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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

2017

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Abstract

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

Today’s modern precision agriculture applications have a huge demand for data with high spatial and temporal resolution. This leads to the need of unmanned aerial vehicles (UAV) as sensor platforms providing both, easy use and a high area coverage. This study shows the successful development of a prototype hybrid UAV for practical applications in precision agriculture. The UAV consists of an off-the-shelf fixed-wing fuselage, which has been enhanced with multi-rotor functionality. It was programmed to perform pre-defined waypoint missions completely autonomously, including vertical take-off, horizontal flight, and vertical landing. The UAV was tested for its return-to-home (RTH) accuracy, power consumption and general flight performance at different wind speeds. The RTH accuracy was 43.7 cm in average, with a root-mean-square error of 39.9 cm. The power consumption raised with an increase in wind speed. An extrapolation of the analysed power consumption to conditions without wind resulted in an estimated 40 km travel range, when we assumed a 25 % safety margin of remaining battery capacity. This translates to a maximal area coverage of 300 ha for a scenario with 18 m/s airspeed, 50 minutes flight time, 120 m AGL altitude, and a desired 70 % of image side-lap and 85 % forward-lap. The ground sample distance with an in-built RGB camera was 3.5 cm, which we consider sufficient for farm-scale mapping missions for most precision agriculture applications.

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Abstract

Although grass dominates most agricultural systems in the North Atlantic region (NAR), spring barley is the most important cereal and is used for animal feed and food and drink products. Recent changes in climate have resulted in warmer conditions across the NAR which have major implications for crop production. In this paper, we investigate the thermal requirement of spring barley in the region and use the results to examine the effects of recent trends in temperature and rainfall on barley cultivation, based on 11 regional meteorological sites. At these sites, between 1975 and 2015, we found significant warming trends for several months of the cropping season and significant trends for increases in the cropping season degree days (CSDD). In recent years, this has resulted in an increased proportion of years when the estimated minimum thermal requirement for barley has been met at sites above about 60°N. However, annual variations in CSDD are large and years still occur at these sites where this is insufficient. While warming could potentially allow an earlier start and later end to the cropping season, it is likely that high rainfall at maritime sites, and low rainfall at continental sites, will limit the ability of growers to benefit from this. Warming is considered to have been one of the main factors contributing to the large expansion of the area of barley cultivated in Iceland since the 1990s.

Abstract

In this paper, we examine citizen and consumer attitudes towards, and preferences for, private and public goods from organic agriculture in Norway. The study is based on a survey among 939 Norwegians. The results show that in the role as citizens, the respondents hold a moderate belief in the superiority of organic farming concerning the production of public goods, but they give relatively low priority to prompting organic farming compared to other agricultural policy goals. In the role as consumers (choice experiment), the respondents were willing to pay for several attributes of organic food. Only 6% of the respondents buy organic food as often as they can. The most important reasons for buying organic food are health and environmental concerns, while animal welfare has little importance. Lack of perceived superiority regarding health benefits, taste, safety and environment are important reasons for not consuming (more) organic food among those who rarely or never buy organic food.

Abstract

The 2015-2018 PROMAC (Energy efficient Processing of Macroalgae in blue-green value chains) is financed by the Norwegian Research Council. The PROMAC consortium is led by Møreforsking AS and consists of both Norwegian (SINTEF, NIBIO, NTNU, NMBU) and European (CEVA, MATIS, SLU)research institutes, as well as industrial partners (TafjordKraftvarme, FelleskjøpetFôrutvikling, Firmenich, LegaseaBiomarine Cluster, The Northern Company, Orkla Foods, Hortimare, Marinox).An advisory panel with public authority and interest groups from the marine, energy and agricultural sectors, also oversee the 4,5Mill EUR project’s relevance in a societal context.The current approaches to meeting the demands for meat and other protein-rich food sources are often associated with damage to natural resources and negative effects on climate, air quality, soils and fresh water availability. Therefore, the PROMAC project (http://promac.no/) investigates an alternative approach for providing food and sources of proteins and energy in animal feed, and health benefits in human food through cultivation of macroalgae. The project focuses on the three macroalgaespecies Alariaesculenta, Saccharinalatissima andPalmariapalmata.The research project (i) assesses variation of raw material composition and quality from both harvested and cultured macroalgae, (ii) develops primary processing methods enhancing desired raw material properties, (iii) establishes fractionation and extraction methods best suited to enrich beneficial proteins or remove undesirable anti-nutrients and (iv) evaluates nutritional and health values of processed macroalgal ingredients for various animal groups and in relation to their distinct digestive systems.PROMAC assesses the costs and benefits of macroalgal products from a value chain perspective (from raw material to primary market) through process-based Life Cycle Assessment (LCA), Material and Energy Flow Analysis (MEFA) and business models. To reduce the substantial energy required for primary processing of macroalgae - organisms characterized by ahigh-water content - PROMAC includes a case study utilizing excess heat from a waste incinerator for primary drying and processing of macroalgae biomass. This case study is integrated into both environmental and economic models.Initialresults identifyingmacroalgae food and feed products (ingredients)and associatedprocessing methods most relevant for commercial applications, will be presented integrated across work packages and subject fields.

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Abstract

1. Increased species diversity promotes ecosystem function; however, the dynamics of multi-speciesgrassland systems over time and their role in sustaining higher yields generated by increased diver-sity are still poorly understood. We investigated the development of species’ relative abundances ingrassland mixtures over 3 years to identify drivers of diversity change and their links to yield diver-sity effects.2. A continental-scale field experiment was conducted at 31 sites using 11 different four-speci esmixtures each sown at two seed abundances. The four species consisted of two grasses and two legumes, of which one was fast establishing and the other temporally persistent. We modelledthe dynamics of the four-species mixtures, and tested associations with diversity effects on yield.3. We found that species’ dynamics were primarily driven by differences in the relative growth rates(RGRs) of competing species, and secondarily by density dependence and climate. The temporallypersistent grass species typically had the highest RGRs and hence became dominant over time. Den-sity dependence sometimes induced stabilising processes on the dominant species and inhibitedshifts to monoculture. Legumes persisted at most sites at low or medium abundances and persistencewas improved at sites with higher annual minimum temperature.4. Significant diver sity effects were present at the majority of sites in all years and the strength ofdiversity effects was improved with higher legume abundance in the previous year. Observed diver-sity effects, when legumes had declined, may be due to (i) important effects of legumes even at lowabundance, (ii) interaction between the two grass species or (iii) a store of N because of previouspresence of legumes.5. Synthesis. Alongside major compositional changes driven by RGR differences , diversity effectswere observed at most sites, albeit at reduced strength as legumes declined. This evidence stronglysupports the sowing of multi-species mixtures that include legumes over the long-standing practiceof sowing grass monocultures. Careful and strategic selection of the identity of the species used inmixtures is suggested to facilitate the maintenance of species diversity and especially persistence oflegumes over tim e, and to preser ve the strength of yield increases associated with diversity.

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Abstract

1. Grassland diversity can support sustainable intensification of grassland production through increased yields, reduced inputs and limited weed invasion. We report the effects of diversity on weed suppression from 3 years of a 31-site continental-scale field experiment. 2. At each site, 15 grassland communities comprising four monocultures and 11 four-species mixtures based on a wide range of species' proportions were sown at two densities and managed by cutting. Forage species were selected according to two crossed functional traits, “method of nitrogen acquisition” and “pattern of temporal development”. 3. Across sites, years and sown densities, annual weed biomass in mixtures and monocultures was 0.5 and 2.0 t DM ha−1 (7% and 33% of total biomass respectively). Over 95% of mixtures had weed biomass lower than the average of monocultures, and in two-thirds of cases, lower than in the most suppressive monoculture (transgressive suppression). Suppression was significantly transgressive for 58% of site-years. Transgressive suppression by mixtures was maintained across years, independent of site productivity. 4. Based on models, average weed biomass in mixture over the whole experiment was 52% less (95% confidence interval: 30%–75%) than in the most suppressive monoculture. Transgressive suppression of weed biomass was significant at each year across all mixtures and for each mixture. 5. Weed biomass was consistently low across all mixtures and years and was in some cases significantly but not largely different from that in the equiproportional mixture. The average variability (standard deviation) of annual weed biomass within a site was much lower for mixtures (0.42) than for monocultures (1.77). 6. Synthesis and applications. Weed invasion can be diminished through a combination of forage species selected for complementarity and persistence traits in systems designed to reduce reliance on fertiliser nitrogen. In this study, effects of diversity on weed suppression were consistently strong across mixtures varying widely in species' proportions and over time. The level of weed biomass did not vary greatly across mixtures varying widely in proportions of sown species. These diversity benefits in intensively managed grasslands are relevant for the sustainable intensification of agriculture and, importantly, are achievable through practical farm-scale actions.