Massa seca de acácia (Acacia mangium Willd) em plantio agroflorestal no município de Barra do Garças – MT

Abstract

Agroforestry systems combine food production with sustainability and environmental conservation. The forest species Acacia mangium stands out for improving soil fertility and capturing carbon, while also diversifying income. Breeding programs for this species in various countries have shown that environmental conditions affect its productivity and quality. In Brazil, A. mangium requires research, including provenance trials for biomass production and its interactions with different crop types. Therefore, this study aims to examine carbon and biomass stocks in six provenances of A. mangium at 16 months of age, in an agroforestry system in Barra do Garças, MT. This system included Arabica and Robusta coffee species, banana plants, Leucaena, Mexican sunflower, Canavalia ensiformis (jack bean), and pumpkins. For each A. mangium provenance, 5–6 plants were sampled, and data on base diameter, apex diameter, and height (h) were collected to estimate aboveground biomass volume. Aboveground biomass was estimated for leaves (phyllodes), branches, and stem (wood) following the methodology of Arevalo, Alegre & Vilcahuaman (2002). The dry matter value was multiplied by 0.45 to estimate total accumulated carbon. Significant differences were observed among provenances for total carbon stock, as well as among leaves, branches, and wood. The provenance Recife-PE stood out in all variables, with the highest total biomass (PTOTAL) at 38.8 Mg ha⁻¹ and 17.46 Mg ha⁻¹ of carbon.