Institut für Agrartechnik


Recent Submissions

Now showing 1 - 20 of 103
  • Publication
    Development and optimisation of a low-temperature drying schedule for Eucalyptus grandis (Hill) ex Maiden in a solar-assisted timber dryer
    (2006) Bauer, Konrad; Mühlbauer, Werner
    The Brazilian furniture industry consumes about 45 million m³ of sawnwood per year which is mainly supplied by deforestation of the tropical rainforest. At the same time, fast growing eucalypt species are produced on almost 3 million ha for the production of wood pulp and charcoal. Meanwhile, several Brazilian companies try to substitute the expensive natural woods by hardwood from eucalypt trees for the production of high quality sawnwood. However, eucalypt wood has to be dried very carefully under controlled conditions to prevent drying defects. Ambient air drying is not suitable since missing control causes high losses and long drying times. Beside this, the low wood moisture content required in the furniture industry cannot be achieved. Artificial drying technologies reduce the drying time, the timber can be dried to a low wood moisture content and the quality can be improved. However, sophisticated high-temperature dryers cause high investments. Locally manufactured timber dryers do not allow an adequate control of the drying process. Furthermore, the required slow drying process is increasing the thermal and electrical energy consumption causing high drying costs. To overcome the existing problems, the Institute of Agricultural Engineering in the Tropics and Subtropics of the University of Hohenheim (ATS) developed in close co-operation with the German company THERMO-SYSTEM Industrie- & Trocknungstechnik Ltd (THS), Alfdorf and the Brazilian forest company CAF Santa Barbara Ltda (CAF) a solar-assisted dryer for sawnwood with integrated solar collector and biomass backup heating system. Aim of this research work was to analyse the newly developed solar dryer and to develop a suitable drying schedule which allows the economical production of high quality sawnwood for the furniture industry. Therefore, a prototype of the greenhouse type dryer was installed under subtropical climate in Brazil. Due to the low thermal insulation of the solar dryer and missing experience with the extremely sensitive Brazilian varieties of Eucalyptus grandis, a new type of drying schedule had to be developed. The new schedule considers not only the general drying demands of eucalypt sawnwood but also the system immanent characteristics of the solar dryer and the ambient air conditions. An oscillation of the drying air temperature according to the ambient air allowed to speed up the drying process and reduces the condensation of water on the cover without a negative impact on the timber quality. In more than 80 drying tests with 16 000 m³ of eucalypt sawnwood the schedule was tested and improved. Based on experiments and information from literature, the course of the temperature, relative humidity and velocity of the drying air and the mode of remoistening was systematically optimised. Thereby, the influence of the changing drying conditions on the drying time, the timber quality, the energy consumption and the drying costs were analysed. With the final version of the drying schedule, 27 mm thick boards could be dried in the solar dryer from a medium wood moisture content of 60 to 12 % d.b. in 27 days. This drying time was about 20 % higher than in a high temperature dryer. However, a drying time of at least 60 days was required to reduce the moisture content to about 20 % d.b. at ambient air drying. The electric energy consumption in the solar dryer was reduced to about 20 kWh per m³ dried eucalypt sawnwood. This is only 20 % of the energy usually consumed in a high temperature dryer. The thermal energy consumption was 1.2 GJ per m³ which is about 60 % less than the energy required in conventional high temperature dryers. The low thermal and electrical energy consumption combined with the considerable lower investment costs for the solar-assisted timber resulted in average drying costs of 7.90 Euro per m³. This is only half of the costs caused by drying 27 mm thick eucalypt hardwood in a high temperature dryer. For an economic evaluation, a sensitivity analysis was done for the most important cost parameters. The electrical energy costs, the currency exchange rate and the interest rate for credits were found to be the main influencing parameters on the Brazilian market conditions. However, solar drying was generally more cost efficient than conventional high temperature drying. In the framework of this research work, it was proved that Brazilian eucalypt timber can be dried economically to a low moisture content of 10 to 12 % at a high quality level by applying the developed drying schedule in the optimised solar-assisted dryer. Meanwhile, approximately 35 000 m³ of eucalypt hardwood is dried annually in two solar-assisted drying plants contributing significantly to the protection of the natural rain forests.
  • Publication
    Energiebedarf von Traktoren und ausgewählten Anbaugeräten in der Außenwirtschaft landwirtschaftlicher Betriebe
    (2024) Schwehn, Julian; Böttinger, Stefan
    Vor dem Hintergrund des Klimawandels und hoher Ressourcenpreise ist der umsichtige Einsatz der zur Verfügung stehenden Energieträger von besonderer Bedeutung. Um die Folgen anthropogener Treibhausgasemissionen auf das Klima zu minimieren, sehen legislative Vorgaben in Europa und Deutschland ambitionierte Reduktionsziele für einzelne Sektoren wie die Landwirtschaft vor. Die heterogene Agrarstruktur erfordert standortgerechte Produktions und Arbeitsverfahren, was zu einer großen Vielfalt an eingesetzten Maschinen und Anbaugeräten führt. Neben der Untersuchung von Einsparpotentialen einzelner Fahrzeugkomponenten bieten landwirtschaftliche Verfahrensketten mögliche weitere Einsparungen. Die Erforschung dieser prozessualen Potentiale macht eine detaillierte Kenntnis der eingesetzten Maschinen und Anbaugeräte aus energetischer Sicht notwendig. Um die Einsparpotentiale innerhalb der Prozesse sowie der eingesetzten Technologien quantifizieren zu können, wird in der vorliegenden Arbeit der Energiebedarf von Traktoren und ausgewählten Anbaugeräten ermittelt. Dazu wird nach der Einführung einzelner Maschinen und Anbaugeräte eine Metastudie verschiedener Testverfahren und Literaturquellen durchgeführt, um die vorhandene Datenbasis zu bewerten und Datenlücken aufzuzeigen. Soweit es die Datenbasis zulässt, werden der aktuelle Stand und eine Entwicklung seit 1990 dargestellt, um die bereits erzielten Einsparungen aufzuzeigen. Darüber hinaus erfolgt ein Vergleich sowie eine Evaluierung bestehender Modellansätze zur Berechnung des Energiebedarfs einzelner Maschinen und Anbaugeräte. Aus der Kenntnis vorhandener Datenlücken sowie der Güte aktueller Parametersätze können systematische Feldversuche für weiterführende Arbeiten abgeleitet werden.
  • Publication
    Laser backscattering imaging in agriculture
    (2023) Wu, Zhangkai; Müller, Joachim
    Non-destructive optical sensor technology (NDOST) is an essential part of agriculture. The unique capabilities of laser notably enhanced NDOST. Laser backscattering imaging (LBI) is a technology that captures light patterns scattered by a material to analyze its properties. It is particularly suitable for agriculture due to its affordability and the optical scattering nature of agricultural products. The images generated by LBI are related to the optical parameters of the examined objects. Crucial tasks in LBI include the selection of an appropriate laser, the extraction of image features, and the utilization of a prediction model for analysis. LBI has been employed in numerous scenarios, such as maturity detection and drying monitoring. The main challenges for LBI involve establishing a precise theoretical framework and uncovering new applications within agriculture. This study aims to enhance the foundational knowledge about LBI and explore additional application scenarios. The first study focused on basic research about LBI. Currently, researchers rarely document the cell size of their samples and treat the optical coefficient as a constant within agricultural products, which is questionable. This studys purpose was to use glass filter matrices as controlled models and to evaluate the effects of pore size, different solutes, concentrations, and wavelength. The used porous glass discs had pore diameters ranging from 1 to 160 µm. We applied aqueous solutions of NaCl (0, 1, 2, 3, and 4 mol/L) and NaH₂PO₄ (0, 0.8, 1.6, 2.4, and 3.2 mol/L) to fill the pores. The LBI system incorporated laser modules at three different wavelengths (405, 635, 780 nm). The results illustrated that three of the four examined experimental factors (the pore diameter, the solutes, and their concentrations) have a substantial impact on LBI. However, no clear differences in LBI patterns were observed among the three utilized wavelengths. Consequently, when deploying LBI on fruits, for instance, a thorough consideration of cell sizes at various depths from the fruit surface is required. The second study focused on a possible application scenario of LBI: the sedimentation process of crude sesame oil. Oil sedimentation is a process where gravity is used to remove solid impurities, resulting in a clearer oil. This study examined the sedimentation process in crude sesame oil using LBI. In situ and laboratory experiments were conducted over 30 days, involving an LBI system directly attached to a transparent sedimentation tank with 120L of crude oil. Both the oil properties and sedimentation curve were analyzed along with the LBI images. There was a dramatic drop in oil particle-related properties (at least 87%), a 90% decrease in water content, and minor changes in oxidation-related properties. The sedimentation speed was about −7 mm/h, then became less than −2 mm/h, revealing two stages: diluted and hindered sedimentation. The crude oils surface displayed a distinctive scattering spot and a Tyndall effect within the oil, showing an increasing path length as sedimentation proceeded. The findings offer practical insights for enhancing sedimentation tank and LBI system design. The third study focused on another possible application scenario of LBI: leaf wetness measurement. Leaf wetness plays a pivotal role in managing plant fungi diseases. Existing optical techniques categorize leaf wetness as a binary problem – either wet or dry. In contrast, this research developed a platform capable of semi-automatically measuring droplet deposition on grape leaves using an LBI system. The leaf area, mean intensity per pixel in the red channel, and droplet count using information from the green channel were extracted from the scattering images. The study employed a generalized additive model (GAM) to predict leaf wetness with the extracted features. The prediction of the test dataset achieved an R-squared value of 0.78. The extraction of image features was found to be influenced by factors such as image resolution and leaf orientation. The method introduced in this study offers the potential for precise quantification of leaf wetness with an LBI system. In conclusion, our study highlights the importance of considering cell size in agricultural applications of LBI. Besides, LBI was found useful in monitoring plant oil sedimentation and quantifying leaf wetness. This suggests its potential for scenarios involving state changes in suspensions or colloids and differentiating materials with distinct optical properties. However, using a porous matrix as a model introduces an inherent error. Additionally, advancements are necessary to transition the application studies into practical use. Future LBI development could be facilitated by building a comprehensive database on light interactions with diverse cells and tissues.
  • Publication
    DIY Insektenscheuche : Konzept und Umsetzung im Projekt InsectMow
    (2024) Frank, Jonas
    Quick guide to building the insect flushing bar from the InsectMow project
  • Publication
    Adaptive operator systems in tractors : analysis of potentials and methods for specification and evaluation
    (2024) Schempp, Timo Thomas
    Der Ackerschlepper wird in der Landwirtschaft, auf dem Bau, im Forst und im Kommunalbereich als Universalmaschine eingesetzt. Dazu wird er wechselnd mit einer Vielzahl von Maschinen gekoppelt, um diese zu betreiben. Es ergeben sich wechselnde Bedienszenarien mit unterschiedlichen Anforderungen an die Bedienung der gekoppelten Maschinen. Heutige Bediensysteme sind statisch und müssen daher als Kompromisslösung für diese unterschiedlichen Anforderungen an die Bedienung eingeordnet werden. Adaptive Bediensysteme können sich hingegen an wechselnde Bedienszenarien anpassen. Diese Arbeit beleuchtet den Stand der Technik der Bediensysteme in Ackerschleppern allgemein und explizit an drei ausgewählten Beispielen. Ferner werden zwei Methoden beschrieben, mit denen ein adaptives Bediensystem spezifiziert werden kann. Für die Bewertung der kognitiven und physischen Ergonomie von Bediensystemen allgemein werden zwei weitere Methoden vorgestellt. Alle Methoden sind für einen auf dem V-Modell basierenden Entwicklungsprozess geeignet. Die beschriebenen Ergebnisse einer theoretischen und praktischen Potentialanalyse motivieren den Einsatz adaptiver Bediensysteme im Ackerschlepper. Die theoretische Potentialanalyse stützt sich auf die Grundlagen der Ergonomie und auf die Art und Weise wie die Funktionen in einem Ackerschlepper genutzt werden. Die praktische Potentialanalyse stützt sich auf die Auswertung und Analyse von Messdaten aus dem Feld mit fast 500 Arbeitsstunden aus 14 Bedienszenarien. Ferner beschreibt diese Arbeit die Anwendung der Methoden zur Spezifikation, das entwickelte und funktionsfähige adaptive Bediensystem und die Anwendung der Bewertungsmethoden, die für das adaptive Bediensystem eine signifikante Verbesserungen der physischen und kognitiven Ergonomie zeigen.
  • Publication
    Integrated technical approach for differentiated nitrogen application based on expert knowledge and multiple parameters
    (2023) Heiß, Andreas; Griepentrog, Hans
    Variable rate nitrogen (N) application is subject to spatio-temporal dynamics of multiple parameters and a high dependency on specific local conditions. Furthermore, existing algorithms are barely capable of considering agronomic expert knowledge and common application technology limits the precise in-field realization. This work approached the complexity of site-specific N management in terms of the decision making, as well as the technical and organizational realization in a systemic manner. A commercial real-time N-sensor system’s behavior was transferred into a fuzzy expert system and extended with soil information. The incorporation into a real-time control included also the spatial synchronization of dose rate determination and realization. A digital process chain to facilitate decision making, data management and execution in the field was conceptualized and evaluated with a prototypical implementation. The N-sensor’s algorithms were precisely imitated with a maximum percentage root mean square error of 0.14%, while the multi-parametric system has implied more robust decisions. In field tests, the real-time control has shown acceptable synchronization errors largely below 1 m and with medians in the range of 0.25 m under realistic conditions. The integrated system architecture has shown a high consistency in terms of straightforward and situative expert knowledge acquisition, as well as the suitability for different sensor and application technologies. The work represents a systemic approach for a derivation and employment of machine-readable algorithms from agronomic expert knowledge defining the cause-effect relationships for a site-specific N application. Its generic properties allow a supplementation by other models and can in turn strengthen them further.
  • Publication
    Aspects of incorporating biodegradable textiles to improve sports turf
    (2023) Stürmer-Stephan, Bastian; Griepentrog, Hans
    Due to climate change and the need to save water, water consumption must be reduced not only in agriculture but also in urban areas. There are 55,072 sports fields in Germany that have to be irrigated in summer. In order to reduce the amount of irrigation, two approaches were researched and discussed in this thesis. The first approach is to adapt new sports fields to the local weather conditions. This approach is a decision support system, based on a model. The input variables are recorded weather data from the German Weather Service for the location where the new sports field is to be built, the hydrological properties of the substrates, and the expected costs. An optimized dimensioning of the rootzone layer is calculated by an EA solver of Microsoft Excel. This thickness of the layer can be used for the construction project. This was calculated exemplary for 3 locations. The presented model needs to be further evaluated through field trials. For existing sports fields, the root zone layer can only be changed with great effort. In this case, a biodegradable nonwoven can be installed in an existing sports field with drainage layer structure. This nonwoven transport water from the deeper drainage layer into the root zone of the turf through the capillaries, so that the water is available to the turf. To achieve this function, the 150 mm wide nonwoven must be installed vertically at a depth of 170 mm +-20 mm. During installation, the ground cover must not be reduced and the roughness of the surface must not be increased. In the present work, a device is presented, that cuts the turf, opens a furrow, incorporates the nonwoven and then closes the furrow. The device is mounted on the tractor and consists of a height guide, a cutting disc, a box coulter and a pressure roller. The device was tested on three plots with a layer structure in Stuttgart. The cutting disc works properly because no clogging was observed. A measurement frame equipped with an ultrasonic sensor, a laser range finder and a feeler wheel determined the surface roughness before and after incorporating the nonwoven. The results showed a significant increase in roughness. In order to reduce the negative impact to the ground surface, it would be possible to increase the ballasting of the device. However, harmful soil compaction must be avoided. The uniform working depth of the developed device was determined with a tachymeter and showed a deviation from the nominal depth of less than 20 mm. The results show that this meets the requirements for the device. Ground cover was measured before and after installing the nonwoven. The turf damage was less than 15 % of the ground cover, which meets the playability requirements. Reconsolidation was determined by penetrologger and evaluated in profile. The soil recompaction, measured as penetration resistance, was similar to the status quo, except in the area close to the nonwoven, where the recompaction failed. The furrows of the developed device can be recompacted more effectively by using two pressure roller, attached V-shaped. But it must be verified that the two pressure rollers do not cause ridge formation, as is the case with seed drills. Overall, the performance of the device can be considered positive, but improvements are still needed to improve reconsolidation. These improvements can be verified in future investigations. At the same time, the effectiveness of the nonwoven must be evaluated in the future. Preliminary tests have shown that the capillary action is sufficient to transport water from the drainage layer to the root zone.
  • Publication
    Potential and prospects of a brand differentiation in the agricultural engineering, using the example of the multi-brand company CNH Industrial
    (2023) Münd, Benjamin; Köller, Karlheinz
    CNH Industrial unites three agricultural brands, Case IH, Steyr and New Holland. With miscellaneous mergers in the past, these former independent manufacturers of agricultural equipment were combined in one company. A lot of synergies were used and are still being used to maximize the profit of the parent company CNH Industrial and to reduce complexity. Through this harmonization process, the tractor models of the three brands became more and more similar with less distinctive features which leads to a high comparability of the brands Case IH, Steyr and New Holland and its tractor product line up above 55 hp. This results in a strong competition between these brands because in most countries the dealer network is separated for New Holland and Case IH/Steyr and every distribution partner is independent and strives for their own profitability. Due to this, the internal competition prevents external competition with tractors from other manufacturers, which generates cannibalization effects and reduces the profit of the three brands, CNH Industrial and the dealers. Structural changes in the European agriculture led to bigger farms with in total less tractor registrations per year what intensifies additionally the competition for tractor manufacturers. A survey with farmers and contractors from Germany, UK and France showed, that a brand and product differentiation would make sense and would bring a sustainable benefit for all three brands and their parent company CNH Industrial. Because of the history of all three brands and loyal long-term customers, a merger to one CNH Industrial brand is not efficient and expedient. It is important to identify the right customer group for each brand, to know the customers’ requirements and to offer the appropriate products and technical solutions. The network of distribution partners (dealers) is the key factor for an efficient market development. The professionalism of the dealers is mainly determining the success of a brand and its products in the market and the perception of the farmers and contractors. The professionalization of the dealer and collaboration between manufacturing company and dealer is essential. Also, the country of production of the tractors has a significant impact on the customer perception and appreciation. “Made in Germany” is still a quality characteristic and explains partially the high appreciation of Fendt and John Deere as premium tractors for professional farmers and contractors. Steyr as one brand of CNH Industrial AG which only produces tractors has a valid potential to establish to a premium tractor brand in Europe. Due to little negative connotations of customers and a straightforward history the brand has a good base for this development purpose. Bottom line, there are manifold possibilities to achieve a differentiation that is perceived by the customers as such. However, several actions are only feasible mid- or long-term. A product differentiation makes sense to reach a broad base of customers. Certainly, it is undisputed that a product differentiation is connected to high investment. If it is economically viable for the CNH Industrial group remains to be evaluated.
  • Publication
    Ökonomische Bewertung der „Doppelernte“ von Getreidekörnern mit den Reststoffen Spreu und Stroh
    (2021) Ortmaier, Jörg; Köller, Karlheinz
    Objective of this work is an economic evaluation of new harvesting methods, so-called “dual- harvesting” methods for common harvesting of grains and their residual biomass. In detail, the aim is on the one hand to evaluate the predicted higher quality and quantity per hectare of har-vestable residual biomass such as chaff and straw that can be realized with dual-harvesting technologies, but on the other hand especially their additional income contrasted to the pro-cess costs by proceeding dual-harvesting. For this purpose, combine harvesting with additional chaff or straw harvesting is compared to some dual-harvesting methods, both in terms of process technology and in monetary terms. Dual-harvesting methods are simulated with self-propelled forage harvester threshing, forage wagon windrow harvesting, compact harvesting and harvesting with a tractor mounted stripper header. The comparison includes the required logistic-chains and crop aftertreatment, i.e. sta-tionary separation of grain and biomass for each method. As basis for calculations is done specific modeling, e.g. for chaff yields and crop volumes as a function of grain yield. Parame-ters such as area size are included and also field distance, loss times, e.g. for turning opera-tions in the field, working speeds and road transport speeds. A calculation model developed for this purpose calculates time required for harvesting of one field for all processes with the greatest possible comparability. Based on machine costs stored in databases, e.g. for depreci-ation or wear and repair, which are automatically transferred to their desired process calcula-tion via selection lists, the costs per operating hour and, including area per hour and area size, costs per hectare can be determined for each harvesting process. Since all processes have different levels of grain and biomass losses, the process-specific, total revenues for grain and biomass are calculated accordingly and process costs calculated in each case are deducted from them. The resulting harvest cost free outputs (HCFO) are used as a comparative value. Without taking into account costs of reproducing soil organic matter as long term result, the following HCFO result for the individual methods according to the assumptions are calculated: combine threshing with bale harvesting 1309.93 €/ha; compact harvesting 1285.66 to 1529.53 €/ha depending on the amount of straw harvested; forage harvester threshing 1421.04 €/ha; forage wagon swath harvesting 1429.40 €/ha; tractor-mounted stripper header 1279.58 €/ha. The compact harvesting method thus has an advantage of up to 219.60 €/ha over the estab-lished combine and bale technology with same given assumptions. The other methods are in between or slightly below the combine harvesting. If costs for nutrient removal and soil organic matter reproduction are included for long term perspective, the advantage of compact harvest-ing is up to 143.44 €/ha. Based on literature research and model calculations, it can be assumed with a high degree of probability that dual-harvesting methods actually make residual materials usable in greater quantities with higher quality than it is possible with widely used combine harvesting. Concerns expressed by Buchmann (1961) and Garmasch (1960) regarding the suitability of combine harvesting for an efficient provision of chaff and straw are substantiated when calculation re-sults are taken into account. In addition, agronomic effects of dual-harvesting methods are positive compared to combine harvesting, which was not able to be evaluated in monetary terms and therefore represents a great need for future research. The positive assessment is due to improved field hygiene by removing weed seeds and plant pathogens from the field during dual-harvest. This could re-duce the need for chemical pesticides. Use of cereal residues not only improves resource effi-ciency and "saves" land for cultivation of renewable raw materials, but the carbon contained in chaff and straw remains bound in sustainable products to a greater extent, such as in biochar. Dual-harvesting is an essential tool for cost-effective provision of plant residues required for that purpose and at the same time offers great potential for more environmentally friendly field management and benefits for biodiversity, e.g. through possibility of regular cultivation of plant mixtures instead of individual crops. Digital development up to autonomous field management can be made more rational in dual-harvesting methods through simplified processes in the field, which can be expected to lead to further increases in efficiency of grain and residue har-vesting in the future.
  • Publication
    Potentialbewertung effizienzsteigernder Technologien bei Landmaschinen in Verfahrensketten mit Körnerfruchternte
    (2023) Meiners, Arwid Steffen
    Reducing fuel consumption in agricultural process chains through increased energy efficiency in machine use is effectively achieved through process-oriented approaches. Although European targets for greenhouse gas reduction are increasingly being demanded legislatively and socially, the farmer’s pressure to act is primarily motivated intrinsically due to economic constraints. There are technologies existing on the market that contribute to increasing machine and process efficiency. To this day, however, it is difficult to evaluate their economic use on a farm-specific basis before deciding on investments. The complexity of agricultural process chains encourages and demands comprehensive approaches for both the use and the evaluation of efficiency-increasing technologies and measures. The objective of this research is to develope and apply a proper evaluation method. As a virtual evaluation environment, a machine model is created which can be used to calculate time-related fuel consumption of agricultural machine combinations under the influence of efficiency-increasing technologies. Supplemented by a process model, the consumption of individual process chains and entire crop rotations can be simulated. A modular model topology allows flexible combinations of tractors and implements for process chains with grain crop production. Corresponding simulation models are built and parametrised. The focus is on developing a model for self-propelled harvesters and on parameterising it for application as a combine harvester. As a data basis for the process components, load and performance data are collected in field tests using a state-of-the-art hybrid combine harvester. At the same time this contributes to the general data availability of performance requirements of process components in harvesting operations. In the model application, a potential evaluation of efficiency-increasing technologies and measures, such as optimised traction conditions, driving strategies or reduced intensities in tillage and harvesting, is carried out on a virtual model farm representing typical process chains with grain crop production in the region of South Hanover. Optimisation potentials for three- and five-part crop rotations are established along the individual process steps. Specific recommendations from individual technology analyses are made for efficient use of the machinery in use. As an overall assessment, a potential for reducing fuel consumption of about 26% resulting from optimised machine efficiency can be identified.
  • Publication
    Analyse der Maschinenkosten mittels automatisierter und manueller Maschinendokumentation im ackerbaulichen Produktionsprozess
    (2023) Lattke, Justus; Böttinger, Stefan
    “Smart Farming”, “Agriculture 4.0” and the “Internet of Things” are terms set to define the future of global agriculture. Many studies predict that these new technologies will have more impact on agricultural productivity than the “Green Revolution” of the 1970s. Upstream and downstream agricultural suppliers claim that their products and services will benefit farmers and their businesses. In this study, several farm management software programs were tested for their capacity to add value to the cropping division of a large and diversified farm. The evaluation showed that a farm management software program based on automatic collection of machinery cost data, gave more precise and timely information than a process relying on manual data collection. This conclusion was arrived at by calculating total cropping equipment costs over a full season using two cost accounting methods – an adaptable planned cost calculation and a process cost calculation – and comparing the results from the automatic and the manual collection of data. To determine the most suitable method and to select the various software programs to evaluate, various trade fairs and companies were visited, and websites searched. The most promising software programs were then tested for functionality and ease of use at the Horsch farm, “Agrovation”. It turned out difficult to establish an incentive system for employees to use the new technologies. For this reason, the farm machines at Agrargesellschaft Pfiffelbach were equipped with the 365FarmNet application without employee registration. The entire production period of crops harvested in 2018 was included. Both automatic and manual data collection took place from August 1, 2017 to December 31, 2018. To evaluate the quality of the two methods of data acquisition, the actual hours worked were compared with the hours recorded according to the type of cost collection.
  • Publication
    Improvement of the acceptance of a solid lying area by fattening pigs and rearing piglets
    (2022) Opderbeck, Svenja; Gallmann, Eva
    Society’s demands for more and better animal welfare in Germany have increased in recent years which has been promoted by the introduction of a lot of animal welfare labels and legislative changes. Therefore, housing systems with fully slatted floors, a minimum space allowance and a few employment opportunities are no longer state of the art. However, the implementation of more animal welfare confronts farmers with a large number of challenges. Among other things, there are still many problems with the integration of a solid lying area, due to the high risk of fouling and the resulting poor indoor climate. Functionally reliable solutions were to be found in the project “Label-Fit” for the integration of a solid lying area into existing conventional housing systems for rearing piglets and fattening pigs. Based on literature research and expert discussions, the influencing factors group size, pen structure, type of perforated floor, light intensity, a cooled/heated lying area and a cover over the lying area were examined. These factors were investigated in four fattening and two rearing compartments over three years (five fattening periods with a total of 2200 pigs; six rearing periods with a total of 1152 piglets) in the Bildungs- und Wissenszentrum Boxberg (LSZ). The lying behavior, the fouling of the pens and animals and various climate parameters were recorded and evaluated to assess the acceptance of the lying area. In order to examine the influence of the light intensity, spotlights were located over the slatted area in fattening pens to make this area unattractive for lying and influence the lying behavior and the soiling of the lying surface positively. This increased light intensity leads to significantly more pigs lying on the solid lying area, but it did not affect the fouling. Furthermore, the effect of a cooled lying area on fattening pigs was tested. The cooling of the lying area leads to significantly more animals on the lying area even at higher temperatures, and the fouling of the animals was reduced significantly. The fouling of the lying area was not affected; however, the fouling was very low in this examination. The temperature requirements in the rearing of piglets change greatly during the rearing period, consequently, two heating systems and a floor cooling system were examined in two rearing compartments. There was no difference between the two heating systems on the lying behavior. However, significantly more piglets lay on the cooled lying area compared with the control pen during the last weeks. The fouling of the pens and animals was very low but not affected by the cooling or heating systems. Two of the fattening compartments were converted with pens for 18 pigs and two compartments with pens for 28 pigs. The two group sizes could only be compared descriptively due to structural and temporal differences. The acceptance and the cleanliness of the lying area in the groups with 28 animals were better than in the smaller groups. Furthermore, two different arrangements of the perforated area on one side or two sides of the lying area were tested, but only descriptively. It was shown that more animals were lying on the lying area in the pen with the slatted area on one side, but the solid lying area was dirtier. The position of the feeding can also influence the acceptance of the designated functional area. Therefore, two feeder positions were examined descriptively: In the middle and at the edge of the lying area. The results showed that more pigs were lying on the solid lying area when the feeding was placed at the edge. In addition, the fouling of the lying area and partly also of the animals was reduced in pens with feeding at the edge. The attractiveness of lying in the designated elimination area can be decreased by the type of floor. Therefore, a concrete slatted area was compared with a triangular grid area. Significantly more pigs lay on the solid lying area in pens with a triangular grid, especially when the temperature was low. Finally, the influence of the heated lying area and a cover over a part of the lying area was compared. The results showed that a cover over the lying area seems to lead to more pigs lying on the solid lying area, which was also fouled less than in pens with heated lying areas (no significant differences). Based on the results of this study and the results of other studies, recommendations for an optimized pen structure with a solid lying area are summarized in a decision aid for the structuring of a pen for fattening pigs or rearing piglets. In addition, as part of this dissertation, an optimized pen for fattening pigs with a solid lying area was designed. The results of the dissertation show that there are many ways to implement a solid lying area. A combination of several of these approaches has the potential to improve the acceptance of a solid lying area in conventional pig housing systems.
  • Publication
    Entwicklung eines neuartigen Selektivhacksystems zur Unkrautkontrolle in Zuckerrüben
    (2022) Heinrich, Stefan; Köller, Karlheinz
    The production of organic sugar beets is one of the biggest challenges in organic farming. Due to its slow youth development, it is less competitive with seed weeds like white goosefoot, knotweed, or cockspur. The control in organic farming is mainly done mechanically with the help of hoeing systems between the rows and with harrow and finger weeders within the rows. The brittleness in the youth stages doesn’t allow an aggressive deployment of the in-row methods mentioned before, so the results stay far behind the expectations. To raise the yields and to make a harvest at least possible a manual removal of the weeds is essential. The effort on manual labor is settled between 50 to 250 hours per hectare. To reduce the costs for man-ual weeding some attempts were made to use automatic weeding systems from the vegetable production. Due to the small distances between the plants and the missing head start of the crop, the losses of the used systems were higher than the generated benefits. The main rea-sons for the fail belong to the plant detection system and the tool design. State-of-the-art tech-nology uses mainly color information and geometrical measurements to separate the plants from each other. Most of the tools use simple systems which open in front of a plant and close behind it. The driving speed is limited throughout the swing-in process. None of the tools that have been used so far have no “zero-intervention”, so the risk of the plants being buried in-creases in proportion to the driving speed. In the present dissertation, new concepts for online plant recognition are first developed. The detection of sugar beet is one of the most complex tasks in mechanical weed control. Due to the small distance between the plants and the special growth habits a precise detection of the center point is challenging. Common systems out of the industrial image processing field can-not be used directly, because of the small similarities between the plants. To get successful detection results important attributes like the distinctive leaf blade must be worked out. The main task is to develop a fully practical proofed selective weeding system. Therefore an evalu-ation between an autonomous platform and a tractor-mounted system has to be made. Due to the fact of the low power supply, it was decided to develop the tractor-mounted system. For the start, a common front weeding system is used to build the prototype. It is first used to collect image data. In the following steps, the platform is required to integrate the first in-row weeding tools. Starting with the results from the previous master thesis classical image recognition methods are used to develop different approaches for the detection of the center points. The approaches mainly differ in the plant growth stages. Until the two-leaf stage, binary operators deliver good results. Starting with the four-leaf stage, the new edge detection system for local-izing the centerline of the leaf reaches an accuracy of up to 20 mm. The single plant detection system achieves recognition rates from 50 % to 98 % depending on different growth stages and lighting conditions. Thanks to the grid seeding system it was possible to reach excellent detection rates even under a high degree of weed cover and harsh conditions. By sowing the plants in a triangular arrangement, it was possible to reduce the plant losses below 1 %. To bring the detection results to the ground the currently developed rotor weeding system from the University of Bonn was used as a starting point for developing new kinematics. It achieves throughout the hydromechanical contact pressure control a better ground contour following. It is also significantly less susceptible to difficult working conditions. Due to the inclination of the rotor, the so-called “zero-intervention” could be developed. Due to the adapted cutting angle to the row, the driving speed is completely compensated. This prevents the crops from covering with soil. The tool is hydraulically driven to create a robust and inexpensive platform. It should also be possible to use the components in future serial production. The cascade controller from the rotor achieved an angular accuracy below 0,7°. The plant positions primarily detected for the in-row system could also be used for the realization of a row guidance system. For this purpose, an active implement steering was designed in addition to the automatic tractor steer-ing system. This improved the guiding behavior of the front weeding system. In order to achieve the highest possible regulating effect for every growth stage, disc colters are used in combination with optional angled shares. In later stages goosefoot shares with optional wings can be used to reach a higher pile effect. Also, the in-row system is fully integrated into the tine carrier to obtain a compact unit. By linking the information from the sowing technology and the image processing, it has been possible to develop a highly robust and fail-safe system for mechanical weed control in organic sugar beet.
  • Publication
    Einfluss der mechanischen und pneumatischen Anregung auf die Entmischung und Abscheidung in der Mähdrescherreinigungsanlage
    (2021) Beckmann, Konstantin
    Due to the legal limitation of the maximum machine width the throughput increase is realized by further developing of the process technology. This requires precise knowledge of the ongoing processes. The aim of this work is the metrological investigation of the combine cleaning system according to the white-box model by analyzing the process sequence of the sub-processes.This enhances process understanding and enables the validation and verification of DEM-CFDsimulations. The evaluation of the segregation and separation process is based on the movement behavior of grain and straw. For this purpose, 2D high-speed x-ray images, static 3D reconstructions and 2D high-speed camera images are analyzed. The segregation in the lower layers is limited by the compression of the material layer due to its own weight. Due to the higher porosity the segregation of the grain near the wall is slightly faster. Additional relative movements of the material based on the superimposed conveying process. The resulting voids are used for a faster segregation. The influence decreases with increasing mechanical and pneumatic excitation in vertical direction. The influencing factors on the movement behavior of the material in the cleaning system is investigated with a test-rig. In the unloaded state the airflow decreases along the sieve. Due to higher sieve loads the airflow is flatter. Therefore the maximum air speed under the lower sieve is shifted to larger sieve lengths. The front area of the upper sieve is less loaded. The air passes by these areas and causes an increase of the air speed. High air speeds in the winnowing steps result in a high grain separation. A high component of the air velocity in the conveying direction between the sieves causes a shift of the separation on the lower sieve to longer lengths. The air throughput must be within the limits between a sufficient material fluidisation and a low conveying process on the sieves. In addition to identifying development potential, the results are used to verify DEM-CFDsimulations. There are deviations of movement behavior between grain and straw. Nevertheless,the influencing factors can also be examined qualitatively on the basis of the simulations.
  • Publication
    Attraktives Beschäftigungsmaterial zur Reduktion von Schwanz- und Ohrschäden beim Schwein
    (2021) Kauselmann, Karen; Schrader, Lars
    Tail biting is a behavioural disorder that often occurs in commercially housed domestic pigs. It may affect welfare of involved pigs and cause economic losses for the farm. The causes of tail biting are multifactorial, which is why preventive tail docking is the most comon method to reduce tail damages in pigs until today. However, besides invasive interventions, the use of enrichment materials can reduce tail biting by increasing species-specific exploration behaviour. Thereby, the rapid habituation of pigs poses a challenge in the selection of enrichment materials. Within the research project “Label-Fit – Schweinehaltung fit für das Tierschutzlabel”, different plant-based enrichment materials for rearing and fattening pigs were investigated, which can be used in conventional housing systems with slatted floors. The aim of the present study was to identify attractive enrichment material based on the exploration duration. Furthermore, the influence of the enrichment materials on tail and ear damages was investigated in pigs with undocked tails. Prior to three long-term investigations, two choice tests were carried out for better delimination of plant-based enrichment materials considered attractive for pigs. Therefore, pigs were offered enrichment materials of different structure or, in the second test, straw with different edible additives. In both tests materials were offered in parallel in six boxes. By means of the individually recorded exploration durations, pigs showed clear preferences for pelleted materials and preferred chopped straw with edible additives, such as maize kernels. These results were used to select enrichment materials for further long-term investigations. In the three long-term investigations, material dispensers were equipped with an UHF-RFID system to record exploration durations of the pigs at the material dispenser filled with enrichment materials. Enrichment materials were offered in an alternating order and at each change of material the tails and ears of the pigs were recorded according to the “Deutscher Schweine Bonitur Schlüssel” (DSBS) regarding partial losses and skin injuries. In the first long-term investigation, rearing and fattening pigs received four enrichment materials with different structures (lucerne pellets, straw pellets, chopped hay and chopped straw) in a two-weekly change. Rearing pigs preferred pelletized materials, while fattening pigs showed preferences for chopped hay and lucerne pellets. Furthermore, exploration duration increased from rearing to fattening. When offering the enrichment materials that achieved the highest exploration durations in rearing (lucerne pellets or straw pellets), the fewest partial losses of the tails were recorded. However, when offering straw pellets in rearing, most injuries at the tails occurred. The second long-term investigation dealed with the question, if exploration duration of rearing and fattening pigs for chopped straw can be increased by adding maize kernels. Compared with pigs that received chopped straw without maize, pigs that received chopped straw with maize kernels showed higher exploration durations at the material dispenser during rearing and fattening. Furthermore, exploration duration could be increased from rearing to fattening, although there was no change of the material within the groups. Additionally, saisonal differences in the diurnal pattern of exploration of pigs were found. Interestingly, pigs that received chopped straw without maize kernels showed fewer length losses of the tails compared to pigs that received chopped straw with maize kernels. In the third long-term investigation, rearing and fattening pigs received different flavoured straw pellets in a weekly change. Different preferences for flavours were found between rearing and fattening pigs. During rearing, highest exploration durations were recorded for straw pellets with fried onion flavour or almond flavour. During fattening, pigs explored straw pellets without flavour or with strawberry flavour longest. Exploration duration could be maintained at a constant level from rearing to fattening. Most skin injuries at the tails occurred when using vanilla flavour or fried onion flavour during rearing, whereby vanilla, unlike fried onion, was one of the flavours with the lowest exploration durations. On the basis of the present investigations clear preferences of pigs for specific plant-based enrichment materials could be shown, which increased species-specific exploration behaviour. However, enrichment materials for which high exploration durations were recorded could not reduce tail damages, such as partial losses or skin injuries. This illustrates that, apart from the access to enrichment material, further factors influence the prevalence of tail damages, which have to be considered in relation to each other.
  • Publication
    Foam mat drying of cassava and associated properties : comparison between white-flesh and yellow-flesh varieties
    (2021) Ayetigbo, Oluwatoyin Elijah; Müller, Joachim
    Cassava is an important staple food crop in Africa, Asia and Americas, serving as food, raw material, feed, and source of livelihoods. However, cassava has poor post-harvest physiological stability, deteriorates rapidly, has high toxic cyanogenic contents and poor physicochemical properties. Foam mat drying was considered as a technique to combat these challenges. First, a comparison of the different properties of variants of cassava based on colour was made from the perspective of sustainability. Afterwards, an optimization of the foaming process was conducted for two varieties (white-fleshed and yellow-fleshed) of cassava using various foaming variables. Optimal variables were not different between both varieties. Foaming reduced cyanogenic toxicity and retained carotenoids in cassava significantly, but also had significant influence on colour. The foams developed had asymmetrical distribution in air bubble diameter, while foam powder microstructure showed close association between the hydrocolloids and starch. Furthermore, an optimization of the drying conditions of optimal cassava foams was conducted based on temperature and foam thickness. Drying kinetics (moisture removal ratio, diffusivity, dying rate) of the cassava foams and the effect of various drying conditions on selected physicochemical properties of cassava foam powder was researched. Two falling rates were found during drying, Diffusivity was significantly affected by temperature but not foam thickness. The cassava foam powders had acceptably low cyanogenic contents, and had high retention of carotenoids. Foam powder microstructure did not change significantly with temperature, but yellow cassava foam powder had higher coalescence.
  • Publication
    Untersuchungen zur pneumatischen Aufnahme von Unkrautsamen
    (1998) Kahrs, Johannes; Kutzbach, Heinz Dieter
    Die Erntearbeit mit dem Mähdrescher kann für die Unkrautbekämpfung genutzt werden. Die Unkrautbekämpfung, bzw. die Beeinflussung der Unkrautpopulation beim Mähdrusch kann mit unterschedlichen Geräten und Einrichtungen durchgeführt werden. Insbesondere in biologischen Betrieben sollte die Erntearbeit mit dem Mähdrescher aus ökonomischen und ökologischen Gründen genutzt werden, um Unkrautsamen von der Ackerfläche zu entfernen und damit den Unkrautsamenvorrat des Bodens zu entziehen. Eine Möglichkleit ist die Sammlung der bei der Getreidernte auf der Bodenoberfläche liegenden Unkrautsamen. Im Rahmen der vorliegenden Arbeit werden spezielle Saugeinrichtungen für die pneumatische Aufnahme von Unkrautsamen untersucht.
  • Publication
    Auswirkungen der flexiblen Biogasproduktion auf die Effizienz von landwirtschaftlichen Biogasanlagen
    (2020) Kress, Philipp; Jungbluth, Thomas
    In future energy systems based on renewable energies, biogas plants can make a significant contribution to stabilizing the electricity grids. However, this requires demand-flexible and load-driven electricity production, which is only made possible by flexible biogas production with extremely versatile feed management. From the process engineering and process biology point of view, this demand-flexible operation represents a major challenge for the operation of biogas plants. Technically, this demand-flexible biogas production requires a complete utilization of the existing fermenter volume, which in turn requires an optimal mixing of the substrates in the fermenter. Similarly, a continuous high-resolution monitoring of the produced biogas composition is also necessary to detect process disturbances or overloads that begin at an early stage. The objective of this work was to test and optimize new measuring methods for the flow velocity measurement and the mixing quality in the biogas reactor. Furthermore, to achieve a high-resolution gas quality measurement, practical scale tests were conducted. From these results, conclusions about possibilities and limitations of a flexibilisation of the biogas production shall be derived. Stirring is one of the most important processes in biogas production. The power input was intended to generate turbulent flows and thus ensure uniform distribution of nutrients and homogeneous temperatures throughout the reactor and avoid sinking and floating layers. In order to be able to assess and optimize these mixing processes, investigations of flow velocities in the fermenter were carried out using a magnetic-inductive measuring system. Additionally, flow profiles were created as a function of the DM content and the viscosity of the fermentation substrate. At a DM content of 9.45% in the fermenter, the average flow velocity measured was 87.5 cm/s. The DM content and the viscosity of the fermenting substrate were also taken into account. This dropped to 0.96 cm/s with a DM content of 9.95%. For the further description of the mixing quality, spatially dissolved nutrient samples were taken from the entire fermenter to determine the biological parameters. It was proven that the punctual input of the solid biomass via the solid input leads to a locally increased DM content and increased concentrations of organic acids in the vicinity of the input. In contrast to the laboratory tests using the process tomography method, no zone was found in the fermenter at which process disturbances were present. Furthermore, in contrast to laboratory tests, no biologically inactive zones could be detected in the fermenter of the research biogas plant. In further investigations, a photoacoustic sensor with a newly developed measuring system for determining the methane and carbon dioxide concentrations of the biogas was installed, tested and optimized for the first time in a biogas plant in the field. The basic applicability of such a system in biogas plants could be demonstrated. The achieved data density was significantly higher than that of conventional devices with a very high precision of the measured values. Using this innovative measuring technique, a flexible substrate supply and its influence on the product gas quality was subsequently evaluated. Substrates with different degradation behavior and different specific methane yields were fed to the fermenter. The influence of the specific substrate used in biogas production was reflected in the biogas quality. In particular, the relation between the relative change in gas quantity and quality makes it possible to detect process changes at an early stage. The presented studies have created a basis that enables a demand-oriented biogas production: Even with high substrate quantities that are fed to the fermenter, a high mixing quality can be achieved in the fermenter with an appropriate design of the agitators, which also prevents local process overloads. The investigations prove that, despite very low flow rates, there is sufficient nutrient supply for the microorganisms. The newly developed sensors for determining the biogas composition provide measured values with high precision and high temporal resolution, so that possible process disturbances can be detected very early. The investigations contribute to optimizing future demand-oriented electricity production on the basis of demand-flexible feeding in biogas plants. As a result, biogas plants can fulfil an important system service in a renewable energy based grid by decentrally stabilizing the electricity supply.
  • Publication
    Anforderungs- und einsatzgerechte Auslegung von Fahrantrieben mobiler Erntemaschinen
    (2019) Häberle, Steffen
    liegt leider nicht vor
  • Publication
    Crop plant reconstruction and feature extraction based on 3-D vision
    (2019) Vázquez Arellano, Manuel; Griepentrog, Hans
    3-D imaging is increasingly affordable and offers new possibilities for a more efficient agricul-tural practice with the use of highly advances technological devices. Some reasons contrib-uting to this possibility include the continuous increase in computer processing power, the de-crease in cost and size of electronics, the increase in solid state illumination efficiency and the need for greater knowledge and care of the individual crops. The implementation of 3-D im-aging systems in agriculture is impeded by the economic justification of using expensive de-vices for producing relative low-cost seasonal products. However, this may no longer be true since low-cost 3-D sensors, such as the one used in this work, with advance technical capabili-ties are already available. The aim of this cumulative dissertation was to develop new methodologies to reconstruct the 3-D shape of agricultural environment in order to recognized and quantitatively describe struc-tures, in this case: maize plants, for agricultural applications such as plant breeding and preci-sion farming. To fulfil this aim a comprehensive review of the 3-D imaging systems in agricul-tural applications was done to select a sensor that was affordable and has not been fully inves-tigated in agricultural environments. A low-cost TOF sensor was selected to obtain 3-D data of maize plants and a new adaptive methodology was proposed for point cloud rigid registra-tion and stitching. The resulting maize 3-D point clouds were highly dense and generated in a cost-effective manner. The validation of the methodology showed that the plants were recon-structed with high accuracies and the qualitative analysis showed the visual variability of the plants depending on the 3-D perspective view. The generated point cloud was used to obtain information about the plant parameters (stem position and plant height) in order to quantita-tively describe the plant. The resulting plant stem positions were estimated with an average mean error and standard deviation of 27 mm and 14 mm, respectively. Additionally, meaning-ful information about the plant height profile was also provided, with an average overall mean error of 8.7 mm. Since the maize plants considered in this research were highly heterogeneous in height, some of them had folded leaves and were planted with standard deviations that emulate the real performance of a seeder; it can be said that the experimental maize setup was a difficult scenario. Therefore, a better performance, for both, plant stem position and height estimation could be expected for a maize field in better conditions. Finally, having a 3-D re-construction of the maize plants using a cost-effective sensor, mounted on a small electric-motor-driven robotic platform, means that the cost (either economic, energetic or time) of gen-erating every point in the point cloud is greatly reduced compared with previous researches.