I dug around on the large hill in front of my property, and it turns out it is at least 40% sandy loam in the spots dug. Madrona, which I have seen growing in sandy soils close to water, is present on my property only on this hill. I think it's good for my Swiss and Korean Stone pines. Better than the clay and silt elsewhere.
I looked up inoculants to use with them, since they arrived today. it seems that these trees normally grow with Suillus SPP fungi. This inoculant contains this fungus, but I am also wondering about the impacts of spreading inoculants around. I have a 2-stroke backpack sprayer I was planning to use for biodynamic preparations and
compost teas.
https://www.kelp4less.com/shop/mycorrhizae-and-inoculants/
this preparation has a bunch of other stuff in it. Although I have heard geoff Lawton talk about inoculants, it's never specific, even down to specific ingredients, never mind brands.
I haven't looked for threads on inoculants yet, I'm sure there must be some.