Keep in mind that the more Nitrogen you put down the more water your Bermuda grass will need. According to Texas A & M Bermuda grasses need about 1 pound of Nitrogen per 1,000 square feet per month, which seems like an awful lot. Up here the recommendation for N on our turf grasses is 2 pounds per 1,000 square feet per year.
Then, it depends on your soil. In clay soils, not well amended with organic matter, the nutrients can be locked away from the grass, not available. In sandy soils the nutrients can be washed right out of the soil unless there is sufficient amounts of organic matter in the soil to hold them.
What to spread, and when, will depend on the needs of your grass and what is available in the soil that grass is growing in, which indicates the need for a good, reliable soil test.

Here is a link that might be useful: About Bermuda Grass

For Bermuda, you will want to use grains with higher protein. CGM, soybean meal, and cotton seed meal are my normal choices. I also use Milorganite a time or two per season. Alfalfa and corn meal are near useless on Bermuda.

You have to think ahead with organic fertilizers as they are slow acting. It's not like chemical fertilizers where you can see results in a couple of days.

I've been using organic fertilizers on my Tif419 lawn for 7 or 8 years now. My first application each year is CGM on Valentine's Day. Starting April 1, I fertilize monthly. I also leave all clippings on the lawn as that is a pretty good source to return nitrogen to the soil.

With CGM, I apply at a rate of 10 lbs/1000 sq ft. With other grains, it's more like 15 lbs/1000 sq ft.

So many people say that it's difficult to get enough nitrogen for Bermuda with organic fertilizers. I've been very happy with my results.