Organic ameliorant and density arrangement affected the growth of Calliandra calothyrsus in nursery

Abstract. Sofyan FPM, Hartati W, Sudarmadji T, Syahrinudin. 2024. Organic ameliorant and density arrangement affected the growth of Calliandra calothyrsus in nursery. Asian J For 8: 107-114. Seedling quality is crucial for forest stand development, but optimizing nursery conditions for specific species like Calliandra calothyrsus Meisn. needs further research. This study aims to investigate how organic ameliorants and seedling density affect C. calothyrsus seedling growth performance in nurseries. Three replicates of 4 levels of organic ameliorant (0%, 25%, 50%, and 100%) and 3 levels of seedling density (100, 25, and 16 seedling/m2) were applied in a compatible arrangement with a factorial randomized design procedure. Each replication of treatment consisted of 30 seedlings for the assessment of the survival rate, diameter, height, and biomass accumulation. Ameliorant treatments and seedling density significantly influenced diameter, height, and biomass, whereas survival rate was unaffected by treatments. Only densities of 25 and 16 seedlings/m² met Indonesian quality standards (SNI 5006.2.2018) for field transplantation. This study demonstrates that improving the root environment through organic ameliorants and density management can enhance C. calothyrsus seedling growth in nurseries. This research offers insights for optimizing agroforestry seedling production. Identifying densities meeting national standards enhances reforestation success. The study lays the groundwork for future research on seedling quality and species-specific protocols in tropical agroforestry. Results can guide practitioners in producing high-quality seedlings, potentially improving reforestation efficiency and effectiveness.