Trees to improve soil conditions , to serve as nurse crops " or other purposes . The case of Leucaena leucocephala . Windbr aks and other tree crops to jpLove climatic conditions for crops and grazing areas .
Ngambeki , D.S. Economic evaluation of alley cropping leucaena with maize - maize and maizeCowpea in Southern Nigeria . ... the West Indies , Africa and Malaysia were it was introduced as a nurse or shade tree for coffee and cocoa .
