Resumen
- The study was carried out in an agroforestry system (AFS) with cacao trees already established in La Suiza Research Center, Corpoica, located in Rionegro, Santander (Colombia). The objective was to evaluate biomass input and nutrient release rate of the species that comprise the AFS (Gmelina arbórea, Gliricidia sepium, Cedrela odorata, Theobroma cacao). The plant material decomposition process of the species was monitored with decomposition bags after 8, 15, 23, 84 and 113 days, evaluating remnant weight and nitrogen, phosphorous, potassium, calcium and magnesium content. Results showed significant differences in plant material decomposition of the species considered. The largest weight loss was found in G. arborea (87.55%) and the lowest in C. odorata (40.01%). The highest nutrient release value was found in G. arborea followed by G. sepium, and the lowest in T. cacao and C. odorata. Therefore, depending on the species that comprise the AFS there is a differential leaf biomass decomposition dynamic and hence, of the nutrient input to the soil. Of the species evaluated the highest input of new organic matter to the soil in this AFS comes from G. arborea. Altogether, the litter generated by the species evaluated contributed with 10% of the nutrients required for a cacao harvest.