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.
2016
Abstract
No abstract has been registered
Authors
Lars T. HavstadAbstract
The market for herbage seed straw has diminished in many seed-production areas due to less livestock. Seed growers are therefore looking for alternatives to straw removal, which up to now has been the most common practice. During 2000–2006, different alternative straw chopping methods, both at the back of the combiner and with a tractor-mounted flail-chopper, and field burning strategies were evaluated in seed crops of timothy (Phleum pratense) and meadow fescue (Festuca pratensis) in southeast Norway. The requirement for an extra N input in autumn (30–40 kg ha-1) when practising straw chopping was also examined. Compared to straw removal, straw chopping at the back of the combiner during seed harvest did not reduce seed yield in the following year as long as stubble height was low (<10 cm in timothy) and the straw spread uniformly in the field. On average, seed yield was 1–4% and 1–9% higher compared to straw removal in timothy and meadow fescue, respectively. If the chopped straw was spread unevenly, or long stubble was left at combining, it is recommended to use a tractor-mounted flail-chopper after harvest. The experiments did not provide any support for an extra input of nitrogen in autumn, either in timothy or meadow fescue, when the straw was chopped rather than removed. Burning of stubble and straw soon after seed harvest was another efficient clean-up method after harvest, which increased seed yield 9–15% and 17–20% compared to straw removal in the two species, respectively. However, as the burning method is risky and causes smoke emissions, it is normally not recommended. It is concluded that for most seed growers, the most effective, least laborious and most environment-friendly alternative to straw removal will be to chop the straw at the back of the combiner during seed harvest.
Abstract
Schistidium marginale is described as a new species from several European states including Austria, Georgia, Italy, Macedonia, Spain, Switzerland and Turkey. The species is fully illustrated, its affinities are discussed in detail and its current distribution is mapped. The new species is closely related to S. confertum and S. echinatum from which it differs in having a coarser and thicker costa which is 3–4-stratose in mid-leaf and 4-layered at the base; strongly thickened, 2–4-stratose and (1–)2–5-seriate leaf margins; and a thicker and stiffer leaf hair-point. It clearly belongs to Schistidium Bruch & Schimp. sect. Conferta (Vilh.) Ochyra on account of the distinct 3–6(–7)-seriate basal marginal border of quadrate to short-rectangular, often subhyaline cells with distinctly thickened transverse walls.
Authors
Ma Xingzhu Baoku Zhou Alice Budai Alhaji S. Jeng Xiaoyu Hao Dan Wei Yulan Zhang Daniel RasseAbstract
Biochar is a carbon-rich solid product obtained by pyrolysis of biomass. Here, we investigated multiple biochars produced under slow pyrolysis (235–800 °C), flash carbonization, and hydrothermal carbonization (HTC), using Scanning Electron Microscope—Energy Dispersive X-ray Spectroscopy (SEM-EDX) in order to determine whether SEM-EDX can be used as a proxy to characterize biochars effectively. Morphological analysis showed that feedstock has an integrated structure compared to biochar; more pores were generated, and the size became smaller when the temperature increased. Maximum carbon content (max. C) and average carbon content (avg. C) obtained from SEM-EDX exhibited a positive relationship with pyrolysis temperature, with max. C correlating most closely with dry combustion total carbon content. The SEM-EDX O/C ratios displayed a consistent response with the highest treatment temperature (HTT). The study suggests that SEM-EDX produces highly consistent C, oxygen (O), and C/O ratios that deserve further investigation as an operational tool for characterization of biochar products.
Authors
K. Candelier Janka Dibdiakova G- Volle P. RoussetAbstract
No abstract has been registered
Authors
Sigrun Aune Knut HovstadAbstract
No abstract has been registered
Authors
Sigrun Aune Knut HovstadAbstract
The present agricultural landscape reflects a long history of changing land-use and farming practices, caused by e.g. technological development, urbanization processes and climate changes. A deeper understanding of how agricultural practices have altered the landscape is essential for the management of biodiversity and conservation of semi-natural grasslands. In this study, we explore the influence that changes in agricultural land-use, and grassland abandonment, have on successional changes in vegetation. The distribution, patch size, and plant species composition of semi-natural grasslands in a Central Norwegian agricultural landscape were mapped during two summers. Semi-natural grassland species decreased from managed grasslands to late regrowth successional phase, while number of forest species increased. Structural changes, e.g. increasing litter and tree cover, were also seen along the succession. Variation in species composition was related to management intensity and successional phase along the main gradient.
Authors
Bjørn ØklandAbstract
No abstract has been registered
Authors
Sekhar Udaya NagothuAbstract
No abstract has been registered
Authors
Aruppillai Suthaparan Knut Asbjørn Solhaug Nils Bjugstad Hans Ragnar Gislerød David M. Gadoury Arne StensvandAbstract
Disease-suppressive effects of nighttime applications of ultraviolet-B (UV-B) were investigated at two irradiance levels (1.6 or 0.8 W/m2) in strawberry and rosemary plants inoculated with Podosphaera aphanis or Golovinomyces biocellatus, respectively. Plants were exposed to each irradiance level every third night for either 9 or 18 min, every night for either 3 or 6 min, or three times every night for either 1 or 2 min. Thus, over time, all plants received the same cumulative dose of UV-B, and severity of powdery mildew was reduced by 90 to 99% compared with untreated controls in both crops. Use of polished aluminum lamp reflectors and UV-B reflective surfaces on greenhouse benches significantly increased treatment efficacy. An automated apparatus consisting of an adjustable boom with directed airflow was used to move UV-B lamps over greenhouse benches at 25 or 50 cm/min. Directed airflow moved leaves on the subtending plants to better expose upper and lower surfaces to UV-B but directed airflow actually decreased the efficacy of UV-B treatments, possibly by dispersing conidia from lesions before they were exposed to a lethal dose of UV-B. Results indicate broad applicability of nighttime applications of UV-B to suppress powdery mildews, and that cumulative UV-B dose is an overriding factor determining efficacy. Finally, enhanced suppression on shaded or obscured tissues is more likely to be affected by reflective bench surfaces than through attempts to physically manipulate the foliage.