If it's true soy hydrolysate, the amino acids have been separated into their L forms. Not all soy protein is soy hydrolysate, BUT I think regular soy protein might work nearly as well. NPK sells a product called "Raw Omina", and as far as I can tell it's just soy protein too. Any of the dry "amino acid" products for plants with an NPK of around 14-0-0 and 80% amino acids are all regular soy protein. I bought a pound of it from GS plant foods (or something similar, forgot the name) for around $12, compared to $15-$20 for the NPK stuff. Don't spend a lot of money for these products. I use 1/4 teaspoon per gallon during bloom. I love amino acids for plants, both soy hydrolysate and fish hydrolysate, and there are studies that actually compare them to each other-they are some of the only products that have a noticeable positive effect on plants, besides just being the ultimate source of nitrogen. I'm not sure how they improve terpenes, essential oils, etc, but my plants are always better when I add some Neptune's Harvest hydrolysate to my base nutes, whether cannabis, tomatoes, berries, etc. It might have something to do with the sulfur containing amino acids, or maybe because it feeds the microbiome so well, or maybe some combination of those and other factors.
