Impact of Wood Biochar Doses on Vegetative Growth of Cauliflower (Brassica oleracea var. botrytis) in Coastal Saline Soils of Bangladesh

Abstract

Background: Continuous cropping and intensive agricultural practices have led to the degradation of many productive soils, resulting in problems such as loss of organic matter and nutrients, drought stress, erosion, waterlogging, salinity, and soil compaction. Biochar has been reported to stimulate plant growth by improving soil structure, enhancing nutrient availability, and increasing soil water-holding capacity. Furthermore, the porous structure of biochar provides a favorable habitat for microorganisms such as bacteria, actinomycetes, and arbuscular mycorrhizal fungi, thereby enhancing soil microbial activity Aims: The present study evaluates the effects of varying wood biochar doses on growth parameters (plant height, leaf number, leaf breadth, and leaf length) of cauliflower in coastal Bangladesh, and assess its potential as a soil amendment for challenging environments. Study Design: Randomized Complete Block Design with three replications. Place and Duration of Study: Noakhali Science and Technology University Campus, Noakhali, Bangladesh, from January to March 2022. Methodology: Five treatments were tested: T0 (0 ton/ha, control), T1 (2 ton/ha), T2 (4 ton/ha), T3 (6 ton/ha), and T4 (8 ton/ha) Meheguni wood biochar. Each plot contained 6 plants per plot. Growth parameters were measured at 20, 40, and 60 days after transplanting (DAT). Results: Biochar significantly influenced all four growth parameters (p < 0.05). Plant height increased with higher doses; maximum values were 17.72 cm (T4) at 20 DAT, 33.97 cm (T4) at 40 DAT, and 38.75 cm (T4) at 60 DAT. Leaf number peaked at 10.77 (T3) at 20 DAT, 12.88 (T3) at 40 DAT, and 15.56 (T4) at 60 DAT. Leaf breadth was highest in T3: 5.8 cm at 20 DAT, 12.53 cm at 40 DAT, and 15.45 cm at 60 DAT. Leaf length reached 14.68 cm (T3) at 20 DAT and 31.11 cm (T4) at 40 DAT. No significant effects on development or yield were observed. Conclusion: Wood biochar at 6-8 ton/ha enhanced vegetative growth of cauliflower, but failed to improve development or yield amid coastal challenges like salinity, waterlogging, and temperature fluctuations. Further studies are needed to optimize biochar for such conditions. These findings demonstrate the potential of biochar to support growth under stress conditions but also indicate the need for optimized application strategies to improve yield.