Separating the Tree–Soil–Crop Interactions in Agroforestry Parkland Systems in Saponé (Burkina Faso) using WaNuLCAS

Abstract

Trees in the parkland systems of West Africa are important for farmers because they provide food and income. However, they also interact with the grain crops, positively as well as negatively. Trees and associated crops differ in their ability to capture and use the most limiting essential growth resources effectively (Monteith, 1981). Thus, competition and complementarity in resource use between the components of parkland systems need to be better understood. These processes occur both above- and belowground as plants balance the aboveground water loss and carbon gain with the belowground access to soil supply of water via the roots. In mixed communities plants rarely compete for light without simultaneously competing for water and nutrients (Ong, 1996; Mobbs et al. 1998; Kho, 2000a,b) and our understanding of how mixed species systems grow and utilize resources will remain restricted unless experiments are designed which explicitly recognize this (Wallace, 1996). The present research was, therefore, designed to study the effect of crown pruning on the productivity of agroforestry parkland systems in terms of resource capture and utilization. The focus was on two species of trees Vitellaria paradoxa C.F. Gaertn (karité) and Parkia biglobosa (Jacq.) Benth. (néré), both producing high-value fruit.