Biochar -assisted mechanisms modulate differential changes on morphometric and biochemical markers as nutrient signaling indices in African spinach (Celosia argentea. L)

Growth and biochemical compositions of plants are influenced by nutritional compositions of growth-media. This study elucidated the influence of guinea grass biochar levels (BL) (0.5–2.0%) on some morphometric and biochemical markers in African Spinach in 2024 and 2025. Ordinary water served as control (0% BL). Morphometric-markers, reactive oxygen species (ROS), antioxidant activities and nutritional compositions of the vegetables were assessed. 1.5% BL produced tallest plant height (51.50 cm) in 2024 and highest number of leaves (29.77) in 2025. Malondialdehyde (18.95 µmol g−1 FW) and (16.15 µmol g−1 FW) was significantly higher in the leaves of control in 2024 and roots (16.88 µmol g−1 FW, 18.15 µmol g−1 FW) in 2025. Hydrogen peroxide in the leaves (37.79 nmol g−1 DW) and roots (23.89 nmol g−1 DW) of the group in 2024 and 37.79 nmol g−1 DW and 25.59 nmol g−1 DW at 0.5% BL in 2025 showed significant increase. Antioxidant activities significantly reduced in A. spinach at 2.0% BL. Ascorbic acid in the leaves (164.16 µmol g−1 FW) and roots (211.13 µmol g− 1 FW) and total soluble sugar (29.05, 24.49 mg g−1 FW) in the vegetable grown under 1.5% BL, glutathione in the leaves (9.77 µmol min−1 mg−1) and roots (8.89 µmol min−1 mg−1) of the vegetables at 2.0% BL showed significant increase. Furthermore, 1.5 and 2.0% BL improved nutritional compositions in A. spinach. In conclusion, 1.5% BL enhanced morphometric-markers and nutritional compositions, while 2.0%BL regulated ROS and suppressed antioxidants in the vegetable.