Rotational perennial grass/clover has multiple effects in cropping systems dominated by cereals. This study evaluated the environmental impact of rotational grass/clover ley for anaerobic digestion in a cer- eal-dominated grain production system in Sweden. Life cycle assessment (LCA) methodology was used to compare two scenarios: (i) a cropping system including only spring barley and winter wheat; and (ii) a cropping system including 2-year grass/clover ley in combination with spring barley and winter wheat. The functional unit was one tonne of grain. The two main functions of the grass/clover crop were to pro- vide feedstock for biogas production and to act as an organic fertiliser for allocation among the cereal crops in the rotation. Special consideration was given to nitrogen (N) management and the rotational effects of the grass/clover ley. In total, 73% of the N requirement of cereals in the ley scenario was met through symbiotic N fixation. Replacing diesel with biogas and mineral fertiliser with digested grass/clo- ver biomass (digestate) reduced the use of fossil fuels substantially, from 1480 MJ per tonne in the ref- erence scenario to 2900 MJ per tonne in the ley scenario. Potential eutrophication per tonne grain increased in the ley scenario, mainly owing to significantly higher ammonia emissions from spreading digestate and the larger area required for producing the same amount of grain. Potential acidification also increased when N mineral fertiliser was replaced by digestate. Crops relying on symbiotic N fixation are a promising feedstock for reducing the use of non-renewable energy in the production chain of farm-based bioenergy, but careful handling of the N-rich digestate is required. Replacing cereals intended for feed or food with bioenergy crops leads to indirect land use changes (iLUC) when the displaced crops must be produced elsewhere and the benefits obtained when biofuels replace fossil fuels may thereby be out- weighed. In this study, the iLUC factor assumed had a critical effect on global warming potential in the ley scenario. However, carbon sequestration and the higher yield potential of subsequent cereal crops can mitigate greenhouse gas emissions from iLUC to a varying extent. We recommend that crop sequences rather than single crops be considered when evaluating the environmental impact of production systems that include perennial legumes for food, feed and bioenergy.
Tag: bioenergy
Brazil-Africa Cooperation: emerging opportunities in Agriculture, Forestry and Bioenergy
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Jatropha bio-diesel production and use
The interest in using Jatropha curcas L. (JCL) as a feedstock for the production of bio-diesel is rapidly growing. The properties of the crop and its oil have persuaded investors, policy makers and clean development mechanism (CDM) project developers to consider JCL as a substitute for fossil fuels to reduce greenhouse gas emissions. However, JCL is still a wild plant of which basic agronomic properties are not thoroughly understood and the environmental effects have not been investigated yet. Gray literature reports are very optimistic on simultaneous wasteland reclamation capability and oil yields, further fueling the Jatropha bio-diesel hype. In this paper, we give an overview of the currently available information on the different process steps of the production process of bio-diesel from JCL, being cultivation and production of seeds, extraction of the oil, conversion to and the use of the bio-diesel and the by-products. Based on this collection of data and information the best available practice, the shortcomings and the potential environmental risks and benefits are discussed for each production step. The review concludes with a call for general precaution and for science to be applied.
Cooking energy emancipation for women, children and mother nature: People-centered woodfuel and cleaner cooking innovations
This factsheet illustrates how we are changing lives and improving drylands through capacity development on sustainable household woodfuel systems. Our ideas and concepts merit catching on as a movement. Our systems thinking and theory of change address how to correct the lack of sustainability and inefficiencies along the entire supply and consumption chain while even recovering resources in the form of energy and biochar.
Forest Plantations in Central Africa
Demand for wood is growing worldwide and this trend is set to accelerate through the remainder of the 21st century. This is the case not just for traditional markets, but for other sectors like construction (responsible for 36 percent of greenhouse gas emissions), bioenergy and green chemistry seeking to de-carbonize and go biobased in an effort to move into the emerging sustainable, green economy in which companies are located closer to their raw materials and local markets.
Bioenergy sustainability in the global South: Constraints and opportunities
Many countries have recently adopted bioenergy as part of a critical strategy to reduce greenhouse gas (GHG) emissions to meet targets under the Paris Climate Agreement. Because of increased efficiency and lower production costs, along with legislative support and investment incentives, bioenergy use is swiftly becoming a renewable energy substitute for fossil fuels. The study provides a better understanding of bioenergy issues, potential and sustainability to inform countries in the global South and provide guidance on integrating bioenergy into their national energy plans by proposing a simplified sustainability framework for wood-based bioenergy.
Arguments are reviewed against biomass energy expansion, mainly developed in the context of the global north. The benefits of biomass energy expansion are also reviewed with a focus on conditions common to the global south. A sustainability framework is presented to illustrate better use of low-value land resources, produce bioenergy, restore ecosystem services, and mitigate and adapt to climate change. The study recommends guidance to establish sustainable, wood-based bioenergy supply in developing countries in the global South, which help ensure that biomass supply chains adhere to the principles and criteria of bioenergy sustainability.
The critical nexus between bioenergy and land use
A new policy brief from leading experts at the Centre for International Forestry Research-World Agroforestry (CIFOR-ICRAF) and IPB University, as a part of the Center for Global Sustainability’s (CGS) Indonesia Program new guest policy brief series, provides an overview of the crucial interconnection between bioenergy and land use, focusing specifically on the production and employment of biomass for bioenergy and biomaterial. This guest analysis evaluates four case studies to understand sustainable biomass management methodologies.
Cleaner Cooking with Charcoal in Kibera Informal Settlement in Nairobi, Kenya, and Its Implications for Livelihoods and the Environment
Woodfuel that is unsustainably sourced and inefficiently used results in negative environmental and health impacts. This study assessed charcoal use and resultant concentrations of indoor air pollutants (IAP) in an urban informal settlement while cooking with a Jikokoa stove (an improved branded charcoal stove) and medium and small-sized artisanal Kenya Ceramic Jikos (KCJs). Fuel stacking was prevalent with charcoal and kerosene being used by 25% of the studied households. Cooking with a Jikokoa stove reduced charcoal consumption by 6.4% and 26% compared to small and medium-sized KCJs, respectively. The small-sized KCJ reduced charcoal consumption by 21% compared to the medium-sized KCJ. The Jikokoa stove reduced concentrations of carbon monoxide (CO) by 10% and 50% and fine particulate matter (PM2.5) by 6% and 77% compared to small-sized and medium-sized KCJs, respectively. The Jikokoa stove reduced carbon dioxide (CO2) concentrations by 15.6% compared to the medium-sized KCJ. The small-sized KCJ reduced CO and PM2.5 concentrations by 45% and 75%, respectively, compared to the medium-sized KCJ. In summary, small-sized KCJs are more effective than medium-sized ones, and Jikokoa stoves more effective than small-sized KCJs, making it the stove of choice. The more efficient charcoal stoves are, the more charcoal consumption and IAP can be reduced, mitigating environmental degradation, climate change and health problems associated with smoke in the kitchen. There is need for participatory research to scale improved stoves and upgrade local practices as they are cheaper and already embedded in the cooking culture.
Improvements in charcoal production and the environmental implications: Potential for the invasive Prosopis juliflora in Kenya
Charcoal is a common woodfuel in sub-Saharan Africa (SSA). Unsustainable wood sourcing and inefficient carbonization result into negative environmental impacts. This action research aimed at building the capacity for sustainable charcoal production including `improving the traditional earth mound kiln (TEK) that is used by 99% of charcoal producers in Kenya. Small stems and branches of the invasive Prosopis juliflora were used and produced quality charcoal with 28 kJ/g which will save trees. Improved earth mound kiln (IEK) increased charcoal yield by 49% per mass of sun dried wood fed into the kiln and reduced emissions of carbon monoxide, carbon dioxide and hydrocarbons by 40%, 49% and 44% respectively. Net charcoal yield by a mass of dry wood in TEK and IEK was 26.4% and 28.4% respectively. Communication and capacity development on sustainable charcoal benefit people and environment. Studies on sustainable charcoal and effects on dryland socio-ecological systems will be needed.
Optimal tree architecture for high-yield yellowhorn (Xanthoceras sorbifolium) management
Tree architectural attributes demonstrate a significant association with fruit yield. Yellowhorn is the future bioenergy tree in China; however, the species suffers from high reproductive energy and exceedingly low reproductive output. To optimize yellowhorn management and pinpoint priority trees featuring optimal architecture, we employed machine learning modeling to develop high fruit yielding predictive models using five yield indicators (dependent variables: FrW, SeW, ShW, FrW, and SeN) and five tree characteristics (independent variables: CA, TH, DGL, HLC, and MBN) of yellowhorn. Results showed that trees characterized by a substantial canopy area (>1.70 m2) and a large diameter at ground level (>3.71 cm) have been found to yield a higher fruit production. However, increased tree height does not invariably correlate with an elevated yield. Effective selection of high-yielding individuals can be accomplished by restricting tree height within the range of 192–232.4 cm. This approach emphasizes the importance of integrating considerations of tree architecture into forestry management practices. Such integration can bolster productivity, thereby contributing to both the sustainability and economic viability of yellowhorn forests.