Mycorrhizal Question

I have read several places that it is good to add mycorrhzal to the soil less mix. My question is how much do I add per cubic foot of mix.

Thank You,

It’s a spore so doesn’t take much my Subculture-M is myko it recommends 1/2 tsp per gal

Mycorrhiza is necessary for great yields - it is a fungus that promotes spider root which ='s bigger root ball’s = bigger plant’s= bigger yields !! (Great White is one also “Kelp4less” and last “Extreme Gardening”) Not sure if this site sell any?