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- ItemDNA and RNA extraction and quantitative real-time PCR-based assays for biogas biocenoses in an interlaboratory comparison(Basel : MDPI, 2016) Lebuhn, Michael; Derenkó, Jaqueline; Rademacher, Antje; Helbig, Susanne; Munk, Bernhard; Pechtl, Alexander; Stolze, Yvonne; Prowe, Steffen; Schwarz, Wolfgang H.; Schlüter, Andreas; Liebl, Wolfgang; Klocke, MichaelFive institutional partners participated in an interlaboratory comparison of nucleic acid extraction, RNA preservation and quantitative Real-Time PCR (qPCR) based assays for biogas biocenoses derived from different grass silage digesting laboratory and pilot scale fermenters. A kit format DNA extraction system based on physical and chemical lysis with excellent extraction efficiency yielded highly reproducible results among the partners and clearly outperformed a traditional CTAB/chloroform/isoamylalcohol based method. Analytical purpose, sample texture, consistency and upstream pretreatment steps determine the modifications that should be applied to achieve maximum efficiency in the trade-off between extract purity and nucleic acid recovery rate. RNA extraction was much more variable, and the destination of the extract determines the method to be used. RNA stabilization with quaternary ammonium salts was an as satisfactory approach as flash freezing in liquid N2. Due to co-eluted impurities, spectrophotometry proved to be of limited value for nucleic acid qualification and quantification in extracts obtained with the kit, and picoGreen® based quantification was more trustworthy. Absorbance at 230 nm can be extremely high in the presence of certain chaotropic guanidine salts, but guanidinium isothiocyanate does not affect (q)PCR. Absolute quantification by qPCR requires application of a reliable internal standard for which correct PCR efficiency and Y-intercept values are important and must be reported.
- ItemHydrothermal Carbonization and Pyrolysis of Sewage Sludge: Effects on Lolium perenne Germination and Growth(Basel : MDPI, 2019) Paneque, Marina; Knicker, Heike; Kern, Jürgen; De la Rosa, José MaríaThe pyrolysis and hydrothermal carbonization (HTC) of sewage sludge (SS) resulted in products free of pathogens, with the potential for being used as soil amendment. With this work, we evaluated the impact of dry pyrolysis-treated (600 °C, 1 h) and HTC-treated (200 °C, 260 °C; 0.5 h, 3 h) SS on the germination, survival, and growth of Lolium perenne during an 80 day greenhouse experiment. Therefore, the hydrochars and pyrochars were amended to a Calcic Cambisol at doses of 5 and 25 t ha−1. The addition of sludge pyrochars to the Cambisol did not affect Lolium germination, survival rates or plant yields. However, the use 25 t ha−1 of wood biochar reduced germination and survival rates, which may be related to the low N availability of this sample. In comparison to the control, higher or equal plant biomass was produced in the hydrochar-amended pots, even though some hydrochars decreased plant germination and survival rates. Among all the evaluated char properties, only the organic and inorganic N contents of the chars, along with their organic C values, positively correlated with total and shoot biomass production. Our work demonstrates the N fertilization potential of the hydrochar produced at low temperature, whereas the hydrochar produced at 260 °C and the pyrochars were less efficient with respect to plant yields.
- ItemPrecise Navigation of Small Agricultural Robots in Sensitive Areas with a Smart Plant Camera(Basel : MDPI, 2015) Dworak, Volker; Huebner, Michael; Selbeck, JoernMost of the relevant technology related to precision agriculture is currently controlled by Global Positioning Systems (GPS) and uploaded map data; however, in sensitive areas with young or expensive plants, small robots are becoming more widely used in exclusive work. These robots must follow the plant lines with centimeter precision to protect plant growth. For cases in which GPS fails, a camera-based solution is often used for navigation because of the system cost and simplicity. The low-cost plant camera presented here generates images in which plants are contrasted against the soil, thus enabling the use of simple cross-correlation functions to establish high-resolution navigation control in the centimeter range. Based on the foresight provided by images from in front of the vehicle, robust vehicle control can be established without any dead time; as a result, off-loading the main robot control and overshooting can be avoided.
- ItemThe Impacts of Water Pricing and Non-Pricing Policies on Sustainable Water Resources Management: A Case of Ghorveh Plain at Kurdistan Province, Iran(Basel : MDPI, 2019) Asaadi, Mohammad Ali; Mortazavi, Seyed Abolghasem; Zamani, Omid; Najafi, Gholam Hassan; Yusaf, Talal; Hoseini, Seyed SalarAs with other regions of Iran, due to excessive extraction of groundwater for intense agricultural activity, Ghorveh plain, a water-scarce irrigation district in the west of Iran, has faced a serious water crisis during the last decade. The present study investigates the impacts of two scenario policies, namely, non-price policy (as a supply-oriented policy) and water pricing policies (as a demand-oriented policy) on agricultural sector of Ghorveh Plain, using positive mathematical programming (PMP). The model was calibrated by using farm-level data for the crop years in 2016–2017. Our findings indicate that applying water supply constraint policy will change the land use and cropping pattern to the crops with higher water productivity. The increase of water resource constraints can lead to the increase of water economic return which indicates a rising value of water resources shortage, warning the producers of the agriculture sector to allocate water to the crops with higher economic value under the water resources shortage conditions. In addition, the findings underline that in a situation where the price of irrigation water is low due to the low elasticity of water demand in the agriculture sector, formulating the economic instruments such as rising water prices does not solely suffice to achieve sustainable water resource management. However, mixed scenarios emphasized that the water distribution policies should be aligned with the increases in water cost. © 2019 by the authors.
- ItemFood safety, a global challenge(Basel : MDPI, 2015) Uyttendaele, Mieke; Franz, Eelco; Schlüter, OliverTo provide more food and make use of precious water and nutrient resources, communities increasingly value sustainable food production. However, this should be done safely to maximize public health gains and environmental benefits. Food safety is being challenged nowadays by the global dimensions of food supply chains, the need for reduction of food waste and efficient use of natural resources such as clean water. Food safety deals with safeguarding the own national food supply chain from the introduction, growth or survival of hazardous microbial and chemical agents. But within a larger international context, borders are fading and surely this is the case for foodstuffs which are an important globally traded commodity. There is great divergence in the degree of organization, infrastructure, teaching capacity across countries and food protection (food quality, food preservation, food safety) needs to be tackled globally. This special issue assembled topics in food safety, with case studies of food safety concerns from various parts of the world, research on risk factors in agricultural production of fresh produce, use of water and water treatment technologies in food production, and outlooks on food safety for vulnerable persons. The main conclusion throughout all papers is that ensuring food safety of the food supply chain is a continuous challenge and needs our attention.
- ItemEvaluation of a Smart System for the Optimization of Logistics Performance of a Pruning Biomass Value Chain(Basel : MDPI, 2018-10-19) Bosona, Techane; Gebresenbet, Girma; Olsson, Sven-Olof; Garcia, Daniel; Germer, SonjaThe paper presents a report on the performance evaluation of a newly developed smart logistics system (SLS). Field tests were conducted in Spain, Germany, and Sweden. The evaluation focused on the performance of a smart box tool (used to capture information during biomass transport) and a web-based information platform (used to monitor the flow of agricultural pruning from farms to end users and associated information flow). The tests were performed following a product usability testing approach, considering both qualitative and quantitative parameters. The detailed performance evaluation included the following: systematic analysis of 41 recordable parameters (stored in a spreadsheet database), analysis of feedback and problems encountered during the tests, and overall quality analysis applying the product quality model adapted from ISO/IEC FDIS 9126-1 standard. The data recording and storage and the capability to support product traceability and supply chain management were found to be very satisfactory, while assembly of smart box components (mainly the associated cables), data transferring intervals, and manageability could be improved. From the data retrieved during test activities, in more than 95% of the parameters within 41 columns, the expected values were displayed correctly. Some errors were observed, which might have been caused mainly by barriers that could hinder proper data recording and transfer from the smart box to the central database. These problems can be counteracted and the performance of the SLS can be improved so that it can be upgraded to be a marketable tool that can promote sustainable biomass-to-energy value chains. © 2018 by the authors.
- ItemA comparison of carbon footprint and production cost of different pasta products based on whole egg and pea flour(Basel : MDPI, 2016) Nette, Antonia; Wolf, Patricia; Schlüter, Oliver; Meyer-Aurich, AndreasFeed and food production are inter alia reasons for high greenhouse gas emissions. Greenhouse gas emissions could be reduced by the replacement of animal components with plant components in processed food products, such as pasta. The main components currently used for pasta are semolina, and water, as well as additional egg. The hypothesis of this paper is that the substitution of whole egg with plant-based ingredients, for example from peas, in such a product might lead to reduced greenhouse gas emissions (GHG) and thus a reduced carbon footprint at economically reasonable costs. The costs and carbon footprints of two pasta types, produced with egg or pea protein, are calculated. Plant protein–based pasta products proved to cause 0.57 kg CO2 equivalents (CO2eq) (31%) per kg pasta less greenhouse gas emissions than animal-based pasta, while the cost of production increases by 10% to 3.00 €/kg pasta.
- ItemHydrothermal Carbonization: Modeling, Final Properties Design and Applications: A Review(Basel : MDPI, 2018-1-16) Román, Silvia; Libra, Judy; Berge, Nicole; Sabio, Eduardo; Ro, Kyoung; Li, Liang; Ledesma, Beatriz; Álvarez, Andrés; Bae, SunyoungActive research on biomass hydrothermal carbonization (HTC) continues to demonstrate its advantages over other thermochemical processes, in particular the interesting benefits that are associated with carbonaceous solid products, called hydrochar (HC). The areas of applications of HC range from biofuel to doped porous material for adsorption, energy storage, and catalysis. At the same time, intensive research has been aimed at better elucidating the process mechanisms and kinetics, and how the experimental variables (temperature, time, biomass load, feedstock composition, as well as their interactions) affect the distribution between phases and their composition. This review provides an analysis of the state of the art on HTC, mainly with regard to the effect of variables on the process, the associated kinetics, and the characteristics of the solid phase (HC), as well as some of the more studied applications so far. The focus is on research made over the last five years on these topics. © 2018 by the authors. Licensee MDPI, Basel, Switzerland.
- ItemDrinking and cleaning water use in a dairy cow barn(Basel : MDPI, 2016) Krauß, Michael; Drastig, Katrin; Prochnow, Annette; Rose-Meierhöfer, Sandra; Kraatz, SimoneWater is used in dairy farming for producing feed, watering the animals, and cleaning and disinfecting barns and equipment. The objective of this study was to investigate the drinking and cleaning water use in a dairy cow barn. The water use was measured on a well-managed commercial dairy farm in North-East Germany. Thirty-eight water meters were installed in a barn with 176 cows and two milking systems (an automatic milking system and a herringbone parlour). Their counts were logged hourly over 806 days. On average, the cows in the automatic milking system used 91.1 (SD 14.3) L drinking water per cow per day, while those in the herringbone parlour used 54.4 (SD 5.3) L per cow per day. The cows drink most of the water during the hours of (natural and artificial) light in the barn. Previously published regression functions of drinking water intake of the cows were reviewed and a new regression function based on the ambient temperature and the milk yield was developed (drinking water intake (L per cow per day) = −27.937 + 0.49 × mean temperature + 3.15 × milk yield (R2 = 0.67)). The cleaning water demand had a mean of 28.6 (SD 14.8) L per cow per day in the automatic milking system, and a mean of 33.8 (SD 14.1) L per cow per day in the herringbone parlour. These findings show that the total technical water use in the barn makes only a minor contribution to water use in dairy farming compared with the water use for feed production.
- ItemComparative advantage of maize- and grass-silage based feedstock for biogas production with respect to greenhouse gas mitigation(Basel : MDPI, 2016) Meyer-Aurich, Andreas; Lochmann, Yulia; Klauss, Hilde; Prochnow, AnnetteThis paper analyses the comparative advantage of using silage maize or grass as feedstock for anaerobic digestion to biogas from a greenhouse gas (GHG) mitigation point of view, taking into account site-specific yield potentials, management options, and land-use change effects. GHG emissions due to the production of biogas were calculated using a life-cycle assessment approach for three different site conditions with specific yield potentials and adjusted management options. While for the use of silage maize, GHG emissions per energy unit were the same for different yield potentials, and the emissions varied substantially for different grassland systems. Without land-use change effects, silage maize-based biogas had lower GHG emissions per energy unit compared to grass-based biogas. Taking land-use change into account, results in a comparative advantage of biogas production from grass-based feedstock produced on arable land compared to silage maize-based feedstock. However, under current frame conditions, it is quite unrealistic that grass production systems would be established on arable land at larger scale.