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The objective of this review is a global assessment of the economics of second‐generation biorefineries, with a focus on the use of food waste and agricultural residues for chemical production by applying biotechnological processes. Analyses are conducted on feedstock and product distribution, applied economic models, and profitability figures for the period 2013–2018. In a study of 163 articles on different biorefinery systems, the production of chemicals is identified as the second major product class, after bioenergy. Bagasse and straw are frequently analyzed second‐generation feedstocks. Based on the evaluation of 22 articles, second‐generation biorefineries producing chemicals by applying biotechnological processes proves to be economically feasible. On average, both the internal rate of return (IRR) and the return on investment (ROI) are 20% and the payback period (PP) is 6 years. The cost share of feedstock in biorefineries is between 0–50%. The price of the end product and the fermentation yields have the most impact on profitability. The processing of food waste that has industrial and municipal origins appears more economical than the processing of agricultural residues. Scientists, policy makers and entrepreneurs with an appropriate risk tolerance are advised to pay particular attention to municipal food waste and the potential economic production of carboxylic acids. For various economic issues related to biorefineries, dynamic‐deterministic models are recommended, which can be extended by a stochastic model. This review provides an initial overview of the economic feasibility of second‐generation biorefineries. Further techno‐economic analyses are required to produce statistically significant statements on key profitability figures. © 2020 The Authors. Biofuels, Bioproducts, and Biorefining published by Society of Chemical Industry and John Wiley & Sons, Ltd.
Organic pot-based production of basil (Ocimum basilicum L.) often has lower biomass yield than conventional cultivation. Previous investigations indicate that this growth impairment is related to high ammonium (NH4+) concentrations in the growing media released by the mineralization of organic nitrogen (N) fertilizers. However, as a result of this ammonification process substrate pH may also increase. Under neutral to alkaline conditions NH4+ is converted to ammonia (NH3), which is known to be phytotoxic even at low concentrations. Therefore, we investigated the impact of both ammonical N species on basil grown in a peat substrate. In total, three fertilization pot experiments were conducted in a greenhouse in order to compare the effect of different organic base dressings [250 and 750 mg N (L substrate)-1 mainly supplied by a liquid amino acid fertilizer (AAF)] and two initial substrate pH levels (5.5 and 6.5). In two treatments, 5% (v/v) mature compost was mixed into the peat 1 day and 12–days before the substrate was used for sowing, respectively. The aim of this procedure was to stimulate nitrification in this way to reduce ammonical N concentration. Ammonia concentration in the aerial plant surrounding environment was measured by using NH3 detector tubes in combination with an open-top chamber method. The results showed that the growth of basil (number of plants, fresh matter yield, plant height) was significantly inhibited in the second and third week of cultivation by rising NH3 and NH4+ exposure, as well as by a substrate pH ≥ 7.0. These adverse effects were reduced by lowering the organic base dressing rate and adjusting the initial substrate pH to 5.5. Furthermore, the addition of mature compost to peat in combination with a 12-day storage was proven to be effective for promoting nitrification in the organically fertilized substrate. As a result, plant growth was improved by both lower NH3 and NH4+ exposure as well as a faster supply of nitrate (NO3-) as an additional N source. Using this approach, it was possible to feed organically fertilized basil right from the seedling stage with a NO3--N/NH4+-N-balanced and later on providing a predominant NO3--N supply.
Um die Milchviehhaltung gibt es seit einigen Jahren auch eine öffentliche Tierwohldiskussion. Zwei Aspekte sind dabei immer wieder Gegenstand der Debatte: Die Anbindehaltung und der Weidegang. Auf Basis von qualitativen Interviews mit zivilgesellschaftlichen Verbänden und landwirtschaftlichen Verbänden zum Thema Tierwohl in der Milchviehwirtschaft wurden die Einstellungen und die Argumentationsmuster beider Verbandsgruppen zu den Haltungsformen Weidegang und Anbindehaltung ergründet. Von Interesse ist dieser Vergleich, da im Rahmen öffentlich-medialer Kommunikation die Diskussionsfronten zwischen beiden Verbandsgruppen als verhärtet dargestellt werden. Die Analyse der Aussagen der qualitativen Interviewreihe dieser Studie erlaubt die begründete Annahme, dass beide Verbandsgruppen mit den Themenkomplexen Anbindehaltung und Weidehaltung in einem wissenschaftlich orientierten Kommunikationskontext differenziert umgehen. Eine klare Polarisierung der Einstellungen zwischen beiden Verbandsgruppen war im Rahmen dieser Gesprächsformen nicht wahrnehmbar.
Bilder, die hängen bleiben. Wie lassen sich transdisziplinäre Transformationsprozesse gestalten?
(2020)
Ecological restoration of an urban demolition site through introduction of native forb species
(2020)
Urban brownfields can provide habitats for endangered native plant species but may also support invasive non native species. The aim of our study was to develop and test different measures for the ecological restoration of an urban brownfield. We aimed to enhance native plant species richness by seeding two native forb seed mix tures containing 25 (HD-mixture) and 13 species (LD-mixture), respectively, without affecting spontaneously colonizing plant species of nature conservation value. Additionally, we tested the effects of species introduction and mowing on the establishment of invasive non-native plant species, woody species development, and per ennial grass dominance.
With establishment rates of 84% (HD) and 92% (LD) in the first study year and about 60% for both seed mixtures in the fourth year, species introduction was successful and led to rapid re-vegetation of the formerly bare brownfield. Although seeding did not result in increased species richness using either seed mixture, the dominance of perennial grasses was significantly reduced by the establishment of forb species from the HD mixture. Overall, we observed the spontaneous establishment of ten plant species of conservation value; seeding affected these species only temporarily, in the second year. Seeding (with either seed mixture) and mowing both resulted in reduced cover of woody species and a lower frequency of the invasive non-native Robinia pseudoa cacia.
Our study demonstrated the high nature conservation value of dry and nutrient-poor urban brownfields for spontaneously occurring threatened plant species. Further studies have to evaluate if the reduced cover of grasses and woody species through introduction of site-specific native forb species might increase these sites’ aesthetic value and broader acceptance of brownfields by urban residents.
Injection of slurry or digestate below maize seeds is a relatively new technique developed to improve nitrogen use efficiency. However, this practice has the major drawback of increasing nitrous oxide (N2O) emissions. The application of a nitrification inhibitor (NI) is an effective method to reduce these emissions. To evaluate the effect of the NI 3,4‐dimethypyrazole phosphate (DMPP) on N2O emissions and the stabilization of ammonium, a two‐factorial soil‐column experiment was conducted. PVC pipes (20 cm diameter and 30 cm length) were used as incubation vessels for the soil‐columns. The trial consisted of four treatments in a randomized block design with four replications: slurry injection, slurry injection + DMPP, digestate injection, and digestate injection + DMPP. During the 47‐day incubation period, N2O fluxes were measured twice a week and cumulated by linear interpolation of the gas‐fluxes of consecutive measurement dates. After completion of the gas flux measurement, concentration of ammonium and nitrate within the soil‐columns was determined. DMPP delayed the conversion of ammonium within the manure injection zone significantly. This effect was considerably more pronounced in treatment digestate + NI than in treatment slurry + NI. Regarding the cumulated N2O emissions, no difference between slurry and digestate treatments was determined. DMPP reduced the release of N2O significantly. Transferring the results into practice, the use of DMPP is a promising way to reduce greenhouse gas emissions and nitrate leaching, following the injection of slurry or digestate.
The aim of the study was to examine different pH parameters, such as variations throughout the day, depending on differing concentrate feed proportions. Moreover, special attention was payed to individual variation in microbial efficiencies (microbial crude protein/fermented organic matter) and their relation to ruminal pH, nutrient flows and digestibilities. For this, cows were grouped according to microbial efficiency (more, n = 5, vs. less efficient cows, n = 4). After calving, thirteen ruminally cannulated pluriparous cows, including nine duodenally cannulated animals, were divided into groups offered rations with a lower (35% on dry matter basis, n = 7) or a higher (60% on dry matter basis, n = 6) concentrate feed proportion. Ruminal pH parameters were assessed continuously by using intraruminal probes. Nutrient flows, nutrient digestibility and microbial efficiency were determined for duodenally cannulated cows. For most ruminal pH parameters it seemed that individual variability was higher than the treatment effect. However, a positive relationship between actual concentrate intake and diurnal pH fluctuations was found. Besides, the effect of individually different microbial efficiencies was assessed. Again, there were no group differences for pH parameters. However, nutrient flows were significantly higher in more efficient cows, whereas digestibilities were lower in in more efficient cows.
Establishment of calcareous grassland on ex-arable fields by introducing target species is one of the most frequently used methods to restore the species assemblages of this highly endangered habitat type. The present study evaluates the long-term success of calcareous grassland restoration on former arable land in the vicinity of one of the oldest nature reserves in Bavaria, the “Garchinger Heide”. The restoration experiment combined different measures like topsoil removal, transfer of freshly cut seed-containing hay and additional sowing to the following variants in a 21-year experiment: (1) No topsoil removal, no hay transfer (control), (2) no topsoil removal with immediate hay transfer, (3) topsoil removal with immediate hay transfer and (4) topsoil removal with hay transfer 10 years after the start of restoration. Eleven Red List species which had not been transferred successfully were additionally sown after 9 to 19 years. Due to a limited availability of seeds, sowing of these species was mainly restricted to areas with topsoil removal, where better establishment was expected due to low vegetation cover. Five rare species with abundant seed production were also sown to plots without topsoil removal and hay transfer. The nature reserve served both as the donor area of the target species and as the reference to evaluate restoration success. Regarding aboveground biomass and total vegetation cover, greatest similarity to the donor site was observed on plots without topsoil removal. In contrast, the highest numbers of target species occurred on plots with topsoil removal, hay transfer and additional sowing. Similarity in species composition between restoration sites and the reference area increased over time, but species composition of restored sites did not fully reflect the reference after 21 years. One reason for the remaining dissimilarity was probably that topsoil removal favored stress tolerant species which were less common on the mature and more fine-grained soils of the nature reserve. Plots without topsoil removal still differed from the reference by their high vegetation cover and a significantly higher proportion of mesophytic grassland species. The study also showed that 19 Red List species were successfully established on the former arable fields, eight of them presumably by sowing. Nevertheless, various other rare species have not been observed yet. Results on functional traits characterizing environmental adaptation and reproduction also underlined the differences between restoration plots and the reference site. Our study presents a ʽdynamic restoration approachʼ where managers evaluated the original factorial treatments after a decade and modified them by additional treatments where development was sub-optimal. Such additional treatments may have confounded the experimental design, but from a management perspective proved to be a promising option to establish species rich grassland of high conservation value with a reasonable expenditure of time.
Gebäude beanspruchen Ressourcen und verändern die Umwelt. Die Landwirtschaft benötigt oftmals großvolumige Gebäude. Eine nachhaltigere landwirtschaftliche Baukultur wäre deshalb begrüßenswert. Für das agrarische Bauen könnte eine verstärkte Verwendung des Rohstoffs Holz eine Perspektive darstellen. Holz überzeugt durch zahlreiche ökologische Vorteile wie die langfristige Kohlenstoffbindung oder eine einfache Recycelbarkeit. In Deutschland spielt Holz beim landwirtschaftlichen Bauen allerdings eine immer geringere Rolle. Diese Studie stellt Meinungsbilder deutscher LandwirtInnen zum Holzeinsatz beim Stallbau zusammen. Es wurden zehn Gruppendiskussionen zum Themenfeld landwirtschaftliche Baukultur in verschiedenen deutschen Schwerpunktregionen der Rinderhaltung gestaltet. Die Auswertungen zeigen, dass die LandwirtInnen weitestgehend die optische Wirkung von Holz schätzen, aber häufig an der Dauerhaftigkeit von Holzställen zweifeln.
Extensive green roofs (EGRs) offer several beneficial ecosystem services for sustainable urban development. However, most standard green roofs have been designed with species-poor plant mixtures containing non-native species. Aiming to increase the nature conservation values of EGRs, we developed and tested a vascular plant seed mixture including regionally occurring native sandy dry grassland species in experimental miniature roofs in Northwestern Germany (temperate oceanic climate) over 4 years. We tested the mixture at two seed densities (1 and 2 g/m2). Additionally, we tested seeding at 1 g/m2 and introducing raked plant material collected from an ancient dry grassland. The total establishment rates of sown species reached 92–96% in the first year, but dropped to 40–60% in the last 2 years, with the highest values for the plots with raked material. Twenty-four additional species (11 vascular, 7 lichen, and 6 moss species, including 7 red-list species) typical of sandy dry grasslands were introduced through the raked material. Vascular plants reached 60–70% cover in the second year. Severe drought periods in the third and the fourth year led to a strong decline of vascular plant cover then. As this cover was higher in the plots with raked material, we assume facilitative effects through the well-developed cryptogam layer containing a mix of pleurocarpous and acrocarpous mosses and lichens. Spontaneously establishing acrocarpous mosses in sown plots did not seem to provide this same function. We conclude that EGRs designed with regionally occurring sandy dry grassland plant species and especially the application of raked plant material from ancient grassland is a fruitful approach to increase the value of green roofs for native phytodiversity.
Quantitative Umweltbewertungen sind von entscheidender Bedeutung, wenn es darum geht, effektiv auf nachhaltige Produktions- und Verbrauchsmuster hinzuarbeiten. In den letzten Jahrzehnten haben sich Lebenszyklusanalysen (LCA) als praktikables Mittel zur Messung der Umweltauswirkungen von Produkten entlang der Lieferkette etabliert. In Bezug auf Nutzer- und Konsummuster wurden jedoch methodische Schwächen festgestellt, und es wurden mehrere Versuche unternommen, Ökobilanzen entsprechend zu verbessern, beispielsweise durch Einbeziehung von Effekten höherer Ordnung und verhaltenswissenschaftlicher Unterstützung. In einer Diskussion solcher Ansätze zeigen wir, dass den Konzepten des Verbrauchs keine explizite Aufmerksamkeit geschenkt wurde, was häufig zu produktzentrierten Bewertungen führt. Wir führen Theorien sozialer Praktiken ein, um Konsummuster für LCA zugänglich zu machen. Soziale Praktiken sind routinierte Handlungen, die aus miteinander verbundenen Elementen (Materialien, Kompetenzen und Bedeutungen) bestehen, die sie als eine Einheit denkbar machen (z. B. Kochen). Da die meisten sozialen Praktiken eine Art von Verbrauch (Material, Energie, Luft) beinhalten, konnten wir einen Rahmen entwickeln, der soziale Praktiken mit der Ökobilanz verbindet. Der vorgeschlagene Rahmen bietet eine neue Perspektive für quantitative Umweltbewertungen, indem er den Schwerpunkt von Produkten oder Nutzern auf soziale Praktiken verlagert. Dementsprechend sehen wir die Chance darin, die reduktionistische Sichtweise zu überwinden, dass Menschen nur Nutzer von Produkten sind, und sie stattdessen als Praktiker in sozialen Praktiken zu sehen. Dieser Wandel könnte neue Methoden der interdisziplinären Konsumforschung ermöglichen, die beabsichtigte Sozialwissenschaften und wirkungsorientierte Bewertungen einbeziehen. Allerdings bedarf der Rahmen einer weiteren Überarbeitung und vor allem einer empirischen Validierung.
Using eye-tracking, this study investigates fixation duration of students viewing pictures of pigs, which systematically vary in the facial expression of the pig and in the barn setting. The aim of this study is to analyze which picture elements are viewed and for how long, as well as how fixation times vary with a change of the expression of the pig and the barn type. The results show clear effects of picture composition: pig expression and pen type affect fixation durations of different areas of interest with the influence of the pig being considerably larger. Face regions are viewed longer in the “happy” pig, while floor/bedding and the eyes are viewed longer in pictures showing the “unhappy” pig which might be a hint for infor-mation search. The power of facial expressions, also for the depiction of farm animals, is a new finding of this paper, which might be of importance when select-ing agricultural pictures for different purposes.
Biofortified apples seem to be a suitable produce. In this study, different selenium forms and application levels were applied to the two apple varieties ‘Golden Delicious’ and ‘Jonagold’, grown in the years 2017 and 2018 in order to increase the selenium uptake within a typical Western diet. It was shown that the biofortification, which was performed as a foliar application implemented in usual calcium fertilization, led to significantly increased selenium contents in the fruits. Furthermore, biofortification affected the total phenolic content (TPC), the polyphenol oxidase activity (PPO), as well as the antioxidant activity (AOA), the latter measured with the two well-known assays Trolox Equivalent Antioxidant Capacity Assay (TEAC) and Oxygen Radical Absorbance Capacity Assays (ORAC). The varying selenium forms and application levels showed a differing influence on the parameters mentioned before. Higher fertilizer levels resulted in higher selenium accumulation. It was found that PPO activity fluctuates less in biofortified apples. With regard to TPC, selenate led to higher amounts when compared to the untreated controls and selenite resulted in lower TPC. AOA analysis showed no clear tendencies as a result of the selenium biofortification. In the case of ‘Jonagold’, a higher AOA was generally measured when being biofortified, whereas, in the case of ‘Golden Delicious’, only one form of application led to higher AOA. Additionally, differences in the amount of major phenolic compounds, measured with High Performance Liquid Chromatography Mass Spectrometry (HPLC-DAD-ESI-MSn), were observed, depending on the conditions of the biofortification and the variety.
Background and Aims: Agronomic biofortification of food crops with iodine may improve the dietary intake of this trace element, which is essential for human development and health. So far, little is known about the suitability of this technique in pome fruits. The objectives of this study were (1) to investigate uptake and translocation of exogenously applied iodine in apple trees, (2) to identify possible strategies of iodine biofortification for this type of fruit, and (3) to evaluate interactions between foliar applied iodine and selenium.
Methods: Apple trees were cultivated in a plastic tunnel for two growing seasons. Iodine was applied via leaves or substrate. During the 2nd year, simultaneous foliar application of iodine and selenium were tested as well. At harvest time, iodine and selenium content in leaves and fruits were determined. The phytoavailable iodine concentration in the growing medium was analyzed following an extraction with calcium chloride. In addition, the dynamics of iodine applied as potassium iodide and iodate in a peat‐based substrate was investigated in an incubation experiment without plants.
Results: The iodine concentration in washed apples increased more than 100‐fold, valuing around 50 µg (100 g FM)−1 by foliar application of iodine as compared to the control treatment. However, this level was only achieved in fruits which were directly wetted by the spray solution. The translocation of leaf‐absorbed iodine to fruits was negligible. Following a substrate fertilization, the fruit iodine content remained rather low due to a strong retention of iodine in the growing medium. When using foliar sprays, the addition of selenium did not affect the iodine enrichment of the apple fruits.
Conclusions: Foliar fertilization of iodine seems to be a promising method to biofortify apples with iodine. The level of I achieved in apple fruits by means of foliar fertilization can significantly contribute to the daily I intake requirement of humans.