Yet it isn't explained anywhere in his comments what this "particular way" exactly is. I guess it's supposed to be common knowledge, but I'm as clueless on that matter as the downvoted commentators in this thread are. Neither does Wikipedia on "Norfolk four-course system" (which it claims Townshend popularized, not invented) mention anything about the fertilizer, simply claiming that inclusion of a turnip as the fodder crop allowed livestock to be bred year-round.