Agricultural Engineering Research, Volume 13 (2007)

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Microbial diversity in a biogas-producing co-fermentation of maize silage and bovine manure
(2007) Souidi, Khadidja; Mumme, Jan; Nettmann, Edith; Bergmann, Ingo; Linke, Bernd; Klocke, Michael
The efficiency of biogas reactors strongly depends on the substrate utilization by the microbial biocoenosis. Up to now, the structure of this microbial community has not been sufficiently characterized. In this study, an overview of the most abundant species within a biogas-producing, completely-stirred tank reactor (CSTR) during the co- fermentation of maize silage and bovine manure was sur- veyed. The analysis based on two 16S rDNA libraries each enriched for methanogenic Archaea (81 clones) and fer- mentative Bacteria (118 clones). The CSTR showed a huge diversity within the methanogenic Archaea. The or- der Methanomicrobiales was present with eight opera- tional taxonomic units (OUT), the order Methanosarcina- les with three OTU and the order Methanobacteriales with two OTU. The order Methanococcales was not detected. One OTU could not be assigned to any order. Most OTU (71 %) were affiliated to hydrogenotrophic methanogens like Methanoculleus bourgensis, Methanobrevibacter ru- minantium, Methanospirilllum hungatei and Methanocor- pusculum parvum. Acetate-utilizing Archaea were detected with 3 OTU related to Methanosarcina barkeri and Methanosaeta concilii. Within the domain Bacteria a rich diversity was found within the members of the phyla Fir- micutes (27 OTU) and Bacterioidetes (13 OTU). Also cer- tain OTU of the phyla Proteobacteria (4 OTU), Spiro- chaetes (2 OTU), Fibrobacteres (1 OTU) and Chloroflexi (1 OTU) were found. Ten OTU could not be grouped with any cultivated type strain. The dominance of OTU related with H2-consuming methanogens in the Archaea-specific 16S rDNA library and their rich diversity point to major formation of methane by oxidation of CO2.
Analysis of site-specific N-fertilization on-farm trials in cereals under assump-tion of spatial covariance structures
(2007) Thöle, Heinrich; Richter, Christel; Kroschewski, Bärbel; Ehlert, Detlef
The application of real-time sensors provides the possi- bility of adapting nitrogen fertilization to requirements in heterogeneous cereal crops site-specifically. Efficient and environmentally sound fertilization strategies can be de- veloped by the use of on-farm trials as a contribution to sensor-based farming. This paper assesses what agro- nomic effects can be found using the mechanical sensor "Crop-Meter" for nitrogen fertilization. On-farm trials were conducted to compare the application of uniform ni- trogen rates with sensor-based site-specifically applied rates. As an example, an approach is demonstrated taking the crop heterogeneity into account as a factor of interest in the statistical analysis, whereas heterogeneity is often treated as undesired noise factor. To include the hetero- geneity, yield data were classified by magnitude of the above-ground plant mass in order to create comparable conditions. Each class was analyzed by assuming mixed models taking into account spatial co-variance structures, which provided substantially better model fits than the classic ANOVA model. The trial considered showed that the reduction of nitrogen fertilizer in site-specific appli- cation (mean: 22 kg ha–1 N) caused no statistically sig- nificant yield differences by comparison with uniform application. Therefore, the spatial variation of nitrogen fertilizers seems a useful contribution to reducing direct cost of crop production and to decreasing environmental impacts.
Body posture analysis during visual control of fruit and vegetables at different directions and speeds of conveyor belt transport
(2007) Jakob, Martina; Geyer, Martin
Visual quality control of fruit and vegetables is a com- plex task. Reliability is important to sustain quality stan- dards. Usually the quality control is followed by or car- ried out after other mechanized processes like washing or packing. The expectations on the worker’s performance are influenced by the machine capacities. Nevertheless work place design is conservative even in modern plants; products are commonly transported on conveyor belts passing the worker from the left to the right or the other way around. Thus the man-machine-interface often be- comes a constructive shortcoming. Based on literature the superiority of a changed product transport, namely moving the products towards the worker, was to be ex- amined. A motion analysis was carried out to measure differences in the body postures as well as the amount of movements for the variations of product transport. The influence of the transport direction was very strong, re- sulting in a 100 % larger sum of motion per piece if the goods passed the worker from the right side. Most effi- cient and most comfortable proved to be the transport di- rection towards the worker.
Process times in logistic chains - New proposals for classification, measurement, and application
(2007) Sonnen, Johannes; Hahn, Jürgen
More than time analysis in individual machines, time measurements in harvest process chains require a gener- ally recognized, practicable structure of work time classi- fication, for which suggestions are given in this contribu- tion. In addition, a process data acquisition system which, among other features, allows critical points to be ana- lyzed and work time to be documented based on auto- matically collected data is put up for discussion.
Occupational accidents in Swedish agriculture
(2007) Pinzke, Stefan; Lundqvist, Peter
The Swedish University of Agricultural Sciences in co- operation with Statistics Sweden carried out a compre- hensive survey of accidents in Swedish farming and for- estry that occurred in 2004. The aim was to get in-depth knowledge about the origin and extent of the accidents and also to obtain information as a basis for the planning of preventive measures in agriculture. The study was fi- nanced by the Swedish Farmers’ Foundation for Agricul- tural Research. In 2004, there were about 67,000 farms with agricultural operations in Sweden. 7,000 question- naires with 14 questions were sent out to a sample of the pure agricultural farms and combined agricul- tural/forestry farms. The most important question was whether any accidents had occurred at the farms during 2004. Those farms that reported accidents were thereafter contacted by telephone with additional questions about the respective accident. A total of 5,646 farms (81 %) answered the questionnaires. About 5,000 accidents oc- curred on agricultural farms in 2004 that resulted in bod- ily injuries and constituted obstacles at work (about 74 % accidents on pure agricultural farms and 18 % on agricul- tural farms with forestry). According to official statistics there were only about 400 registered accidents. This means that only 8 % of the reported accidents found in this study emerge in the official statistics of occupational injuries. In all, at least one accident occurred on about 7 % of all farms practicing agriculture. About 70 % of the affected farms had animal production and 15 % of all farms with milk production had one or more accidents during 2004. In order to reduce the number of accidents in agriculture it is important to take effective measures.
Bavarian animal welfare pilot farms - Labor input by comparison
(2007) Haidn, Bernhard; Schleicher, Thomas; Macuhová, Juliana
The aim of this working time study was to obtain basic data from all 34 monitored farms with different farm ac- tivities. Moreover, an overview of the labor management and working conditions in Bavarian livestock husband- ries was to be given to assess their national and interna- tional level. To collect labor input data, the farmers kept working diaries for 16 weeks over one or more periods (e.g. at least during one whole fattening period, or dis- tributed equally over the whole year), depending on their specialization. They were to enter all working procedures performed during this period. For seven farms the re- cording quality was evaluated as “unsatisfactory” or “in- sufficient”. Reliable data on labor input were obtained from the others. For the 12 dairy farms (18–99 cows) a labor input of 42 – 114 working hours (WH) per cow and year was ascertained. Milking, feeding, young cattle care and management required the greatest shares of working time in descending order. Only five farms do not exceed the available labor capacity. Three organic farms keeping 20–52 suckler cows had a labor input of 16–27 WH per cow and year. These are typical results for the herd sizes observed. In the piggeries the organic production method had a bearing on the labor input. Three organic farms keeping breeding sows needed 22–35 WH per sow and year, while four conventional farms had results between 10 and 14 WH per sow und year. Also in the pig fatten- ing activity the one organic farm tested differs substan- tially (3.7 WH per pig place and year) from the three conventional farms with 0.6–1.1 WH per pig place and year. In pig fattening production, the labor input is be- tween 4 and 98 % of the available work capacity. This was mostly influenced by the volume of production and the better utilization of the housing capacity after moving into a new building. Three farms with laying hens (500– 3,000 hen places) had a decreasing labor input per place und year with increasing herd size. Only 15–30 % of their available work capacity was used.
Work-related musculoskeletal disorder and vibration risk in forestry
(2007) Calvo, Angela
In forestry yards we find hard environmental conditions and dangerous tools and machinery such as chainsaws. In this context forestry workers are exposed to many safety risk factors: injuries, noise, hand-arm and whole body vibrations, dust, back pains, manual work load. The high manual work load is tiring and can cause work-related musculoskeletal disorder (MSD) amongst the loggers. This pathology increases with the component ‘vibration’ induced by chainsaws, tractors, skidders and other machinery. In fact, both the Whole Body Vibration (WBV) and the Hand Arm Vibration (HAV) have been detected as important risk factors, which must be strictly controlled. In this study we consider two different logger groups working in public forestry yards and we analyze their MSD risk exposure, using the Ovako Working- posture Analysis System (OWAS) technique and the 2002/44/EC vibration Directive. In the first yard, mechanical tree felling using chainsaws and manual deforestation are the tasks performed; in the second yard, the operations are mechanical tree felling and log stacking using a tractor also. The work of five loggers was analyzed, evaluating all risk types. The result was that both the OWAS index and the vibration indicators were quite high. This demonstrated the critical situation for forestry workers.
Data acquisition in Precision Livestock Farming for improved calf rearing
(2007) Spreng, Viktoria; Ehrl, Markus; Bachmaier, Martin; Auernhammer, Hermann
The networking of electronic process control systems of- fers new possibilities for individual calf management. The different systems are implemented as automatic sys- tems or robots in order to reduce labor. Within this paper, the experimental setup of the underlying investigation and first results with a statistical evaluation of feeding data are presented. Intake amounts of water and dry mat- ter as a function of age are shown. The results require an individual adaptation of the milk-drinking programme. All known authors either refer separately to drinking wa- ter, feed concentrate, forage intake or body weight but so far there has been no evaluation of combining these data. Use of computer-controlled interlinked feeding systems allows economic advantages in many respects and pro- vides a comprehensive decision-support system for the management.
Modeling of pollution removal in constructed wetlands with horizontal subsurface flow
(2007) Brasil, Mozart da Silva; de Matos, Antonio Teixeira; Silva, Cláudio Mudado; Cecon, Paulo Roberto; Soares, Antonio Alves
This study was carried out to obtain the parameters of the kinetics equation for removal of the organic load and to evaluate the performance of four constructed wetland systems with subsurface flow (CWHSSF) measuring 24.0 x 1.0 x 0.3 m for treatment of the domestic wastewater from an anaerobic septic tank. The system was filled with a course of crushed stone that served as substrate for the macrophyte under study, which was cattail (Typha sp.). Two hydraulic retention times (t) of 1.9 and 3.8 days were used. Different volumetric organic load rates (116, 164 and 210 g m3 d-1) were tested. The following vari- ables were measured: chemical oxygen demand (COD) and total suspended solids (TSS). The parameters KV and n of the kinetic model for organic load removal were ob- tained by nonlinear regression. The organic load rates had no negative influence on pollutant removal. A hy- draulic retention time of 3.8 days was more effective in removing COD and TSS than a hydraulic retention time of 1.9 days. The model (Co/Ci = exp(-1.6221 t0.2491) for organic load removal, which is proposed in the present work, showed satisfactory adjustment and describes the organic load removal kinetics in the evaluated system appropriately.
Long-term studies of crop yields with changing rainfall and fertilization
(2007) Márton, László; Pilar, Pereda Merino; Grewal, Mohinder Singh
The anthropogenic effects of global climate change on water resources may be masked by natural climate vari- ability. With a warmer climate, drought and excess rain- fall conditions could become more frequent, severe, and longer-lasting. The potential increase in these natural hazards is of concern, given the stresses they place on water resources and agricultural production, and the high costs that result from these hazards. For these reasons, long-term studies were conducted in Eastern Hungary from 1962-2001 in order to obtain the relationship be- tween rainfall quantities, soil agrochemical properties, and mineral fertilization on yields of rye, potato, winter wheat and triticale. Averaged rainfall quantities over many years, experimental years, and phenological phases over many years and experimental years for rye were 567 mm, 497 mm, 509 mm and 452 mm; for potato 551 mm, 537 mm, 337 mm and 294 mm; for winter wheat 586 mm, 509 mm, 518 mm and 467 mm; for triti- cale 551 mm, 537 mm, 489 mm and 497 mm respec- tively. Rainfall deviations (+/-) from the average over many years in the experimental years and during the phenological phases for rye were –12 % and –11 %; for potato –3 % and –13 %; for winter wheat –13 % and –10 %; and for triticale –3 % and 2 %. During the vegeta- tion period, the relationships between rainfall quantity, nutrition (N, P, K, Ca, Mg), and yield were characterized by polynomial correlations “R” (rye: 0.65-0.99, potato: 0.95-0.98, winter wheat: 0.54-0.76, triticale: 0.28-0.67). Maximum yields of 4.0 t ha Neben dem globalen Klimawandel können Veränderun- gen im Wasserhaushalt ihre Ursache auch in natürlichen Klimaschwankungen haben. Mit wärmerem Klima kön- nen sich extreme Witterungsbedingungen mit ausgepräg- ten Trocken- und Niederschlagsphasen häufen und länger andauern. Der potenziellen Zunahme von Naturrisiken ist wegen der Auswirkungen auf die Wasserressourcen und die landwirtschaftliche Produktion besondere Rechnung zu tragen. Von 1962-2001 wurden Dauerfeldversuche in Ostungarn durchgeführt, um die Zusammenhänge zwi- schen Niederschlag, Düngung und Bodeneigenschaften auf der einen Seite und dem Pflanzenertrag von Roggen, Kartoffeln, Winterweizen und Triticale auf der anderen Seite zu ermitteln. Im langjährigen Mittel lagen die Nie- derschlagsmaxima in den Vegetationsperioden während der Versuchsjahre für Roggen bei 567, 497, 509 und 452 mm, für Kartoffel bei 551 mm, 537 mm, 337 mm und 294 mm für Winterweizen bei 586 mm, 509 mm, 518 mm und 467 mm sowie für Triticale bei 551 mm, 537 mm, 489 mm und 497 mm. Niederschlagsabwei- chungen vom langjährigen Mittel betrugen während der Versuchsjahre und der Vegetationsperioden für Roggen –12 % bzw. –11 %; für Kartoffel –3 % bzw. –13 %; für Winterweizen –13 % bzw. –10 % und für Triticale –3 % bzw. 2 %. Die Zusammenhänge zwischen der Vegetati- onsperiode, der Niederschlagshöhe, der Nährstoffsituati- on (N, P, K, Ca, Mg) und dem Ertrag lassen sich anhand polynominaler Korrelationen beschreiben mit R = 0,65- 0,99 für Roggen, R = 0,95-0,98 für Kartoffeln, R = 0,54- 0,76 für Winterweizen und R = 0,28-0,67 für Triticale. Jährliche Höchsterträge ergaben sich in folgenden Nie- derschlagsbereichen: 4.0 t Roggen ha -1 * Corresponding author. Tel: ++36 1 355 8491; Fax: ++36 1 355 84 91; E-mail: marton@rissac.hu 1 Introduction Climate change has been recognized as a serious envi- ronmental issue already since the 1980s and 1990s. The present increase of greenhouse gases (GHG) such as carbon dioxide, methane, water vapour, ozone, ni- trous oxide, sulphur hexafluoride, hydrofluorocarbons, perfluorocarbons and chlorofluorocarbons in the atmo- sphere probably will lead to significant climate for rye, 21.0 t. -1 ha for potato, 3.4 t ha-1 for winter wheat, and 5.5 t ha-1 for triticale were observed when the respective natural rain- fall amount was in the range of 430-500, 280-330, 449-495 and 550-600 mm. At rainfall amounts above and below these ranges, crop yields are drastically reduced.
Tube Ensiling of Hemp - Initial Practical Experience
(2007) Pecenka, Ralf; Idler, Christine; Grundmann, Philipp; Fürll, Christian; Gusovius, Hans-Jörg
The conventional production of natural fibres from e.g. hemp or flax is based on field drying and retting of fibre straw. Since at the usual harvest time in September, weather conditions are often problematical for harvesting and retting hemp, a weather-independent post-harvest technique was studied. The harvesting of hemp by means of a chopper followed by anaerobic storage is favourable for the farmer because the weather risk can be avoided. Additional steps are the same as those for ensiling of fod- der. As a further advantage of this novel processing tech- nology, the whole plant material will be processed to form final products such as insulation materials and fibre boards, or semi-finished products for injection moulding. At present, a pilot plant with a processing capacity of 1 t per hour hemp silage is being built up and tested. The in- vestigations regarding storage costs and appropriate stor- age technology have shown that both stack silos and film silos are capable of preserving the raw material for more than one year. Initial results of the preservation of hemp in film tubes are presented.

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