The application rate was in my first reply. How often? I apply fertilizer on the federal holidays. I start on Washington's Birthday and repeat on Memorial Day, 4th of July, Labor Day, and Thanksgiving. If you want to go a little heavier to get started, you can use it at that same rate every month.
You cannot overdo it. One of my co-moderators on another forum just realized he had been making a mistake in his calculation for square footage. He was using the square footage of his entire property without subtracting off the house, driveway, patio, and flower garden. After refiguring it, he decided he had been applying soy bean meal at a rate of 100 pounds per 1,000 square feet, three times per year. I can't imagine making a mistake that big...and the smell !!! But his lawn is very impressive by any measure or standard you can come up with. In the pictures people accuse him of Photoshopping the colors.
If the grass does not seem to respond in a month, it might be time for a soil test from The Texas Plant and Soil Lab
. Tell them you are starting on an organic program and they will give you lots of ideas how to proceed. Follow their advice above all others (including, if not especially, mine). They perform miracles.