Effect of Cattails (Typha angustifolia L.) Biochar on Soil Fertility and Okra Productivity as an Effective Eco-Friendly Soil Amendment

The conversion of aquatic biomass into biochar offers a sustainable strategy for improving soil fertility and mitigating ecological imbalances caused by its rapid proliferation. In this study, Typha angustifolia, a widely distributed aquatic weed, was utilized for biochar production. Three biochar types (TABC400, TABC500, and TABC600) were synthesized through pyrolysis at 400 °C, 500 °C, and 600 °C temperature. It was hypothesized that Typha angustifolia biochar would positively influence the growth and development of okra (Abelmoschus esculentus L.). The results demonstrate that biochar yield subsequently decreases with increasing pyrolysis temperature, with the highest yield at 400 °C temperature (49.03%), followed by 500 °C (38.02%) and 600 °C temperature (32.01%). However, carbon content 67.01 to 83.12%, higher heating value (17.31 to 27.42 MJ/kg), and mineral contents (K, Mg, P, Ca, Fe, Cu, Zn) increase significantly with higher pyrolysis temperature. However, oxygen, hydrogen, nitrogen, bulk density, moisture contents, and volatile context exhibited an inverse relationship with pyrolysis temperature, highlighting biochar stability and its potential for soil amendment. Among the three synthesized biochar, the 4%TABC600 (600 °C) revealed the most substantial improvement in plant height (110.11 ± 4.12 cm), plant dry biomass (6.12 ± 0.41 gm), and chlorophyll contact (39.34 ± 3.33 SPAD values), whereas the 2% and 6% TABC600 demonstrated significant influence on fruit yield (9.11 ± 2.11 gm) and fruit weight (750.44 ± 7.83 g), and chlorophyll contact (32–38 SPAD values). Based on our results, we can conclude that Typha angustifolia biochar prepared at 600 °C (TABC600) has great potential as a biofertilizer, promoting soil fertility and growth and development of crops, particularly for vegetable cultivation such as okra.