Does anyone know of a book (or other source) that shows the specific nutrient requirements for individual vegetables?
Certified GKH Gardening Expert
This is quite hard to come by, as a compiled source. I still do it the old fashioned way, by writing down the requirements when I learn them for plants. Keep them in alphabetical order, and it will be easy to maintain.
Most crop producers will focus on maintaining proper nutrient levels as a whole for the entire field, as well as planting certain crops together to maximize uptake of each.
Unfortunately, it will be best to, either, fertilize the crops as a whole, or do individual research on each plant for feeding.