I have been using soy hydrosylates for the last few years. They are expensive, probably you could make your own if motivated. I find them helpful as foliar (or even in drip for Greenhouse), have not found they push crops too far like other N sources. I am working with pretty degraded and poor soils, so I don’t mind adding some as a regular part of my foliar. Like I said, they don’t seem to throw things out of balance. If you are certified, make sure you get an OMRI product, since some are not “Organic”.