Just thought I would update y'all on some things we have learned in the past few years in attempting to improve florida sand soil for vegetable production.
For years we have hauled mushroom compost from the plant in zellwood. Results were never great, and only lasted for a season or two at most. We learned that the mushroom compost is microbially dead and has little or no nutrients in it.
Last year we discovered azomite and south GA-source humate, which I have added to a variety of areas, some that had mushroom compost in it, others not, such as around citrus trees which from one application have greatly improved flavor in the fruit as well as greatly increased flowering now and good flush-out of new leaves on some trees and much less black spot on the leaves.
Also we started a new garden near a lake, a year ago, using humates and azomite in the sand (along with a little very old mushroom compost because we had no other OM at that time). Results were pretty good, no nematode problems, much better production than ever before. At other drier sites legume production with zero irrigation has been successful. Azomite appears to considerably increase drought tolerance in crops, so far IME.
In the process of buying bulk amounts of these materials recently, we discovered someone who makes compost in bulk, from woody materials and amended with the azomite and young humate. We got some of that as well. We potted up some tomatoes in it and plants have tripled in size in the last two weeks. We got six yards of it and put a thick bed of it right on top of the lawn, I dug down there the other day and after two weeks the sod is completely rotted out.
If anyone is interested in the name and location of the compost-maker, send me a message. I don't stand to gain from this, I simply think that people could with one haul and modest expense create a long-term production garden without having to constantly add low-quality box store materials and/or be confined to grow-boxes with their very small output.