Enhancing Black Gram Growth in Acid Soil Using Seaweed Biochar and Lignite Humic Acid

• Published in: Journal of soil science and plant nutrition 2024-10, Vol.24 (4), p.7129-7150
• Main Authors: Shanmugasundaram, R., Somasundaram, S. T.
• Format: Article
• Language: English
• Subjects: Acidic soils; Acidification; Acids; Agriculture; Algae; Alternative energy sources; Aquaculture; Biomass; Biomedical and Life Sciences; Carbon; Charcoal; Coal; Ecology; Energy consumption; Environment; Free atmosphere; Germination; Humic acids; Life Sciences; Lignite; Lignocellulose; Microorganisms; Mineral composition; Nitrogen; Organic soils; Original Paper; Phosphorus; Plant layout; Plant Sciences; Pore size; Potassium; Raw materials; Scanning electron microscopy; Seaweeds; Silica; Soil amendment; Soil lime; Soil Science & Conservation; Soils; Surface properties
• ISSN: 0718-9508; 0718-9516
• DOI: 10.1007/s42729-024-02029-9

In acid soils, organic amendments surpass lime, which can be detrimental if applied excessively. Since they are both high in important minerals, researchers are especially interested in seaweed-derived biochar and lignite-based humic acid. Their combined impacts on crops grown on acidic soils, however, have not yet been investigated. This study investigates the effects of these amendments on black gram growth and yield. Sargassum wightii was used to make the biochar at 450 °C in a nitrogen-free atmosphere, which was then examined for its mineral composition. Pore size and volume were measured using the Brunauer-Emmet-Teller (BET) technique, and surface characteristics and elemental content were analyzed via Scanning Electron Microscopy (SEM/EDX). In a pot experiment, the effects of biochar on plant development and yield were evaluated at three different concentrations (2%, 5%, and 10% w/w), with and without 2% w/w humic acid derived from lignite. In the S. wightii biochar, silica, carbon, nitrogen, and potassium were detected by SEM/EDX analysis. Its pore volume, pore volume, pore diameter, and BET surface area were 0.033 cc g -1 , 2.55 nm, and 5.23 m² g -1 respectively. When compared to the control and other treatments, the plants under treatment T6 (2% w/w humic acid and 2% w/w biochar) had the highest rates of germination (97%), vigor index (1532.6 ± 42.4), nodule number (40.5 ± 0.4 plant-1), and 100-grain weight (3.5 ± 0.08 g). Black gram growth and yield can be enhanced by combining 2% w/w biochar and 2% w/w humic acid. This provides a sustainable, eco-friendly agriculture option.