Over time, agricultural soil begins to resemble hydroponic growth medium. It’s not soil, it’s just something to hold roots and deliver water and fertizers.
Which means it definitely doesn’t have much nitrifying bacteria and absolutely doesn’t have any fungi transporting minerals from deeper underground or by organically weathering sand particles.
I keep sharing Gabe Brown's three-part video series titled Treating the Farm as an Ecosystem, now and then, here on HN, whenever such threads come up.
Some really solid practical and pragmatic stuff there, on regenerative agriculture, which, as I understand it [1], goes beyond organic farming, and is related to many of the issues talked about in this thread.
[1] I had done organic gardening successfully, for a few years, some time earlier, so I have at least some practice and experience (and also a lot of reading and thinking about what I read) as the basis for my opinions of his work and those of others I mention, such as Elaine Ingham (a video by her is below too).
One of her most astonishing finds / claims is that (IIRC, I saw the video a few years ago), almost all soils anywhere on earth have more than enough nutrients for plants for many many years.
She said the real issue and limitation is the lack of soil organic content and soil structure and mycorrhiza ( https://en.m.wikipedia.org/wiki/Mycorrhiza), without which even applying tons of nutrients is useless.
And, Gabe has a big farm, a few thousand acres (so not small scale) in North Dakota, USA, with field crops, green manure, livestock on pasture / prairie, etc. And is making profits from his farming operations, sustainably, even regeneratively, without government subsidies, and more than his conventionally-farming neighbors, some of whose soils are getting worse, while his get better over time, by objective measures (checked by external govt. agencies) that he mentions.
Here is an earlier comment subthread by me, on an earlier HN thread on the same general topic, as I said I've done, above. It mentions Gabe, Elaine, and a few others, including Geoff Lawton, permaculture pioneer, who are doing good work in this area, with a few more details:
Which means it definitely doesn’t have much nitrifying bacteria and absolutely doesn’t have any fungi transporting minerals from deeper underground or by organically weathering sand particles.