Characterization of soil amendment potential of 18 different biochar types produced by slow pyrolysis

Abstract

Feedstock type is the most dominant factor influencing the physical characteristics and chemical composition of biochar. The main purpose of this study was to characterize and compare some of the physical and chemical properties of biochars produced by slow pyrolysis of 18 feedstocks, which are locally available agricultural residues. Moreover, elucidating the potential agronomic benefits of these biochars was the other objective of the study. Biochars were produced at 500 o C in an ingeniously developed reactor. The biochars were characterized for specific surface area (SSA), field capacity (FC), wilting point (WP), plant available water content (AW), pH, electrical conductivity (EC), cation exchange capacity (CEC), total carbon (C) and nitrogen (N), plant available phosphorus (P) and potassium (K) concentrations. Considerable variation of characteristics among biochars indicates the dominant impact of feedstock type on physical properties and chemical composition of biochars. Total C contents were highly variable with values up to 91.9% for pine sawdust. Phosphorus and K in feedstocks were concentrated in the biochars and were two to four times higher in the biochars. The CEC of biochars varied from 79.5 cmol kg-1 (pepper residues) to 5.77 cmol kg-1 (poplar sawdust). The CEC and SSA had a significant negative correlation (P<0.01, r=-0.70) that probably be attributed to the loss of functional groups during pyrolysis. The results revealed that depending on the feedstock, some biochars have potential to serve as nutrient sources as well as an additive to improve soil quality.

Production of biochar from crop residues and its application for anaerobic digestion

“…However, heating rate, reaction temperature, and feedstock all affect biochar characteristics, including the fixed carbon content, nutrient content and availability, cation exchange capabilities and pH (Ghodake et al, 2021). The characteristics of biochar are closely linked with its potential to sequester inhibitors present in the AD system (Günal et al, 2019).…”

Spectroscopic and chemical properties of biochar and water treatment residual nanoparticles and their effects on canola growth and biological activity

“…This value was lower than those identi ed by Song and Guo 55 in the biochars of pepper residues and canola with values of 79.5 and 179 .0 cmol c kg − 1 , respectively. Silber et al 56 and Günal et al 57 reported that CEC values for different types of biochar ranged from 5 to 50 cmol c kg − 1 .…”

Assessment of Pistachio Shell-Based Biochar Application in the Sustainable Amendment of Soil and Its Performance in Enhancing Bell Pepper (Capsicum annuum L.) Growth

“…Also, the conversion of bio-waste to biochar represents a potential solution to increase soil organic carbon content, improve soil quality, and address the problem of excessive waste management [10]. All these features show the opportunity to use biochar as a soil amendment to enhance cultivation performance (growth and yield) and production over extended periods [11][12][13].…”