Erythrina fusca: a leguminous tree of the Colombian north coast with agroforestry potential

Erythrina fusca (Stam.) is perhaps the second most common leguminous tree on the northern coast of Colombia, after Gliricidia sepium. It is most commonly found on the outer margins of swamps, on sites that are not permanently flooded. Farmers traditionally use E. fusca as live fences and shade trees in pastures. In comparison to other woody legumes, its potential as an agroforestry species would appear to be limited. It produces only 2.7 ta-1 year-1 dry weight of biomass when planted in pure stands at a spacing of 2 x 2 m, which is much less than G. sepium or Cassia siamea grown under similar conditions. The N content of E. fusca is about 27 g. kg-1, which is considerably less than that of G. sepium or E. poeppigiana. Nevertheless, in areas with irregular rainfall of less than 1000 mm yr-1, E. fusca can resist prolonged drought without losing its leaves, recirculating 55 kg of N, 31 kg of K, 18 kg of Ca, and 11 kg of Mg ha-1 yr-1 from two prunings. These findings suggest that E. fusca may be a promising species for agroforestry systems on the northern coast of Colombia that include maize and cassava.