My approach to farming is to try to find what nature in my area supports best and to mould my needs according to nature's abilities. Allow each element in the system to contribute to it's best ability.

Soil- Provides anchoring, moisture, aeration and nutrition. Over time, what goes into the soil should contribute to those jobs. Avoid fertilizers as much as possible. If the soil is poor (as in Florida sand) when you start, you'll need to supply elements that aren't available in the soil using fertilizers. However, you should always work toward creating a natural system in the soil that provides for the natural generation of essential elements. Do this by contributing to conditions and soil amendments that help support microorganisms in the soil that take organic matter and mulch and convert it to food for microorganisms and subsequently food for your crop plant.

When I use fertilizers in food production, I use these things for the essential three N,P,K.:
Nitrogen- Blood meal
Phosphorous- Super Phosphate
Potassium- Potash