Biochar type and pyrolysis temperature effects on soil quality indicators and structural stability

• Published in: Journal of environmental management Vol. 261; p. 110190
• Main Authors: Saffari, N., Hajabbasi, M.A., Shirani, H., Mosaddeghi, M.R., Mamedov, A.I.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.05.2020
• Subjects: Animals; Carbon; Charcoal; Corn residue; High-energy moisture characteristic; Poultry manure; Pyrolysis; Soil; Temperature; Water-dispersible clay; Water-stable aggregates; Water-dispersible clay; Water-stable aggregates; High-energy moisture characteristic; Corn residue; Poultry manure
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2020.110190

Quality of soils of the arid zones with low organic matter can be improved through the application of natural amendments especially biochar from various available feedstocks. The objective of this study was to evaluate the impacts of corn residue and poultry manure and their biochars on soil organic carbon (SOC), hot-water soluble carbohydrates (HWSC), basal soil respiration (BSR),and structural stability determined by HEMC (high-energy moisture characteristic). A sandy loam soil in pots were thoroughly mixed with 1, 2 and 4% w/w of corn residues (CR) and poultry manure (PM) feedstock and their biochars prepared at 350 and 650 °C of slow pyrolysis. Maize seeds were planted in pots and grown until physiological maturity when soil characteristics were measured. Treatments considerably altered the means of studied soil quality indicators, and increased SOC (1.5–10 times) and HWSC (1–7 times), and HEMC indices: volume of drainable pores ratio (VDPR, 1.5– 3.5 times), and stability ratio (SR, 1–3 times). Increasing pyrolysis temperature, regardless of the type and rate of feedstock, significantly decreased the SOC, BSR and percent of water-stable aggregates, and consequently structural stability indices. Contribution of both PM feedstock and its biochars was less effective than the CR ones (particularly the biochar produced at higher pyrolysis temperature), due to elevated sodium adsorption ratio (SAR) associated with higher slaking, physico-chemical dispersion and lower aggregate and structural stability. •Treating soil with low-temperature biochars enhanced soil structural stability.•Corn residue and its biochars had higher effect on structural stability indices.•Basal soil respiration reduced as feedstock converted to biochar.•High-temperature biochars decreased soil organic carbon and structural stability.•Various soil structural stability indicators showed similar results.