best soil for mycorrhizae growth??

I compost my own soil, and for a while it worked from start to finish, however I just did some research of mycorrhizae (best as I can remember how to spell it lol) and decided I want to inoculate my soil with it, only things is it doesn't grow well with lots of phosphorus present in the soil, so I need a soil for the veg cycle which will allow it to grow as quickly and efficiently as possible,
Thanks in advance!

Trying to inoculate soil for myco's is a bit of a fools errand since they grow from a live root into the soil, but don't grow in the soil on their own. Soils that are inoculated don't do much of anything until/if a root comes into contact with a spore and gets infected. BTW, "infected" is the scientist's term, not mine.

This is why most dust the roots directly, usually during the first transplant, or, at least early in the life cycle.

It is easy to grow though. What the Rodale institute (Organic Gardening and Farming) does is inoculate Leeks in a P poor soil (totally right about high P inhibiting growth), harvesting most of the roots and then replanting the leeks to grow more roots/myco's. I do similar with garlic. Myco's love Alliums (Onions, Garlic, Leeks, etc.), so growing something you will eat is a win/win.

Myco's take something like 4 months to become well established and the 8 months to grow garlic works very well. Plus, my wife and I both love garlic. Have been doing this for going on 7 years now.

Google the Rodale Institute for more information as what I've written is the most brief of overviews and mainly to point you in the right direction.

HTH

Wet

I agree with everything @Wetdog just said. If you use a granular myco product just put it around your roots and transplant and as long as you keep it organic they will flourish. If you use any synthetic or even some bottled organic nutes you can do major damage to your fungi. I like to use some plant success granular at transplant and I also use Recharge which is a dry product that you would mix with water for a soil drench. I always use that about once a month throughout the grow. But for sure you need to use myco's they will supercharge your organic garden. Look into the recharge, it is from Scotty from the Dude Grows Show. His website it www.realgrowers.com Scotty is a good dude and I have used this product for years.

I was really just wondering if there was a commercial soil I could buy containing low amounts of phosphorus to try and get optimal growth out of the fungus during veg, to try and establish it as much as possible and then transplant into my composted soil! I assume it has too much phosphorus for the fungus to grow at maximum efficiency.

Really think you are better off just dusting granular myco directly onto the roots & leave it at that. You can brew up a fungal tea which will help promote healthy fungal growth in your containers but it's not really a game changer more like basic fungal maintenance. There are several fungal dominant tea recipes in the stickies at the top but for most you'll need to grow the myco on something like compost for it to grab onto & multipy.
Simply mix a cup of fresh EWC with a tsp or 2 of baby oatmeal & hydrate it. Keep the compost mixture uncovered in a warm dry place for 72 hrs or until you see white myco breaking the surface. Then bubble this overnight & add whatever else if anything & give to your plants.