This grass is great, the only guide I can give as I use regular fertilizer is to keep it mowed high. 2-4 inches. I find that at the higher levels, it shades the ground better so your soil retains moisture. If you mow low, the soil goes bone dry and inhibits the grass from spreading.

When the grass sends up its seed heads, the black V's, they need to stay on for at least 60 days for them to become viable seeds. If you can, along a fence or property line, keep a 1' strip unmowed all summer long, then mow it high in the late fall.

To know which fertilzer, if any, to use you need to know what your soil has and that can only be determinbed by a good, reliable soil test. Contact your local office of your University of Florida Cooperative Extension Service to find out about doing this.
Most all commercially avaialable fertilizers have way too much Nitrogen in the mix so most of that is simply washed out of your soil and into the ground water as a pollutant.

Here is a link that might be useful: UF CES

kimmsr, are you saying commercial organic ferts have too much nitrogen? Or too much for bahia grass? Except possibly for centipede, I don't think I've ever heard of a grass that can't take the N from a bag of corn meal.

LadyDi, look in the Organic Gardening forum FAQ pages for the Organic Lawn Care FAQ.