Commercial cultivation of the Macauba palm is growing due to its agro-energy potential. This study quantified carbon stock in two macauba plantations (4.8 and 9.0 years old), considering carbon stored in soil and biomass. We assessed total organic carbon (TOC) stocks in labile (EOC and LF-C) and non-labile (NL-C) soil fractions, comparing these with a forest regenerating for over 30 years. Soil samples were collected within the palm plantation (rows and inter-rows) and the forest area at five depths (0–10, 10–20, 20–40, 40–60, and 60–100 cm). The impact of plantation age and sampling position on TOC stocks and organic matter fractions across different soil layers (0–100 cm) was assessed. The Carbon Management Index (CMI) was calculated to evaluate carbon recovery. Plantation age and sampling position influenced soil TOC stocks across all depths up to 1 m. Higher TOC and NL-C soil stocks were observed in the older plantation (9.0 years) and inter-row. EOC and LF-C fractions varied by soil layer. The inter-row region of the 9.0-year-old plantation exhibited higher carbon recovery based on the CMI. Over 4.2 years of palm cultivation (between 4.8 and 9.0 years), carbon accumulation in biomass and soil reached 75.36 Mg C ha−1. These findings underscore the potential of commercial macauba plantations to enhance soil carbon stocks rapidly, particularly in inter-row areas. Plantations younger than a decade surpassed the soil carbon stock of a forest regenerating for over 30 years, highlighting significant environmental benefits of macauba cultivation, including soil and biomass carbon sequestration.

中文翻译：

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玛卡巴棕榈商业种植园土壤碳积累和生物量


由于其农业能源潜力，麦巴棕榈的商业种植正在不断增长。本研究量化了两个猕猴桃种植园（4.8 和 9.0 年）的碳储量，考虑了土壤和生物量中储存的碳。我们评估了不稳定（EOC 和 LF-C）和不稳定（NL-C）土壤部分中的总有机碳 (TOC) 储量，并将其与 30 多年再生的森林进行比较。在棕榈种植园（行和行间）和森林区域的五个深度（0-10、10-20、20-40、40-60 和 60-100 厘米）内采集土壤样本。评估了种植园年龄和采样位置对不同土层（0-100 厘米）的 TOC 库和有机质分数的影响。计算碳管理指数（CMI）来评估碳回收。种植园年龄和采样位置影响 1 m 以内所有深度的土壤 TOC 储量。在较老的种植园（9.0 年）和行间观察到较高的 TOC 和 NL-C 土壤储量。 EOC 和 LF-C 分数因土层而异。根据 CMI，9.0 年种植园的行间区域表现出较高的碳回收率。经过 4.2 年的棕榈种植（4.8 至 9.0 年），生物量和土壤中的碳积累达到 75.36 Mg C ha−1。这些发现强调了商业玛卡巴种植园快速增加土壤碳储量的潜力，特别是在行间区域。不到十年的种植园超过了森林再生30多年的土壤碳储量，突显了玛卡巴种植的显着环境效益，包括土壤和生物质碳固存。