Teak–arrowroot agroforestry on marginal forest land: Implications for tuber production and soil fertility dynamic

Teak-arrowroot agroforestry offers a potential strategy to optimize forest land utilization, while supporting local food security and farmer livelihoods. Arrowroot is a promising tuber crop with nutritional and health potential, but its performance on marginal forest soil remains underexplored. This research examines the optimal use of marginal soil through teak-arrowroot agroforestry, conducted in Parung Panjang Forest Management Unit Section, West Java Province, Indonesia, from November 2023 to August 2024. The research employed a split-plot design with six planting patterns (main plots), and two fertilizer treatments (sub-plot). The results showed no significant difference in teak growth between monoculture and agroforestry patterns. Arrowroots could adapt to the marginal soil, with grown rates of 92-100%. The planting patterns and fertilizer treatments significantly affected arrowroot growth and tuber yield. Teak-arrowroot agroforestry pattern with organic fertilizer produced 260.0 g tuber/clump, significantly higher than unfertilizer treatment (127.1 g tuber/clump). Arrowroot crop contributed positively to soil organic carbon content. Teak-arrowroot agroforestry model produces higher land productivity compared to monoculture of each plant species, with LER value of 1.36. However, the sustainability of arrowroot tuber yield on marginal soil will be greatly affected by fertilizer inputs. Local community already knows the arrowroot crop, but only consumes its tuber for domestic use due to limited post-harvest processing knowledge and skills. Improving local post-harvest processing skills may enhance its economic value. Teak-arrowroot agroforestry on marginal forest soil could maintain and improve soil fertility and organic carbon content compared to a monoculture system.