Fakultät Agrarwissenschaften

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Die Fakultät entwickelt in Lehre und Forschung nachhaltige Produktionstechniken der Agrar- und Ernährungswirtschaft. Sie erarbeitet Beiträge für den ländlichen Raum und zum Verbraucher-, Tier- und Umweltschutz.

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Approaches to increase digestibility of Bangladesh ruminant feed resources in order to mitigate enteric methane production
(2024) Bashar, Muhammad Khairul; Rodehutscord, Markus
Multiple analyses have shown that the rising human population, urbanization, and consumer preferences affect the demand for livestock products in developing countries. Concurrently, human population and urbanisation growth are reducing the likelihood of newly cultivated land producing feeds or restoring damaged pastures. Using low-quality roughage more efficiently is an option, but such roughages have drawbacks, including high structural carbohydrate and low nitrogen contents, which lead to poor palatability and nutrient utilisation including emission of methane (CH4) that is harmful to the environment and a loss of energy to the animal. Using commonly accessible legumes and tree foliage could be a possibility to address the need for N and CH4 mitigation due to their high crude protein and secondary compound contents. In order to evaluate the potential of specific combinations of roughages, concentrates, and other feeds, it is necessary to determine the feeding values, in vitro ruminal fermentation, and CH4 production of single feeds, as well as the promising interaction (associative) effects between single feeds when combinded in a ration. This may allow for formulating a better balanced total mixed ration (TMR) for ruminants, which was the main goal of the present doctoral study. Eighteen feedstuffs from Bangladesh were chosen, including roughages such as crop residues (rice straw, urea molasses treated straw and maize stover), silages (Napier silage and Maize silage), common grasses (German grass, Para grass and Napier grass) and leguminous fodder (Ipil-ipil, Glicidia, Alfalfa hay and Moringa tops) and concentrates (crushed wheat, crushed maize, Wheat bran, Kashari bran, and Rice bran). In Study 1, the single feeds were characterized by comprehensive chemical analysis and in vitro production of total gas and methane using the Hohenheim gas test. Based on the results of Study 1, rice straw, German grass, Napier silage, and maize silage were used in Study 2 and incubated in vitro alone or after substitution by Ipil-ipil and Gliricidia at levels of 10%, 20%, 30%, and 40%, respectively. In Study 3, mixtures of roughages and leguminous fodder (rice straw + 40% Ipil-ipil, German grass + 10% Ipil-ipil, Napier silage + 30% Ipil ipil, and maize silage + 30% Ipil-ipil) were combined with single concentrates in order to identify the most promising mixtures in regard to digestibility and methane production. Eventually, 24 TMR were formulated using six for each type of roughage in Study 4. These TMR were comprised of 60% of the same combination of roughage as used in Study 3 and 40% of various combinations of concentrates including TMR-1 (60% rice bran + 10% wheat bran + 30% kashari bran), TMR-2 (30% rice bran + 10% wheat bran + 60% kashari bran), TMR-3 (10% rice bran + 60% wheat bran + 30% kashari bran), TMR-4 (10% rice bran + 30% wheat bran + 60% kashari bran), TMR-5 (60% rice bran + 30% wheat bran + 10 kashari bran), and TMR-6 (30% rice bran + 60% wheat bran + 10% kashari bran) in order to identify suitable TMR for maximising ruminal fermentation and reducing the CH4 production in vitro. In all studies, the total gas production (GP), digestibility of organic matter (dOM), metabolisable energy (ME), and net energy for lactation (NEL) were determined after incubating 200 mg of feed with a rumen fluid-buffer solution for 72 hours. In addition, the CH4 concentration in the produced gas was measured after incubating 120 mg of feed for 24 hours. Measured values of the mixed feed were compared to estimated values, where the estimated values were weighted means of the values of the individual feeds, to determine the associative effects between the feed ingredients (Study 2 and Study 4). In Study 1, the concentration of acid detergent fibre (ADF), neutral detergent fibre (NDF), and acid detergent lignin (ADL) was the lowest in leguminous fodder while the crude protein (CP) concentration was the hightest, followed by the common grasses and the silages. The crop residues showed the lowest CP and the highest cell wall fraction concentrations. The dOM, ME, and NEL of crushed wheat and crushed maize were significantly higher (p<0.05) than those of other feedstuffs. The same differences were found (p<0.05) for CH4 concentration (% of GP) and CH4 production (L CH4/kg dOM). The dOM and ME of German grass and Ipil-ipil were higher (p<0.05), whereas the CH4 concentration and CH4 production were lower compared to that of crop residues and other common grasses. The CH4 production of single feeds decreased with increasing concentrations of CP, ADF, and ADL, whereas it increased with NDF concentration. These findings enabled development of more balanced diets for ruminants with the aim of improved digestibility and reduced CH4 emission while making use of widely available feed resources in Bangladesh. Study 2 aimed to evaluate the in vitro ruminal fermentation, CH4 production, and associative effects between low-quality roughages and CP supplements. The gas production after 24 hours (GP24) and rumen fermentation rate increased (p<0.05) with increasing addition of Ipil-ipil to rice straw. It also resulted in a gradual increase of dOM and ME (p<0.05) of the mixture, reaching maximum values (59.1% and 7.60 MJ ME/kg DM) and maximum reductions in CH4 concentration and CH4/dOM (6.9% and 11.7%) compared to the control with Ipil-ipil addition at 40% of DM. When Ipil-ipil was added at 30% to Napier silage, the same trend was observed for dOM and ME (56.5%, and 7.55 MJ ME/kg DM) and CH4 concentration and CH4/dOM (5.3% and 13.3%). Ipil-ipil did not significantly interact with high quality roughages such as German grass and maize silage. Increasing the addition of Gliricidia to the roughages in Study 2 led to a decrease in GP24, dOM, ME, and CH4 production. The highest levels of the associative effects (p<0.05) were seen when 40% Ipil-ipil was added to rice straw and 30% was added to Napier silage. In conclusion, adding Ipil-ipil to low-quality roughages is superior to Gliricidia and showed promising results, with the ranking as follows: rice straw + 40% Ipil-ipil > Napier silage + 30% Ipil-ipil > maize silage + 30% Ipil-ipil > German gras + 10% Ipil-ipil. Study 3 and Study 4 had the overarching purpose to determine which combination of single concentrates and combinations of concentrates with roughage produced the best mixed feed in terms of rumen fermentation, CH4 reduction potential, and associative effect. The CP and non-stach carbohydrate contents of the Ipil-ipil-based mixed feed was enhanced by adding Wheat bran and Kashari bran as single concentrates, which had a favourable effect on rumen fermentation and gas production but had the opposite effect on CH4 production when compared to the addition of Rice bran. In Study 4, TMR were formulated using roughages and Ipil-ipil and addition of Wheat bran, Kashari bran, and Rice bran in various combinations. The TMR based on German grass and maize silage with specific bran combinations showed significant reductions in in vitro CH4 production, CH4 concentration, and CH4/dOM while maximising GP, dOM, ME, and the associative effects. To conclude, the results of chemical analyses and in vitro fermentation studies showed that specific combinations of roughages, protein feeds, and by-products available in Bangladesh have the potential to formulate rations for cattle that help making livestock production more sustainable. The results may be also relevant for other developing nations. It is suggested to verify the results of the present project by animal trials at local conditions.
Arbuscular mycorrhizal fungi-based bioremediation of mercury: insights from zinc and cadmium transporter studies
(2023) Guo, Yaqin; Martin, Konrad; Hrynkiewicz, Katarzyna; Rasche, Frank; Guo, Y.; Faculty of Agricultural Sciences, Institute of Agricultural Sciences in the Tropics (Hans-Ruthenberg-Institute), University of Hohenheim, 70593, Stuttgart, Germany; Martin, K.; Faculty of Agricultural Sciences, Institute of Agricultural Sciences in the Tropics (Hans-Ruthenberg-Institute), University of Hohenheim, 70593, Stuttgart, Germany; Hrynkiewicz, K.; Department of Microbiology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, 87-100, Torun, Poland; Rasche, F.; Faculty of Agricultural Sciences, Institute of Agricultural Sciences in the Tropics (Hans-Ruthenberg-Institute), University of Hohenheim, 70593, Stuttgart, Germany
Phytoremediation, a sustainable approach for rehabilitating mercury (Hg)-contaminated soils, can be enhanced by arbuscular mycorrhizal (AM) fungi, which promote plant growth and metal uptake, including Hg, in contaminated soils. Hg, despite lacking a biological function in plants, can be absorbed and translocated using Zn and/or Cd transporters, as these elements belong to the same group in the periodic table (12/2B). In fact, the specific transporters of Hg in plant roots remain unknown. This study is therefore to provide fundamental insights into the prospect to remediate Hg-contaminated soils, with a focus on the role of AM fungi. The hypothesis posits that Hg uptake in plants may be facilitated by transporters responsible for Zn/Cd, affected by AM fungi. The Scopus database was used to collect studies between 2000 and 2022 with a focus on the ecological role of AM fungi in environments contaminated with Zn and Cd. Particular emphasis was laid on the molecular mechanisms involved in metal uptake and partitioning. The study revealed that AM fungi indeed regulated Zn and/or Cd transporters, influencing Zn and/or Cd uptake in plants. However, these effects vary significantly based on environmental factors, such as plant and AM fungi species and soil conditions (e.g., pH, phosphorus levels). Given the limited understanding of Hg remediation, insights gained from Zn and Cd transporter systems can guide future Hg research. In conclusion, this study underscores the importance of considering environmental factors and provides fundamental insights into the potential of Hg phytoremediation with the assistance of AM fungi.
Automatic classification of submerged macrophytes at Lake Constance using laser bathymetry point clouds
(2024) Wagner, Nike; Franke, Gunnar; Schmieder, Klaus; Mandlburger, Gottfried; Wagner, Nike; Department of Geodesy and Geoinformation, TU Wien, Wiedner Hauptstr. 8-10, 1040 Vienna, Austria;; Franke, Gunnar; Institute of Landscape and Plant Ecology (320), University of Hohenheim, Ottilie-Zeller-Weg 2, 70599 Stuttgart, Germany; (G.F.); (K.S.); Schmieder, Klaus; Institute of Landscape and Plant Ecology (320), University of Hohenheim, Ottilie-Zeller-Weg 2, 70599 Stuttgart, Germany; (G.F.); (K.S.); Mandlburger, Gottfried; Department of Geodesy and Geoinformation, TU Wien, Wiedner Hauptstr. 8-10, 1040 Vienna, Austria;; Stateczny, Andrzej
Submerged aquatic vegetation, also referred to as submerged macrophytes, provides important habitats and serves as a significant ecological indicator for assessing the condition of water bodies and for gaining insights into the impacts of climate change. In this study, we introduce a novel approach for the classification of submerged vegetation captured with bathymetric LiDAR (Light Detection And Ranging) as a basis for monitoring their state and change, and we validated the results against established monitoring techniques. Employing full-waveform airborne laser scanning, which is routinely used for topographic mapping and forestry applications on dry land, we extended its application to the detection of underwater vegetation in Lake Constance. The primary focus of this research lies in the automatic classification of bathymetric 3D LiDAR point clouds using a decision-based approach, distinguishing the three vegetation classes, (i) Low Vegetation, (ii) High Vegetation, and (iii) Vegetation Canopy, based on their height and other properties like local point density. The results reveal detailed 3D representations of submerged vegetation, enabling the identification of vegetation structures and the inference of vegetation types with reference to pre-existing knowledge. While the results within the training areas demonstrate high precision and alignment with the comparison data, the findings in independent test areas exhibit certain deficiencies that are likely addressable through corrective measures in the future.
Biomonitoring via DNA metabarcoding and light microscopy of bee pollen in rainforest transformation landscapes of Sumatra
(2022) Carneiro de Melo Moura, Carina; Setyaningsih, Christina A.; Li, Kevin; Merk, Miryam Sarah; Schulze, Sonja; Raffiudin, Rika; Grass, Ingo; Behling, Hermann; Tscharntke, Teja; Westphal, Catrin; Gailing, Oliver; Carneiro de Melo Moura, Carina; Department of Forest Genetics and Forest Tree Breeding, University of Göttingen, Göttingen, Germany; Setyaningsih, Christina A.; Department of Palynology and Climate Dynamics, Albrecht-von-Haller-Institute for Plant Sciences, University of Göttingen, Göttingen, Germany; Li, Kevin; Agroecology, Department of Crop Sciences, University of Göttingen, Göttingen, Germany; Merk, Miryam Sarah; Statistics and Econometrics, University of Göttingen, Göttingen, Germany; Schulze, Sonja; Agroecology, Department of Crop Sciences, University of Göttingen, Göttingen, Germany; Raffiudin, Rika; Department of Biology, IPB University ID, Bogor, Indonesia; Grass, Ingo; Department of Ecology of Tropical Agricultural Systems, University of Hohenheim, Stuttgart, Germany; Behling, Hermann; Department of Palynology and Climate Dynamics, Albrecht-von-Haller-Institute for Plant Sciences, University of Göttingen, Göttingen, Germany; Tscharntke, Teja; Agroecology, Department of Crop Sciences, University of Göttingen, Göttingen, Germany; Westphal, Catrin; Functional Agrobiodiversity, Department of Crop Sciences, University of Göttingen, Göttingen, Germany; Gailing, Oliver; Centre of Biodiversity and Sustainable Land Use, University of Göttingen, Göttingen, Germany
Background: Intense conversion of tropical forests into agricultural systems contributes to habitat loss and the decline of ecosystem functions. Plant-pollinator interactions buffer the process of forest fragmentation, ensuring gene flow across isolated patches of forests by pollen transfer. In this study, we identified the composition of pollen grains stored in pot-pollen of stingless bees, Tetragonula laeviceps , via dual-locus DNA metabarcoding (ITS2 and rbcL ) and light microscopy, and compared the taxonomic coverage of pollen sampled in distinct land-use systems categorized in four levels of management intensity (forest, shrub, rubber, and oil palm) for landscape characterization. Results: Plant composition differed significantly between DNA metabarcoding and light microscopy. The overlap in the plant families identified via light microscopy and DNA metabarcoding techniques was low and ranged from 22.6 to 27.8%. Taxonomic assignments showed a dominance of pollen from bee-pollinated plants, including oil-bearing crops such as the introduced species Elaeis guineensis (Arecaceae) as one of the predominant taxa in the pollen samples across all four land-use types. Native plant families Moraceae, Euphorbiaceae, and Cannabaceae appeared in high proportion in the analyzed pollen material. One-way ANOVA (p > 0.05), PERMANOVA (R² values range from 0.14003 to 0.17684, for all tests p-value > 0.5), and NMDS (stress values ranging from 0.1515 to 0.1859) indicated a lack of differentiation between the species composition and diversity of pollen type in the four distinct land-use types, supporting the influx of pollen from adjacent areas. Conclusions: Stingless bees collected pollen from a variety of agricultural crops, weeds, and wild plants. Plant composition detected at the family level from the pollen samples likely reflects the plant composition at the landscape level rather than the plot level. In our study, the plant diversity in pollen from colonies installed in land-use systems with distinct levels of forest transformation was highly homogeneous, reflecting a large influx of pollen transported by stingless bees through distinct land-use types. Dual-locus approach applied in metabarcoding studies and visual pollen identification showed great differences in the detection of the plant community, therefore a combination of both methods is recommended for performing biodiversity assessments via pollen identification.
Challenges of green production of 2,5‐furandicarboxylic acid from bio‐derived 5‐hydroxymethylfurfural: Overcoming deactivation by concomitant amino acids
(2022) Neukum, Dominik; Baumgarten, Lorena; Wüst, Dominik; Sarma, Bidyut Bikash; Saraçi, Erisa; Kruse, Andrea; Grunwaldt, Jan‐Dierk
The oxidation of 5‐hydroxymethylfurfural (HMF) to 2,5‐furandicarboxylic acid (FDCA) is highly attractive as FDCA is considered as substitute for the petrochemically derived terephthalic acid. There are only few reports on the direct use of unrefined HMF solutions from biomass resources and the influence of remaining constituents on the catalytic processes. In this work, the oxidation of HMF in a solution as obtained from hydrolysis and dehydration of saccharides in chicory roots was investigated without intermediate purification steps. The amount of base added to the solution was critical to increase the FDCA yield. Catalyst deactivation occurred and was attributed to poisoning by amino acids from the bio‐source. A strong influence of amino acids on the catalytic activity was found for all supported Au, Pt, Pd, and Ru catalysts. A supported AuPd(2 : 1)/C alloy catalyst exhibited both superior catalytic activity and higher stability against deactivation by the critical amino acids.
Composition of the ileum microbiota is a mediator between the host genome and phosphorus utilization and other efficiency traits in Japanese quail (Coturnix japonica)
(2022) Haas, Valentin; Vollmar, Solveig; Preuß, Siegfried; Rodehutscord, Markus; Camarinha-Silva, Amélia; Bennewitz, Jörn; Haas, Valentin; Institute of Animal Science, University of Hohenheim, Stuttgart, Germany; Vollmar, Solveig; Institute of Animal Science, University of Hohenheim, Stuttgart, Germany; Preuß, Siegfried; Institute of Animal Science, University of Hohenheim, Stuttgart, Germany; Rodehutscord, Markus; Institute of Animal Science, University of Hohenheim, Stuttgart, Germany; Camarinha-Silva, Amélia; Institute of Animal Science, University of Hohenheim, Stuttgart, Germany; Bennewitz, Jörn; Institute of Animal Science, University of Hohenheim, Stuttgart, Germany
Background: Phosphorus is an essential nutrient in all living organisms and, currently, it is the focus of much attention due to its global scarcity, the environmental impact of phosphorus from excreta, and its low digestibility due to its storage in the form of phytates in plants. In poultry, phosphorus utilization is influenced by composition of the ileum microbiota and host genetics. In our study, we analyzed the impact of host genetics on composition of the ileum microbiota and the relationship of the relative abundance of ileal bacterial genera with phosphorus utilization and related quantitative traits in Japanese quail. An F2 cross of 758 quails was genotyped with 4k genome-wide single nucleotide polymorphisms (SNPs) and composition of the ileum microbiota was characterized using target amplicon sequencing. Heritabilities of the relative abundance of bacterial genera were estimated and quantitative trait locus (QTL) linkage mapping for the host was conducted for the heritable genera. Phenotypic and genetic correlations and recursive relationships between bacterial genera and quantitative traits were estimated using structural equation models. A genomic best linear unbiased prediction (GBLUP) and microbial (M)BLUP hologenomic selection approach was applied to assess the feasibility of breeding for improved phosphorus utilization based on the host genome and the heritable part of composition of the ileum microbiota. Results: Among the 59 bacterial genera examined, 24 showed a significant heritability (nominal p ≤ 0.05), ranging from 0.04 to 0.17. For these genera, six genome-wide significant QTL were mapped. Significant recursive effects were found, which support the indirect host genetic effects on the host’s quantitative traits via microbiota composition in the ileum of quail. Cross-validated microbial and genomic prediction accuracies confirmed the strong impact of microbial composition and host genetics on the host’s quantitative traits, as the GBLUP accuracies based on the heritable microbiota-mediated components of the traits were similar to the accuracies of conventional GBLUP based on genome-wide SNPs. Conclusions: Our results revealed a significant effect of host genetics on composition of the ileal microbiota and confirmed that host genetics and composition of the ileum microbiota have an impact on the host’s quantitative traits. This offers the possibility to breed for improved phosphorus utilization based on the host genome and the heritable part of composition of the ileum microbiota.
Connecting resonance theory with social-ecological thinking: Conceptualizing self-world relationships in the context of sustainability transformations
(2025) Brossette, Florian; Bieling, Claudia
Relationships and interactions between humans and their environment play an important role in sustainability transformations. However, their conceptualization remains a big challenge in current social-ecological research. We propose resonance theory by the German sociologist Hartmut Rosa as a fruitful framework to advance social-ecological thinking. Resonance theory investigates the quality of the relationships between self and world and scrutinizes their relevance for transformations. To illustrate the potentials of resonance theory, we use a vignette approach to cases of landscape stewardship initiatives in the Black Forest Biosphere Reserve in Germany. In distinguishing between self and world and highlighting the role of relationships, resonance theory brings ontological and epistemological clarity, while overcoming a strict dichotomy between social and ecological. We find that resonance theory provides a much needed framework to describe how system-wide transformations emerge from interactions and out of relationships at the individual level. We argue that resonance theory contributes to social-ecological systems thinking by adding the notion of uncontrollability in transformations and shifting the debate on agency towards relationships. Synthesis and applications: This paper demonstrates the meaningfulness of relational paradigms for real-world transformations in theory and practice.
Distribution of Al, Fe, Si, and DOC between size fractions mobilised from topsoil horizons with progressing degree of podzolisation
(2022) Krettek, Agnes; Stein, Mathias; Rennert, Thilo
Aluminium, Fe, Si, and dissolved organic C (DOC) accumulate in the subsoil of Podzols after mobilisation in the topsoil. We conducted laboratory experiments with topsoil horizons with progressing degree of podzolisation by irrigation with artificial rainwater at varying intensity and permanence. We monitored the concentrations and distribution of mobilised Al, Fe, Si, and DOC between size fractions (< 1000 Dalton, 1 kDa– < 0.45 µm, and > 0.45 µm). Total eluate concentrations were increased at the onset of the experiments and after the first irrigation interruption, indicating non-equilibrium release. There was no statistical effect of the degree of podzolisation on element concentrations. Release of Al, Fe, and DOC was mostly dominant in the fraction 1 kDa– < 0.45 µm, indicating metals complexed by larger organic molecules and colloids. Silicon released was dominantly monomeric silicic acid < 1 kDa. Particularly with the least podzolised soils, Al and Si concentrations < 1 kDa might have been controlled by short-range ordered aluminosilicates, while their transport in colloidal form was unlikely. Our study pointed to both quantitative and qualitative seasonality of element release during podzolisation, to decoupling of Al and Si release regarding size, and to different minerals that control element release as a function of the degree of podzolisation.
Do lower nitrogen fertilization levels require breeding of different types of cultivars in triticale?
(2022) Neuweiler, Jan E.; Trini, Johannes; Maurer, Hans Peter; Würschum, Tobias
Breeding high-yielding, nitrogen-efficient crops is of utmost importance to achieve greater agricultural sustainability. The aim of this study was to evaluate nitrogen use efficiency (NUE) of triticale, investigate long-term genetic trends and the genetic architecture, and develop strategies for NUE improvement by breeding. For this, we evaluated 450 different triticale genotypes under four nitrogen fertilization levels in multi-environment field trials for grain yield, protein content, starch content and derived indices. Analysis of temporal trends revealed that modern cultivars are better in exploiting the available nitrogen. Genome-wide association mapping revealed a complex genetic architecture with many small-effect QTL and a high level of pleiotropy for NUE-related traits, in line with phenotypic correlations. Furthermore, the effect of some QTL was dependent on the nitrogen fertilization level. High correlations of each trait between N levels and the rather low genotype-by-N-level interaction variance showed that generally the same genotypes perform well over different N levels. Nevertheless, the best performing genotype was always a different one. Thus, selection in early generations can be done under high nitrogen fertilizer conditions as these provide a stronger differentiation, but the final selection in later generations should be conducted with a nitrogen fertilization as in the target environment.
Do we need post-tree thinning management? Prescribed fire and goat browsing to control woody encroacher species in an Ethiopian savanna
(2024) Abate, Teshome; Abebe, Tesfaye; Treydte, Anna; Abate, Teshome; College of Agriculture, Hawassa University, Hawassa, Ethiopia; Abebe, Tesfaye; College of Agriculture, Hawassa University, Hawassa, Ethiopia; Treydte, Anna; Department of Sustainable Agriculture and Biodiversity Conservation, The Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
Worldwide, bush encroachment threatens rangeland ecosystem services, including plant biodiversity and forage for livestock. Various control methods for encroaching woody species and restoring herbaceous vegetation exist but have rarely been explored experimentally. We assessed the impact of post-tree thinning management on tree mortality, the herbaceous community, and overall rangeland condition in Borana, an Ethiopian savanna ecosystem. At two 1.4 ha areas of encroached mono-specific Vachellia drepanolobium (whistling thorn) stands, we set up twenty-four 20 × 10 m experimental plots with four post-tree-thinning treatments (goat browsing only (1), prescribed fire (2), fire and goat browsing (3), and control (4) (i.e., no management after tree cutting), with three replications in a complete block design. Over two growing periods, we monitored resulting tree mortality, coppicing, seedling mortality and recruitment, as well as herbaceous layer attributes (diversity, biomass) and overall rangeland condition. All three post-tree thinning management scenarios significantly enhanced tree mortalities, reduced seedling recruitment and increased the abundance of the dominant desirable grass species. Prescribed fire and fire and goat-browsing treatments resulted in significantly greater grass and forb species richness, forb diversity, and biomass, as well as the overall rangeland condition compared to goat browsing only and the control treatment. However, grass species diversity did not respond to treatments. Post-tree management significantly increased tree mortality, reduced seedling recruitment, and increased the abundance of desirable grass species. Our findings strongly suggest that post-thinning management, particularly prescribed fire or a combination of fire and browsing, is highly effective in suppressing woody encroachment and improving biomass and overall rangeland condition.
Effects of harvest date and ensiling additives on the optimized ensiling of Silphium perfoliatum to prevent faulty fermentation
(2024) Baumgart, Marian; Hülsemann, Benedikt; Sailer, Gregor; Oechsner, Hans; Müller, Joachim; Baumgart, Marian; State Institute of Agricultural Engineering and Bioenergy, University of Hohenheim, Garbenstraße 9, 70599 Stuttgart, Germany; (B.H.); (G.S.); (H.O.); Hülsemann, Benedikt; State Institute of Agricultural Engineering and Bioenergy, University of Hohenheim, Garbenstraße 9, 70599 Stuttgart, Germany; (B.H.); (G.S.); (H.O.); Sailer, Gregor; State Institute of Agricultural Engineering and Bioenergy, University of Hohenheim, Garbenstraße 9, 70599 Stuttgart, Germany; (B.H.); (G.S.); (H.O.); Oechsner, Hans; State Institute of Agricultural Engineering and Bioenergy, University of Hohenheim, Garbenstraße 9, 70599 Stuttgart, Germany; (B.H.); (G.S.); (H.O.); Müller, Joachim; Institute of Agricultural Engineering, Tropics and Subtropics Group, University of Hohenheim, Garbenstraße 9, 70599 Stuttgart, Germany;; Hu, Wei; Zhou, Zhiguo; Zhao, Wenqing
Silphium perfoliatum , an energy crop with a high fiber content but low concentrations of fermentable carbohydrates, presents challenges for complete fermentation in biogas production. To overcome this, a bioeconomic approach proposes the use of the fibers for paper and board production, which requires high-quality silage with minimal butyric acid, which affects the marketability of the fibers. This study aims to optimize the silaging process of Silphium perfoliatum by investigating the effects of harvest date, bacterial cultures and additives on fermentation results. Laboratory experiments were conducted to evaluate the effect of three harvest dates on fermentation acid composition, with a focus on increasing lactic acid production to inhibit butyric acid formation. Results indicate that an early harvest date (early September) is critical for achieving stable fermentation and minimizing ensiling losses. The addition of sugar-rich additives, such as syrup, was found to be essential, especially for later harvest dates. Despite these interventions, a late harvest (early November) consistently resulted in suboptimal fermentation. The results suggest that optimizing harvest timing and incorporating appropriate additives are key strategies for producing high quality silage and ensuring the suitability of Silphium perfoliatum fibers for industrial applications.
Exploring the plausibility of inoculated cowpeas as a climate adaptation strategy for Namibian smallholder farmers
(2025) Rasche, Livia; Katjana, Johannes; Jantke, Kerstin; Uchezuba, David; Schneider, Uwe A.; Rasche, Livia; Research Unit Sustainability and Climate Risks, Center for Earth System Research and Sustainability (CEN), Universität Hamburg, 20144 Hamburg, Germany; Katjana, Johannes; School of Agriculture and Natural Resource Sciences, Namibia University of Science and Technology, Windhoek 10005, Namibia; Jantke, Kerstin; Research Unit Sustainability and Climate Risks, Center for Earth System Research and Sustainability (CEN), Universität Hamburg, 20144 Hamburg, Germany; Uchezuba, David; School of Agriculture and Natural Resource Sciences, Namibia University of Science and Technology, Windhoek 10005, Namibia; Schneider, Uwe A.; Research Unit Sustainability and Climate Risks, Center for Earth System Research and Sustainability (CEN), Universität Hamburg, 20144 Hamburg, Germany; Lombardi, Mariarosaria
Increased cultivation of cowpeas is a possible adaptation option for Namibian farmers under changing climatic conditions. Using inoculated cowpeas can potentially double the yields under favorable climate conditions. But is such a potentially beneficial agricultural adaptation technique likely to be adopted? We surveyed 90 cowpea farmers from 30 villages in the Kavango region of northern Namibia on their households and farms, access to institutions and services, food consumption and preferences, and perceptions of climate change. Our survey reveals that smallholder farmers will not readily adopt the new technology. At most, about 50% of farmers can be convinced by new information to change their agricultural activities. When specifically asked about their willingness to grow inoculated cowpeas, almost all farmers responded that they would be willing to do so. However, the farmers are reluctant to allocate more land for cowpea cultivation, mainly because harvesting is very time and labor-intensive. The study shows that technology assessments should be conducted in combination with socio-economic assessments to realistically assess the potential success of proposed adaptation measures, as the extent to which a new technology may be adopted is an essential indicator for justifying funding of new technologies or adaptation programs.
Fed-batch bioreactor cultivation of Bacillus subtilis using vegetable juice as an alternative carbon source for lipopeptides production: a shift towards a circular bioeconomy
(2024) Gugel, Irene; Vahidinasab, Maliheh; Benatto Perino, Elvio Henrique; Hiller, Eric; Marchetti, Filippo; Costa, Stefania; Pfannstiel, Jens; Konnerth, Philipp; Vertuani, Silvia; Manfredini, Stefano; Hausmann, Rudolf; Gugel, Irene; Department of Life Sciences and Biotechnology, University of Ferrara, 44121 Ferrara, Italy, (S.V.);; Vahidinasab, Maliheh; Department of Bioprocess Engineering (150k), Institute of Food Science and Biotechnology, University of Hohenheim, Fruwirthstrasse 12, 70599 Stuttgart, Germany; (E.H.B.P.);; Benatto Perino, Elvio Henrique; Department of Bioprocess Engineering (150k), Institute of Food Science and Biotechnology, University of Hohenheim, Fruwirthstrasse 12, 70599 Stuttgart, Germany; (E.H.B.P.);; Hiller, Eric; Department of Bioprocess Engineering (150k), Institute of Food Science and Biotechnology, University of Hohenheim, Fruwirthstrasse 12, 70599 Stuttgart, Germany; (E.H.B.P.);; Marchetti, Filippo; Department of Life Sciences and Biotechnology, University of Ferrara, 44121 Ferrara, Italy, (S.V.);; Costa, Stefania; Department of Life Sciences and Biotechnology, University of Ferrara, 44121 Ferrara, Italy, (S.V.);; Pfannstiel, Jens; Core Facility Hohenheim, Mass Spectrometry Unit, University of Hohenheim, Ottlie-Zeller-Weg 2, 70599 Stuttgart, Germany; Konnerth, Philipp; Department of Conversion Technology of Biobased Resources, University of Hohenheim, Garbenstrasse 9, 70599 Stuttgart, Germany;; Vertuani, Silvia; Department of Life Sciences and Biotechnology, University of Ferrara, 44121 Ferrara, Italy, (S.V.);; Manfredini, Stefano; Department of Life Sciences and Biotechnology, University of Ferrara, 44121 Ferrara, Italy, (S.V.);; Hausmann, Rudolf; Department of Bioprocess Engineering (150k), Institute of Food Science and Biotechnology, University of Hohenheim, Fruwirthstrasse 12, 70599 Stuttgart, Germany; (E.H.B.P.);; Gudiña, Eduardo
In a scenario of increasing alarm about food waste due to rapid urbanization, population growth and lifestyle changes, this study aims to explore the valorization of waste from the retail sector as potential substrates for the biotechnological production of biosurfactants. With a perspective of increasingly contributing to the realization of the circular bioeconomy, a vegetable juice, derived from unsold fruits and vegetables, as a carbon source was used to produce lipopeptides such as surfactin and fengycin. The results from the shake flask cultivations revealed that different concentrations of vegetable juice could effectively serve as carbon sources and that the fed-batch bioreactor cultivation strategy allowed the yields of lipopeptides to be significantly increased. In particular, the product/substrate yield of 0.09 g/g for surfactin and 0.85 mg/g for fengycin was obtained with maximum concentrations of 2.77 g/L and 27.53 mg/L after 16 h, respectively. To conclude, this study provides the successful fed-batch cultivation of B. subtilis using waste product as the carbon source to produce secondary metabolites. Therefore, the consumption of agricultural product wastes might be a promising source for producing valuable metabolites which have promising application potential to be used in several fields of biological controls of fungal diseases.
Genetic architecture underlying the expression of eight α-amylase trypsin inhibitors
(2021) El Hassouni, Khaoula; Sielaff, Malte; Curella, Valentina; Neerukonda, Manjusha; Leiser, Willmar; Würschum, Tobias; Schuppan, Detlef; Tenzer, Stefan; Longin, C. Friedrich H.
Amylase trypsin inhibitors (ATIs) are important allergens in baker’s asthma and suspected triggers of non-celiac wheat sensitivity (NCWS) inducing intestinal and extra-intestinal inflammation. As studies on the expression and genetic architecture of ATI proteins in wheat are lacking, we evaluated 149 European old and modern bread wheat cultivars grown at three different field locations for their content of eight ATI proteins. Large differences in the content and composition of ATIs in the different cultivars were identified ranging from 3.76 pmol for ATI CM2 to 80.4 pmol for ATI 0.19, with up to 2.5-fold variation in CM-type and up to sixfold variation in mono/dimeric ATIs. Generally, heritability estimates were low except for ATI 0.28 and ATI CM2. ATI protein content showed a low correlation with quality traits commonly analyzed in wheat breeding. Similarly, no trends were found regarding ATI content in wheat cultivars originating from numerous countries and decades of breeding history. Genome-wide association mapping revealed a complex genetic architecture built of many small, few medium and two major quantitative trait loci (QTL). The major QTL were located on chromosomes 3B for ATI 0.19-like and 6B for ATI 0.28, explaining 70.6 and 68.7% of the genotypic variance, respectively. Within close physical proximity to the medium and major QTL, we identified eight potential candidate genes on the wheat reference genome encoding structurally related lipid transfer proteins. Consequently, selection and breeding of wheat cultivars with low ATI protein amounts appear difficult requiring other strategies to reduce ATI content in wheat products.
Improving cover crop mixtures to increase soil carbon inputs and weed suppression as a tool to promote yield potential
(2024) Groß, Jonas; Müller, Torsten
Arable cropping systems are facing challenges imposed by climate change and are, at the same time, a tool to mitigate climate change. Soils are essential in securing yield potential and acting as a carbon sink. Recognizing small-scale site-specific differences in crop management and integrating cover crops, which provide ecosystem services such as carbon sequestration and weed suppression, are two approaches to climate-smart agriculture. To investigate site-specific soil heterogeneity, soil properties were analyzed in a field trial, measuring at three soil depths in 42 plots to determine their influence on yield measures. Soil organic carbon, silt, and clay contents in both topsoil and subsoil explained 45-46% of the variability in grain yield. Additionally, a positive correlation was found between increasing clay content in the topsoil and grain yield and tiller density. A higher clay content in the subsoil resulted in a decrease in grain yield. Soil organic carbon was identified as a soil property that positively influences yield and yield formation at any soil depth through multiple regressions and cluster analysis. Soil organic carbon is a critical soil measure that can significantly improve yield potential and can be manipulated by crop management practices like cover cropping. In a second field experiment, the impacts of increasing plant diversity of cover crop mixtures on rhizosphere carbon input and microbial utilization were investigated. A comparison was made between Mustard (Sinapis alba L.) planted as a sole crop and diversified cover crop mixtures of four (Mix4) or twelve (Mix12) species. A 13C-pulse labeling field experiment traced C transfer from shoots to roots to the soil microbial community. Mix 4 doubled the net CO2-C removal from the atmosphere, while Mix 12 more than tripled it, indicating that plant diversity positively impacts carbon cycling. This is reflected in higher atmospheric C uptake, higher transport rates to the rhizosphere, higher microbial incorporation, and longer residence time in the soil environment, improving the efficiency of C cycling in cropping systems. Root C-transfer could be identified as a fast pathway for C to reach soil C-compartments, but a substantial share of atmospheric C-catch comes from shoot biomass. In a third field experiment, the influence of species combination on shoot biomass formation was systematically assessed by investigating species interactions in dual cover crop mixtures and their competitiveness to suppress weeds before winter under different growing conditions. The shoot biomass share of a cover crop species in a dual-species mixture was found to be directly linked to its shoot biomass in a pure stand. Mustard and phacelia had similar effects on the shoot biomass production of the second species added to the mixture. Cruciferous species were more competitive against weeds than other cover crop species and could suppress weeds even when mixed with a less competitive partner. Weed suppression in mixtures with phacelia depended on the second component. Our results indicate that dual mixtures containing one competitive species reduce weed shoot biomass before winter, comparable to competitive pure stands. The research in this thesis shows that C content in the soil plays a crucial role in yield formation in arable cropping systems in Germany. Finally, the study has demonstrated that implementing cover crop mixtures can enhance soil C input and represent a valuable method for preserving yield potential. It was also shown that an intelligent combination of cover crop species can determine successful development and weed suppression.
Kunststoffabfallmanagement und Strategien für eine Kreislaufwirtschaft in der Lebensmittelindustrie
(2025) Mielinger, Ellen; Weinrich, Ramona
The increasing global volume of waste poses a threat to the environment and the climate. Limiting the amount of waste and transforming the prevailing linear systems into a circular economy is an important task of our time. Packaging waste and especially plastic food packaging, account for a large proportion of waste due to their strong frequency and short lifespan. Avoiding waste from the outset and reducing food packaging is a top priority. At the same time, however, packaging increases the shelf life and transportability of foods, which is why it is often necessary to package food. Besides the threat to the earth’s health caused by plastic waste, food waste is also a major problem. To relieve the burden on ecosystems and achieve sustainability at all levels, it is therefore fundamental to prevent food waste and increase the recycling rates for packaging waste. In addition to technical innovations and the upgrading of recycling plants, consumer behaviour and the behaviour of the food industry play a decisive role. Through correct sorting behaviour at the household level and separately collected waste higher recycling rates can be achieved. On the other hand, which packaging and packaging materials are placed on the market by the food industry is crucial for a functioning circular economy. Against this background, the dissertation Plastic waste management and strategies for a circular economy in the food industry was authored. The first part of this dissertation analyses the introduction of sustainable food packaging from a social science perspective. Cross-national expert interviews provide information on what influences decision-making in companies in the food industry concerning sustainable packaging and what role consumers play from the experts' point of view. Although packaging sustainability is important, the economic aspect prevails when trade-offs between environmental compatibility and (additional) costs occur. According to the experts, consumers do not have sufficient knowledge and interest in packaging, leading to poor purchase decisions. This hinders the establishment of sustainable packaging. Moreover, the establishment of sustainable packaging is impeded by a certain disempowerment the interviewed experts feel exposed to. As a result, the experts dismiss the responsibility for more sustainable packaging solutions and shift it onto the state and food retailers. In line with a circular economy, in addition to the design and utilisation of environmentally friendly product packaging, the handling of the packaging after the consumption of the product is also of essential importance. Therefore, the second part of this thesis deals with the waste disposal behaviour of consumers. Influencing factors of waste separation behaviour at the private household level, preferred ways of information transmission concerning recycling rules and an extended deposit system as an approach to promoting the circular economy are analysed. Apart from packaging factors such as labels, internal factors that can be directly linked back to consumers can influence plastic packaging sorting behaviour. Focus group discussions reveal that uncertainty and confusion regarding the type of material often stand in the way of correct sorting behaviour. The internet and social media in particular are preferred for the information transmission of waste separation practices. Also, external factors, such as financial incentives or the prevalent waste disposal system, can influence consumers' sorting behaviour. One type of financial incentive is, for example, a deposit paid on single-use plastic packaging. This deposit is refunded as soon as the packaging is returned. This ensures a clean material flow, which can lead to higher recycling rates. Such a deposit refund system (DRS) already exists in Germany, including single-use beverage packages. Expert interviews with various stakeholders in the German waste management industry suggest that the success of the system in use and consumers' familiarity with it speaks for extending it also onto other single-use plastic food packages. However, this would require various different legal adjustments and the cooperation of all stakeholders involved in the process. There are also a number of organisational, economic and technical challenges that might stand in the way of an extension. In addition to the ecological optimisation of food packaging and resulting packaging waste, avoiding food waste at the private household level is an important sustainability goal. Therefore, in the digression of this work, a smartphone application aiming at reducing food waste is presented. The presented prototype can help consumers to better assess the shelf life of food and reduce uncertainty. Limitations concerning the results of the work arise primarily from the qualitative, explorative research approaches. Qualitative research is used to gain detailed and in-depth insights. Due to smaller sample sizes, it is not possible to derive generalisable results.
Local and systemic metabolic adjustments to drought in maize: hydraulic redistribution in a split‐root system
(2022) Werner, Lena Maria; Hartwig, Roman Paul; Engel, Isabelle; Franzisky, Bastian Leander; Wienkoop, Stefanie; Brenner, Martin; Preiner, Julian; Repper, Dagmar; Hartung, Jens; Zörb, Christian; Wimmer, Monika Andrea
Background: It is yet unknown how maize plants respond to a partial root drying under conditions of a limited total water supply, and which adaptation mechanisms are triggered under these conditions. Aims: The aims of this study were to assess whether partial root drying results in distinguishable local and systemic physiological and metabolic drought responses, and whether compensatory water uptake and/or alteration of root architecture occurs under these conditions. Methods: Maize plants were grown in a split-root system. When plants were 20 days old, the treatments ‘well-watered’, ‘local drought’ and ‘full drought’ were established for a period of 10 days. Shoot length and gas exchange were measured non-destructively, root exudates were collected using a filter system and biomass, relative water content, osmolality and proline content were determined destructively at final harvest. Results: Local drought triggered stress responses such as reduced biomass, shoot length, relative water content and increased osmolality. Maintained root growth was systemically achieved by hydraulic redistribution rather than by altering root architecture. Local and systemic osmolyte adjustments contributed to this hydraulic redistribution. Conclusions: Both local and systemic metabolic responses helped the plants to induce hydraulic redistribution, enhance water availability and in consequence plant water relations. This resulted in a surprisingly well-maintained root growth even in the drought stressed root compartment.
Long-term breeding progress of yield, yield-related, and disease resistance traits in five cereal crops of German variety trials
(2021) Laidig, Friedrich; Feike, T.; Klocke, B.; Macholdt, J.; Miedaner, Thomas; Rentel, D.; Piepho, Hans-Peter
Plant breeding and improved crop management generated considerable progress in cereal performance over the last decades. Climate change, as well as the political and social demand for more environmentally friendly production, require ongoing breeding progress. This study quantified long-term trends for breeding progress and ageing effects of yield, yield-related traits, and disease resistance traits from German variety trials for five cereal crops with a broad spectrum of genotypes. The varieties were grown over a wide range of environmental conditions during 1988–2019 under two intensity levels, without (I1) and with (I2) fungicides and growth regulators. Breeding progress regarding yield increase was the highest in winter barley followed by winter rye hybrid and the lowest in winter rye population varieties. Yield gaps between I2 and I1 widened for barleys, while they shrank for the other crops. A notable decrease in stem stability became apparent in I1 in most crops, while for diseases generally a decrasing susceptibility was found, especially for mildew, brown rust, scald, and dwarf leaf rust. The reduction in disease susceptibility in I2 (treated) was considerably higher than in I1. Our results revealed that yield performance and disease resistance of varieties were subject to considerable ageing effects, reducing yield and increasing disease susceptibility. Nevertheless, we quantified notable achievements in breeding progress for most disease resistances. This study indicated an urgent and continues need for new improved varieties, not only to combat ageing effects and generate higher yield potential, but also to offset future reduction in plant protection intensity.
NAC transcription factors ATAF1 and ANAC055 affect the heat stress response in Arabidopsis
(2022) Alshareef, Nouf Owdah; Otterbach, Sophie L.; Allu, Annapurna Devi; Woo, Yong H.; de Werk, Tobias; Kamranfar, Iman; Mueller-Roeber, Bernd; Tester, Mark; Balazadeh, Salma; Schmöckel, Sandra M.; Alshareef, Nouf Owdah; Division of Biological and Environmental Sciences and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia; Otterbach, Sophie L.; Department Physiology of Yield Stability, Institute of Crop Science, University of Hohenheim, Stuttgart, Germany; Allu, Annapurna Devi; Department of Biology, Indian Institute of Science Education and Research (IISER), Tirupati, India; Woo, Yong H.; Division of Biological and Environmental Sciences and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia; de Werk, Tobias; Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany; Kamranfar, Iman; Institute of Biochemistry and Biology, University of Potsdam, Potsdam‐Golm, Germany; Mueller-Roeber, Bernd; Center of Plant Systems Biology and Biotechnology (CPSBB), Plovdiv, Bulgaria; Tester, Mark; Division of Biological and Environmental Sciences and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia; Balazadeh, Salma; Institute of Biology, Leiden University, Leiden, The Netherlands; Schmöckel, Sandra M.; Department Physiology of Yield Stability, Institute of Crop Science, University of Hohenheim, Stuttgart, Germany
Pre-exposing (priming) plants to mild, non-lethal elevated temperature improves their tolerance to a later higher-temperature stress (triggering stimulus), which is of great ecological importance. ‘Thermomemory’ is maintaining this tolerance for an extended period of time. NAM/ATAF1/2/CUC2 (NAC) proteins are plant-specific transcription factors (TFs) that modulate responses to abiotic stresses, including heat stress (HS). Here, we investigated the potential role of NACs for thermomemory. We determined the expression of 104 Arabidopsis NAC genes after priming and triggering heat stimuli, and found ATAF1 expression is strongly induced right after priming and declines below control levels thereafter during thermorecovery. Knockout mutants of ATAF1 show better thermomemory than wild type, revealing a negative regulatory role. Differential expression analyses of RNA-seq data from ATAF1 overexpressor, ataf1 mutant and wild-type plants after heat priming revealed five genes that might be priming-associated direct targets of ATAF1: AT2G31260 (ATG9), AT2G41640 (GT61), AT3G44990 (XTH31), AT4G27720 and AT3G23540. Based on co-expression analyses applied to the aforementioned RNA-seq profiles, we identified ANAC055 to be transcriptionally co-regulated with ATAF1. Like ataf1, anac055 mutants show improved thermomemory, revealing a potential co-control of both NAC TFs over thermomemory. Our data reveals a core importance of two NAC transcription factors, ATAF1 and ANAC055, for thermomemory.
Quantifying patch‐specific seed dispersal and local population dynamics to estimate population spread of an endangered plant species
(2021) Zhu, Jinlei; Hrušková, Karolína; Pánková, Hana; Münzbergová, Zuzana
Aim: Habitat loss and fragmentation impose high extinction risk upon endangered plant species globally. For many endangered plant species, as the remnant habitats become smaller and more fragmented, it is vital to estimate the population spread rate of small patches in order to effectively manage and preserve them for potential future range expansion. However, population spread rate has rarely been quantified at the patch level to inform conservation strategies and management decisions. To close this gap, we quantify the patch-specific seed dispersal and local population dynamics of Minuartia smejkalii, which is a critically endangered plant species endemic in the Czech Republic and is of urgent conservation concern. Location: Želivka and Hrnčíře, Czechia. Methods: We conducted demographic analyses using population projection matrices with long-term demographic data and used an analytic mechanistic dispersal model to simulate seed dispersal. We then used information on local population dynamics and seed dispersal to estimate the population spread rate and compared the relative contributions of seed dispersal and population growth rate to the population spread rate. Results: We found that although both seed dispersal and population growth rate in M. smejkalii were critically limited, the population spread rate depended more strongly on the maximal dispersal distance than on the population growth rate. Main conclusions: We recommend conservationists to largely increase the dispersal distance of M. smejkalii. Generally, efforts made to increase seed dispersal ability could largely raise efficiency and effectiveness of conservation actions for critically endangered plant species.

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