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
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No abstract has been registered
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In this study, we investigated the potential of airborne imaging spectroscopy for in-season grassland yield estimation. We utilized an unmanned aerial vehicle and a hyperspectral imager to measure radiation, ranging from 455 to 780 nm. Initially, we assessed the spectral signature of five typical grassland species by principal component analysis, and identified a distinct reflectance difference, especially between the erectophil grasses and the planophil clover leaves. Then, we analyzed the reflectance of a typical Norwegian sward composition at different harvest dates. In order to estimate yields (dry matter, DM), several powered partial least squares (PPLS) regression and linear regression (LR) models were fitted to the reflectance data and prediction performance of these models were compared with that of simple LR models, based on selected vegetation indices and plant height. We achieved the highest prediction accuracies by means of PPLS, with relative errors of prediction from 9.1 to 11.8% (329 to 487 kg DM ha−1) for the individual harvest dates and 14.3% (558 kg DM ha−1) for a generalized model.
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No abstract has been registered
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No abstract has been registered
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Based on soil temperature, snow depth and the grown cultivar's maximum attainable level of frost tolerance (LT50c), the FROSTOL model simulates development of frost tolerance (LT50) and winter damage, thereby enabling risk calculations for winter wheat survival. To explore the accuracy of this model, four winter wheat cultivars were sown in a field experiment in Uppsala, Sweden in 2013 and 2014. The LT50 was determined by tests of frost tolerance in November, and the cultivars’ LT50c was estimated. Further, recorded winter survival from 20 winter wheat field variety trials in Sweden and Norway was collected from two winter seasons with substantial winter damages. FROSTOL simulations were run for selected cultivars at each location. According to percentage of winter damage, the cultivar survival was classified as “survived,” “intermediate” or “killed.” Mean correspondence between recorded and simulated class of winter survival was 75% and 37% for the locations in Sweden and Norway, respectively. Stress factors that were not accounted for in FROSTOL might explain the poorer accuracy at the Norwegian locations. The accuracy was poorest for cultivars with intermediate LT50c levels. When low temperature was the main cause of damage, as at the Swedish locations, the model accuracy was satisfying.
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No abstract has been registered
Authors
P. Schröder B. Beckers S. Daniels F. Gnädinger E. Maestri N. Marmiroli M. Mench R. Millan M.M. Obermeier N. Oustriere Tomas Persson C. Poschenrieder F. Rineau B. Rutkowska T. Schmid W. Szulc N. Witters Arne SæbøAbstract
The rapid increase of the world population constantly demands more food production from agricultural soils. This causes conflicts, since at the same time strong interest arises on novel bio-based products from agriculture, and new perspectives for rural landscapes with their valuable ecosystem services. Agriculture is in transition to fulfill these demands. In many countries, conventional farming, influenced by post-war food requirements, has largely been transformed into integrated and sustainable farming. However, since it is estimated that agricultural production systems will have to produce food for a global population that might amount to 9.1 billion by 2050 and over 10 billion by the end of the century, we will require an even smarter use of the available land, including fallow and derelict sites. One of the biggest challenges is to reverse non-sustainable management and land degradation. Innovative technologies and principles have to be applied to characterize marginal lands, explore options for remediation and re-establish productivity. With view to the heterogeneity of agricultural lands, it is more than logical to apply specific crop management and production practices according to soil conditions. Cross-fertilizing with conservation agriculture, such a novel approach will provide (1) increased resource use efficiency by producing more with less (ensuring food security), (2) improved product quality, (3) ameliorated nutritional status in food and feed products, (4) increased sustainability, (5) product traceability and (6) minimized negative environmental impacts notably on biodiversity and ecological functions. A sustainable strategy for future agriculture should concentrate on production of food and fodder, before utilizing bulk fractions for emerging bio-based products and convert residual stage products to compost, biochar and bioenergy. The present position paper discusses recent developments to indicate how to unlock the potentials of marginal land.
Authors
Vigdis Vandvik Tessa Bargmann Sigrid Skrivervik Bruvoll Matthew I. Daws Kristine Grimsrud Hanna Lee Pål Thorvaldsen Liv Guri Velle Joachim Paul TöpperAbstract
No abstract has been registered
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Changes in land-use and climate represent major threats to Atlantic heathlands, and extreme climatic events, such as droughts, are likely to increase in frequency and intensity in the future. This is of particular relevance for nature management, and conservation, as extreme events are expected to have system-wide impacts on species and ecosystems. During the winter of 2014 an intense drought combined with low temperatures resulted in a massive dieback of Calluna vulgaris in the Norwegian heathlands, and two severe heathland wildfires occurred. With this as a background, a new Norwegian research project: Land use management to ensure ecosystem service delivery under new societal and environmental pressures in heathlands (LandPress) were initiated. LandPress combines observational data on ecosystem responses and resilience after the 2014 event with targeted experiments, one of them the International Drought Experiment, integrating our project into an international context. Drought impacts in mature Calluna-stands is investigated along a 650-km latitudinal gradient in Norway. Our first results indicate more drought damage in northern heathlands than in southern. Healthy Calluna was only observed in scattered patches with more suitable micro-climate, and, interestingly, in some areas regenerating after recent prescribed management burning. Moreover, drying experiments to learn how quickly Calluna plants dry up at 20°C and 50% relative humidity from rain-wet conditions showed that old Calluna stands represents a severe fire risk within two days. Young and more vigorous plants in the building phase (6–15 years old), as well as freeze drought damaged (typically some dead small branches), old but still live plants, showed different drying characteristics and dried more slowly. LandPress interlaces five work packages, exploring the impact of land-use change in combination with extreme climatic events in terms of vegetation change, ecosystem resilience, ecosystem services provisioning, sustainability, and evidence-based management and fire risk prevention.
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No abstract has been registered