If you want to get behind the science of how fertilizer recommendations are made, there is no better source than the University of Georgia Soil Test Handbook.
This large publication is developed with the collaboration of soil scientists and plant health experts.
There are two parts:
includes specific recommendations for every crop grown in Georgia. Bermudagrass lawns, soybeans, pine trees, home vegetables, roses, peaches, cotton….if you can grow it, you’ll find the best way to fertilize it.