[farmin]

The overarching problem with the statement is soil is so different everywhere. And managed differently everywhere. You can't just make a blanket statement. If I was going to make a blanket statement I would be more concerned with erosion than nutrition because soil is an ecosystem that can be repaired. But if it is gone, then that's a different story.

[toss1]

True, and good point — erosion rates also fit the "50 years and it's gone" prediction