Bactris gasipaes agroecosystems for heart-of-palm production in Costa Rica: changes in biomass, nutrient and carbon pools with stand age and plant density

Abstract

Perennial tree crops develop through growth phases that differ in the rate of biomass and carbon build-up, and in the relative contribution of various pools and fluxes to nutrient cycles and nutrient supply for plant growth. To define these phases in peach palm ( Bactris gasipaes) agroecosystems for heart-of-palm production, we estimated biomass in stands up to 20 years of age in the humid tropical lowlands of Costa Rica. Dry biomass of foliage, petioles and stems were estimated using allometric equations which have been previously generated by applying nonlinear seemingly unrelated regression procedures to data from harvests of peach palm plants. Total aboveground biomass trajectories through time were fitted by a three-parameter logistic function with total biomass stabilizing at about 6.3 Mg/ha. There were no differences in standing biomass between stands on Andisols and Ultisols. Trends in nutrient pools through time were similar to those for biomass. The order in size of nutrient pools was N (up to approximately 120 kg/ha)> K (up to 90 kg/ha)> Ca (up to 45 kg/ha)> Mg , S, P (all up to 15–17 kg/ha). Peach palm plant bases and coarse roots are relatively large fractions of total plant biomass, and consequently of sequestered carbon and nutrients. The amount of carbon per unit area in plant tissue in peach palm agroecosystems in the Atlantic region of Costa Rica was about 8% of the carbon in forests of the same region.