Comparative Assessment of the Physical Characteristics of Biochar Derived from Different Agricultural Residues
Tanaya Dutta
Department of Soil Science and Agricultural Chemistry, School of Agriculture and Allied Sciences, The Neotia University, Diamond Harbour Road, West Bengal-743368, India.
Sourav Mullick *
Department of Soil Science and Agricultural Chemistry, School of Agriculture and Allied Sciences, The Neotia University, Diamond Harbour Road, West Bengal-743368, India.
Monisankar Bera
Department of Soil Science and Agricultural Chemistry, School of Agriculture and Allied Sciences, The Neotia University, Diamond Harbour Road, West Bengal-743368, India.
Indrani Mullick
Department of Agriculture Economics, School of Agriculture and Allied Sciences, The Neotia University, Diamond Harbour Road, West Bengal-743368, India.
Shovonika Barik
Department of Agronomy and Agroforestry, School of Agriculture and Allied Sciences, The Neotia University, Diamond Harbour Road, West Bengal-743368, India.
Riman Saha Chowdhury
Department of Horticulture and Food Science, School of Agriculture and Allied Sciences, The Neotia University, Diamond Harbour Road, West Bengal-743368, India.
Pragun Pal
School of Smart Agriculture, Adamas University, Barasat, West Bengal-700126, India.
Mousumi Mondal
Department of Agronomy and Agroforestry, School of Agriculture and Allied Sciences, The Neotia University, Diamond Harbour Road, West Bengal-743368, India.
*Author to whom correspondence should be addressed.
Abstract
Agricultural residues can be converted into biochar through pyrolysis, but the physical characteristics of the resulting material depend on feedstock type. This study compared bulk density (BD), water-holding capacity (WHC), volatile matter (VM), and ash content of biochars produced from rice straw, wheat straw, jute stick, mustard pods, mustard straw, mustard leaves, and sunflower stem under oxygen-limited conditions. Each feedstock was analysed in triplicate, and feedstock effects were evaluated using one-way ANOVA followed by Tukey’s honestly significant difference test. Feedstock type significantly affected all four characteristics (P < 0.001). BD ranged from 0.117 to 0.369 g cm⁻³, with the lowest value in jute-stick biochar and the highest in mustard-leaf biochar. WHC ranged from 99.753 to 230.756%, with jute-stick biochar showing the highest value. VM ranged from 46.492 to 58.753%, whereas ash content ranged from 40.375 to 53.966%. The corresponding F₆,₁₄ values were 739.96, 647.90, 26.48, and 77.60 for BD, WHC, VM, and ash content, respectively. BD was strongly negatively correlated with WHC (r = −0.84), while VM was strongly negatively correlated with ash content (r = −0.99). These findings demonstrate that agricultural-residue feedstocks produce biochars with distinct physical characteristics, supporting feedstock-specific characterisation before their use in subsequent soil and crop evaluations.
Keywords: Biochar, agricultural residues, bulk density, water-holding capacity, volatile matter, ash, pyrolysis, soil amendment