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.
2022
Forfattere
Zahra BitarafanSammendrag
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Sammendrag
Tomato greenhouses at high latitudes (≥58°North) require supplemental light to enable high yields and year-round production. Supplemental light systems can differ in lamp type, high-pressure sodium (HPS) or light emitting diode (LED), and also vary in lamp capacity. Based on a combined greenhouse climate, tomato yield, and greenhouse economics model, a methodology was developed, for determining the optimal supplemental light system, dependent on local climate and economic conditions. Two optimisation objectives were considered separately, maximal energy use efficiency (EUE) and maximal net financial result (NFR). The developed methodology was applied to four different greenhouse locations in Norway. At each location, both optimisation objectives were reached with LEDs. The optimal lamp capacities range from 256 to 341 μmol m−2 s−1 (maximal EUE) and 302–323 μmol m−2 s−1 (maximal NFR). The economically optimal lamp capacity is little sensitive to climate conditions. At the lamp type respective NFR maxima, LEDs resulted, on average, in 10% higher tomato yield, 102.2 NOK m−2 year−1 higher NFR, and 35% higher EUE. Consequently, switching from HPS lamps to LEDs enables increasing productivity, energy efficiency and profitability of greenhouse tomato production. Furthermore, the difference between EUE and NFR optima was, on average, 24% lower in terms of EUE and 56% lower in terms of NFR, when using LEDs instead of HPS lamps. On farm-scale, the proposed methodology can be used as decision-support-tool for selecting an efficient and profitable supplemental light system for greenhouse tomato production, dependent on local climate and economic conditions.
Sammendrag
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Forfattere
Michel VerheulSammendrag
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Forfattere
Marzieh Hasanzadeh Saray Aziza Baubekova Alireza Gohari Seyed Saeid Eslamian Bjørn Kløve Ali Torabi HaghighiSammendrag
Water-Energy-Food (WEF) Nexus and CO2 emissions for a farm in northwest Iran were analyzed to provide data support for decision-makers formulating national strategies in response to climate change. In the analysis, input–output energy in the production of seven crop species (alfalfa, barley, silage corn, potato, rapeseed, sugar beet, and wheat) was determined using six indicators, water, and energy consumption, mass productivity, and economic productivity. WEF Nexus index (WEFNI), calculated based on these indicators, showed the highest (best) value for silage corn and the lowest for potato. Nitrogen fertilizer and diesel fuel with an average of 36.8% and 30.6% of total input energy were the greatest contributors to energy demand. Because of the direct relationship between energy consumption and CO2 emissions, potato cropping, with the highest energy consumption, had the highest CO2 emissions with a value of 5166 kg CO2eq ha−1. A comparison of energy inputs and CO2 emissions revealed a direct relationship between input energy and global warming potential. A 1 MJ increase in input energy increased CO2 emissions by 0.047, 0.049, 0.047, 0.054, 0.046, 0.046, and 0.047 kg ha−1 for alfalfa, barley, silage corn, potato, rapeseed, sugar beet, and wheat, respectively. Optimization assessments to identify the optimal cultivation pattern, with emphasis on maximized WEFNI and minimized CO2 emissions, showed that barley, rapeseed, silage corn, and wheat performed best under the conditions studied.
Sammendrag
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Sammendrag
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Forfattere
Claire Coutris Erik J. Joner Cecilie Singdahl-Larsen Ana Catarina Almeida Muhammad Umar Sissel Brit Ranneklev Cecilia AskhamSammendrag
Microplastics ending up in nature as a result of end-of-life processes for plastic packaging is a serious environmental concern, and was addressed in the Packnoplast project through sampling at three sites: one biogas facility in Norway and two thermoplastic recycling plants, one in Norway and one in The Netherlands. The amounts of microplastics ending up in soil from biogas digestate was estimated to represent 0.4-2 mg/kg soil per year if 6 t/daa of biogas digestate is used as fertilizer. Food packaging is estimated to represent 75% of this. The amounts of microplastics measured are significant, but too small to affect soil properties even on a time-scale of decades. The risk of adverse effects on soil quality, plant growth or soil organisms seem very low at the current predicted rates of plastic inputs to soil. Since plastics are virtually non-degradable, they are still prone to accumulate in soil, and waste streams recycled to soil need to address and prevent plastic contamination even better than today. Thermoplastic recycling plants are handling large amounts of plastic, and during processes in the plant, microplastics are generated. Concentrations of microplastic particles varied from 7 to 51 particles per lite rin the effluent water from the two plants. Discharges of effluent water are often through the sewer system and/or into a water body. Today regulations regarding discharges of microplastics are missing. Sand filter treatment of the effluent water was a promising treatment technique to remove the microplastics. Background concentrations of microplastics, comparable to pristine areas, were found in blue mussels sampled outside the thermoplastic recycling plant in Norway. Knowledge about the risk imposed by microplastics to the aquatic environment is today not known.
Forfattere
Janet G. Atandi Noah Adamtey Agnes W. Kiriga Edward N. Karanja Martha W. Musyoka Felix M. Matheri Chrysantus M. Tanga Danny L. Coyne Komi K. M. Fiaboe David Bautze Solveig HaukelandSammendrag
Despite their important ecological roles for soil health and soil fertility, free-living nematodes (FLN) have received relatively limited research attention. The present study evaluated the community structure and diversity of FLN in a field setting. The experiments were conducted in on-farm and on-station field plots sown to maize (Zea mays) and beans (Phaseolus vulgaris) under four cropping practices. These farming systems included organic (compost and biopesticide use), conventional (synthetic fertilizer and pesticide applications), farmer practice (organic and synthetic amendments) and a control (non-amended plots). Nineteen genera of free living nematodes, belonging to bacterivores, fungivores, omnivores and predators were recorded. Among these, bacterivores (Cephalobidae and Rhabditidae) were the most dominant group in the organic systems when compared to the conventional and control systems. Farming systems influenced the abundance and diversity of free living nematodes, with the organic farming system having higher values of maturity, enrichment and structural indices than other farming systems. This would indicate greater stability in soil health and improved soil fertility. This implies that the organic farming systems play a key role in improving the biodiversity and population buildup of FLN, compared with other systems. Our study helps to improve our understanding of how farming systems influence soil biodynamics, while studies on the longer-term effects of organic and conventional farming systems on the build-up or reduction of free living nematodes for improved ecosystem services are needed.
Forfattere
Frode VeggelandSammendrag
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