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.
2017
Authors
Nicholas ClarkeAbstract
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Authors
Anne Kjersti Bakken Kristin Daugstad Astrid Johansen Anne-Grete Roer Hjelkrem Gustav Fystro Anders Hammer Strømman Audun KorsæthAbstract
The aim of the study was to explore whether and how intensification would contribute to more environmentally friendly dairy production in Norway. Three typical farms were envisaged, representing intensive production strategies with regard to milk yield both per cow and per hectare in the three most important regions for dairy production in Norway. The scores on six impact categories for produced milk and meat were compared with corresponding scores obtained with a medium production intensity at a base case farm. Further, six scenario farms were derived from the base case. They were either intensified or made more extensive with regard to management practices that were likely to be varied and implemented under northern temperate conditions. The practices covered the proportion and composition of concentrates in animal diets and the production and feeding of forages with different energy concentration. Processes from cradle to farm gate were incorporated in the assessments, including on-farm activities, capital goods, machinery and production inputs. Compared to milk produced in a base case with an annual yield of 7250 kg energy corrected milk (ECM) per cow, milk from farms with yields of 9000 kg ECM or higher, scored better in terms of global warming potential (GWP). The milk from intensive farms scored more favourably also for terrestrial acidification (TA), fossil depletion (FD) and freshwater eutrophication (FE). However, this was not in all cases directly related to animal yield, but rather to lower burden from forage production. Production of high yields of energy-rich forage contributed substantially to the better scores on farms with higher-yielding animals. The ranking of farms according to score on agricultural land occupation (ALO) depended upon assumptions set for land use in the production of concentrate ingredients. When the Ecoinvent procedure of weighting according to the length of the cropping period was applied, milk and meat produced on diets with a high proportion of concentrates, scored better than milk and meat based on a diet dominated by forages. With regards to terrestrial ecotoxicity (TE), the score was mainly a function of the amount of concentrates fed per functional unit produced, and not of animal yield per se. Overall, the results indicated that an intensification of dairy production by means of higher yields per animal would contribute to more environment-friendly production. For GWP this was also the case when higher yields per head also resulted in higher milk yields and higher N inputs per area of land.
Abstract
This concluding report contains all the monitoring data collected in the course of five years, from Jan. 2013 to Aug. 2017 from the protected archaeological deposits at Øvregaten 19, Bergen. The deposits had high contents of organic material and high water content before monitoring started. Data showed minimum temperatures close to 0-2°C under winter conditions and Maximum temperatures at 14°C during the first year of monitoring 2013. In 2014 the minimum temperature increased to 6-7°C and the maximum temperature increased to 17-18°C. Data recorded in 2015 showed minimum temperature 7-9°C and maximum temperature at 16-19°C. The average and median values calculated in the last two years 2016 & 2017 were increased to 22°C in the upper part of the pit and stable at 14°C in the deeper layers. This high temperature in the upper part of the pit, which is higher than mean ambient air temperature, may be due to the new house and the flagstones placed over and close to the pit where the monitoring equipment was installed.High soil moisture was found in all layers, and fluctuated with precipitation. This increased more frequently in 2014 and 2015 under periods with high precipitation. This high precipitation frequency and the infiltration of roof water has decreased the redox potential to more anoxic conditions, which is positive for the preservation of the archaeological remains.
Abstract
Despite global deforestation some regions, such as Europe, are currently experiencing rapid reforestation. Some of this is unintended woodland encroachment onto farmland as a result of reduced livestock pasture management. Our aim was to determine the likely impacts of this on exposure to ticks and tickborne disease risk for sheep in Norway, a country experiencing ecosystem changes through rapid woodland encroachment as well as increases in abundance and distribution of Ixodes ricinus ticks and tick-borne disease incidence. We conducted surveys of I. ricinus ticks on ground vegetation using cloth lure transects and counts of ticks biting lambs on spring pastures, where lambs are exposed to infection with Anaplasma phagocytophilum, the causative agent of tick-borne fever in livestock. Pastures had higher densities of I. ricinus ticks on the ground vegetation and more ticks biting lambs if there was more tree cover in or adjacent to pastures. Importantly, there was a close correlation between questing tick density on pastures and counts of ticks biting lambs on the same pasture, indicating that cloth lure transects are a good proxy of risk to livestock of tick exposure and tick-borne disease. These findings can inform policy on environmental tick control measures such as habitat management, choice of livestock grazing area and off-host application of tick control agents.
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Authors
Nils-Otto KitterødAbstract
Unconsolidated sediment cover thickness (D) above bedrock was estimated by using a publicly available well database from Norway, GRANADA. General challenges associated with such databases typically involve clustering and bias. However, if information about the horizontal distance to the nearest bedrock outcrop (L) is included, does the spatial estimation of D improve? This idea was tested by comparing two cross-validation results: ordinary kriging (OK) where L was disregarded; and co-kriging (CK) where cross-covariance between D and L was included. The analysis showed only minor differences between OK and CK with respect to differences between estimation and true values. However, the CK results gave in general less estimation variance compared to the OK results. All observations were declustered and transformed to standard normal probability density functions before estimation and back-transformed for the cross-validation analysis. The semivariogram analysis gave correlation lengths for D and L of approx. 10 and 6 km. These correlations reduce the estimation variance in the cross-validation analysis because more than 50 % of the data material had two or more observations within a radius of 5 km. The small-scale variance of D, however, was about 50 % of the total variance, which gave an accuracy of less than 60 % for most of the cross-validation cases. Despite the noisy character of the observations, the analysis demonstrated that L can be used as secondary information to reduce the estimation variance of D.