Well my worm castings is used for both, mainly as a source of p, but also because all the other micro nutrients it contains, as for the biochar its already pre-mixed in the organic soil enhancer at 20% roughly, so its bot something I can alter or am adding in myselr per se. It literally comes as about 20% pre mixed in. They said they done their tests and those were the results they got beat out of.I've experimented a lot with bio char in mixes, and I love it, but in small amounts. Each bio-char brand varies in how alkaline it is, depending on the wood used, and other aspects of the pyrolysis process, but typically bio-char is highly alkaline at 8+ ph. I like to soak it in fish hydrolysate for a week then you're good to add it, but don't go over 5% of the total mix as bio-char. The high alkalinity makes it a great addition to peat based mixes, but it does add something to a coco grow too at 1% to 5% of a mix. The main reason I add it is because rhizobacteria love it, and even at 1% of a mix, it creates so many tiny oasis where bacteria can thrive-not that they don't already thrive in coco or peat, we're just talking about the internal surface area of bio-char that gives it such special properties. I like earthworm castings for a similar reason-not for their nutritive value, but for their value in spreading beneficial bacteria/fungi through the media.
i plan on running biowar inoculants as well just to boost the process and have diversity in there