Quality Evaluation of Poultry Litter Biochar Produced at Different Pyrolysis Temperatures as a Sustainable Management Approach and Its Impact on Soil Carbon Mineralization

Abstract

Poultry litter biochar (PLB) is a value-adding soil amendment and an economically sustainable approach that is used to enhance food safety and reduce environmental harm. Poultry litter biochar has promising potential but has been under-examined in regards to carbon (C) sequestration in relation to its type and application rate. The objective of this study was to investigate the effectiveness of PLB in enhancing the C sequestration of acid soils through a short-term incubation experiment. The soil was amended with different materials: PLB (1%, 5%, and 10%) and a control (non-amended). The results indicated that PLB application increased soil C mineralization relative to the control (19–1562%), it significantly increased with an increasing application rate (e.g., increased addition 29, 99, and 172% for 1, 5, and 10% of 400 °C PLB), and the soil C mineralization and applied carbon mineralized (ACM) significantly decreased with temperature (e.g., the cumulative C pool ranges of ACM with 1% PLB, added at pyrolysis temperatures of 200, 300, 400, 500, and 600 °C, were 42.0, 34.4, 19.6, 6.16, and 4.04%, respectively). To assist sustainable soil management and to aid the achievement of multiple sustainable development goals (SDGs), as well as to maximize the benefits of PLB applications and minimize the potential environmental risk, it is suggested that application of PLB, pyrolyzed within 400–600 °C at a rate between 1% to 5%, should be adopted in acidic soils in Taiwan.

Qualities and Quantities of Poultry Litter Biochar Characterization and Investigation

“…This study also found that pyrolysis temperature plays a key role in changing the extractable phosphorus, sulfur, and PLB yield. PLB yield was reduced by 13% when the pyrolysis temperature increased from 300 • C to 500 • C, which is consistent with previous studies [26,27]. Meanwhile, a higher pyrolysis temperature can reduce the extractable P by 37% because the high temperature may help to transform labile P in raw PL into non-labile P in PLB.…”

“…Understanding these factors is essential for maximizing the yield, quality, and potential applications of PLB in agriculture, environmental remediation, and other fields. Pyrolysis temperature is the key factor in determining the yield and quality of biochar from slow pyrolysis of PL [26,27]. A previous study investigated the effect of pyrolysis temperature on the quality of PL biochar, and an optimal pyrolysis temperature of within 300-500 • C was suggested to convert PL to agricultural-use biochar.…”

Thermal treatment of poultry litter: Part I. Characterization by immediate analysis and gravimetric yield

“…As for the temperature used in the pyrolysis of poultry litter, some studies have already been carried out, such as Sobik-Szołtysek et al (2021), who studied the sorption capacity of heavy metals in biochars produced at 425, 525, and 752 °C. Tsai & Chang (2021; evaluated the impacts of biochars pyrolyzed at 200, 300, 400, 500 and 600 °C, on soil carbon mineralization and on the preservation of nutrients and immobilization of contaminants.…”