Nitrogen and fine root length dynamics in a tropical agroforestry system with periodically pruned Erythrina poeppigiana

摘要: The effect of pruning all branches (complete pruning) or retaining one branch (partial on the dynamics nitrogen cycling in aboveground biomass, supplying power an amended Eutric Cambisol, and fine root length, was studied Erythrina poeppigiana (Walp.) O.F. Cook—tomato (Lycopersicon esculentum Mill.) alley cropping practice Turrialba, Costa Rica during 1999–2000. Over 1 year cycle, which trees were completely partially pruned four times, respective biomass production 4.4 Mg 7 ha−1 (2-year-old trees) 5.5 9 (8-year-old trees); N cycled 123 kg 187 160 256 mean length 489 821 m (2-year-old-trees), 184 364 per tree (8-year-old-trees). Pruning intensity did not significantly affect net mineralisation nitrification rates tomato-cropping season. For tomato crop, pre-plant rate 2.5 mg kg−1 soil day−1 lower than 16.7 11.6 at end vegetative development flowering, respectively. Mean 3.5, 4.3 day−1, development, respectively, higher 0.3 flowering. In humid tropical low-input agroforestry practices that depend organic inputs from for crop nutrition, retention a stump appears to be good alternative removal reducing losses through conserving uptake, although it might enhance competition associated crops.