So when was it last fertilized and when is your grass going dormant? Off hand I would say that there is no need to fertilize now...
But there are factors that may indicate otherwise,,,
did the sod go down in July?
are you on sand and did all the N leach away becuz of too much water for the sod?
Now that I know that clay's texture(platelets) has nothing to do with water infiltration, percolation, or drainage,,, I wonder what does...