An interesting statement in an interesting article on another topic altogether.

“The Christian missionaries came with an information package, having had access to Roman texts on farming. They knew how to make up for deficiencies in local soils by adding manure, by adding peat to sand, by adding sand to peat, and so on. And together with the very deep ditches, it is definitely signalling the Dark Age”.

from Scotsman.com via mirabilis.ca