Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2013
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No abstract has been registered
2012
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The source of input data for soil physical properties may contribute to uncertainty in simulated catchment response. The objective of this study was to quantify the uncertainty in catchment surface runoff and erosion predicted by the physically based model LISEM, as influenced by uncertainty in soil texture and SOM content, and the pedotransfer function derived soil water retention curve, hydraulic conductivity, aggregate stability and cohesion. LISEM was first calibrated using measured data in a sub-catchment, and then run for the whole catchment for a summer storm event with basic input data from two data sources: soil series specific generic data from the national soil survey database, and measured data collected in a grid within the catchment. The measured data were assigned in two ways: mean values per map unit, or random distribution (50 realizations) per map unit. The model was run both for a low risk situation (crop covered surface) and a high risk situation (without crop cover and with reduced aggregate stability and cohesion). The main results were that 1) using non-local database data yielded much higher peak discharge and five to six times higher soil loss than using locally measured data, 2) there was little difference in simulated runoff and soil loss between the two approaches (mean value versus randomdistribution) to assign locally measured data, 3) differences between the 50 random realizationswere insignificant, for both low-risk and high-risk situations, and 4) uncertainty related to input data could result in larger differences between runswith different input data source than between runswith the same input data source but extreme differences in erosion risk. The main conclusion was that inadequate choice of input data source can significantly affect general soil loss and the effect of measures.
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The current IPCC guidelines define an estimate for the fraction of mineral fertilizer and animal waste (manure) lost to leaching and runoff (FracLEACH). The FracLEACH default is 30 %. In Norway, 18 % has been used based on calculations made in 1998 (Vagstad et al., 1998). The main purpose of this study was to give an updated estimate of nitrogen (N) leaching in relation to the amounts of N applied in agriculture (FracLEACH). The term losses in this report include both surface and subsurface runoff. The estimates of FracLEACH presented in this report were based on data from the Agricultural Environmental monitoring program (JOVA). The JOVA-program includes catchment and field study sites representing typical situations in Norwegian agriculture with regard to production system, management, intensity, soil, landscape, region and climate. Data from plot- scale study sites confirmed the level of N leaching from the agricultural areas within the JOVA catchments. The overall FracLEACH estimated in this study was 22 % of the N applied. This average covers a variation between sites from 16 % on grassland in Valdres to 44 % in intensive vegetable, potato and cereal production areas in the southernmost part of Norway. Runoff is the most significant parameter for the difference in FracLEACH between catchments. In addition, production system and to some degree soil type are important for FracLEACH. It is thus suggested to use different FracLEACH-values for the different production systems and adjust FracLEACH according to average runoff for the region.
Authors
Jan Mulder Xiaoshan Zhang Jing Zhu Peter Dörsch Jannes Stolte Thorjørn Larssen Lei Duan Yanhui WangAbstract
No abstract has been registered
Authors
Frans van den Berg A. Tiktak G. B. M. Heuvelink S. L. G. E. Burgers D. J. Brus F. de Vries Jannes Stolte J. G. KroesAbstract
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Residues of pharmaceuticals present in wastewater and sewage sludge are of concern due to their transfer to aquatic- and terrestrial food chains and possible adverse effects on non-targeted organisms. In the present work, uptake and translocation of metformin, an anti-diabetic II medicine, by edible plant species cultivated in agricultural soil has been investigated in greenhouse experiment. Metformin demonstrated a high uptake and translocation to oily seeds of rape (Brassica napus cv. Sheik and Brassica rapa cv. Valo). Expressed as an average bioconcentration factor, (BCF, plant concentration over initial concentration in soil, both in dry weight), BCF as high as 21.72 was measured. In comparison, BCFs for grains of the cereals wheat, barley and oat were in the range of 0.29 - 1.35. Uptake and translocation to fruits and vegetables of tomato (BCFs 0.02-0.06), squash (BCFs 0.12-0.18) and bean (BCF 0.88) were also low compared to rape. BCFs for carrot, potato and leaf forage Brassica napus cv. Sola were similar (BCF 1-4). Guanylurea, a known degradation product of metformin by microorganisms in activated sludge, was found in seeds from barley, beans and potatoes. The mechanisms for transport of metformin and guanidine in plants are still unknown, whereas organic cation transporters (OCTs) in mammals are known to actively transport such compounds and may guide the way for further understanding of mechanisms also in plants.