I am a lot smarter now than I was 5 years ago when I bought 25 pounds of non-organic soy meal as fertilizer.
Now, because, if soy is non-orgnic it is probably GMO, I would not touch the stuff. I thought I was doing the best thing by avoiding cottonseed meal, since cotton is the most sprayed crop of all. I eat all organic at least, and had not been keeping track of the GMO issue.
Today I found the soy meal in a remote corner of a shed I was cleaning out. I never used it.
Is it just useless and full of toxins, such that I should bring it to the dump?
I hope not, but I will before I will pollute my body.
Isn't it dumb that we have to worry about this? It is so refreshing to read my Mother's old gardeningbooks published in the late 30's and early 40's. A different world.
Well, you could detox it with mushrooms. You'd have to mix it up with horse poo, compost that, grow portabellos in the result, and then use the spent mushroom compost as a top dressing for some wood-eating mushrooms for a year or so, just to be reasonably sure that it's detoxed well enough. Even then there may still be things that resist fungal decomposition, and of course you probably won't want to be eating any of the mushrooms that come out of it until then.
Overall, it would probably be a lot less work to just take it to the dump.
Cotton is indeed the most heavily sprayed crop in North America, but soy is the most heavily sprayed 'food crop'.
The fact that it is GMO probably won't effect it's usefulness as compost, but the spraying will.
Since you say you bought it 5 years ago, it has probably lost most of its toxicity.
What I would do is to mix it (something like) 3 parts soil to 1 part soy, and just let it age another year.
After that, if you still do not want it on food crops, you could use it (as potting soil?) to grow 'weeds', or green manure crops.
Location: Portland, Oregon Maritime, temperate, zone 7-8.