Putting the carbon back: Black is the new green
Abstract
ID: L_FINEL_NATURE; Context: ...past six years. Loam ranger The main stimulus for this interest was the work of Wim Sombroek , who died in 2003 and is still mourned in the field. Sombroek was born in the...; ID: Nature
... The idea did not take off in 1992, but when researchers picked up on it again, a decade later, the claim was quickly made that biochars, when added to soils, represented a uniquely beneficial solution to a number of soil-related problems, most notably to combat climate change (e.g., Bruges, 2009;Laird, 2008;Lean, 2008;Lehmann, 2007aLehmann, , 2007bLehmann et al., 2006;Renner, 2007). Its alleged benefits also extended far beyond soils, since as advocated by Marris (2006), it could be viewed as 'the only way to make a fuel that is actually carbon negative'. Despite a fundamental lack of corroborating F I G U R E 2 Ingenious visual demonstration of the intrinsic self-similarity of soils and therefore of the appeal of fractal geometry to describe them. ...
... That was also definitely the case with biochars. Research on the topic took off like a rocket as soon as biochars were advertised as a providential, 'win-win' or even 'win-win-win' solution to a number of problems of great societal relevance, like global climate change and food insecurity (e.g., Bruges, 2009;Laird, 2008;Lean, 2008;Lehmann, 2007aLehmann, , 2007bLehmann et al., 2006;Marris, 2006;Renner, 2007). ...
Over the last decade, the fact that novel perspectives on various aspects of soils have remained strongly controversial long after they emerged, without any kind of consensus being reached about them, raises question about the underlying reasons for this phenomenon. The on‐going debate on the usefulness of aggregates to describe the functions of soils illustrates some of the key aspects of that question. Similar debates on other soil‐related issues also appear stalled, or have been for a long time and are only now moving forward. This might suggest a fundamental aversion to change, which when it gets overcome, only does so slowly. However, at the same time, somewhat surprisingly, researchers appear willing to quickly seize opportunities provided by new idea or novel perspectives on other topics. In that context, the objective of the present article is to analyse in detail what may cause such contrasting reactions to novelty. We consider, then ultimately dismiss, explanations based on how strongly or not novel perspectives have been actively promoted, on how access to suitable technology may impede or only slow down perspective shifts and on whether a recent theory of the ‘slowed canonical progress in large fields of science’ applies to the relatively small soil science community. Then, taking soil aggregates as a case in point, we come to realize that it is the extent to which a novel perspective mandates an interdisciplinary approach that determines whether or not it is adopted quickly. From that standpoint, we envisage a number of practical actions that could be taken to facilitate in the future the emergence in soil science of interdisciplinary research efforts, which we argue are absolutely essential to successfully tackle the enormous complexity of soils and to come up with satisfactory answers to the daunting environmental and food security problems we currently face in their management.
... wapń, magnez, fosfor itd.); -mikrozanieczyszczenia, takie jak: wielopierścieniow e węglowodory aromatyczne (WWA), dioksyny i furany oraz jony metali cięż kich (w zależności od zastosowanego materiału wsadowego). Na podstawie informacji przedstawionych przez Marris a w artykule [10] można stwierdzić, że im wyższa temperatura procesu pirolizy, tym niższa wydajność otrzymanego biowęgla, ale z kolei wysoka temperatura procesu może zoptymalizować strukturę aromatyczną (zwiększając żywotność biowęgla), powierzchnię właściwą (dostępność makroelementów, zwiększenie prze wodności elektrycznej i zdolność wymiany kationów) oraz porowatość (odpowie dnią dla wzrostu mikroorganizmów) [10]. Właściwości fizyko-chemiczne biowęgla mają znaczący w pływ na jego zdolność do sorbowania jonów metali. ...
... wapń, magnez, fosfor itd.); -mikrozanieczyszczenia, takie jak: wielopierścieniow e węglowodory aromatyczne (WWA), dioksyny i furany oraz jony metali cięż kich (w zależności od zastosowanego materiału wsadowego). Na podstawie informacji przedstawionych przez Marris a w artykule [10] można stwierdzić, że im wyższa temperatura procesu pirolizy, tym niższa wydajność otrzymanego biowęgla, ale z kolei wysoka temperatura procesu może zoptymalizować strukturę aromatyczną (zwiększając żywotność biowęgla), powierzchnię właściwą (dostępność makroelementów, zwiększenie prze wodności elektrycznej i zdolność wymiany kationów) oraz porowatość (odpowie dnią dla wzrostu mikroorganizmów) [10]. Właściwości fizyko-chemiczne biowęgla mają znaczący w pływ na jego zdolność do sorbowania jonów metali. ...
Biowęgiel jest materiałem, który zyskuje coraz większą uwagę jako opłacalny
sorbent do oczyszczania roztworów wodnych z toksycznych dla środowiska
jonów metali ciężkich (As, Cr, Pb, Cu, Zn i Cd). Brakuje jednak informacji na
temat mechanizmów sorpcji dla różnych jonów metali. Niniejsze opracowanie
prezentuje kluczowe czynniki oraz proponowane mechanizmy adsorpcji
w celu wyjaśnienia zachowania adsorpcyjnego biowęgla. Artykuł podsumowuje
charakterystyczne właściwości biowęgla (np. pole powierzchni, porowatość,
pH, ładunek powierzchniowy, grupy funkcyjne i składniki mineralne)
oraz główne mechanizmy regulujące sorpcję. Własności biowęgla różnią się
znacznie między sobą w zależności od rodzaju materiału wsadowego oraz
zastosowanej temperatury pirolizy. W wyższej temperaturze wytwarzany jest
biowęgiel o większej powierzchni, porowatości, pH i zawartości minerałów,
ale o mniejszej liczbie grup funkcyjnych. W niniejszej pracy zaprezentowano
biowęgiel jako materiał wykazujący duży potencjał skutecznego zwalczania
zanieczyszczeń ze środowiska wodnego, biorąc pod uwagę szeroką dostępność
surowca, korzystne fizyczne i chemiczne właściwości powierzchni.
... In contrast, hydrochar's chemical stability and resistance to biodegradation allow it to persist in soils for decades or even centuries. Hydrothermal carbonization is a process that stabilizes the carbon in the soil carbon pool in a secure form, and this efficient carbon sink pathway plays a significant role in carbon sequestration and emission reduction [205,206]. Notably, understanding how the feedstock composition influences hydrochar stability aids in designing sustainable hydrochar production methods. In co-HTC processes, interactions between two or more biomass types can affect these stability characteristics [205]. ...
This study presents a novel approach that integrates hydrothermal carbonization (HTC) technology with circular economy principles to optimize the management of nitrogen and phosphorus in agricultural wastewater. Given the increasing global resource scarcity and continuous ecological degradation, the valorization of biomass wastewater has become a critical pathway for the promotion of sustainable development. Biomass wastewater, which contains crop residues, forestry leftovers, and food processing byproducts, has long been regarded as useless waste. However, this wastewater contains abundant organic matter and possesses significant renewable energy potential. The valorization of biomass wastewater can significantly reduce environmental pollution. Through the optimization of the HTC process parameters, we achieved an improvement in the quality and yield of carbonized products, facilitating the efficient recycling and utilization of resources. This research demonstrates that HTC technology can transform agricultural wastewater into valuable biofertilizers, biomass energy, and organic feed, while simultaneously reducing the reliance on fossil fuels, decreasing greenhouse gas emissions, and mitigating the environmental impact of agricultural activities. This paper provides a comprehensive exploration of the application of HTC technology in agricultural ecosystems, highlighting its beneficial role in nitrogen and phosphorus management, resource utilization efficiency, and environmental pollution reduction. The findings of this study suggest that HTC technology holds significant potential in optimizing agricultural wastewater treatment, promoting resource recycling, and advancing sustainable agricultural development. Furthermore, this research offers theoretical support and practical guidance for the implementation of HTC technology in agricultural ecosystems, which is of paramount importance in fostering circular economic development and achieving sustainable agriculture.
... Climate change-induced disruptions, such as altered rainfall patterns, more frequent and severe droughts, and increased temperatures, directly impact agricultural productivity, biomass production, and rural poverty, intensifying food insecurity and economic vulnerability (Shafiee et al., 2023). One way to keep CO2 out of the atmosphere is to put it back in the ground (Marris, 2006). To this end, the IPCC recognizes soil C management (IPCC, 2022), including biochar application as a promising CDR method. ...
This review critically evaluates biomass-derived chars produced via thermochemical processes, i.e., pyrolysis, gasification, and hydrothermal carbonization, as potential alternatives to synthetic fertilizers. Among the three biomass-derived chars, biochar stands out as the most viable option for soil amendment due to its high stability, nutrient retention capacity, and long-term carbon sequestration benefits.
... PyC has also been found to improve soil water retention, aeration, pH, and nutrient availability (Biederman and Harpole, 2013), and provide a habitat structure for soil microorganisms (Eckdahl et al., 2022). Most PyC addition experiments have been conducted in agricultural fields, where PyC has been found to improve soil nutrient availability and increase productivity (Marris, 2006;Nair et al., 2017). However, the remediation effects of post-fire byproducts on soil and vegetation remain unexplored in forest ecosystems, particularly in boreal forests. ...
... Microalgal biomass can be converted to syngas, bio-oil, and biochar through pyrolysis at 350-700 °C in the absence of air [211]. Anhydrous charcoal can be used as a biofertilizer and carbon sequestration agent [76], serving as a suitable source for fuel and energy production. By using biochar in the carbon sequestration process, CO 2 emissions can be reduced by 84%, potentially leading to a negative carbon footprint through production stages and biofuel use [71]. ...
This paper presents a comprehensive literature review and analysis of sustainable biomass exploitation strategies, focusing on agro-waste residues and animal excreta. The research explores potential microalgal cultivation and utilization as a promising, low-energy alternative biomass source. While many production pathways are technologically feasible, their commercial viability under current market conditions is limited. The study aims to highlight sustainable water and biomass treatment methods and identify potential obstacles preventing agro-entrepreneurs from adopting integrated, viable algal-derived biomass exploitation. These strategies could contribute to greenhouse gas (GHG) mitigation, aligning with UN targets and EU legislation for a sustainable future. An extensive literature review was carried out over relative algae exploitation issues. A synthesis of techniques, innovative technologies and strategies were recorded so as to aim minimized mass and energy flux towards sustainable pathways. The proposed solutions, including soft water reclamation and novel biomass production, utilize well-established techniques and significant operational parameters for smart circular biomass flows. These approaches are interrelated to agribusiness and contribute to replenishing carbon and nitrogen surface pools, enabling better emission control and overall energy savings. The study emphasizes the potential for synergies in organized activities, such as co-locating cattle farms, greenhouses, and biogas plants to produce sustainable energy and create agri-biomass-based clusters with remarkable operational autonomy. The findings suggest that there are various areas of biomass exploitation which are quite promising in terms of embracing circular economy approaches and mitigating negative impacts in the agribusiness industry.
... Despite its potential to support cropping by serving as a soil amendment, biochar produced from microalgal biomass is not covered in the present review. While this microalgal application may hold promise [43], such studies were not identified by the literature search conducted, perhaps because they may focus on the carbon sequestration benefits of biochar rather than its potential for crop support [44,45]. Each efficacy pathway is described, then evidence is presented. ...
This review summarises the available evidence on the prospects for using microalgae or their extracts to support crop production. The evidence is limited but suggests technological promise in several distinct ways, namely, higher core productivity, enhanced resilience to biotic and abiotic stresses, and better-quality produce. The different efficacy pathways of these microalgal technologies were examined to assess their scope to help address key farmer priorities. Their scope to help farmers face climate change and land degradation was a particular focus, given the magnitude of these threats. These microalgal technologies are framed in terms of their pertinence to farmer priorities due to the centrality of farmers to food systems. Notably, farmers' technology adoption decisions are key to food system outcomes. The findings reported suggest that these crop support technologies could potentially deliver major benefits to farmers, consumers, and the environment. For the moment, however, this emerging literature remains largely neglected. Possible reasons for this are considered, as are potential ways forward. The review focuses particularly on the two most researched and widely available microalgae, the genera Arthrospira and Chlorella, in the interest of highlighting options farmers could adopt rapidly while research on the wider body of microalgae-based crop technologies continues.
Agronomic benefits of applying biochar into soils, as a sustainable and environment-friendly soil amendment approach, have been well-documented for decades, known for improving soil water and nutrient retention capacity followed by better crop production. Still, research on the effects of certain locally sourced biochar waste and combined use with fertilizer and compost on agricultural lands with sandy soils is rather limited. Therefore, our study attempted to explore the effects of locally produced biochar waste amended with compost and fertilizer on the water retention, pH, and nutrients of the sandy wild blueberry soil in Maine. We found that the studied biochar (either mixed with compost or fertilizer) effectively improved the water holding capacity (WHC) of the sandy wild blueberry field soil, with 15% and 20% application (biochar mix % in soil by weight) showing the highest effect. On the other hand, the studied alkaline biochar caused a significant increase in the soil pH up to 7–8, which would not be favorable for wild blueberry plants naturally growing in acidic soil (pH: 4–5). While our study also attempted to lower the soil pH by treating the studied alkaline biochar with mild acid, it did not lower the soil pH below 7. Our study further revealed that the 50–50 ratio for the biochar-compost/fertilizer mix application could be the most beneficial for the wild blueberry soil. This ratio could enhance WHC significantly while providing the most useful nutrient elements (P, K, Ca, B) for the wild blueberry plants, and keeping the heavy metals (Al, Fe) in check.
Graphical Abstract
The relationship between ecosystem disturbance and biodiversity levels has been a central focus of ecological research for the past half-century. The intermediate disturbance hypothesis, which suggests that maximum biodiversity is achieved through the coexistence of early and late successional species, however, has been challenged for its lack of clarity regarding the intensity, duration and extent of disturbances. This Perspective article advocates for a broader biocultural framework to move from the notion of disturbance to an understanding of human-environment mediations. Our proposed biocultural hypothesis acknowledges that, in certain cultural contexts, interventions by Homo sapiens at different environmental scales-mainly at the landscape level-can generate peaks in beta and gamma biodiversity compared to reference ecosystems. We illustrate these human-environment mediations through studies conducted in the biocultural region of Mesoamerica and comparative research findings, particularly from the Amazon Basin and West and Central Africa. In our conclusions, we discuss the need to establish collaborative research programmes around the proposed biocultural hypothesis, addressing management and institutional actions that will strengthen the engagement of Indigenous people and rural local communities with their historical territories that we name 'Priority Biocultural Areas'.
The application of bio-char (charcoal or biomass-derived black carbon (C)) to soil is proposed as a novel approach to establish a significant, long-term, sink for atmospheric carbon dioxide in terrestrial ecosystems. Apart from positive effects in both reducing emissions and increasing the sequestration of greenhouse gases, the production of bio-char and its application to soil will deliver immediate benefits through improved soil fertility and increased crop production. Conversion of biomass C to bio-char C leads to sequestration of about 50% of the initial C compared to the low amounts retained after burning (3%) and biological decomposition (∘C common for pyrolysis). Existing slash-and-burn systems cause significant degradation of soil and release of greenhouse gases and opportunies may exist to enhance this system by conversion to slash-and-char systems. Our global analysis revealed that up to 12% of the total anthropogenic C emissions by land use change (0.21 Pg C) can be off-set annually in soil, if slash-and-burn is replaced by slash-and-char. Agricultural and forestry wastes such as forest residues, mill residues, field crop residues, or urban wastes add a conservatively estimated 0.16 Pg C yr−1. Biofuel production using modern biomass can produce a bio-char by-product through pyrolysis which results in 30.6 kg C sequestration for each GJ of energy produced. Using published projections of the use of renewable fuels in the year 2100, bio-char sequestration could amount to 5.5–9.5 Pg C yr−1 if this demand for energy was met through pyrolysis, which would exceed current emissions from fossil fuels (5.4 Pg C yr−1). Bio-char soil management systems can deliver tradable C emissions reduction, and C sequestered is easily accountable, and verifiable.