Biochar最新文献

Living wall systems (LWSs) help to alleviate the climate and biodiversity harms associated with buildings and bring benefits to building occupants. Their performance can be variable and existing research points to the planting substrate as a key design factor. This study provides quantitative evidence on the physical, thermal and moisture performance of three planting substrates that vary according to the proportion of biochar added to green waste compost (GWC). Thermal conductivity (Wm^-1 K^-1), thermal resistivity (mK W^-1), volumetric moisture content (%) and mass (g) are measured for each fraction, replicated six times. Controlled drying procedures were employed, measuring these properties at a range of moisture levels. Data analysis finds that volumetric moisture content and biochar fraction have a statistically significant (p ≤ 0.05) effect on thermal conductivity. Added biochar is associated with non-linear reductions in thermal conductivity at low moisture levels. This suggests increasing the biochar fraction while reducing moisture in the substrate of a LWS will reduce its thermal conductivity, with a 100 mm planting substrate with 30% biochar and 30%vol moisture content providing 0.82 m² KW^-1 of thermal resistance, compared to 0.46 m² KW^-1 without added biochar. The methods build on previous work to assess the properties of different planting substrates for LWSs, providing a practical, lab-based assessment of biochar. The data produced are useful for researchers and professionals seeking to understand how biochar additions impact irrigation and thermal performance when specifying and designing LWSs and underline the potential value of biochar for improving the thermal performance of green infrastructure more widely.

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The global annual production of animal by-product (ABP)-derived bone, estimated at 95‒126 million tonnes, presents both an environmental challenge and an opportunity for sustainable resource utilization. We estimate that bone char (BC) could theoretically replace 13‒32% of the global phosphorus (P) fertilizer market. BC, produced through the pyrolysis of animal bones, has emerged as a promising material for use in a range of agricultural applications related to soil fertility and water quality. The conversion of ABP-derived bone into BC through pyrolysis not only eliminates potential human and animal pathogens (e.g., prions, viruses, bacteria), but also creates a valuable resource rich in P, calcium, and magnesium. This review synthesizes current research on the potential applications of BC in agriculture, focusing on its multifunctional role as a slow-release P fertilizer, a carbon (C) storage material, and an effective adsorbent for remediating contaminated soils. Field and laboratory studies demonstrate that BC's performance is strongly influenced by pyrolysis conditions, with optimal temperatures between 300 and 500 °C for nutrient release applications and above 600-800 °C for enhanced surface area and contaminant remediation. Its hydroxyapatite structure enables gradual P release and potential toxic element (PTE) immobilization, while its porous nature can provide new habitat niches for soil microorganisms and improve soil water retention. In comparison to most conventional inorganic fertilisers, BC can enhance soil fertility by releasing P slowly, thereby improving plant growth and productivity, particularly in acidic soils. The low cost, renewable nature, and ease of regeneration of BC further enhance its appeal as a viable solution for mitigating environmental pollution and promoting sustainable resource management practices. Beyond its established applications, this review identifies critical knowledge gaps, including the need to investigate BC's long-term impacts on soil health, microbial communities, and greenhouse gas emissions. We also discuss opportunities for optimizing production methods and expanding applications beyond agriculture. Given BC's potential to address multiple agricultural and environmental challenges, we emphasize the importance of interdisciplinary research to evaluate implementation barriers, including economic viability, social acceptance, and regulatory frameworks.

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Sandy soils, with inherently low water retention and poor hydraulic properties, present significant challenges for sustainable agriculture, particularly in water-limited conditions. This study investigates the impact of biochar, sludge, and compost amendments on the soil hydraulic properties and water balance of a sandy soil. A 441-day lysimeter experiment evaluated six treatments: biochar (A), sludge (B), compost (C), biochar + sludge (D), biochar + compost (E), and biochar + sludge + compost (F). Results showed that combined treatments outperformed single amendments, with treatment F (biochar + sludge + compost) exhibiting the most pronounced improvements in soil water dynamics. This treatment reduced cumulative drainage by over 40% relative to individual amendments and exhibited higher average soil water content and more stable water storage across seasonal fluctuations. Biochar addition enhanced soil porosity and water-holding capacity, while compost and sludge improved retention through organic matter input and fine particle contributions. Treatments containing biochar reduced drainage and increased actual evaporation, indicating improved soil water retention and availability. Saturated hydraulic conductivity, field capacity, and plant available water were closely correlated with observed drainage behavior, confirming the functional relevance of these soil hydraulic indicators. Statistical analyses, including one-way ANOVA and Tukey's HSD, supported the significance of treatment differences in drainage and actual evaporation. Overall, the study demonstrates that integrating biochar, compost, and sludge can synergistically enhance water retention, reduce drainage, and stabilize soil water contents in sandy soils. These findings offer practical insights for improving water use efficiency and resilience in arid and semi-arid agroecosystems.

Supplementary information: The online version contains supplementary material available at 10.1007/s42773-025-00509-4.

The agricultural sector urgently requires scalable solutions to reduce greenhouse gas (GHG) emissions from residue management. Biochar offers a promising carbon removal pathway, but its adoption is limited by technical, regulatory, and economic barriers. A key constraint is the lack of system designs that can accommodate multiple feedstocks while complying with land application regulations. This study designs and evaluates an integrated biochar production system that enables the separate processing of straw and manure through parallel pyrolysis lines, while optimising internal energy use. Environmental and economic assessments were conducted using a case study of the University of Leeds Research Farm, under a cradle-to-grave system boundary. The results show that the system can produce 300 t of biochar annually, sequester 350 t CO₂e, and reduce manure management emissions by 75%, with an additional 30 t CO₂e avoided through surplus heat utilisation. The carbon abatement cost is estimated at £226 per t CO₂e, primarily driven by capital (38%), operational (32%), and electricity (30%) costs. Sensitivity analysis highlights that straw availability, determined by both yield and crop rotation, is the primary factor influencing system performance. Among the mitigation strategies for addressing heat shortfalls, procuring external straw is identified as the most effective option. This study presents a novel and adaptable system framework for on-farm biochar deployment, addressing key barriers to implementation. The findings provide quantitative insights into the trade-offs between cost, carbon removal, and design decisions, and offer a foundation for scaling biochar use across the agricultural sector.

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Supplementary information: The online version contains supplementary material available at 10.1007/s42773-025-00527-2.

Biochar is widely recognised as a carbon dioxide removal (CDR) technology, but its stability depends on feedstock, pyrolysis conditions, and the soil environment. Current CDR schemes prioritise highly stable biochars to ensure long-term permanence, requiring high pyrolysis temperatures that reduce carbon yield and intensify competition for biomass. This perspective explores potential synergies between two distinct CDR approaches, biochar application and peatland rewetting, where rewetted peatlands could enhance biochar permanence by suppressing microbial decomposition, offering a means to improve both carbon retention and resource efficiency. Using decomposition rate modifiers from biogeochemical models, we estimate biochar stability in rewetted peat and assess its CDR efficiency relative to a counterfactual of high-stability biochar application to dry soils. This perspective suggests that rewetted peatlands significantly reduce biochar carbon losses, particularly for lower-stability biochars, making them more viable for long-term CDR. By allowing greater flexibility in biochar selection, this approach could improve the scalability of biochar deployment while alleviating biomass supply constraints. While challenges such as land-use transitions and methane emissions must be addressed, integrating biochar with peatland rewetting presents a high-impact strategy to optimise the efficiency of biomass-based CDR.

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Supplementary information: The online version contains supplementary material available at 10.1007/s42773-025-00524-5.

Not all biochar is equal. We clarify the frequent conflation between biochar carbon stability and soil co-benefits across research, policy, and markets. While stability ensures long-term carbon storage, co-benefits rely on more surface functionality from less stable biochar. Decoupling these dimensions enables designing biochar optimized for distinct functions.

The draining and conversion of peatlands for agriculture has led to their degradation globally, diminishing their carbon (C) storage capacity and functioning. However, rewetting, alongside the addition of organic/inorganic amendments, has the potential to accelerate peat formation and C accrual. The aim of this experiment was therefore to examine the combined benefits of altering water table depth and adding organic (e.g., biochar, paper waste, biosolids, cereal straw; 20 t C ha^-1) and inorganic (e.g., FeSO₄; 0.5 t ha^-1) materials on net C storage and peatland functioning (i.e., microbial communities, greenhouse gas emissions and biogeochemical cycling). The experiment consisted of outdoor agricultural peat mesocosms monitored over 1 year. The relative effectiveness of the amendments in preserving peat-C (t C ha^-1) followed the series: Miscanthus biochar (18.9 t C ha^-1) > Miscanthus residues (17.3 t C ha^-1) > biosolids (17.2 t C ha^-1) > cereal straw (14.5 t C ha^-1) > paper waste (13.3 t C ha^-1) based on C additional rate (20 t C ha^-1). Overall, a high-water table combined with biochar and FeSO₄ addition was the most effective at suppressing enzyme activity (e.g., β-glucosidase, phenol oxidase, cellobiase), methanogen activity (e.g., Methanosarcina) and peat mineralization rate. We ascribe this in part to changes in the fungal and bacterial community structure (e.g., reductions in Actinobacteria by - 22% and Ascomycota by - 61%). FeSO₄ also increased the Fe-bound C content in the non-rewetted treatment, supporting the 'iron gate' mechanism for C preservation. The mechanisms behind our results appear to be both abiotic (affecting SOC solubility through changes in redox conditions and Fe-C interactions) and biotic (via shifts in microbial community and enzyme activities), creating conditions that enhance C preservation. These findings provide evidence for implementing biochar and FeSO₄ amendments alongside water table management as practical, scalable strategies for restoring C storage capacity in agricultural peatlands.

Supplementary information: The online version contains supplementary material available at 10.1007/s42773-025-00501-y.

Biochar has high potential for long-term atmospheric carbon storage in terrestrial environments, contributing to meeting the UK and global greenhouse gas emission reduction targets. This study investigates the greenhouse gas emissions and techno-economics associated with biochar produced from food waste anaerobic digestate using hydrothermal carbonisation followed by high-temperature post carbonisation. Owing to high moisture contents, digestates are challenging to valorise. However, these low-value feedstocks have steady availability with minimal competition for other applications. The study focuses on food waste digestate supply, biochar production, biochar agricultural field application, and transportation activities. Minimising digestate transport through co-locating biochar production facilities with anaerobic digestion displayed greenhouse gas mitigation costs of < £100 tCO₂eq^-1 (125 USD tCO₂eq^-1). The 88% stable carbon fraction of the biochar, which is resistant to degradation in soil, is primarily responsible for the effective removal of atmospheric greenhouse gases. This results in net emissions reductions of 1.15-1.20 tCO₂eq per tonne of biochar, predominantly due to the long-term storage of durable carbon (1.7 tCO₂eq per tonne of biochar). Using 50% of the UK's projected available food waste digestate by 2030 offers a sequester potential of 93 ktCO₂eq p.a., requiring 28 biochar facilities at 20 kt p.a. capacity. Sensitivity analysis emphasises the influence of the gate fee charged to process digestate, highlighting its importance for economic success of the biochar production. Further studies are needed to investigate the potential technology enhancements to reduce fossil-fuel use and provide greater certainty of the co-benefits of biochar application in agricultural soil.

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Supplementary information: The online version contains supplementary material available at 10.1007/s42773-025-00456-0.

Biochar is a carbon-rich material produced through the pyrolysis of various feedstocks. It can be further modified to enhance its properties and is referred to as modified biochar (MB). The research interest in MB application in soil has been on the surge over the past decade. However, the potential benefits of MB are considerable, and its efficiency can be subject to various influencing factors. For instance, unknown physicochemical characteristics, outdated analytical techniques, and a limited understanding of soil factors that could impact its effectiveness after application. This paper reviewed the recent literature pertaining to MB and its evolved physicochemical characteristics to provide a comprehensive understanding beyond synthesis techniques. These include surface area, porosity, alkalinity, pH, elemental composition, and functional groups. Furthermore, it explored innovative analytical methods for characterizing these properties and evaluating their effectiveness in soil applications. In addition to exploring the potential benefits and limitations of utilizing MB as a soil amendment, this article delved into the soil factors that influence its efficacy, along with the latest research findings and advancements in MB technology. Overall, this study will facilitate the synthesis of current knowledge and the identification of gaps in our understanding of MB.

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Despite their high agricultural productivity, drained and cultivated peats are highly susceptible to degradation and significant sources of greenhouse gas (GHG) emissions. This study investigates the potential of water table manipulation and biochar application to mitigate GHG losses from agricultural peats. However, balancing the need for agricultural production with securing the ecosystem function of the peat under high water table (WT) conditions poses a significant challenge. Therefore, we grew lettuce in a controlled mesocosm experiment with either a high (HW) or low (LW) water table and monitored emissions of CO₂, CH₄ and N₂O over 4 months using a mesocosm method. Concurrent measurements of soil solution, plant measurements and microbial sequencing allowed identification of the key controls on GHG emissions. Raising the WT significantly reduced CO₂ emissions (18%), and N₂O emission (40%), but eventually increased CH₄ emission (2.5-fold) compared to the Control + LW. Biochar amendment with raised WT provided the strongest reduction in CO₂ equivalent GHG emission (4.64 t CO₂eq ha^-1 yr^-1), compared to Control + LW. We found that biochar amendment modified the microbial community composition and diversity (Shannon index 8.9-9.3), lowering the relative abundance of peat decomposers (such as Ascomycota). Moreover, biochar amendments produced 38-56% greater lettuce biomass compared to the unamended controls, irrespective of water table level, suggesting that biochar application could generate economic benefits in addition to reduced GHG emissions. Mechanisms responsible for these effects appeared to be both abiotic (e.g. via effects of the biochar physicochemical composition) and biotic via changing the soil microbiome. Overall, the combination of high-water table and biochar amendment enhanced total soil C, reduced peat decomposition, suppressed CH₄ and N₂O emissions, and enhanced crop yields.

Supplementary information: The online version contains supplementary material available at 10.1007/s42773-025-00487-7.