You could try a search for Phil Nauta on YouTube.

Watched some phil nauta videos yesterday and asked a question ...thanks for response!

I liked "A Complete How-To: On-farm AM fungus inoculum production" from Rodale Institute.

Here is a link that might be useful: Rodale.

Look up Paul Stamets, he's a fungus nut and wrote a book called How Fungi Can Save the World that has a lot of info on propogating fungi. He even puts spores into chainsaw cutting oil so they are spread on the stumps as they are cut. Lots of great ideas.

The evidence that artificially added Mycorrhizal fungi help is a bit shaky. It clearly plays a role in the wild, but at this point no one really knows how to process mycorrhizal fungi, or quite what to use.

If you are growing a tree that also grows in the wild, there is a school of thought that taking some dirt from around where a tree grows wild in the woods and mixing it in with the soil you use when you plant a tree of that species in your yard would help...It has all the bacteria and fungi the wild plant was using as symbionts.

Not sure if that would work with carrots...but Queen Anne's Lace grows wild and is related to carrots, right?

Compost probably provides food for many kinds of helpful fungi.