• Energy Research

Many scientific disciplines currently are experiencing a “reproducibility crisis” because numerous scientific findings cannot be repeated consistently. A novel but controversial hypothesis postulates that stringent levels of environmental and biotic standardization in experimental studies reduces reproducibility by amplifying impacts of lab-specific environmental factors not accounted for in study designs. A corollary to this hypothesis is that the deliberate introduction of controlled systematic variability (CSV) in experimental designs can increase reproducibility. We tested this hypothesis using a multi-laboratory microcosm study in which the same ecological experiment was repeated in 14 laboratories across Europe. Each laboratory introduced environmental and genotypic CSV within and among replicated microcosms established in either growth chambers (with stringent control of environmental conditions) or glasshouses (with more variable environmental conditions). The introduction of genotypic CSV led to lower among-laboratory variability in growth chambers, indicating increased reproducibility, but had no significant effect in glasshouses where reproducibility also was lower. Environmental CSV had little effect on reproducibility. Although there are multiple causes for the “reproducibility crisis”, deliberately including genetic variation may be a simple solution for increasing the reproducibility of ecological studies performed in controlled environments.

<div class="section abstract"><div class="htmlview paragraph">Biomethane is a valuable alternative to fossil fuels, specifically in transport sector, contributing to “energy security” and “carbon neutrality”. Though at present, research has mainly invested in the automotive sector, the demand for alternative and low environmental impact fuels is growing. Hence, in the scope of energy transition, also in the agricultural sector machinery manufacturers have started developing the first solutions able to reduce the environmental impact of tractors. In addition, on-farm biomethane production would represents a great opportunity for the development of more “circular” systems producing renewable energy from “residual biomass” (e.g. livestock effluents, agricultural waste). Under this framework, the TOBIAS project, launched in 2020 and funded by the Piedmont Region (North-western Italy), is aimed to investigate the development and application of a biomethane supply chain for agricultural tractors engines. The project involves both industrial and academic partners: FPT Industrial, the project-leader, focusing on development and industrialization of the engines; STC srl, providing support to R&amp;D; DIMSPORT srl, integrating engines and biomethane fuel systems; Torino Crea Engineering srl, specialized in the construction of special vehicles; Hysytech srl, skilled in gas treatment and recovery; CNR-STEMS, focusing on the assessment of the system sustainability and promoting the advancement and dissemination of knowledge and technologies. The project will lead to the development of two biomethane-powered prototypes, one wheeled and one crawler. The development will consist of: i) vehicle and engine components design; ii) engine construction and testing to identify optimal operating conditions; iii) tractors configuration for the use of compressed or liquefied biomethane; iv) field-tests to determine vehicle performance (power, torque, consumption, etc.) in real conditions; v) demonstration of the specialized biomethane-powered tractors while performing agricultural operation in a vineyard and on-farm refueling. In the present contribution, project framework, preliminary results and future implications are discussed.</div></div>

Municipal and agricultural biowaste are a significant portion of the global waste stream and represent an environmental challenge that must be addressed sustainably. The literature on the topic has increased dramatically, and a bibliometric analysis is a necessary guide through this ever-growing production. This study gives an objective overview of the state of the art and topic evolution of biowaste within sustainability/circular economy frameworks. This bibliometric analysis serves as a starting point for further qualitative research, while offering opportunities for future collaborations. Two parallel searches were conducted in Scopus, agri-food/agricultural (2391 papers) and municipal (264 papers) biowaste within sustainability/circular economy concepts, and analyzed with VosViewer (version 1.6.20.0) and Excel (version 1808). This review analyzes the following: annual scientific production and countries involved, showing the US and Italy as leaders on both topics; most productive authors (only 0.2% wrote at least five papers) and affiliations and underlying international, even if static, collaborations; most influential publications and sources (Science of the Total Environment, Journal of Cleaner Production, Sustainability); evolution of keywords over time; and strengths and limitations of the bibliometric approach. It also highlights the potential for future research and collaboration. Furthermore, it underlines waste management’s evolution from a sustainable point of view towards a circular economy approach and differences between municipal and agricultural biowaste scientific production.

Although microcosm experiments are a frequent tool used to address fundamental ecological questions, there has been no quantitative assessment of the reproducibility of any microcosm experiment. This dataset contains the response variables measured in a multi-laboratory microcosm study in which the same microcosm experiment was repeated in 14 laboratories across Europe. All laboratories simultaneously run a simple microcosm experiment using grass (Brachypodium distachyon L.) monocultures and grass and legume (Medicago truncatula Gaertn.) mixtures. All twelve variables were then used to calculate the effect of the presence of nitrogen-fixing legume on the grass-legume mixtures (i.e. the net legume effect).The project tested a controversial hypotheses postulating that stringent levels of environmental and biotic standardization in experimental studies reduces reproducibility by amplifying impacts of lab-specific environmental factors not accounted for in the experimental design. This implies that the deliberate introduction of controlled systematic variability (CSV) in experimental designs can increase reproducibility. To test this hypothesis, each laboratory followed the same experimental protocol and introduced environmental and genotypic controlled systematic variability (CSV) within and among replicated microcosms established in either growth chambers (with stringent control of environmental conditions) or glasshouses (with more variable environmental conditions). Data were used to test the extent to which the effect size of the net legume effect varied with the CSV treatment and to estimate the number of laboratories that produced results that can be considered reproducible. Supplement to: Milcu, Alexandru; Puga-Freitas, Ruben; Ellison, Aaron M; Blouin, Manuel; Scheu, Stefan; Girin, Thomas; Freschet, Grégoire T; Rose, Laura; Scherer-Lorenzen, Michael; Barot, Sebastien; Lata, Jean-Christophe; Cesarz, Simone; Eisenhauer, Nico; Gigon, Agnès; Weigelt, Alexandra; Hansart, Amandine; Greiner, Anna; Pando, Anne; Gessler, Arthur; Grignani, Carlo; Assandri, Davide; Gleixner, Gerd; LeGalliard, Jean-Francois; Urban-Mead, Katherine; Zavattaro, Laura; Müller, Marina E H; Lange, Markus; Lukac, Martin; Bonkowski, Michael; Mannerheim, Neringa; Buchmann, Nina; Butenschoen, Olaf; Rotter, Paula; Seyhun, Rahme; Devidal, Sébastien; Kayler, Zachary; Roy, Jacques (2018): Genotypic variability enhances the reproducibility of an ecological study. Nature Ecology & Evolution, 2, 279-287