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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

Research is being poured into developing both potential products and the processes required to convert seaweed, or macroalgae, into products. So far, the results are products for high-end markets, such as restaurants, but in very modest volumes. To understand what it will take to create a large-scale seaweed industry, research is conducted into the strategic-, environmental- and economic realities such an industry would have to deal with as suppliers of fish-feed. The idea is that unless the industry has something to offer that competing products do not, in terms of cost, performance or environmental- and economic footprint, the seaweed industry will be delegated to small volumes for special needs and high value products. These topics are discussed below.

Abstract

High concentrations of the mycotoxins HT-2 and T-2 (HT2 + T2), primarily produced by Fusarium langsethiae, have occasionally been detected in Norwegian oat grains. In this study, we identified weather variables influencing accumulation of HT2 + T2 in Norwegian oat grains. Oat grain samples from farmers’ fields were collected together with weather data (2004–2013). Spearman rank correlation coefficients were calculated between the HT2 + T2 contamination in oats at harvest and a range of weather summarisations within estimated phenological windows of growth stages in oats (tillering, flowering etc.). Furthermore, we developed a mathematical model to predict the risk of HT2 + T2 in oat grains. Our data show that adequate predictions of the risk of HT2 + T2 in oat grains at harvest can be achieved, based upon weather data observed during the growing season. Humid and cool conditions, in addition to moderate temperatures during booting, were associated with increased HT2 + T2 accumulation in harvested oat grains, whereas warm and humid weather during stem elongation and inflorescence emergence, or cool weather and absence of rain during booting reduced the risk of HT2 + T2 accumulation. Warm and humid weather immediately after flowering increased the risk, while moderate to warm temperatures and absence of rain during dough development, reduced the risk of HT2 + T2 accumulation in oat grains. Our data indicated that HT2 + T2 contamination in oats is influenced by weather conditions both pre- and post-flowering. These findings are in contrast with a previous study examining the risk of deoxynivalenol contamination in oat reporting that toxin accumulation was mostly influenced by weather conditions from flowering onwards.

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Abstract

This study examines the relationships between profitability, nitrogen (N) surplus, greenhouse gas emissions (GHG), and energy intensity and factors influencing these relationships in dairy farming. In-depth data from 10 conventional and 8 organic dairy farms in Western Norway were analyzed. Organic farms had lower N surplus per hectare (local, onfarm) and per unit output (global, cradle-to-farm-gate), and lower estimated GHG emissions and energy intensity per unit output, whereas labor input and farm profits did not differ. Higher profitability tended to be associated with improved performance of the environmental indicators examined. Intensification through increased use of concentrates tended to improve profit and reduce N surplus, GHG emissions, and energy intensity per unit output within each farming system while N surplus per hectare could be negatively affected. To ensure a balanced representation of the environmental consequences of both organic and conventional farming systems,our results give support to extensive examination of both area and product-based environmental performance indicators.

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Abstract

Docks (Rumex spp.) are a considerable problem in grassland production worldwide. We investigated how different cultural management techniques affected dock populations during grassland renewal: (I) renewal time, (II) companion crop, (III) false seedbed, (IV) taproot cutting (V), plough skimmer and (VI) ploughing depth. Three factorial split-split plot experiments were carried out in Norway in 2007–2008 (three locations), 2008–2009 (one location) and 2009 (one location). After grassland renewal, more dock plants emerged from seeds than from roots. Summer renewal resulted in more dock seed and root plants than spring renewal. Adding a spring barley companion crop to the grassland crop often reduced dock density and biomass. A false seedbed resulted in 71% fewer dock seed plants following summer renewal, but tended to increase the number of dock plants after spring renewal. In some instances, taproot cutting resulted in less dock biomass, but the effect was weak and inconsistent, and if ploughing was shallow (16 cm) or omitted, it instead increased dock root plant emergence. Fewer root plants emerged after deep ploughing (24 cm) compared to shallow ploughing, and a plough skimmer tended to reduce the number further. We conclude that a competitive companion crop can assist in controlling both dock seed and root plants, but it is more important that the renewal time is favourable to the main crop. Taproot cutting in conjunction with ploughing is not an effective way to reduce dock root plants, but ploughing is more effective if it is deep and a skimmer is used.

2017

Abstract

To improve environmental sustainability it is important that all sectors in a society contribute to improving the utilization of inputs as energy and nutrients. In Norway, dairy farming contributes with an important share to the added value from the agricultural sector, although there is little information available about utilization of energy and nitrogen (N). Many results on sustainability have been published on dairy farming. However, due to Norway’s Nordic climatic conditions, mountainous and rugged topography and an agricultural policy that can design its own prices and subsidies, results from other countries are hardly representative for Norwegian conditions. To bridge this gap, the objective of this study was to analyse if the utilisation of nitrogen and energy in dairy farming in Norway can be improved to strengthen its environmental sustainability. Data were collected from 2010 to 2012 on 10 conventional and 10 organic farms in a region in central Norway with dairy farming as the main enterprise. The farms varied in area, number of dairy cows and milk yield. For nitrogen, a farm gate balance was applied and supplemented with nitrogen fixation by clover and atmospheric N-deposition. The total farm area was broken down into three categories: dairy farm area utilized directly by the farm, off-farm area needed to produce imported roughages and concentrates, and free rangeland that only can be used for grazing.

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Abstract

Reduced N-surpluses in dairy farming is a strategy to reduce the environmental pollution from this production. This study was designed to analyse the important variables influencing nitrogen (N) surplus per hectare and per unit of N in produce for dairy farms and dairy systems across 10 certified organic and 10 conventional commercial dairy farms in Møre og Romsdal County, Norway, between 2010 and 2012. The N-surplus per hectare was calculated as N-input (net N-purchase and inputs from biological N-fixation, atmospheric deposition and free rangeland) minus N in produce (sold milk and meat gain), and the N-surplus per unit of N-produce as net Ninput divided by N in produce. On average, the organic farms produced milk and meat with lower N-surplus per hectare (88 ± 25 kg N·ha−1) than did conventional farms (220 ± 56 kg N·ha−1). Also, the N-surplus per unit of N-produce was on average lower on organic than on conventional farms, 4.2 ± 1.2 kg N·kg N−1 and 6.3 ± 0.9 kg N·kg N−1, respectively. All farms included both fully-cultivated land and native grassland. Nsurplus was found to be higher on the fully cultivated land than on native grassland. N-fertilizers (43%) and concentrates (30%) accounted for most of the N input on conventional farms. On organic farms, biological Nfixation and concentrates contributed to 32% and 36% of the N-input (43 ± 18 N·kg N−1 and 48 ± 11 N·kg N−1), respectively. An increase in N-input per hectare increased the amount of N-produce in milk and meat per hectare, but, on average for all farms, only 11% of the N-input was utilised as N-output; however, the N-surplus per unit of N in produce (delivered milk and meat gain) was not correlated to total N-input. This surplus was calculated for the dairy system, which also included the N-surplus on the off-farm area. Only 16% and 18% of this surplus on conventional and organic farms, respectively, was attributed to surplus derived from off-farm production of purchased feed and animals. Since the dairy farm area of conventional and organic farms comprised 52% and 60% of the dairy system area, respectively, it is crucial to relate production not only to dairy farm area but also to the dairy system area. On conventional dairy farms, the N-surplus per unit of N in produce decreased with increasing milk yield per cow. Organic farms tended to have lower N-surpluses than conventional farms with no correlation between the milk yield and the N-surplus. For both dairy farm and dairy system area, N-surpluses increased with increasing use of fertilizer N per hectare, biological N-fixation, imported concentrates and roughages and decreased with higher production per area. This highlights the importance of good agronomy that well utilize available nitrogen.

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Abstract

Due to the limited resources of fossil fuels and the need to mitigate climate change, energy utilisation for all human activity has to be improved. The objective of this study was to analyse the correlation between energy intensity on dairy farms and production mode, to examine the influence of machinery and buildings on energy intensity, and to find production related solutions for conventional and organic dairy farms to reduce energy intensity. Data from ten conventional and ten organic commercial dairy farms in Norway from 2010 to 2012 were used to calculate the amount of embodied energy as the sum of primary energy used for production of inputs from cradle-to-farm gates using a life cycle assessment (LCA) approach. Energy intensities of dairy farms were used to show the amount of embodied energy needed to produce the inputs per metabolizable energy in the output. Energy intensities allow to easily point out the contribution of different inputs. The results showed that organic farms produced milk and meat with lower energy intensities on average than the conventional ones. On conventional farms, the energy intensity on all inputs was 2.6 ± 0.4 (MJMJ?1) and on organic farms it was significantly lower at 2.1 ± 0.3 (MJ MJ?1). On conventional farms, machinery and buildings contributed 18% ± 4%, on organic farms 29% ± 4% to the overall energy use. The high relative contribution of machinery and buildings to the overall energy consumption underlines the importance of considering them when developing solutions to reduce energy consumption in dairy production. For conventional and organic dairy farms, different strategies are recommend to reduce the energy intensity on all inputs. Conventional farms can reduce energy intensity by reducing the tractor weight and on most of them, it should be possible to reduce the use of nitrogen fertilisers without reducing yields. On organic dairy farms, energy intensity can be reduced by reducing embodied energy in barns and increasing yields. The embodied energy in existing barns can be reduced by a higher milk production per cow and by a longer use of the barns than the estimated lifetime. In the long run, new barns should be built with a lower amount of embodied energy. The high variation of energy intensity on all inputs from 1.6 to 3.3 (MJ MJ?1) (corresponding to the energy use of 4.5e9.3 MJ kg-1 milk) found on the 20 farms shows a potential for producing milk and meat with lower energy intensity on many farms. Based on the results, separate recommendations were provided for conventional and organic farms for reducing energy intensity.