What is proper nitrogen content in fertilizer for St. Aug. in south Louisiana?

I typically stay around Randy Lemmon's recommendation: 3-1-2 or 4-1-2 NPK ratio, usually with some mix of immediate release and slow release. But there is no right or wrong answer to how much %nitrogen is "proper."

The more important point is how much nitrogen to apply at one time. 1lb of nitrogen per 1000 sq ft is the standard, usually applied 3-4 times during the growing season (every 6 to 8 weeks from April through August).