| Agroforestry production methods present one option for addressing growing concerns about the long term sustainability of intensive coffee production techniques. A study was designed to compare the effects of fertilization and shading from two leguminous species, Erythrina poeppigiana and Chloroleucon eurycyclum, on coffee grown at a Costa Rican research site. Coffee below biannually pruned, conventionally fertilized Erythrina exhibited the highest photosynthetic performance under both low and high light levels as well as greater biomass and higher N concentration. Soil P did not affect coffee performance, although shade trees on sites with higher soil P fixed more N compared to trees grown on low P sites, most of which were not found to be fixing. Results suggest shade mechanisms are the most important drivers of coffee adaptation in coffee agroforestry systems, though proper soil nutrient management and legume species pairing also appear to augment coffee response to microclimate conditions. |
