I love this question! Mainly because first I laughed at "But that would be silly -- we spent all this effort taking it out of the ground", but on second thought

I love this question! Mainly because first I laughed at "But that would be silly -- we spent all this effort taking it out of the ground", but on second thought it represents a reasonable thought of "We got it from the ground, therefore the ground isn't the worst place for this stuff maybe?". In crux, thanks for asking :)