I have found a simple trick to adding mycorrhizal fungi to the planting
area... Get a straw bale (or 100*) in the summer and let it sit through
the wet season. Then mulch with it around the tree or planting bed in
the spring. It is the molding straw which will add the fungal mat to the
soil... this gives the roots of any plant a foundation for health and
immunity for the future stability it needs.
Adding 'CARBON' to your system is always going to help in the long term.
Carbon with help tie up nutrients and store them for a slow release in
the future.
*I usually buy straw in the summer when it is cheap and dry. I will use
it through out the summer and fall for seating, walls (stacked) garden
bed sides, tables or anything you can think of. Then after the winter
rains have soaked the bales and they start to rot and grow fungus in
Feb. or March I will use the straw as a top mulch or to plant directly
in with bedding plants or seeds.