Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2017
Sammendrag
Extensive green roofs have become a frequently used option for stormwater retention across manydifferent climates including cold and wet regions. Despite the extensive documentation of green rooftechnology for stormwater management, the knowledge about their function and potential use in wetand cold regions is deficient. Using historic data on daily temperature and precipitation in a green roofwater balance model coupled with the Oudin model of evapotranspiration (ET), we evaluated the effects ofmaximum green roof storage capacities (Smax) and ET on stormwater retention along climatic gradientsin Northern Europe. Large differences in potential annual stormwater retention were found betweenlocations, driven by differences in temperature and precipitation amounts. Highest retention in abso-lute values was found for the wettest locations, while the warmest and driest locations showed highestretention in percentage of annual precipitation (up to 58% compared to 17% for the lower range). Alllocations showed a considerable retention of stormwater during summer, ranging from 52% to 91%. Stor-age capacities accepting drought conditions once every 3.3–3.9 year were found to be about 25 mm inthe cold and wet locations increasing to 40–50 mm in the warmer and drier locations. Correspondingstorage capacities to prevent wilting of non-succulent vegetation was on average a factor of 1.5 larger(not including Sheffield and Malmö). Annual retention increased both with an increase in plant wateruse (specific crop factors, Kc) and with an increase in Smax, but was found to be more sensitive to changesin Kcthan to changes in Smax. Hence, ET was the limiting factor for green roof retention capacity in thecold and wet locations, but relatively large changes in evapotranspiration would be needed to have animpact on retention. The potential to use vegetation with higher water use to better restore the storagecapacity between storm-events in these regions was however limited by the risk of permanent wilting ofnon-succulent vegetation, even on the wettest locations. A considerable increase in roof storage capacityand substrate thickness would be required to reduce this risk; still the increase in stormwater retentionwould be marginal.
Sammendrag
Pre-sprouting of potato seed tubers (Solanum tuberosum L.) in light (greensprouting) is an established practice in short growing seasons to speed up plant development. Light exposure secures short and robust sprouts for mechanical planting. In 2014–2015, different pre-sprouting treatments were investigated, including different daily durations of light exposure during 6 to 12 weeks at 10 °C in controlled environments. The effects on sprout growth, early growth vigour and field performance in four cultivars were assessed in the greenhouse and in the field. Results indicated that the light treatments involving 8, 16 and 24 h light exposure per day all strongly inhibited sprout growth, with only minor differences between treatments. Compared to untreated tubers, within all cultivars, emergence and early plant growth was clearly and similarly accelerated by all light treatments. At harvest, cultivars were differently affected by the pre-sprouting treatments with regard to haulm senescence (greenness), tuber DM and total yield, and the latest cultivars seemed to benefit more from green-sprouting than the earliest. Different daily durations of light exposure during green-sprouting had a largely similar impact on seed tuber performance in all cultivars. Dark-sprouted tubers (de-sprouted before planting) performed largely similar to control tubers from 4 °C storage. Results demonstrate a potential for shorter daily light exposure during greensprouting with less energy use and heating problems.
Forfattere
Trygve S. AamlidSammendrag
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Forfattere
Lars NesheimSammendrag
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Sammendrag
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Sammendrag
Growing substrates, fertilizer inputs, and irrigation are important factors for grow-in of sand-based putting greens. The research reported here was triggered by grow-in problems encountered in 2015 after replacing garden compost with Sphagnum peat in the rootzone on a sand-based green at the NIBIO Turfgrass Research Center, Norway. A pot trial was conducted with the same type of sand amended with: (i) 20% (v/v) garden compost, (ii) 10% (v/v) Sphagnum peat, (iii) equal volumes of (i) and (ii), (iv) 10% (v/v) Sphagnum peat plus lime (200 g CaCO3 m−2), and (v) 10% (v/v) Sphagnum peat plus phosphoric acid, 5 g P m−2. The amendments were tested with or without preplant application of chicken manure (5 g N and 2.5 g P m−2) and at the two irrigation rates: 3 and 12 mm d−1. The pots were seeded with creeping bentgrass (Agrostis stolonifera L.), and turfgrass coverage and clipping yields were recorded for 5 wk after seeding. Turfgrass coverage developed significantly faster and clipping yields were significantly higher after amendment with compost than after amendment with peat or peat plus lime. Incorporation of chicken manure did not enhance grow-in on substrates containing full or half rates of compost but improved grow-in on peat, especially when combined with phosphoric acid. Excessive irrigation had no impact on turfgrass coverage but reduced clipping yields on substrates containing compost, compost plus peat, or peat plus phosphoric acid. We conclude that the grow-in problems encountered in 2015 were most likely due to inadequate quality of the Sphagnum peat.
Sammendrag
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Forfattere
Åsmund Mikalsen KvifteSammendrag
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Forfattere
Ola FlatenSammendrag
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Forfattere
Randi Berland FrøsethSammendrag
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