Showing papers by "University of Hohenheim published in 2021"

Beyond organic farming - harnessing biodiversity-friendly landscapes.

Abstract: We challenge the widespread appraisal that organic farming is the fundamental alternative to conventional farming for harnessing biodiversity in agricultural landscapes. Certification of organic production is largely restricted to banning synthetic agrochemicals, resulting in limited benefits for biodiversity but high yield losses despite ongoing intensification and specialisation. In contrast, successful agricultural measures to enhance biodiversity include diversifying cropland and reducing field size, which can multiply biodiversity while sustaining high yields in both conventional and organic systems. Achieving a landscape-level mosaic of natural habitat patches and fine-grained cropland diversification in both conventional and organic agriculture is key for promoting large-scale biodiversity. This needs to be urgently acknowledged by policy makers for an agricultural paradigm shift.

The global water resources and use model WaterGAP v2.2d: model description and evaluation

Abstract: . WaterGAP is a global hydrological model that quantifies human use of groundwater and surface water as well as water flows and water storage and thus water resources on all land areas of the Earth. Since 1996, it has served to assess water resources and water stress both historically and in the future, in particular under climate change. It has improved our understanding of continental water storage variations, with a focus on overexploitation and depletion of water resources. In this paper, we describe the most recent model version WaterGAP 2.2d, including the water use models, the linking model that computes net abstractions from groundwater and surface water and the WaterGAP Global Hydrology Model (WGHM). Standard model output variables that are freely available at a data repository are explained. In addition, the most requested model outputs, total water storage anomalies, streamflow and water use, are evaluated against observation data. Finally, we show examples of assessments of the global freshwater system that can be achieved with WaterGAP 2.2d model output.

Combining food and energy production: Design of an agrivoltaic system applied in arable and vegetable farming in Germany

Abstract: Combining agriculture and photovoltaics on the same land area gains in attention and political support in a growing number of countries accompanied by notable research activities in France, USA and Korea, amongst others. This study assesses the technical feasibility of agrivoltaic (APV), while it gives insights on how to design an APV system. Furthermore, it analyses the electrical yield and the behavior and productivity of four crops grown in Germany's largest agrivoltaic research facility installed in 2016 near Lake Constance within the research project APV-RESOLA by Fraunhofer Institute for Solar Energy Systems ISE. The German design differs from most other agrivoltaic approaches by allowing for a wide range of machine employment, facilitated by a vertical clearance of 5 m and a width clearance of up to 19 m. Crops cultivated under the APV system and on the reference field under a crop rotation scheme include potato, celeriac, clover grass and winter wheat. The land use efficiency measured by the Land Equivalent Ratio (LER) indicated a rise between 56% and 70% in 2017 while the dry and hot summer in 2018 demonstrated that the agrivoltaic system could increase land productivity by nearly 90%. Radiation simulations showed that deviating from full south by around 30° resulted in equal distribution of radiation on ground level, representing the basis for the agrivoltaic design. Considering climate change and increasing land scarcity, our overall results suggest a high potential of agrivoltaics as a viable and efficient technology to address major challenges of the 21rst century.

Assessment of the European Climate Projections as Simulated by the Large EURO-CORDEX Regional and Global Climate Model Ensemble

Abstract: This paper analyzes the ensemble of regional climate model (RCM) projections for Europe completed within the EURO‐CORDEX project. Projections are available for the two greenhouse gas concentration scenarios RCP2.6 (22 members) and RCP8.5 (55 members) at 0.11° resolution from 11 RCMs driven by eight global climate models (GCMs). The RCM ensemble results are compared with the driving CMIP5 global models but also with a subset of available last generation CMIP6 projections. Maximum warming is projected by all ensembles in Northern Europe in winter, along with a maximum precipitation increase there; in summer, maximum warming occurs in the Mediterranean and Southern European regions associated with a maximum precipitation decrease. The CMIP6 ensemble shows the largest signals, both for temperature and precipitation, along with the largest inter‐model spread. There is a high model consensus across the ensembles on an increase of extreme precipitation and drought frequency in the Mediterranean region. Extreme temperature indices show an increase of heat extremes and a decrease of cold extremes, with CMIP6 showing the highest values and EURO‐CORDEX the finest spatial details. This data set of unprecedented size and quality will provide the basis for impact assessment and climate service activities for the European region.

An Agenda for Open Science in Communication

Abstract: In the last 10 years, many canonical findings in the social sciences appear unreliable. This so-called “replication crisis” has spurred calls for open science practices, which aim to increase the reproducibility, replicability, and generalizability of findings. Communication research is subject to many of the same challenges that have caused low replicability in other fields. As a result, we propose an agenda for adopting open science practices in Communication, which includes the following seven suggestions: (1) publish materials, data, and code; (2) preregister studies and submit registered reports; (3) conduct replications; (4) collaborate; (5) foster open science skills; (6) implement Transparency and Openness Promotion Guidelines; and (7) incentivize open science practices. Although in our agenda we focus mostly on quantitative research, we also reflect on open science practices relevant to qualitative research. We conclude by discussing potential objections and concerns associated with open science practices.

Board Characteristics and Corporate Social Responsibility: A Meta-Analytic Investigation:

Abstract: Boards of directors affect corporate strategy and decision-making through monitoring of management and resource provision Recently, an increasing number of studies have examined the relationships

Eurec 4 a

Abstract: The science guiding the EUREC$^4$A campaign and its measurements is presented. EUREC$^4$A comprised roughly 5 weeks of measurements in the downstream winter trades of the North Atlantic – eastward and southeastward of Barbados. Through its ability to characterize processes operating across a wide range of scales, EUREC$^4$A marked a turning point in our ability to observationally study factors influencing clouds in the trades, how they will respond to warming, and their link to other components of the earth system, such as upper-ocean processes or the life cycle of particulate matter. This characterization was made possible by thousands (2500) of sondes distributed to measure circulations on meso- (200 km) and larger (500 km) scales, roughly 400 h of flight time by four heavily instrumented research aircraft; four global-class research vessels; an advanced groundbased cloud observatory; scores of autonomous observing platforms operating in the upper ocean (nearly 10 000 profiles), lower atmosphere (continuous profiling), and along the air–sea interface; a network of water stable isotopologue measurements; targeted tasking of satellite remote sensing; and modeling with a new generation of weather and climate models. In addition to providing an outline of the novel measurements and their composition into a unified and coordinated campaign, the six distinct scientific facets that EUREC$^4$A explored – from North Brazil Current rings to turbulence-induced clustering of cloud droplets and its influence on warm-rain formation – are presented along with an overview of EUREC$^4$A’s outreach activities, environmental impact, and guidelines for scientific practice. Track data for all platforms are standardized and accessible at https://doi.org/10.25326/165 (Stevens, 2021), and a film documenting the campaign is provided as a video supplement

The relationship between smartphone use and subjective well-being in rural China

Abstract: Due to the popularization of the Internet in rural China, mobile Internet use has become an essential part of rural residents’ lives and work. No studies, however, have investigated the potential effect of smartphone use on quality of life among rural residents in China. This study thus applies ordinary least squared, conditional quantile and instrumental variable techniques to survey data for 493 rural Chinese households to assess the impact of smartphone use (SU) on their subjective well-being (SWB). The results reveal an association between SU and increases in both life satisfaction and happiness that remains even after we adjust for possible endogeneity. The analysis also indicates that SU intensity is associated with lower levels of both SWB measures, especially when it exceeds 3 h per day. Quantile estimates further indicate that in both participation and intensity, SU has a much greater impact on SWB at the median level of the SWB distribution. Our multiple mediation results show that the positive SU–SWB linkage is partially mediated by both farm income and off-farm income. This may suggest that the local government should invest in Internet infrastructure to promote agricultural activities and develop specific rural services to boost farm income via better access to information of agricultural production and market networks. Mobile information and communication technologies can also provide more opportunities for rural entrepreneurship and innovation, in particular by motivating young farmers to actively engage in rural e-business ventures which can raise off-farm income.

Enviromics in breeding: applications and perspectives on envirotypic-assisted selection

Abstract: We propose the application of enviromics to breeding practice, by which the similarity among sites assessed on an “omics” scale of environmental attributes drives the prediction of unobserved genotype performances. Genotype by environment interaction (GEI) studies in plant breeding have focused mainly on estimating genetic parameters over a limited number of experimental trials. However, recent geographic information system (GIS) techniques have opened new frontiers for better understanding and dealing with GEI. These advances allow increasing selection accuracy across all sites of interest, including those where experimental trials have not yet been deployed. Here, we introduce the term enviromics, within an envirotypic-assisted breeding framework. In summary, likewise genotypes at DNA markers, any particular site is characterized by a set of “envirotypes” at multiple “enviromic” markers corresponding to environmental variables that may interact with the genetic background, thus providing informative breeding re-rankings for optimized decisions over different environments. Based on simulated data, we illustrate an index-based enviromics method (the “GIS–GEI”) which, due to its higher granular resolution than standard methods, allows for: (1) accurate matching of sites to their most appropriate genotypes; (2) better definition of breeding areas that have high genetic correlation to ensure selection gains across environments; and (3) efficient determination of the best sites to carry out experiments for further analyses. Environmental scenarios can also be optimized for productivity improvement and genetic resources management, especially in the current outlook of dynamic climate change. Envirotyping provides a new class of markers for genetic studies, which are fairly inexpensive, increasingly available and transferable across species. We envision a promising future for the integration of enviromics approaches into plant breeding when coupled with next-generation genotyping/phenotyping and powerful statistical modeling of genetic diversity.

Prebiotic Inulin and Sodium Butyrate Attenuate Obesity-Induced Intestinal Barrier Dysfunction by Induction of Antimicrobial Peptides.

Abstract: Defects in the mucosal barrier have been associated with metabolic diseases such as obesity and non-alcoholic fatty liver disease (NAFLD). Mice fed a Western-style diet (WSD) develop obesity and are characterized by a diet-induced intestinal barrier dysfunction, bacterial endotoxin translocation and subsequent liver steatosis. To examine whether inulin or sodium butyrate could improve gut barrier dysfunction, C57BL/6 mice were fed a control diet or a WSD ± fructose supplemented with either 10% inulin or 5% sodium butyrate for 12 weeks respectively. Inulin and sodium butyrate attenuated hepatosteatitis in the WSD-induced obesity mouse model by reducing weight gain, liver weight, plasma and hepatic triglyceride level. Furthermore, supplementation with inulin or sodium butyrate induced expression of Paneth cell α-defensins and matrix metalloproteinase-7 (MMP7), which was impaired by the WSD and particularly the fructose-added WSD. Effects on antimicrobial peptide function in the ileum were accompanied by induction of β-defensin-1 and tight junction genes in the colon resulting in improved intestinal permeability and endotoxemia. Organoid culture of small intestinal crypts revealed that the short chain fatty acids (SCFA) butyrate, propionate and acetate, fermentation products of inulin, induce Paneth cell α-defensin expression in vitro, and that histone deacetylation and STAT3 might play a role in butyrate-mediated induction of α-defensins. In summary, inulin and sodium butyrate attenuate diet-induced barrier dysfunction and induce expression of Paneth cell antimicrobials. The administration of prebiotic fiber or sodium butyrate could be an interesting therapeutic approach to improve diet-induced obesity.

Alternative Protein Sources as Technofunctional Food Ingredients.

Abstract: Proteins obtained from alternative sources such as plants, microorganisms, and insects have attracted considerable interest in the formulation of new food products that have a lower environmental footprint and offer means to feed a growing world population. In contrast to many established proteins, and protein fractions for which a substantial amount of knowledge has accumulated over the years, much less information is available on these emerging proteins. This article reviews the current state of knowledge on alternative proteins and their sources, highlighting gaps that currently pose obstacles to their more widespread application in the food industry. The compositional, structural, and functional properties of alternative proteins from various sources, including plants, algae, fungi, and insects, are critically reviewed. In particular, we focus on the factors associated with the creation of protein-rich functional ingredients from alternative sources. The various protein fractions in these sources are described as well as their behavior under different environmental conditions (e.g., pH, ionic strength, and temperature). The extraction approaches available to produce functional protein ingredients from these alternative sources are introduced as well as challenges associated with designing large-scale commercial processes. The key technofunctional properties of alternative proteins, such as solubility, interfacial activity, emulsification, foaming, and gelation properties, are introduced. In particular, we focus on the formation of isotropic and anisotropic structures suitablefor creating meat and dairy product analogs using various structuring techniques. Finally, selected studies on consumer acceptance and sustainability of alternative protein products are considered.

Dynamics of wellbeing co-creation: a psychological ownership perspective

Abstract: Purpose People are responsible for their wellbeing, yet whether they take ownership of their own or even others' wellbeing might vary from actor to actor Such psychological ownership (PO) influences the dynamics of how wellbeing is co-created, particularly amongst actors, and ultimately determines actors' subjective wellbeing The paper's research objective pertains to explicating the concept of the co-creation of wellbeing and conceptualizing the dynamics inherent to the co-creation of wellbeing with consideration of the influences of all involved actors from a PO perspective Design/methodology/approach To provide a new conceptualization and framework for the dynamics of wellbeing co-creation, this research synthesizes wellbeing, PO and value co-creation literature Four healthcare cases serve to illustrate the effects of engaged actors' PO on the co-creation of wellbeing Findings The derived conceptual framework of dynamic co-creation of wellbeing suggests four main propositions: (1) the focal actor's wellbeing state is the intangible target of the focal actor's and other engaged actors' PO, transformed throughout the process of wellbeing co-creation, (2) PO over the focal actor's wellbeing state is subject to the three interrelated routes of exercising control, investing in the target, and intimately knowing the target, which determine the instigation of wellbeing co-creation, (3) the level of PO over the focal actor's wellbeing state can vary, influence and be influenced by the extent of wellbeing co-creation, (4) the co-creation of wellbeing, evoked by PO, is founded on resource integration, which influences the resources–challenges equilibrium of focal actor and of all other engaged actors, affecting individual subjective wellbeing Originality/value This article provides a novel conceptual framework that can shed new light on the co-creation of wellbeing in service research Through the introduction of PO the transformation of lives and wellbeing can be better understood

Issues surrounding consumer trust and acceptance of existing and emerging food processing technologies.

Abstract: The purpose of food processing today is to make food safer, more nutritious and tastier, and to increase storage life. Consumers have a lack of trust in the way food is produced, formulated and processed, particularly with possible contaminants or chemical residues from production. Food manufacturers are not seen as being highly trusted sources. This may partly result from manufacturers' reluctance to share all information and to protect intellectual property via patents and thus maintain a competitive edge. There is a need to inform the consumer better about what operations the involved ingredients are subjected to and why. Various ways of food processing are reviewed. New food processing technologies face challenges when introduced and factors influencing consumers' and other stakeholders' acceptance should be part of decision-making process when adopting new technologies. Consumers' perception of risks is not the same as the risk assessment made by experts. A few specific cases are being discussed to further highlight the multiplicity of factors that may contribute to the development of a certain consumer perception about a product or a class of products. This is also linked to the emergence of certain terminologies that are associated with an increasingly negative perception of the processing of foods. We recommend more transparency on food formulation and food processing to restore consumer trust, which enables to take the advantage of the benefits different processing methods offer. Food manufacturers must make an effort to let consumers know how their food is being processed within the walls of the factory and highlight the benefits vis-a-vis preparing foods in a domestic environment.

Climate change will influence disease resistance breeding in wheat in Northwestern Europe

Abstract: Wheat productivity is threatened by global climate change. In several parts of NW Europe it will get warmer and dryer during the main crop growing period. The resulting likely lower realized on-farm crop yields must be kept by breeding for resistance against already existing and emerging diseases among other measures. Multi-disease resistance will get especially crucial. In this review, we focus on disease resistance breeding approaches in wheat, especially related to rust diseases and Fusarium head blight, because simulation studies of potential future disease risk have shown that these diseases will be increasingly relevant in the future. The long-term changes in disease occurrence must inevitably lead to adjustments of future resistance breeding strategies, whereby stability and durability of disease resistance under heat and water stress will be important in the future. In general, it would be important to focus on non-temperature sensitive resistance genes/QTLs. To conclude, research on the effects of heat and drought stress on disease resistance reactions must be given special attention in the future.

Host-induced gene silencing - mechanisms and applications.

Abstract: Host-induced gene silencing (HIGS) technology has emerged as a powerful alternative to chemical treatments for protecting plants from pathogens or pests. More than 170 HIGS studies have been published so far, and HIGS products have been launched. First, we discuss the strengths and limitations of this technology in a pathosystem-specific context. Next, we highlight the requirement for fundamental knowledge on the molecular mechanisms (i.e., uptake, processing, and translocation of transgene-expressed double-stranded RNAs) that determine the efficacy and specificity of HIGS. Additionally, we speculate on the contribution of host and target RNA interference machineries, which may be incompatible depending on the lifestyle of the pathogen or pest. Finally, we predict that closing these gaps in knowledge will lead to the development of novel integrative concepts, precise risk assessment, and tailor-made HIGS therapy for plant diseases.

The broad impacts of corn stover and wheat straw removal for biofuel production on crop productivity, soil health and greenhouse gas emissions: A review

Abstract: Biofuel production from crop residues is widely recognized as an essential component of developing a bioeconomy, but the removal of crop residues still raises many questions about the sustainability of the cropping system. Therefore, this study reviews the sustainability effects of crop residues removal for biofuel production in terms of crop production, soil health and greenhouse gas emissions. Most studies found little evidence that residue management had long‐term impacts on grain yield unless the available water is limited. In years when water was not limiting, corn and wheat removal rates ≥90% produced similar or greater grain yield than no removal in most studies. Conversely, when water was limiting, corn grain yield decreased up to 21% with stover removal ≥90% in some studies. Changes in soil organic fractions and nutrients depended largely on the amount of residue returned, soil depth and texture, slope and tillage. Reductions in organic fractions occurred primarily with complete stover removal, in the top 15–30 cm in fine‐textured soils. Soil erosion, water runoff and leaching of nutrients such as total nitrogen (N) and extractable soil potassium decreased when no more than 30% of crop residues were removed. Stover management effects on soil bulk density varied considerably depending on soil layer, and residue and tillage management, with removal rates of less than 50% helping to maintain the soil aggregate stability. Reductions in CO2 and N2O fluxes typically occurred following complete residue removal. The use of wheat straw typically increased CH4 emissions, and above or equal to 8 Mg/ha wheat straw led to the largest CO2 and N2O emissions, regardless of N rates. Before using crop residues for biofuel production, it should therefore always be checked whether neutral to positive sustainability effects can be maintained under the site‐specific conditions.

Soil texture affects the coupling of litter decomposition and soil organic matter formation

Abstract: Incomplete knowledge on the environmental factors linking litter decomposition and the formation of soil organic matter (SOM) hampers the sustainable management of soil as a carbon (C) sink. Here, we explored the effect of soil texture on the fate of C from decomposing litter (Indiangrass; Sorghastrum nutans (L.) Nash) and the concurrent formation of SOM in mineral soils of different textures (sand- and clay-rich) and forest floor material. We quantified the amount of litter C respired, C remaining in the litter, and litter C retained in the soil/forest floor in a 186-day incubation employing stable isotope analyses (13C). We complemented our isotopic approach with the extraction of microbial biomarkers from the litter and soils/forest floor material and spectroscopic studies into the compositional changes of the incubated materials. We found that soil texture affected both the decomposition of litter and the retention of litter-derived C in the soil. The soil rich in clay provided conditions favorable for a more efficient microbial utilization of the litter material (high pH and high C use efficiency) as compared to the sand-rich soil and the forest floor. This resulted in lower amounts of litter C respired as CO2 (25.0%, vs. 55.6 and 56.1% in clay vs. sand and forest floor material, respectively) and higher amounts of litter C retained in the clay-rich soil (12.6% vs. 3.5 and 5.3% in clay vs. sand and forest floor material, respectively). High contents of silt- and clay-sized mineral particles in the clay-rich soil likely resulted in the ability to stabilize litter C in aggregates and organo-mineral associations, perhaps as microbial residues. This ability was low in the sand-rich soil and virtually absent in the forest floor, where the recalcitrance of the litter and native SOM was probably more relevant, and a larger portion of litter C may have been retained in the soil as relatively untransformed plant compounds. We emphasize that litter decomposition, the formation of SOM, and soil texture are tightly linked, such that any differences in soil texture alter litter decomposition and SOM formation patterns for the same litter.

Drought and crop yield.

Abstract: Episodes of water shortage occur in most agricultural regions of the world. Their durations and intensities increase, and their seasonal timing alters with changing climate. During the ontogenic cycle of crop plants, each development stage, such as seed germination, seedling establishment, vegetative root and shoot growth, flowering, pollination and seed and fruit development, is specifically sensitive to dehydration. Desiccation threatens yield and leads to specific patterns, depending on the type of crop plant and the harvested plant parts, e.g. leafy vegetables, tubers, tap roots or fruits. This review summarizes the effects of drought stress on crop plants and relates the dehydration-dependent yield penalty to the harvested organ and tissue. The control of shoot transpiration and the reorganization of root architecture are of core importance for maintaining proper plant water relationships. Upon dehydration, the provision and partitioning of assimilates and the uptake and distribution of nutrients define remaining growth activity. Domestication of crops by selection for high yield under high input has restricted the genetic repertoire for achieving drought stress tolerance. Introgression of suitable alleles from wild relatives into commercial cultivars might improve the ability to grow with less water. Future research activities should focus more on field studies in order to generate more realistic improvements to crops. Robotic field phenotyping should be integrated into genetic mapping for the identification of relevant traits.