J. said:

I've set up a watering system, amended soil with peat, lime, straw, or
other organic matter, but ....


The corn and beans are doing well -- better than they've ever done --
but the tomatoes, onions and cukes are languishing, the asparagus is
just as fern like as it has always been, and the lettuce/mustard patch
is just so-so. All plots of soil in this raised bed garden have been
handled/treated in the same way over the years -- a dose of 10-10-10
in
Spring, set out plants, grow plants, cover with grass/mulch in winter,
start over.

Zone 5b, NY, 20 miles due north of NYC. I see blooming fields all
around, just not mine.

Any suggestions?

#1: Get yourself a soil test, ASAP. Contact Cornell:
http://www.css.cornell.edu/soiltest/newindex.asp

You want to check the major nutrients, most important minor
nutrients, and pH.

#2: Follow their recommendations, which may be to lay off some
nutrients (years of 10-10-10 may have oversupplied phosphorous)
and add in others (micronutrients like magnesium, for example).

My personal preference is for organic fertilizers on my own sandy
soil, and my main additions each year are compost and alfalfa
pellets.
--
Pat in Plymouth MI ('someplace.net' is comcast)

Any technology distinguishable from magic is insufficiently advanced.
(attributed to Don Marti)