FANTABULOUS STUFF - natures wonder tonic!
One of the best tonics to use on soil, IT IS natures nectar of the Gods!
Be aware though, it is not a fertilizer in the true sense, but a soil tonic or conditioner/enhancer.
It is full of useful things that will enhance soil microbial life immensely. I have been using it, as well as worm castings, for 25+ years and swear by them.
How much to use depends on the concentration of the product you get, but in any case, it is impossible to use too much and burn your plants, even if used undiluted. It will no doubt be stated on the bottle how much to use.
I say "go for it!" your plants will love you and your soil too! It really is a fantastic elixir of health for your plants. Absolutely full of goodness!
Hope this helps,.......
Organoman.