Quantification of biomass in cocoa systems (Theobroma cacao L.) in the Duarte province, Dominican Republic

Abstract

Theobroma cacao (cocoa) in the Dominican Republic is one of the main export items, registering a sustained growth in the last five years. There are more than 36,000 producers in the country, indirectly benefiting more than 300 thousand people. The country has great potential for cocoa production, but due to the lack of fertilization of the plantations combined with the lack of information on the contribution of nutrients from the mineralization of biomass in the production systems, low yields are presented. The study was carried out in the Duarte province in the period from July 2016 to June 2017, with the objective of quantifying the biomass production in four agroforestry systems: cocoa in monoculture (C), cocoa plus Erythrina spp (C+ Am), cocoa plus Persea americana (C+Ag ), and cocoa plus citrus (C+Ci). A multifactorial experimental design 4x15x12 was used: with four agroforestry systems, in fifteen locations and twelve sampling dates, where each farm was considered as a replicate. Four pipe and sack mesh traps were installed per farm, with an area of 1 m². The average biomass by location and date was analyzed by analysis of variance and Duncan test (P = 0.05 %). The highest average biomass production was obtained in C + Am with 49.3 T ha^-1 year^-1 (41.08 % of the total). It was followed by system C with 27.02 T ha^-1 year^-1, C + Ag with 22.2 T ha^-1 year^-1 and C + Ci with 17.2 T ha^-1 year^-1. The annual net production was 120 T ha^-1 year^-1, of which 115.2 T ha^-1 year^-1 was attributable to the species under study, and 4.2 T ha^-1 year^-1 to other species. The values demonstrate a high biomass production in agroforestry systems associated with cocoa.