We've been having some discussions in other scattered threads about making your own nutrient mix for citrus. This looked like the best place to consolidate it.
Anyway, the hot topic has been "how to mix natural sources of plant nutrients for citrus?". The answer is: there are many ways to do it, but ultimately the goal is to have the N, P, and K in ratios of 3 to 1 to 2 -- with respect to each other.
Since we are also having this discussion with regard to tomatoes, I have created an excel spreadsheet that might help you make decisions on fertilizer mixes for citrus and other fruiting plants. Well see
Here's a link to the spreadsheet:
N-P-K_Mix_Analysis_v02.xls