Template-Type: ReDIF-Article 1.0 Author-Name: P. Šařec Author-Workplace-Name: Department of Machinery Application, Faculty of Technology, Czech University of Live Sciences in Prague, Prague, Czech Republic Author-Name: O. Šařec Author-Workplace-Name: Department of Machinery Application, Faculty of Technology, Czech University of Live Sciences in Prague, Prague, Czech Republic Author-Name: V. Prošek Author-Workplace-Name: Department of Machinery Application, Faculty of Technology, Czech University of Live Sciences in Prague, Prague, Czech Republic Author-Name: K. Čížková Author-Workplace-Name: Department of Machinery Application, Faculty of Technology, Czech University of Live Sciences in Prague, Prague, Czech Republic Title: Laser profilometer testing by laboratory measurements Abstract: Measuring soil surface profile has many purposes in the field of agriculture and landscape management. For example, it concerns quantitative evaluation of work quality of soil cultivation implements, and related assessment of soil surface status prior sowing. For this purpose, a prototype of laser profilometer was produced whose key parts are a laser sensor Banner LT3 fixed together with a control section, a converter etc. on a carriage that travels propelled by an electromotor along an aluminum girder. In 20 mm intervals determined by an optical sensor, the laser sensor measures a distance to a soil surface. The aim of the work is to verify some laser sensor properties such as a linearity of measurement, sensitivity to surface color, and furthermore to establish appropriate window limits of laser sensor measurement. Keywords: soil surface, profile, roughness, laser sensor, profilometer Journal: Research in Agricultural Engineering Pages: 1-7 Volume: 53 Issue: 1 Year: 2007 DOI: 10.17221/2134-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/2134-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-200701-0001.txt Handle: RePEc:caa:jnlrae:v:53:y:2007:i:1:id:2134-RAE Template-Type: ReDIF-Article 1.0 Author-Name: P. Prikner Author-Workplace-Name: Department of Vehicles and Ground Transport, Faculty of Technology, Czech University of Live Sciences in Prague, Prague, Czech Republic Author-Name: A. Grečenko Author-Workplace-Name: Department of Vehicles and Ground Transport, Faculty of Technology, Czech University of Live Sciences in Prague, Prague, Czech Republic Author-Workplace-Name: Institute of Production Technology and Management, University J.E. Purkyně, Ústí nad Labem, Czech Republic Title: Farmland protection by means of tyre load rating Abstract: At present, the professionals in the industry and farming still miss comparative technical data indicating the potential of agricultural vehicles and mobile machinery to inflict compaction damage upon the cultivated soil. Harmful compaction means especially the increase of soil bulk density above a critical level required for efficient plant production. In general, it seems reasonable to restrict the excessive soil compaction by loaded wheels starting from the design of farm power and machinery, which means to provide technical data on the compaction potential of tyres. This paper presents the technique of tyre rating by means of the index Compaction Capacity (CC), which simply reflects the compaction potential of any individual tyre contained in a tyre catalogue within the whole range of loads and inflation pressures. Keywords: agricultural tyres, soil compaction modelling, compaction capacity, tyre rating Journal: Research in Agricultural Engineering Pages: 8-13 Volume: 53 Issue: 1 Year: 2007 DOI: 10.17221/2131-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/2131-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-200701-0002.txt Handle: RePEc:caa:jnlrae:v:53:y:2007:i:1:id:2131-RAE Template-Type: ReDIF-Article 1.0 Author-Name: R. Rusinek Author-Workplace-Name: Institute of Agrophysics, Polish Academy of Sciences, Lublin, Poland Author-Name: M. Molenda Author-Workplace-Name: Institute of Agrophysics, Polish Academy of Sciences, Lublin, Poland Title: Static and kinetic friction of rapeseed Abstract: he present paper examines the static and kinetic coefficient of friction of rapeseed. The project utilized two methods of determination of coefficient of friction of rapeseed: according Eurocode 1 (kinetic) in direct shear test and (static) in model silo. Samples of rapeseed in a range of moisture content from 6 to 15% w.b. were used and the tests were performed for galvanized steel, stainless steel and concrete B 30. Coefficient of friction for both steel types approached stable value for all levels of moisture content w.b. in a range from 0.11 to 0.18, for concrete B 30 it was found in a range from 0.25 to 0.43. The coefficient of static friction found in model silo decreased with an increase in vertical pressure from 0.3 to 0.2 for first loading, while in subsequent loading cycles decreased from 0.2 to 0.1. Keywords: rapeseed, static friction, kinetic friction, galvanized steel, stainless steel, concrete B 30 Journal: Research in Agricultural Engineering Pages: 14-19 Volume: 53 Issue: 1 Year: 2007 DOI: 10.17221/2129-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/2129-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-200701-0003.txt Handle: RePEc:caa:jnlrae:v:53:y:2007:i:1:id:2129-RAE Template-Type: ReDIF-Article 1.0 Author-Name: T. Włodarczyk Author-Workplace-Name: Institute of Agrophysics, Polish Academy of Sciences, Lublin, Poland Author-Name: P. Szarlip Author-Workplace-Name: Institute of Agrophysics, Polish Academy of Sciences, Lublin, Poland Author-Name: M. Brzezińska Author-Workplace-Name: Institute of Agrophysics, Polish Academy of Sciences, Lublin, Poland Author-Name: U. Kotowska Author-Workplace-Name: Institute of Agrophysics, Polish Academy of Sciences, Lublin, Poland Title: Redox potential, nitrate content and pH in flooded Eutric Cambisol during nitrate reduction Abstract: Topsoils from 16 arable Cambisols developed from sand, loam and silt were used to study soil ability to nitrate reduction under flooding conditions. The strongest drop of redox potential (Eh) was observed during the first day of soil flooding. Decreasing tendency in pH values was observed of alkaline and neutral soils, and an increase in pH of acid and strongly acid soils, accompanied by a fall in Eh values. Redox potential was negatively correlated with the pH values (R2 = 0.3041; p < 0.001). The fall of NO3- varied from 20 to 100% depending on the type of soil and on the time of incubation. With a decrease of nitrate content within the range from 100 to 10 mg NO3--N/kg, the value of redox potential decreased from 250 to 190 mV. The highest reduction of nitrates coincided with Eh values within a narrow range between 200 and 210 mV. Statistical analysis of redox potential in the function of the content of nitrates showed a curvilinear relation (R2 = 0.3823; p < 0.001). Keywords: soil, redox potential, denitrification, pH Journal: Research in Agricultural Engineering Pages: 20-28 Volume: 53 Issue: 1 Year: 2007 DOI: 10.17221/2132-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/2132-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-200701-0004.txt Handle: RePEc:caa:jnlrae:v:53:y:2007:i:1:id:2132-RAE Template-Type: ReDIF-Article 1.0 Author-Name: J. Cieśla Author-Workplace-Name: Institute of Agrophysics, Polish Academy of Sciences, Lublin, Poland Author-Name: M. Ryżak Author-Workplace-Name: Institute of Agrophysics, Polish Academy of Sciences, Lublin, Poland Author-Name: A. Bieganowski Author-Workplace-Name: Institute of Agrophysics, Polish Academy of Sciences, Lublin, Poland Author-Name: P. Tkaczyk Author-Workplace-Name: Regional Chemical-Agricultural Station in Lubin, Lubin, Poland Author-Name: R.T. Walczak Author-Workplace-Name: Institute of Agrophysics, Polish Academy of Sciences, Lublin, Poland Title: Use of ion-selective electrodes for determination of content of potassium in Egner-Rhiem soil extracts Abstract: Potassium is one of the most important nutrients for plants and its content in the soil should be monitored. In the precision agriculture, which is recommended now, the ion selective electrodes are tested to determine chemical properties of the soil. The objective of this work was an evaluation of use of the valinomycin-based ion selective sensors for determination of assimilated potassium in Egner-Rhiem soil extracts. Flame photometry was used as a reference method. Results obtained from potentiometric and photometric methods in soil extracts correlated linearly (R2 = 0.84). Analysis of soil extracts by the ion selective electrodes is simple and there is not a need for calcium ions precipitation. Keywords: potassium, ISE (ion selective electrode), Egner-Rhiem soil extract, precision agriculture Journal: Research in Agricultural Engineering Pages: 29-33 Volume: 53 Issue: 1 Year: 2007 DOI: 10.17221/2130-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/2130-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-200701-0005.txt Handle: RePEc:caa:jnlrae:v:53:y:2007:i:1:id:2130-RAE Template-Type: ReDIF-Article 1.0 Author-Name: M. Ryżak Author-Workplace-Name: Institute of Agrophysics, Polish Academy of Sciences, Lublin, Poland Author-Name: A. Bieganowski Author-Workplace-Name: Institute of Agrophysics, Polish Academy of Sciences, Lublin, Poland Author-Name: R.T. Walczak Author-Workplace-Name: Institute of Agrophysics, Polish Academy of Sciences, Lublin, Poland Title: Application of laser diffraction method for determination Abstract: Particle size distribution affects many physical soil properties and processes taking place in soil. There are many methods to determine the particle size distribution. The most frequently used are the sieve, sieve-pipette and sedimentation methods. Technological progress in electronics permitted a wide use of new methods of particle size distribution measurement in soil, e.g. the laser diffraction method. A comparison of particle size distribution obtained with the universally used areometer method (Cassagrande, modified by Prószynski) with results from the laser diffraction method for soil material received from grey-brown podzolic soil is presented in this work. The largest differences between the results were obtained for the smallest fraction determined with the areometer and laser diffraction methods. In a majority of other cases the slopes of interpolated straight lines were contained within the range of 0.81 / 1.09. Keywords: soil particle size, determination of grain size distribution, laser diffraction method Journal: Research in Agricultural Engineering Pages: 34-38 Volume: 53 Issue: 1 Year: 2007 DOI: 10.17221/2133-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/2133-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-200701-0006.txt Handle: RePEc:caa:jnlrae:v:53:y:2007:i:1:id:2133-RAE