Published online by Cambridge University Press: 03 October 2008
Experiments were carried out to examine the effects of agri-silviculture in three different ecological zones of Southern Nigeria. The four treatments considered were Gmelina arborea (forest tree crop) alone, Gmelina + maize, Gmelina + yam, and Gmelina + cassava, each treatment being replicated 8 times in each location. Composite soil samples, collected from two surface layers of each treatment plot, were analysed. Inter-planting young forest plantations with food crops usually increased soil N and P, at the slight expense of soil organic carbon. However, exchangeable Ca, Mg and K contents, pH, and soil N and P contents, were not statistically different among the treatment plots.