There is no sure way to tell what your soil has for nutrients without having a soil test done. You appear to have spent a great deal of time on those beds and caring for those
plants, so why not spend another $10 and get a soil test done to know for sure? Relying on aged manures and compost in all but the more fertile soils is not enough. These are organic forms of nutrients. They need to be broken down by the soil organisms first to be made available to
plant life. Generally speaking and HIGHLY variable, compost, measured in terms of N-P-K numbers is only in the 1-1-1 range and manures are less than that. I'll post a decent article below.
If I were you I would certainly supplement the
plants with some sort of fertilizer based on the recommendations of a laboratory soil test.
I know a couple people in the DFW area that may be able to help find a soil testing service if you cannot. Otherwise, you have a beautiful garden!
http://www.poultrywaste.okstate.edu/files/f-2228web.pdf
