Template-Type: ReDIF-Article 1.0 Author-Name: Radim VAŠÁT Author-Workplace-Name: Department of Soil Science and Soil Protection, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: Lenka PAVLŮ Author-Workplace-Name: Department of Soil Science and Soil Protection, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: Luboš BORŮVKA Author-Workplace-Name: Department of Soil Science and Soil Protection, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: Ondřej DRÁBEK Author-Workplace-Name: Department of Soil Science and Soil Protection, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: Antonín NIKODEM Author-Workplace-Name: Department of Soil Science and Soil Protection, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Prague, Czech Republic Title: Mapping the topsoil pH and humus quality of forest soils in the North Bohemian Jizerské hory Mts. region with ordinary, universal, and regression kriging: cross-validation comparison Abstract: North Bohemia belongs to one of the most heavily industrialized and polluted regions in Europe. The enormous acid deposition which culminated in the 1970s has largely contributed to the accelerated acidification process in the soils and consequently to the wide forest decline in North Bohemian mountains. In this paper we map the active topsoil pH and humus quality with ordinary, universal, and regression kriging and compare the accuracy of resulting maps with cross-validation. For the regression kriging we use two types of spatially exhaustive auxiliary information, first the altitude derived from digital elevation model and second the land cover classes derived from satellite imagery. The leave-one-out (cross-validation) statistics, i.e. mean error, root mean squared error, and mean squared deviation ratio, are taken for comparison since they are widely accepted as measurements of the accuracy of digital soil maps. The results show that the regression kriging is superior over other kriging methods in this case. Out of 97 sampling sites the regression kriging with land cover classes is the best predictor at 32 sites for pH and at 30 sites for humus quality, the regression kriging with altitude at 31 and 25 sites, the universal kriging at 21 and 23 sites, and the ordinary kriging at 13 and 18 sites. The highest number of best predictions for regression kriging implies that the topsoil pH and humus quality are driven approximately equally by land cover and altitude and little less by pure geographic position. Furthermore, the universal kriging maps show a northeast to southwest spatial trend of topsoil pH and a northwest to southeast spatial trend for humus quality. Keywords: Black Triangle, digital soil mapping, geostatistics, map accuracy Journal: Soil and Water Research Pages: 97-104 Volume: 8 Issue: 3 Year: 2013 DOI: 10.17221/62/2012-SWR File-URL: http://swr.agriculturejournals.cz/doi/10.17221/62/2012-SWR.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/swr-201303-0001.txt Handle: RePEc:caa:jnlswr:v:8:y:2013:i:3:id:62-2012-SWR Template-Type: ReDIF-Article 1.0 Author-Name: Eva NOVÁKOVÁ Author-Workplace-Name: Research Institute for Soil and Water Conservation, Brno, Czech Republic Author-Name: Miloš KAROUS Author-Workplace-Name: GEONIKA, Ltd., Prague, Czech Republic Author-Name: Antonín ZAJÍČEK Author-Workplace-Name: Research Institute for Soil and Water Conservation, Prague, Czech Republic Author-Workplace-Name: Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: Magda KAROUSOVÁ Author-Workplace-Name: GEONIKA, Ltd., Prague, Czech Republic Title: Evaluation of ground penetrating radar and vertical electrical sounding methods to determine soil horizons and bedrock at the locality Dehtáře Abstract: Recently, geophysical methods have been widely used in many fields including pedology. Two of them, ground penetrating radar (GPR) and vertical electrical sounding (VES) were employed at the Dehtáře experimental site with the aim to evaluate their application in the Cambisol and Stagnosol soil types and crystalline bedrock survey in Czech conditions. These measurements were complemented by the classical soil survey using a gouge auger. As a result, interpreted soil and rock environment profiles were obtained, with the identification of boundaries of Bg, C, and R soil horizons and bedrock at various degrees of weathering. The interpretation of measurement records demonstrated suitability of the VES and GPR method application, using GPR for imaging the soil profile and the top of bedrock, while the VES method gave better results in imaging greater depths. The research demonstrated advantages of the geophysical methods such as instancy, continuous imaging, and no disturbance of the subsurface. In spite of needing classical survey data for interpretation of the results obtained by the geophysical methods, their usage can bring better quality to the soil profile imaging. Keywords: geophysical method, parent rock, soil layer, soil survey Journal: Soil and Water Research Pages: 105-112 Volume: 8 Issue: 3 Year: 2013 DOI: 10.17221/6/2012-SWR File-URL: http://swr.agriculturejournals.cz/doi/10.17221/6/2012-SWR.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/swr-201303-0002.txt Handle: RePEc:caa:jnlswr:v:8:y:2013:i:3:id:6-2012-SWR Template-Type: ReDIF-Article 1.0 Author-Name: Scott Stephen KNIGHT Author-Workplace-Name: National Sedimentation Laboratory, USDA-ARS, Oxford, USA Author-Name: Martin Anderson LOCKE Author-Workplace-Name: National Sedimentation Laboratory, USDA-ARS, Oxford, USA Author-Name: Sammie SMITH Author-Workplace-Name: National Sedimentation Laboratory, USDA-ARS, Oxford, USA Title: Effects of agricultural conservation practices on oxbow lake watersheds in the Mississippi River alluvial plain Abstract: Agricultural lands are considered to be a major source of nonpoint source pollutants such as sediment, pesticides and nutrients in the United States. Conservation practices have been tested for their effectiveness in reducing agricultural related pollutants on smaller scales, but farm watershed scale assessments of these practices are limited and few of these have evaluated the impacts on downstream ecology. Several projects focused on oxbow lake watersheds in the Mississippi River alluvial plain were designed to utilize working farms to evaluate primary pollutants in water resources and to identify conservation practices that are most effective in reducing the transport of those pollutants in surface and ground water on a watershed scale. Major findings of these studies include: (1) conservation practices reduced sediment in oxbow lakes, resulting in improved water clarity, plankton growth, and fish stocks; (2) total phosphorus in lakes decreased between 39-50% following application of conservation practices; (3) conservation tillage and cover crops reduced NO3-N losses by 73%, sediment losses by 70; and (4) riparian areas mitigated the transport of sediment in runoff and enhanced the degradation of pesticides. Keywords: limnology, management systems evaluation area, nutrients, pesticides, sediment, water quality Journal: Soil and Water Research Pages: 113-123 Volume: 8 Issue: 3 Year: 2013 DOI: 10.17221/45/2012-SWR File-URL: http://swr.agriculturejournals.cz/doi/10.17221/45/2012-SWR.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/swr-201303-0003.txt Handle: RePEc:caa:jnlswr:v:8:y:2013:i:3:id:45-2012-SWR Template-Type: ReDIF-Article 1.0 Author-Name: Mehdi BASHARI Author-Workplace-Name: Department of Watershed Science and Engineering, Faculty of Natural Resources, Tarbiat Modares University, Noor, Iran Author-Name: Hamid Reza MORADI Author-Workplace-Name: Department of Watershed Science and Engineering, Faculty of Natural Resources, Tarbiat Modares University, Noor, Iran Author-Name: Mir Masoud KHEIRKHAH Author-Workplace-Name: Soil Conservation and Watershed Management Research Institute, Tehran, Iran Author-Name: Majid JAFARI-KHALEDI Author-Workplace-Name: Department of Statistics, Faculty of Mathematical Sciences, Tarbiat Modares University, Tehran, Iran Title: Temporal variations of runoff and sediment in different soil clay contents using simulated conditions Abstract: Soil clay content (SCC) plays an essential role in the processes of infiltration, seal and crust formation, runoff, and soil erosion. The role played by SCC in water erosion has received much attention in recent years. Hence, in order to investigate these effects on a small scale, a simulation experiment was conducted. Soil lacking clay content was combined with 0, 10, 20, 30, 40, and 50% of clay soil, respectively. The experimental setup consisted of rectangular metal plots (1.5 × 1 m) comprising soil with selected combinations of clay content, placed at a 9% slope. Six treatments, three replicates each (totally 18 plots), were exposed to simulated rainfall at an intensity of 70 mm/h for 30 min. The results were compared by means of statistical tests. General trends in runoff volume were similar for different SCCs and decreasing and increasing trends were achieved for sediment and runoff, respectively. The results showed significant differences in the hydrological and erosional responses of these soils based on their clay contents. The soils with intermediate clay content were more resistant to erosion and had lower values of the runoff. Finally, time had significant (P < 0.00) effects on both runoff and sediment production during the rainfall. Keywords: clay, erosion plot, rainfall simulator Journal: Soil and Water Research Pages: 124-132 Volume: 8 Issue: 3 Year: 2013 DOI: 10.17221/60/2012-SWR File-URL: http://swr.agriculturejournals.cz/doi/10.17221/60/2012-SWR.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/swr-201303-0004.txt Handle: RePEc:caa:jnlswr:v:8:y:2013:i:3:id:60-2012-SWR Template-Type: ReDIF-Article 1.0 Author-Name: Martin HEŘMANOVSKÝ Author-Workplace-Name: Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic Author-Name: Pavel PECH Author-Workplace-Name: Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic Title: Selection of catchment descriptors for the physical similarity approach. Part I: Theory. Abstract: This paper focuses on a description of the method used for the identification of optimal catchment descriptors for the physical similarity approach consisting of a scheme for the identification of optimal catchment descriptors and the procedure for finding hydrologically homogeneous regions using inverse clustering. Andrews' curves are used as the basis for homogeneity checking. The identification of an optimum catchment descriptor is based on the assumption that the addition of an optimal catchment descriptor to a predefined set of catchment descriptors improves the accuracy of model parameter estimation within a set of tested catchments. Two criteria are proposed for the selection of optimal catchment descriptors - a criterion evaluating estimates of model parameters on the basis of different potentially optimal groups of catchment descriptors, MIN, and a criterion evaluating the improvement in model parameter estimation after the addition of a potentially optimal catchment descriptor into the group of preliminarily identified optimal catchment descriptors, MAX. The proposed method provides an alternative to the trial-and-error method for the identification of optimal catchment descriptors. Keywords: catchment characteristic, inverse clustering, regionalisation Journal: Soil and Water Research Pages: 133-140 Volume: 8 Issue: 3 Year: 2013 DOI: 10.17221/22/2012-SWR File-URL: http://swr.agriculturejournals.cz/doi/10.17221/22/2012-SWR.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/swr-201303-0005.txt Handle: RePEc:caa:jnlswr:v:8:y:2013:i:3:id:22-2012-SWR