Yeah, I see the point. Well digging with spades in the Ardennes is just plain stupid. As I recall, that was one of the largest artillery duels in history.

I feel sorry for the farmers though. There really isn't much they can do to avoid it, having to plow their fields. Something could be very deeply buried; but over time the heating and cooling of the soil pushes things up, especially in areas where temperatures can get below freezing. That's how it works in archaeology, so I imagine it works that way with munitions as well.

Thanks for the info, Louis!