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- ItemDirect nitrous oxide emissions from oilseed rape cropping – a meta-analysis(Milton Park : Taylor & Francis, 2014) Walter, Katja; Don, Axel; Fuß, Roland; Kern, Jürgen; Drewer, Julia; Flessa, HeinzOilseed rape is one of the leading feedstocks for biofuel production in Europe. The climate change mitigation effect of rape methyl ester (RME) is particularly challenged by the greenhouse gas (GHG) emissions during crop production, mainly as nitrous oxide (N2O) from soils. Oilseed rape requires high nitrogen fertilization and crop residues are rich in nitrogen, both potentially causing enhanced N2O emissions. However, GHG emissions of oilseed rape production are often estimated using emission factors that account for crop-type specifics only with respect to crop residues. This meta-analysis therefore aimed to assess annual N2O emissions from winter oilseed rape, to compare them to those of cereals and to explore the underlying reasons for differences. For the identification of the most important factors, linear mixed effects models were fitted with 43 N2O emission data points deriving from 12 different field sites. N2O emissions increased exponentially with N-fertilization rates, but interyear and site-specific variability were high and climate variables or soil parameters did not improve the prediction model. Annual N2O emissions from winter oilseed rape were 22% higher than those from winter cereals fertilized at the same rate. At a common fertilization rate of 200 kg N ha−1 yr−1, the mean fraction of fertilizer N that was lost as N2O-N was 1.27% for oilseed rape compared to 1.04% for cereals. The risk of high yield-scaled N2O emissions increased after a critical N surplus of about 80 kg N ha−1 yr−1. The difference in N2O emissions between oilseed rape and cereal cultivation was especially high after harvest due to the high N contents in oilseed rape's crop residues. However, annual N2O emissions of winter oilseed rape were still lower than predicted by the Stehfest and Bouwman model. Hence, the assignment of oilseed rape to the crop-type classes of cereals or other crops should be reconsidered.
- ItemWater footprint analysis for the assessment of milk production in Brandenburg (Germany)(München : European Geopyhsical Union, 2010) Drastig, K.; Prochnow, A.; Kraatz, S.; Klauss, H.; Plöchl, M.The working group "Adaptation to Climate Change" at the Leibniz-Institute for Agricultural Engineering Potsdam-Bornim (ATB) is introduced. This group calculates the water footprint for agricultural processes and farms, distinguished into green water footprint, blue water footprint, and dilution water footprint. The green and blue water demand of a dairy farm plays a pivotal role in the regional water balance. Considering already existing and forthcoming climate change effects there is a need to determine the water cycle in the field and in housing for process chain optimisation for the adaptation to an expected increasing water scarcity. Resulting investments to boost water productivity and to improve water use efficiency in milk production are two pathways to adapt to climate change effects. In this paper the calculation of blue water demand for dairy farming in Brandenburg (Germany) is presented. The water used for feeding, milk processing, and servicing of cows over the time period of ten years was assessed in our study. The preliminary results of the calculation of the direct blue water footprint shows a decreasing water demand in the dairy production from the year 1999 with 5.98×109 L/yr to a water demand of 5.00×109 L/yr in the year 2008 in Brandenburg because of decreasing animal numbers and an improved average milk yield per cow. Improved feeding practices and shifted breeding to greater-volume producing Holstein-Friesian cow allow the production of milk in a more water sustainable way. The mean blue water consumption for the production of 1 kg milk in the time period between 1999 to 2008 was 3.94±0.29 L. The main part of the consumed water seems to stem from indirect used green water for the production of feed for the cows.
- ItemNeues Prinzip eines Mähhackers für Kurzumtriebsplantagen(Darmstadt : KTBL, 2012) Ehlert, Detlef; Pecenka, Ralf; Wiehe, JensGegenwärtig auf dem Markt verfügbare Mähhacker für Kurzumtriebsplantagen (KUPs) auf Basis von Feldhäckslern haben Nachteile hinsichtlich der Maschinenmasse und der hohen Investitionskosten. Traktorgebundene Geräte sind bisher nur begrenzt leistungsfähig. Um einen Beitrag zur Erweiterung des Angebots kostengünstiger Erntetechnik zu leisten, wurde ein neuartiges Prinzip eines traktorbasierten Mähhackers für einreihige KUPs entwickelt, der sich durch einen einfachen Aufbau und ein breites Einsatzspektrum auszeichnet.
- ItemStrategy for the development of a smart NDVI camera system for outdoor plant detection and agricultural embedded systems(Basel : MDPI, 2013) Dworak, Volker; Selbeck, Joern; Dammer, Karl-Heinz; Hoffmann, Matthias; Zarezadeh, Ali Akbar; Bobda, ChristopheThe application of (smart) cameras for process control, mapping, and advanced imaging in agriculture has become an element of precision farming that facilitates the conservation of fertilizer, pesticides, and machine time. This technique additionally reduces the amount of energy required in terms of fuel. Although research activities have increased in this field, high camera prices reflect low adaptation to applications in all fields of agriculture. Smart, low-cost cameras adapted for agricultural applications can overcome this drawback. The normalized difference vegetation index (NDVI) for each image pixel is an applicable algorithm to discriminate plant information from the soil background enabled by a large difference in the reflectance between the near infrared (NIR) and the red channel optical frequency band. Two aligned charge coupled device (CCD) chips for the red and NIR channel are typically used, but they are expensive because of the precise optical alignment required. Therefore, much attention has been given to the development of alternative camera designs. In this study, the advantage of a smart one-chip camera design with NDVI image performance is demonstrated in terms of low cost and simplified design. The required assembly and pixel modifications are described, and new algorithms for establishing an enhanced NDVI image quality for data processing are discussed.
- ItemRecovery and techno-functionality of flours and proteins from two edible insect species: Meal worm (Tenebrio molitor) and black soldier fly (Hermetia illucens) larvae(Amsterdam : Elsevier, 2016) Bußler, Sara; Rumpold, Birgit A.; Jander, Elisabeth; Rawel, Harshadrai M.; Schlüter, Oliver K.Depending on the species, edible insects are highly nutritious and thus represent a noteworthy alternative food and feed source. The current work investigates the protein extractability and techno-functionality of insect flour fractions recovered from Tenebrio molitor and Hermetia illucens. T. molitor and H. illucens flours contained about 20% crude fat and 60% and 36 % crude protein, respectively. Defatting reduced the crude fat content to 2.8% (T. molitor) and 8.8% (H. illucens) and increased the crude protein content to 68% and 47%, respectively. To isolate proteins from the flours, protein solubility was optimized by varying the pH, the ionic strength, and the extraction temperature of the solvent. All products and by-products accumulated in the protein production process were characterized by composition, selected techno-functional properties, protein solubility, composition and structure as well as their microbial load.
- ItemImpact of different water activities (aw) adjusted by solutes on high pressure high temperature inactivation of Bacillus amyloliquefaciens spores(Lausanne : Frontiers Media, 2015) Sevenich, Robert; Reineke, Kai; Hecht, Philipp; Fröhling, Antje; Rauh, Cornelia; Schlüter, Oliver; Knorr, DietrichMuch research has been conducted to comprehend the mechanisms of high pressure (HP) inactivation of spores in aqueous systems but for food model systems these information are scarce. In these systems spores can interact with ingredients which then could possibly lead to retarded or reduced inactivation, which can cause a problem for the sterilization process. The protective mechanism of a reduced aw-value is still unclear. HP processing might prove valuable to overcome protective effects of solutes and achieve shorter process times for sterilization under HP. To gain insight into the underlying mechanisms five aw-values (0.9, 0.92, 0.94, 0.96, 1) were adjusted with two different solutes (NaCl, sucrose). Solutions were inoculated with spores of Bacillus amyloliquefaciens and treated at 105, 110, and 115°C at 600 MPa. Further a thermal inactivation was conducted at the same temperatures for a comparison with the HP data. Afterward, the influence of HP high temperature treatment on the inactivation, the dipicolinic acid (DPA)-release and membrane constitution was assessed by plate count, HPLC and flow cytometry (FCM). The results show that during HP treatments sucrose and salt both have a protective effect, in which the influence of sucrose on the retarded inactivation is higher. The threshold water activities (aw), which is 0.94, here salt and sucrose have a significant influence on the inactivation. The comparison of thermal (105–115°C) and HP and high temperature (600 MPa, 105–115°C) treated samples showed that the time needed to achieve a 4–5 log10 inactivation is reduced from 45 (aw = 1) to 75 (aw = 0.9) min at 105°C to 3 (aw = 1) to 15 (aw = 0.9) minutes at 600 MPa and 105°C. The release of DPA is the rate limiting step of the inactivation and therefore monitoring the release is of great interest. The DPA-release is slowed down in high concentrated solutions (e.g., sucrose, salt) in comparison to aw 1. Since there is a difference in the way the solutes protect the spore it could be seen as an inner spore membrane effect. Maybe as shown for vegetative microorganism the solutes can interact with membranes, e.g., the inner spore membrane. Flow cytometry (FCM) measurement data show a similar trend.
- ItemA computational model for path loss in wireless sensor networks in orchard environments(Basel : MDPI, 2014) Anastassiu, Hristos T.; Vougioukas, Stavros; Fronimos, Theodoros; Regen, Christian; Petrou, Loukas; Zude, Manuela; Käthner, JanaA computational model for radio wave propagation through tree orchards is presented. Trees are modeled as collections of branches, geometrically approximated by cylinders, whose dimensions are determined on the basis of measurements in a cherry orchard. Tree canopies are modeled as dielectric spheres of appropriate size. A single row of trees was modeled by creating copies of a representative tree model positioned on top of a rectangular, lossy dielectric slab that simulated the ground. The complete scattering model, including soil and trees, enhanced by periodicity conditions corresponding to the array, was characterized via a commercial computational software tool for simulating the wave propagation by means of the Finite Element Method. The attenuation of the simulated signal was compared to measurements taken in the cherry orchard, using two ZigBee receiver-transmitter modules. Near the top of the tree canopies (at 3 m), the predicted attenuation was close to the measured one—just slightly underestimated. However, at 1.5 m the solver underestimated the measured attenuation significantly, especially when leaves were present and, as distances grew longer. This suggests that the effects of scattering from neighboring tree rows need to be incorporated into the model. However, complex geometries result in ill conditioned linear systems that affect the solver’s convergence.
- ItemAwassi sheep keeping in the Arabic steppe in relation to nitrous oxide emission from soil(Amsterdam : Elsevier, 2013) Hijazi, Omar; Berg, Werner; Moussa, Samouil; Ammon, Christian; von Bobrutzki, Kristina; Brunsch, ReinerSheep husbandry is the main source of income for farmers in arid zones. Increasing sheep production on steppes may increase the greenhouse gas production. The objective of this study was to investigate the nitrous oxide (N2O) emissions from the steppes for Awassi sheep keeping and feed cropping in arid zones such as Syria. The methodology developed by the Intergovernmental Panel on Climate Change (IPCC) was used to estimate N2O emissions. A survey was conducted on 64 farms in Syria to gather data for analysis. Precipitation and crop yield data from 2001 to 2009 were also used for calculation and modelling. Sheep-keeping systems, precipitation, year and the region have significant effects on N2O emissions (p<0.05). Emissions of N2O from lands with extensive, semi-intensive and intensive systems were 0.30 ± 0.093, 0.598± 0.113 and 2.243± 0.187 kg sheep1year1, respectively. Crop production was higher in regions with high precipitation levels, which helped to reduce N2O emissions. Using more residuals of wheat, cotton and soya as feed for sheep in the keeping systems evaluated may decrease the overuse of steppe regions and N2O emissions. Nitrous oxide emissions of N2O from sheep-keeping areas can be reduced by changing sheep-keeping systems and increasing the crop production in arid zones through artificial irrigation.
- ItemHigh pressure thermal inactivation of Clostridium botulinum type E endospores – kinetic modeling and mechanistic insights(Lausanne : Frontiers Media, 2015) Lenz, Christian A.; Reineke, Kai; Knorr, Dietrich; Vogel, Rudi F.Cold-tolerant, neurotoxigenic, endospore forming Clostridium (C.) botulinum type E belongs to the non-proteolytic physiological C. botulinum group II, is primarily associated with aquatic environments, and presents a safety risk for seafood. High pressure thermal (HPT) processing exploiting the synergistic effect of pressure and temperature can be used to inactivate bacterial endospores. We investigated the inactivation of C. botulinum type E spores by (near) isothermal HPT treatments at 300–1200 MPa at 30–75°C for 1 s to 10 min. The occurrence of heat and lysozyme susceptible spore fractions after such treatments was determined. The experimental data were modeled to obtain kinetic parameters and represented graphically by isoeffect lines. In contrast to findings for spores of other species and within the range of treatment parameters applied, zones of spore stabilization (lower inactivation than heat treatments alone), large heat susceptible (HPT-induced germinated) or lysozyme-dependently germinable (damaged coat layer) spore fractions were not detected. Inactivation followed first order kinetics. Dipicolinic acid release kinetics allowed for insights into possible inactivation mechanisms suggesting a (poorly effective) physiologic-like (similar to nutrient-induced) germination at ≤450 MPa/≤45°C and non-physiological germination at >500 MPa/>60–70°C. Results of this study support the existence of some commonalities in the HPT inactivation mechanism of C. botulinum type E spores and Bacillus spores although both organisms have significantly different HPT resistance properties. The information presented here contributes to closing the gap in knowledge regarding the HPT inactivation of spore formers relevant to food safety and may help industrial implementation of HPT processing. The markedly lower HPT resistance of C. botulinum type E spores compared with the resistance of spores from other C. botulinum types could allow for the implementation of milder processes without endangering food safety.
- ItemSchnelle Identifizierung von Mikroorganismen mittels MALDI-TOF MS(Darmstadt : KTBL, 2015) Fröhling, Antje; Erhard, Marcel; Muranyi, Peter; Schlüter, OliverSichere Lebensmittel von hoher Qualität stellen besonders bei leicht verderblichen Frischeprodukten eine Herausforderung für die Gestaltung der Nacherntekette dar. Da die Beprobung von Lebensmittelchargen in der Praxis meist anhand ausgewählter Indikatororganismen erfolgt, bleiben unerwartete, potenziell gefährliche Mikroorganismen häufig unentdeckt. Die Detektion dieser Bakterien ist jedoch von Interesse, um potenzielle Gefahren für den Verbraucher zu vermeiden. Am Beispiel von Mungobohnensprossen wurde die mikrobielle Diversität mittels Plattenzählverfahren und MALDI-TOF MS (matrix-assisted laser desorption/ionisation – time of flight mass spectrometry) ermittelt. Bei einer Gesamtkeimzahl zwischen 8 und 9 log KbE/g Sprossen konnten unter anderem Bakterien der Bacillus cereus Gruppe, Yersinia sp., Enterobacter spp., Klebsiella spp., Pantoea spp. und Pseudomonas spp. identifiziert werden.