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.
2018
Abstract
Due to their Mendelian inheritance, microsatellites or SSRs (simple sequence repeats) can readily be used for parentage analyses of pear seedlings, thus revealing the female and male parents of the plant. However, in cases where obtained pear seeds display low viability, conducting a parentage analyses on the pear seeds themselves could be used in order to identify the male parent (successful pollinator). In this study, batches of seeds were extracted from fruits of the triploid ‘Ingeborg’ pear (‘Conference’ × ‘Bonne Louise’), the main commercial pear cultivar in Norway. Mature pears were collected from eight commercial pear orchards located in Ullensvang, at 60° North and seeds were collected. Genomic DNA was subsequently isolated from the obtained seed batches and genotyped using 12 microsatellite markers. The same markers were also used for the genetic characterization of ‘Ingeborg’ and five pear genotypes used as pollinators in the sampled orchards (‘Clara Frijs’, ‘Herzogine Elsa’, ‘Anna’, ‘Colorée de Juillet’ and ‘Belle lucrative’). The obtained SSR profiles were used in paternity analyses, as well as for gene assignment analyses. Both approaches identified pear ‘Clara Frijs’ to be the most successful pollinator in most of the sampled orchards. Subsequent S allele genotyping of ‘Ingeborg’ and five pear genotypes used as pollinators in the sampled orchards revealed that the preferential pollination by individual genotypes was not caused by gametophytic incompatibility or semi-compatibility.
Authors
Adam O'Toole Christophe Moni Simon Weldon Anne Schols Monique Carnol Bernard Bosman Daniel RasseAbstract
The application of biochar to soils is a promising technique for increasing soil organic C and offsetting GHG emissions. However, large-scale adoption by farmers will likely require the proof of its utility to improve plant growth and soil quality. In this context, we conducted a four-year field experiment between October 2010 to October 2014 on a fertile silty clay loam Albeluvisol in Norway to assess the impact of biochar on soil physical properties, soil microbial biomass, and oat and barley yield. The following treatments were included: Control (soil), miscanthus biochar 8 t C ha1 (BC8), miscanthus straw feedstock 8 t C ha1 (MC8), and miscanthus biochar 25 t C ha1 (BC25). Average volumetric water content at field capacity was significantly higher in BC25 when compared to the control due to changes in BD and total porosity. The biochar amendment had no effect on soil aggregate (2–6 mm) stability, pore size distribution, penetration resistance, soil microbial biomass C and N, and basal respiration. Biochar did not alter crop yields of oat and barley during the four growing seasons. In order to realize biochar’s climate mitigation potential, we suggest future research and development efforts should focus on improving the agronomic utility of biochar in engineered fertilizer and soil amendment products.
Abstract
The awareness of sediment and nutrient loss from non-point sources are of increasing environmental concern as measures to reduce point source inputs to surface waters have been introduced. Mitigation efforts to reduce loss of particles and nutrients from agriculture in Norway and other countries have mainly focused on surface runoff, whereas sub-surface drainage has received little attention. However, research has shown that the sub-surface field drains are transporting both sediment and nutrients rapidly to the watercourses. Despite these established facts there has been little development of measures to reduce these losses. This article describes how Lightweight Aggregates (LWA), Leca®, can mitigate some of the environmental challenges connected to sub-surface field drains. A field experimental project was performed to assess the effects on drainage water quality hydrological performance and functionality of drainage systems based on Lightweight Aggregates compared to traditional pipe drains. Registrations of the performance of the systems were done in two separate periods, 1992–1993 and 1999–2000. After 2000 no measurement programme has run. The functionality of the drainage systems was registered in connection to ordinary farming activity. In 1999–2000 LWA drains showed particularly good performance with regard to reducing the content of Phosphorus, 40–90 % reduction in Total-P. The drainage water from the LWA drains contained less than half the amount of suspended solids compared to traditional pipe drains. The results from 1993 showed no significant difference between LWA drains and pipe drains with respect to Nitrogen. The results from 1999/2000 showed higher loss of Nitrogen through pipe drains with no envelope compared to all other systems. LWA drains may be particularly useful in reducing particles and nutrient loads from cultivated flat drained areas adjacent to environmentally sensitive and ecologically important water ecosystems. Further investigations are recommended to optimise the design of LWA drains.
Authors
Anna Bucharova Oliver Bossdorf Norbert Hölzel Johannes Kollmann Rüdiger Prasse Walter DurkaAbstract
One of the main questions in ecosystem restoration is where to obtain the seeds to re-establish plant communities. While the most commonly advocated approach is to use seeds from local sources, some experts argue against this because local populations may harbour little genetic variability for the restored populations to be able to adapt to and survive global change. Instead, they propose alternative strategies such as mixing seeds from various sources to increase genetic variability and adaptive potential, or using seeds from populations that have a similar climate as predicted for the target locality in the future. All these alternative seed-sourcing strategies have in common that they involve a transplanting of plant ecotypes, sometimes over large spatial scales. This is risky because plants from distant origins may be maladapted to the current local abiotic and biotic environment. In addition, introduction of non-local provenances will disrupt natural patterns of withinspecies biodiversity and will affect ecological networks, with unpredictable consequences. To balance the value of local adaptation with the need for future adaptation potential, we propose ‘regional admixture provenancing’ as a compromise strategy. Here seeds are sourced from multiple populations within the same region as the target locality and mixed prior to use. The mixing of seeds will increase the genetic diversity necessary for future adaptation, while restricting seed origins to a regional scale will maintain regional adaptation and reduce the risk of unintended effects on other biota. This approach is feasible in practice and has recently been implemented in Germany. We believe that it represents a compromise to reconcile opposing views on ecological restoration.
Authors
Svetlana Pakhomova Evgeniy Yakushev Elizaveta Protsenko Sylvain Rigaud Daniel Cossa Joel Knoery Raoul-Marie Couture Olivier Radakovitch Shamil Yakubov Dominika Krzeminska Alice NewtonAbstract
This study presents a specifically designed Mercury module in a coupled benthic-pelagic reactive-transport model - Bottom RedOx Model (BROM) that allows to study mercury (Hg) biogeochemistry under different conditions. This module considers the transformation of elemental mercury (Hg(0)), divalent mercury (Hg(II)) and methylmercury (MeHg). The behavior of mercury species in the model is interconnected with changes of oxygen, hydrogen sulfide, iron oxides, organic matter, and biota. We simulated the transformation and transport of Hg species in the water column and upper sediment layer under five different scenarios, combining various levels of oxygenation and trophic state in the Berre lagoon, a shallow eutrophic lagoon of the French Mediterranean coast subjected to seasonal anoxia. The first scenario represents the conditions in the lagoon that are compared with experimental data. The four other scenarios were produced by varying the biological productivity, using low and high nutrient (N and P) concentrations, and by varying the redox conditions using different intensity of vertical mixing in the water column. The results of the simulation show that both oxidized and reduced sediments can accumulate Hg, but any shifts in redox conditions in bottom water and upper sediment layer lead to the release of Hg species into the water column. Eutrophication and/or restricted vertical mixing lead to reducing conditions and intensify MeHg formation in the sediment with periodic release to the water column. Oxygenation of an anoxic water body can lead to the appearance of Hg species in the water column and uptake by organisms, whereby Hg may enter into the food web. The comparison of studied scenarios shows that a well-oxygenated eutrophic system favors the conditions for Hg species bioaccumulation with a potential adverse effect on the ecosystem. The research is relevant to the UN Minimata convention, EU policies on water, environmental quality standards and Mercury in particular.
Authors
Panu Korhonen Taru Palosuo Tomas Persson Mats Höglind Guillaume Jégo Marcel Van Oijen Anne-Maj Gustavsson Gilles Bélanger Perttu VirkajärviAbstract
During the past few years, several studies have compared the performance of crop simulation models to assess the uncertainties in model-based climate change impact assessments and other modelling studies. Many of these studies have concentrated on cereal crops, while fewer model comparisons have been conducted for grasses. We compared the predictions for timothy grass (Phleum pratense L.) yields for first and second cuts along with the dynamics of above-ground biomass for the grass simulation models BASGRA and CATIMO, and the soil-crop model STICS. The models were calibrated and evaluated using field data from seven sites across Northern Europe and Canada with different climates, soil conditions and management practices. Altogether the models were compared using data on timothy grass from 33 combinations of sites, cultivars and management regimes. Model performances with two calibration approaches, cultivar-specific and generic calibrations, were compared. All the models studied estimated the dynamics of above-ground biomass and the leaf area index satisfactorily, but tended to underestimate the first cut yield. Cultivar-specific calibration resulted in more accurate first cut yield predictions than the generic calibration achieving root mean square errors approximately one third lower for the cultivar-specific calibration. For the second cut, the difference between the calibration methods was small. The results indicate that detailed soil process descriptions improved the overall model performance and the model responses to management, such as nitrogen applications. The results also suggest that taking the genetic variability into account between cultivars of timothy grass also improves the yield estimates. Calibrations using both spring and summer growth data simultaneously revealed that processes determining the growth in these two periods require further attention in model development.
Authors
Marleen Pallandt Bernhard Ahrend Sönke Zaehle Marion Schrumpf Holger Lange Markus ReichsteinAbstract
Soil organic carbon (SOC) is the largest terrestrial carbon pool. Changes in the hydrological cycle affect C-cycle turnover, with potential effects on the global C balance’s response to global change. However, large scale model representations of the sensitivity of soil carbon to soil moisture, through decomposition and interactions with nutrient cycles, are largely empirical to semi-empirical and uncertain. To better represent these dynamics, the aims of this PhD project* are to: • Investigate the role of soil moisture on SOC decomposition over a vertical profile; • Assess which moisture controls are (most) important in a multi-layered, mechanistic soil biogeochemistry model, the Jena Soil Model (JSM, Fig 2); • Update and improve the representations of soil moisture dynamics in JSM and evaluate this model for multiple sites along a moisture gradient and global scale
Abstract
No abstract has been registered
Abstract
In recent years, slatted floors made of materials like fiber composite and plastic have been introduced in animal housing systems. These modern floor types are claimed to have low heat conductivity and hence be “better” for the sheep than expanded metal, but the actual preference in sheep has not yet been tested. The aim of this study was to investigate the preference of ewes for different floor materials at low ambient temperatures. The experiment was performed in a non-insulated building and the indoor air temperature varied from -11.8 to + 3 °C. Each experimental pen measured 3.0 x 2.0 m (total 6.0 m2) and were divided into two equal sections (A and B). A total of 30 non-pregnant ewes were sheared and allocated to one of ten stable groups with three animals per group. Five different floor types – expanded metal, slatted floor made of fiber composite, slatted floor made of plastic, solid floor made of wood and solid floor consisting of a rubber mat, were installed in section A and B in the experimental pens. Groups were habituated to all floor material combinations and systematically rotated through the ten pens. Behaviors were scored from 20 hour video recordings using instantaneous sampling at 10 minute intervals. In addition, heat conductivity properties of the five different floor materials were tested. On days with low temperatures, the ewes were standing or walking more, resting less, eating or drinking more and resting more in physical contact than on days with higher temperatures. When given the choice, ewes showed clear preferences for standing/walking and resting on solid floor materials than on slatted floors. This is consistent with earlier preference tests on sheared sheep. Ewes did not seem to show a clear preference for one slatted floor material over another for resting. The proportion of time spent standing/walking in the pen was steadily reduced as air temperature in the barn increased. The present experiment suggests that none of the floor combinations had thermal properties that adversely affect resting and other general behaviors of the animals. The heat conductivity properties were similar among the slatted floors. In conclusion, the claimed favorable thermal properties of plastic slatted floors and fiber composite were not confirmed. There must be other properties of the floor than heat conductivity that influences the preference in ewes.
Abstract
In recent years, slatted floors made of materials like fiber composite and plastic have been introduced in animal housing systems. These modern floor types are claimed to have low heat conductivity and hence be “better” for the sheep than expanded metal, but the actual preference in sheep has not yet been tested. The aim of this study was to investigate the preference of ewes for different floor materials at low ambient temperatures. The experiment was performed in a non-insulated building and the indoor air temperature varied from -11.8 to + 3 °C. Each experimental pen measured 3.0 x 2.0 m (total 6.0 m2) and were divided into two equal sections (A and B). A total of 30 non-pregnant ewes were sheared and allocated to one of ten stable groups with three animals per group. Five different floor types – expanded metal, slatted floor made of fiber composite, slatted floor made of plastic, solid floor made of wood and solid floor consisting of a rubber mat, were installed in section A and B in the experimental pens. Groups were habituated to all floor material combinations and systematically rotated through the ten pens. Behaviors were scored from 20 hour video recordings using instantaneous sampling at 10 minute intervals. In addition, heat conductivity properties of the five different floor materials were tested. On days with low temperatures, the ewes were standing or walking more, resting less, eating or drinking more and resting more in physical contact than on days with higher temperatures. When given the choice, ewes showed clear preferences for standing/walking and resting on solid floor materials than on slatted floors. This is consistent with earlier preference tests on sheared sheep. Ewes did not seem to show a clear preference for one slatted floor material over another for resting. The proportion of time spent standing/walking in the pen was steadily reduced as air temperature in the barn increased. The present experiment suggests that none of the floor combinations had thermal properties that adversely affect resting and other general behaviors of the animals. The heat conductivity properties were similar among the slatted floors. In conclusion, the claimed favorable thermal properties of plastic slatted floors and fiber composite were not confirmed. There must be other properties of the floor than heat conductivity that influences the preference in ewes.