Plot 14 is our hardest plot to farm. The slope runs eighteen degrees in places. We have been trialling cover crops between the rows — clover, vetch, a particular Vietnamese groundnut — for three years now. The first year we overdid it and crowded the young Bourbon. The second year we got it right and the yields stayed the same. The third year the soil tests showed something we have never seen before: a measurable bump in microbial diversity.