Yeah - I commented on this REPEATEDLY already - starting with POST #2!!
I promise you you do NOT know more than I do about this. I have a PhD in physical chemistry and maintain a small personal farm.
Don’t go all Dunning-Kruger because you have Google.
“have a PhD in physical chemistry and maintain a small personal farm.”
Which is why you should not have made that mistake in the real math. I am a Geologist and understand elemental soils a bit myself. Whether it be mining or agriculture the elemental assessment content of soil or stone does not change. Right off the bat you should have known that 5% aluminum content of all soil does not equate to 5% as “Exchangeable” aluminum content. There is a huge difference between the two.