P applied to stands beginning at age 5 in intensive management, or following thinnings. 200 lbs of DAP is a good treatment here as well. Timing of N is in the spring or fall. Most intensive management aimed at short-rotation fiber production. Overall, little differences in fertilizer sources.
Cost is generally the overriding consideration.
Chicken litter - perhaps difficult to uniformly apply, but a good option. Make a composite sample from 6 to 7 trees. Keep samples on ice until the are sent for analysis.