Ingunn Øvsthus
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(+47) 482 07 250
ingunn.ovsthus@nibio.no
Sted
Ullensvang
Besøksadresse
Ullensvangvegen 1005, 5781 Lofthus
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Ingunn Øvsthus Kristian Thorup-Kristensen Randi Seljåsen Hugh Riley Peter Dörsch Tor Arvid BrelandSammendrag
Mechanistic models are useful tools for understanding and taking account of the complex, dynamic processes such as carbon (C) and nitrogen (N) turnover in soil and crop growth. In this study, the EU-Rotate_N model was first calibrated with measured C and N mineralization from nine potential fertilizer resources decomposing at controlled soil temperature and moisture. The materials included seaweeds, wastes from the food industry, food waste anaerobically digested for biogas production, and animal manure. Then the model’s ability to predict soil and crop data in a field trial with broccoli and potato was evaluated. Except for seaweed, up to 68% of added C and 54–86% of added N was mineralized within 60 days under controlled conditions. The organic resources fell into three groups: seaweed, high-N industrial wastes, and materials with high initial content of mineral N. EU-Rotate_N was successfully calibrated for the materials of industrial origin, whereas seaweeds, anaerobically digested food waste and sheep manure were challenging. The model satisfactorily predicted dry matter (DM) and N contents (root mean square; RMSE: 0.11–0.32) of the above-ground part of broccoli fertilized with anaerobically digested food waste, shrimp shell pellets, sheep manure and mineral fertilizers but not algal meal. After adjusting critical %N for optimum growth, potato DM and N contents were also predicted quite well (RMSE: 0.08–0.44). In conclusion, the model can be used as a learning and decision support tool when using organic materials as N fertilizer, preferably in combination with other models and information from the literature.
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Ingunn ØvsthusSammendrag
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Secured supply of apple fruit for industrial use, especially for production of cider was investigated. The research questions were; is it more land to be used for apple growing in the Hardanger region?, is it possible to develop an own growing concept for fruit for industrial use?, how is the economy in an own concept? And what quality demands for the raw material is needed? More land is available in the region and how much is dependent on which quality the producers demand. The input factors in a growing concept were evaluated for economically impact and price level for the different classes were the most important. Fruit of different origin (discarded at picking or at grading) were compared. Yield level was most likely the most important factor for the differences found. Prognose of amount available for industry was calculated based on models from other countries and found to have potential. Knowledge gaps were identified, and further work is needed to determine quality demands.
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Ingunn ØvsthusSammendrag
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Gunnhild Jaastad Jorunn Børve Ingunn Øvsthus Tage Thorstensen Erik J. Joner Ivar PettersenSammendrag
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Foredrag – Koplingar mellom etylen fruktkvalitet og skade
Hanne Larsen, Ingunn Øvsthus, Jorunn Børve
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Ingunn Øvsthus Theresa Weigl Hanne Larsen Erlend Indergård Siv Fagertun Remberg Jorunn BørveSammendrag
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The major part of Norwegian apples is marketed within 3-4 months after harvest. ‘Summerred’ is a popular medium early cultivar in Norway, however, it is known to soften quickly during storage and marketing. Storing apples in low temperature and low oxygen atmosphere will slow down the ripening and the fruit will keep green and firm. Delayed cooling has been reported to reduce susceptibility to develop physiological disorders like scald. The experiment included different strategies in delaying cooling (5 days at 7°C) and allowing the apples to reach 1 kPa oxygen storage after an intermediate period (5 days) at 3 kPa oxygen. The main focus was on changes in firmness, degreening, scald and fruit rots. The apples were stored for 3, 6 or 9 weeks in 1 or 4°C and analyzed for standard fruit quality factors (color, firmness, IAD-index, starch, soluble solids content and titratable acidity) as the samples were removed from low temperature and low oxygen storage and after a week at 20°C in regular atmosphere (shelf life). Physiological disorders and fruit rots were registered. In these experiments the fruit quality changes were greater (poorer quality) in apples kept at 7°C for 5 days before storage at 1 or 4°C compared to apples stored immediately at low temperature. The intermediate storage in 3 kPa oxygen tended to make the apples keep firmer during storage. The stepwise reduction in oxygen content reduced the negative effect of delayed cooling. Delayed cooling slowed the starch degradation. The incidences of soft scald and fruit rots were low, and the effects of delayed cooling and/or delayed low oxygen storage were weak.
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Jorunn Børve Ingunn Øvsthus Kristin Nymoen Paulsen Hanne Larsen Erlend Indergård Siv Fagertun RembergSammendrag
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In organic plant production, nitrogen (N) availability is often a growth-limiting factor. Under such conditions, off-farm waste-derived nutrient resources may be an alternative to meet the N demand. In this study, we described a production method for a shrimp shell (SS) pellet Product and evaluated the N fertiliser effect and N recovery efficiency (NRE) in a controlled climate pot experiment with potatoes. The experiment was set up with low, medium and high N levels of SS pellets in comparison with a standard mineral fertiliser (MF) at 9°C, 15°C and 21°C. In a separate study, we examined the loss of N as N2O from SS pellets in comparison with SS powder in a 100 days incubation experiment. The results documented the possibility to formulate a fertiliser pellet product from SS, and that SS pellets were an effective N fertiliser in potato at all Growth temperatures. Nevertheless, a slightly slower development and lower tuber yields than for MF indicated a delayed N-availability from SS pellet fertiliser. NRE after use of MF was around 90%, and about 70% for the different levels of SS pellets. The incubation experiment showed a higher rate of available N for SS powder than for pellets (67% and 39%, respectively) after 100 days of incubation at constant humidity and temperature. This difference was attributed to a lower degree of dissolved materials and a higher rate of denitrification and N2O emissions for pellets than for powder, probably caused by differences in physical properties, occurrence of anoxic hotspots and higher microbial activity around and inside the SS pellets.
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Ingunn Øvsthus Randi Seljåsen Elizabeth Stockdale Christian Uhlig Torfinn Torp Tor Arvid BrelandSammendrag
More sustainable production of high-quality, nutritious food is of worldwide interest. Increasing nutrient recycling into food systems is a step in this direction. The objective of the present study was to determine nitrogen (N) fertiliser effects of four waste-derived and organic materials in a cropping sequence of broccoli, potato and lettuce grown at two latitudes (58° and 67° N) in Norway during three years. Effects of anaerobically digested food waste (AD), shrimp shell (SS), algae meal (AM) and sheep manure (SM) at different N application rates (80 and 170 kg N ha–1 for broccoli, and 80 and 60 kg N ha–1 for potato and lettuce, respectively) and residual effects were tested on crop yield, N uptake, N recovery efficiency (NRE), N balance, N content in produce, mineral N in soil, product quality parameters and content of nitrate in lettuce. Mineral fertiliser (MF) served as control. Effects on yield, N uptake, NRE, N balance and product quality parameters could to a great extent be explained by estimated potentially plant-available N, which ranked in the order of AD>SS>SM>AM. Results for crops fertilised with AD and SS were not significantly different from MF at the same N application rate, while AM, in agreement with its negative effect on N mineralisation, gave negative or near-neutral effects compared to the control. No residual effect was detected after the year of application. The results showed that knowledge about N dynamics of relevant organic waste-derived fertilisers is necessary to decide on the timing and rate of application.
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Ingunn Øvsthus Tor Arvid Breland Sidsel Fiskaa Hagen Kirsten Brandt Anne-Berit Wold Gunnar Bengtsson Randi SeljåsenSammendrag
Organic vegetable production attempts to pursue multiple goals concerning influence on environment, production resources, and human health. In areas with limited availability of animal manure, there is a need for considering various off-farm nutrient resources for such production. Different organic and waste-derived fertilizer materials were used for broccoli production at two latitudes (58° and 67°) in Norway during two years. The fertilizer materials were applied at two rates of total N (80 and 170 kg ha–1) and compared with mineral fertilizer (170 kg ha–1) and no fertilizer. Broccoli yield was strongly influenced by fertilizer materials (algae meal < unfertilized control < sheep manure < extruded shrimp shell < anaerobically digested food waste < mineral fertilizer). Yield, but not glucosinolate content, was linearly correlated with estimated potentially plant-available N. However, extruded shrimp shell and mineral NPK fertilizer gave higher glucosinolate contents than sheep manure and no fertilizer. Sensory attributes were less affected by fertilizer material and plant-available N.
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Margarita Novoa-Garrido Celine Rebours Ingunn Øvsthus Marte Meland Christian Guido Bruckner Pierrick Stevant Christian Uhlig Åsbjørn KarlsenSammendrag
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Margarita Novoa-Garrido Celine Rebours Ingunn Øvsthus Marte Meland Christian Uhlig Åsbjørn KarlsenSammendrag
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Use of organic fertilizers in fish pond has been common since ancient times. Applying fertilizers stimulates the growth of phytoplankton, primary producers of the fish food chain. Artificial nitrogen and phosphorus fertilizers are nowadays the main types of nutrients supply in ponds. However, the use of mineral fertilizers is not sustainable due to the use of nonrenewable resource and the impact on the environment. Moreover, the Norwegian government has defined the national ambition that organic food production and food consumption should be more than 15% by 2020. Modern societies produce large amount of organic wastes, which could be reused. Ahead of utilizing such waste as fertilizers in aquaculture, the first step is to gain knowledge about the mineralization patterns in seawater. This knowledge is important to ensure proper supply time and proper amount of nutrients from waste for optimal production with minimal negative impact on the environment This poster will present a study about nitrogen mineralization pattern from organic materials relevant as fertilizers in sustainable aquaculture.
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Ingunn ØvsthusSammendrag
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In Norway there is an incomplete resource management of side products and residuals from the main primary sectors of agriculture, fish farming and fishery. For example is the theoretically hitherto unused energy content in animal manure estimated to approximately 2,5 TWh per year, while Norwegian fish farming annually emits about 40.000 ton nitrogen and 8400 ton phosphorous into the coastal environments. Furthermore, recycling of nutrients and energy from marine fish waste of approximately 3.2 million ton fish is still at its early stages. The incomplete resource management results in environmental, economically and social costs. Consequently, an optimisation of national nutrient and energy cycling is required to increase sustainability. The establishment of individual driven resource optimisation enterprises, e.g. local biogas reactors, are often challenging both logistically and financially, particularly at relatively remote sites. This paper presents an overall conceptual approach to optimize energy and nutrient cycling, due to a cooperatively and integrated resource management system on a regional scale in Steigen, Northern Norway.
Divisjon for matproduksjon og samfunn
Uncorking wine & cider typicality
Uncorking rural heritage: indigenous production of fermented beverages for local cultural and environmental sustainability is funded by Iceland, Liechtenstein and Norway
Divisjon for matproduksjon og samfunn
Sider - Smaken av Hardanger
Kunnskapen utvikla i prosjektet skal sikre jamn, stabil og god kvalitet av Sider frå Hardanger.