My word, I already have soybean meal in my beds and I have another huge truck load to be put out. We get it every year. Soybean meal is what all the gardeners in this area use. The thing is to get it without weeds. Well, that was easy to fix!
Alfalfa pellets works wonders!!!
8ft
Ask at Wadsworth Feeds, they are very old & tiny and just may still be there.
It's been about 30 years since I was there last.