.
We all are merely gleaners from the masters who were here before us.