Zürich, Switzerland
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Sintermann J.,Agroscope ISS | Schallhart S.,University of Helsinki | Kajos M.,University of Helsinki | Jocher M.,Agroscope ISS | And 5 more authors.
Biogeosciences | Year: 2014

Degradation of plant material by animals is an important transformation pathway in the nitrogen (N) cycle. During the involved processes, volatile reduced alkaline nitrogen compounds, mainly ammonia (NH3) and aliphatic amines such as trimethylamine (TMA), are formed. Today, animal husbandry is estimated to constitute a main source of aliphatic amines in the atmosphere with TMA being the main emitted compound. Here, we show how the interaction between faeces and urine in animal production systems provides the primary source for agricultural TMA emissions. Excreted urine contains large quantities of urea and TMA-N-oxide, which are transformed into NH3and TMA, respectively, via enzymatic processes provided by microbes present in faeces. TMA emissions from areas polluted with urine-faeces mixtures are on average of the order of 10 to 50 nmol m-2s-1. Released amines promote secondary aerosol particle formation in the agricultural emission plume. The atmospheric lifetime of TMA, which was estimated to be of the order of 30 to 1000 s, is determined by the condensation onto aerosol particles.


Mayer P.,Technical University of Denmark | Hilber I.,Agroscope ISS | Gouliarmou V.,University of Aarhus | Hale S.E.,Norwegian Geotechnical Institute | And 4 more authors.
Environmental Science and Technology | Year: 2016

Biochars are obtained by pyrolyzing biomass materials and are increasingly used within the agricultural sector. Owing to the production process, biochars can contain polycyclic aromatic hydrocarbons (PAHs) in the high mg/kg range, which makes the determination of the environmental exposure of PAHs originating from biochars relevant. However, PAH sorption to biochar is characterized by very high (104-106 L/kg) or extreme distribution coefficients (KD) (>106 L/kg), which makes the determination of exposure scientifically and technically challenging. Cyclodextrin extractions, sorptive bioaccessibility extractions, Tenax extractions, contaminant traps, and equilibrium sampling were assessed and selected methods used for the determination of bioavailability parameters for PAHs in two model biochars. Results showed that: (1) the KD values of typically 106-109 L/kg made the biochars often act as sinks, rather than sources, of PAHs. (2) Equilibrium sampling yielded freely dissolved concentrations (pg-ng/L range) that were below or near environmental background levels. (3) None of the methods were found to be suitable for the direct measurement of the readily desorbing fractions of PAHs (i.e., bioacessibility) in the two biochars. (4) The contaminant-trap method yielded desorption-resistant PAH fractions of typically 90-100%, implying bioaccessibility in the high μg/kg to low mg/kg range. © 2016 American Chemical Society.


PubMed | University of Aarhus, Norwegian Geotechnical Institute, Agroscope ISS and Technical University of Denmark
Type: Journal Article | Journal: Environmental science & technology | Year: 2016

Biochars are obtained by pyrolyzing biomass materials and are increasingly used within the agricultural sector. Owing to the production process, biochars can contain polycyclic aromatic hydrocarbons (PAHs) in the high mg/kg range, which makes the determination of the environmental exposure of PAHs originating from biochars relevant. However, PAH sorption to biochar is characterized by very high (10(4)-10(6) L/kg) or extreme distribution coefficients (KD) (>10(6) L/kg), which makes the determination of exposure scientifically and technically challenging. Cyclodextrin extractions, sorptive bioaccessibility extractions, Tenax extractions, contaminant traps, and equilibrium sampling were assessed and selected methods used for the determination of bioavailability parameters for PAHs in two model biochars. Results showed that: (1) the KD values of typically 10(6)-10(9) L/kg made the biochars often act as sinks, rather than sources, of PAHs. (2) Equilibrium sampling yielded freely dissolved concentrations (pg-ng/L range) that were below or near environmental background levels. (3) None of the methods were found to be suitable for the direct measurement of the readily desorbing fractions of PAHs (i.e., bioacessibility) in the two biochars. (4) The contaminant-trap method yielded desorption-resistant PAH fractions of typically 90-100%, implying bioaccessibility in the high g/kg to low mg/kg range.


Goldberg E.,ETH Zurich | Scheringer M.,ETH Zurich | Scheringer M.,Lüneburg University | Bucheli T.D.,Agroscope ISS | Hungerbuhler K.,ETH Zurich
Environmental Science: Nano | Year: 2015

In the last 15 years, the development of advection-dispersion particle transport models (PTMs) for the transport of nanoparticles in porous media has focused on improving the fit of model results to experimental data by inclusion of empirical parameters. However, the use of these PTMs has done little to elucidate the complex behavior of nanoparticles in porous media and has failed to provide the mechanistic insights necessary to predictively model nanoparticle transport. The most prominent weakness of current PTMs stems from their inability to consider the influence of physicochemical conditions of the experiments on the transport of nanoparticles in porous media. Qualitative physicochemical influences on particle transport have been well studied and, in some cases, provide plausible explanations for some aspects of nanoparticle transport behavior. However, quantitative models that consider these influences have not yet been developed. With the current work, we intend to support the development of future mechanistic models by relating the physicochemical conditions of the experiments to the experimental outcome using ensemble machine learning (random forest) regression and classification. Regression results demonstrate that the fraction of nanoparticle mass retained over the column length (retained fraction, RF; a measure of nanoparticle transport) can be predicted with an expected mean squared error between 0.025-0.033. Additionally, we find that RF prediction was insensitive to nanomaterial type and that features such as concentration of natural organic matter, ζ potential of nanoparticles and collectors and the ionic strength and pH of the dispersion are strongly associated with the prediction of RF and should be targets for incorporation into mechanistic models. Classification results demonstrate that the shape of the retention profile (RP), such as hyperexponential or linearly decreasing, can be predicted with an expected F1-score between 60-70%. This relatively low performance in the prediction of the RP shape is most likely caused by the limited data on retention profile shapes that are currently available. © 2015 The Royal Society of Chemistry.


Umstatter C.,Agroscope ISS | McSweeney D.,Teagasc | Foley C.,Teagasc | Halton P.,Paddy Halton | And 3 more authors.
Precision Livestock Farming 2015 - Papers Presented at the 7th European Conference on Precision Livestock Farming, ECPLF 2015 | Year: 2015

Optimizing grazing management is fundamental to economic return in grassland production systems. However, costs of labour and fencing may represent obstacles to optimizing profitability from the system. The task of grass allocation usually involves subjective visual assessment and intuitive decision-making on farms implementing an intensive grazing system, followed by putting in place extensive lengths of fencing to enclose the animals. This preliminary study examined the labour requirements associated with a strip grazing system. In addition, the development of a fencing system which could support farmers in optimizing grazing management while reducing labour costs is described and discussed in the latter part of the paper.


Kempf K.,Agroscope ISS | Mora-Ortiz M.,National Institute of Agricutural Botany | Smith L.M.J.,National Institute of Agricutural Botany | Kolliker R.,Agroscope ISS | Skot L.,Aberystwyth University
BMC Genetics | Year: 2016

Background: Sainfoin is a perennial forage legume with beneficial properties for animal husbandry due to the presence of secondary metabolites. However, worldwide cultivation of sainfoin is marginal due to the lack of varieties with good agronomic performance, adapted to a broad range of environmental conditions. Little is known about the genetics of sainfoin and only few genetic markers are available to assist breeding and genetic investigations. The objective of this study was to develop a set of SSR markers useful for genetic studies in sainfoin and their characterization in diverse germplasm. Results: A set of 400 SSR primer combinations were tested for amplification and their ability to detect polymorphisms in a set of 32 sainfoin individuals, representing distinct varieties or landraces. Alleles were scored for presence or absence and polymorphism information content of each SSR locus was calculated with an adapted formula taking into account the tetraploid character of sainfoin. Relationships among individuals were visualized using cluster and principle components analysis. Of the 400 primer combinations tested, 101 reliably detected polymorphisms among the 32 sainfoin individuals. Among the 1154 alleles amplified 250 private alleles were observed. The number of alleles per locus ranged from 2 to 24 with an average of 11.4 alleles. The average polymorphism information content reached values of 0.14 to 0.36. The clustering of the 32 individuals suggested a separation into two groups depending on the origin of the accessions. Conclusions: The SSR markers characterized and tested in this study provide a valuable tool to detect polymorphisms in sainfoin for future genetic studies and breeding programs. As a proof of concept, we showed that these markers can be used to separate sainfoin individuals based on their origin. © 2016 The Author(s).


Koltowski M.,Maria Curie Sklodowska University | Hilber I.,Agroscope ISS | Bucheli T.D.,Agroscope ISS | Oleszczuk P.,Maria Curie Sklodowska University
Environmental Science and Pollution Research | Year: 2016

Coal production negatively affects the environment by the emission of polycyclic aromatic hydrocarbons (PAHs). Two soils (KOK and KB) from a coking plant area was investigated and their total PAH concentration was 40 and 17 mg/kg for the sum (∑) 16 US EPA PAHs, respectively. A third soil was sampled from a bitumen plant area and was characterized by 9 mg/kg ∑16 US EPA PAHs. To reduce the freely dissolved concentration (Cfree) of the PAHs in the soil pore water, active carbon (AC) and two biochars pyrolysed from wheat straw (biochar-S) and willow (biochar-W) were added to the soils at 0.5–5 % (w/w), each. The AC performed best and reduced the Cfree by 51–98 % already at the lowest dose. The biochars needed doses up to 2.5 % to significantly reduce the Cfree by 44–86 % in the biochar-S and by 37–68 % in the biochar-W amended soils. The high black carbon (BC) content of up to 2.3 % in the Silesian soils competed with the sorption sites of the carbon amendments and the performance of the remediation was a consequence of the contaminant’s source and the distribution between the BC and the AC/biochars. In contrast, the carbon amendment could best reduce the Cfree in the Lublin soil where the BC content was normal (0.05 %). It is therefore crucial to know the contaminant’s source and history of a sample/site to choose the appropriate carbon amendment not only for remediation success but also for economic reasons. © 2016 Springer-Verlag Berlin Heidelberg


PubMed | Maria Curie Sklodowska University and Agroscope ISS
Type: Journal Article | Journal: Environmental science and pollution research international | Year: 2016

Coal production negatively affects the environment by the emission of polycyclic aromatic hydrocarbons (PAHs). Two soils (KOK and KB) from a coking plant area was investigated and their total PAH concentration was 40 and 17mg/kg for the sum () 16 US EPA PAHs, respectively. A third soil was sampled from a bitumen plant area and was characterized by 9mg/kg 16 US EPA PAHs. To reduce the freely dissolved concentration (Cfree) of the PAHs in the soil pore water, active carbon (AC) and two biochars pyrolysed from wheat straw (biochar-S) and willow (biochar-W) were added to the soils at 0.5-5% (w/w), each. The AC performed best and reduced the Cfree by 51-98% already at the lowest dose. The biochars needed doses up to 2.5% to significantly reduce the Cfree by 44-86% in the biochar-S and by 37-68% in the biochar-W amended soils. The high black carbon (BC) content of up to 2.3% in the Silesian soils competed with the sorption sites of the carbon amendments and the performance of the remediation was a consequence of the contaminants source and the distribution between the BC and the AC/biochars. In contrast, the carbon amendment could best reduce the Cfree in the Lublin soil where the BC content was normal (0.05%). It is therefore crucial to know the contaminants source and history of a sample/site to choose the appropriate carbon amendment not only for remediation success but also for economic reasons.

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