Or were they the most accurate and it throws your others out?

Why are you gridding your soil samples if you don't trust a lab yet?

Have you ever tissue tested?

Are your soils in balance or are you in need of certain elements?

The grinding issue is probably bigger than anyone of us know or want to acknowledge.

You are correct in that we have too much knowledge and not enough practical experience.

Only asking to help, not to muddle the issue.

When I did what you did, the Ammonium Acetate extraction lined up with what I had in the past, the other extractions did not and really confused me.

Sounds like you are confused the other direction, are  you only used to that data?

Ed