Alley cropping along the contour lines and working with a keyline system is a highly productive, sustainable way to farm. Here is a shot from Mark Shephard’s co-operative farm, New Forest Farm in the Driftless region Southwestern Wisconsin, USA. The secret is the prune the roots regularly by running a deep blade-shaped plough in the pathway between the trees and perennial vegetable rows. This forces the roots to dive deep and not compete with the next row of crops.