Soilless horticultural media offer a solution to limited arable land but are often nutrient-inert, requiring efficient nutrient management strategies. This study aimed to evaluate the potential of seaweed biochar-amended vermicompost (VC) as a nutrient-supplying growing medium for tomato (Solanum lycopersicum L.) seedling establishment and vegetative growth. Coco peat was progressively replaced with VC (0–100%, w/w) under fertilized and unfertilized conditions during seedling development, and selected treatments were further evaluated during vegetative growth. Growth parameters, including emergence, plant height, leaf area, stem diameter, biomass, and chlorophyll content, were measured. Treatments significantly affected (p < 0.05) all parameters. The highest VC level (100%) reduced seedling emergence by 10.42% compared to the control but significantly improved seedling height (13.69 cm) and leaf area (49.45 cm2 plant−1) under fertilized conditions. During vegetative growth, the control (0% VC) produced the highest biomass (9.55 g) and plant height (67.43 cm), while higher VC rates (75–100%) enhanced chlorophyll content and maintained acceptable plant growth. Overall, VC showed potential as a sustainable growing medium component for tomato production, although plant responses varied according to growth stage and incorporation rate. Reduced emergence at higher VC levels indicates that further research is needed to optimize substrate management strategies for seedling establishment.
Ruben et al. (Sat,) studied this question.