A simple tree-crop interaction equation is re-interpreted in terms of resource capture. Benefits in physical yields from agroforestry are to be expected only when there is complementarity of resource capture by trees and crops. Most of the current biophysical hypotheses formulated for agroforestry research are based on this central tenet, specified for various resources, soil and climatic conditions.
Agroforestry Systems (1996) 34 27-31 [10.1007/BF00129630]
The central agroforestry hypothesis: the trees must acquire resources that the crop would not otherwise acquire