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.
2023
Abstract
No abstract has been registered
Abstract
High yields are needed for profitability under shielded strawberry production. June bearing strawberry cultivars require a short day (SD) period in order to initiate generative growth. Nitrogen availability going into the SD-period, as well as during the period, can affect the process. To increase the knowledge about optimized nitrogen fertilizing, an experiment was set up under controlled conditions. Strawberry plants of the cultivar ‘Sonata’ were grown under combinations of different levels of nitrogen to evaluate its effect on timing on growth, flowering time and the number of flowers produced. The result showed that the time for opening of the first flower, the interaction between the pre-SD nitrogen level and the nitrogen level applied during the SD had the highest impact, and that low levels pre-SD flowered earlier. The number of flowers produced was affected by both pre-SD and SD nitrogen level as well as its interactions. Low nitrogen levels throughout had low yield potential while when low pre-SD nitrogen level was followed by high levels during SD, the yield increased.
Abstract
No abstract has been registered
Abstract
Closing nutrient cycles by bio-based fertilizer products (BFPs) can improve the environmental sustainability of food systems and facilitate a more circular economy. Although the theoretical potential for nutrient recycling has been explored in detail, BFPs still seldom replace mineral fertilizer products in practice. The aim of the present study was to explore the critical enabling and limiting factors for the use of BFPs as seen from the perspective of farmers, suppliers, and civil society. To this aim, qualitative interviews were conducted with seven conventional grain farmers, six suppliers of BFPs, and five representatives of civil society, limited to environmental non-governmental organizations. The presented results illustrate a mismatch between demand and supply. On the one hand, the interviewed farmers were only interested in using BFPs if they are practical to use, balanced with respect to nutrient contents, and potentially provide the same earnings as mineral fertilizers. Positive effects for soil quality were an important driver for many of the farmers. On the other hand, the suppliers of BFPs were generally not able to offer products that fulfilled the farmers’ demands without economic losses, and they emphasized that they have faced several regulatory challenges. Representatives of regional civil society organizations expressed concern that new technical solutions could cause new environmental challenges, and that BFPs could enable further intensification of livestock production. The central-level representatives from the same NGOs, however, were positive about that BFPs can solve environmental problems. Policy instruments will be needed to increase the adoption of PFPs. Fostering BFPs’ that contribute to a sustainable agriculture is important to consider when formulating these polices.
Abstract
There is an increased interest in the hydroponic production of strawberries in protected cultivation systems, and it is, therefore, urgent to develop new, more sustainable growing media alternatives. This study investigated the physical properties of wood fiber produced from Norway spruce (Picea abies (L.) H. Karst.) and peat:wood fiber substrate blends as well as the performance of the wood fiber in comparison to the industry standards, i.e., peat and coconut coir in the cultivation of hydroponic strawberry. Tray plants of the June-bearing strawberry (Fragaria × ananassa Duch.) cultivar ‘Malling Centenary’ were transplanted into five different growing media: a peat (80%) and perlite (20%) mixture, stand-alone (100%) coconut coir and three stand-alone (100%) Norway spruce wood fiber substrates (including coarse textured fibers with compact and loose packing density and compacted fine-textured fibers). Ripe strawberries were harvested and registered throughout the production season. The overall marketable yield was comparable across all the tested growing media; however, after 4 weeks of harvest, both coarse wood fiber and fine wood fiber showed better fruiting performance than the peat-perlite mixture. A trend for earlier berry maturation was observed for all wood fiber-based substrates. Plant parameters recorded after the end of production showed that plant height, number of leaves, and biomass production were higher in coarse wood fiber than in the peat-perlite mixture. Moreover, plants grown in wood fiber-based substrates had less unripe berries and flowers not harvested in comparison to both the peat and coir treatments.
Authors
Kannan Mohan Durairaj Karthick Rajan Abirami Ramu Ganesan Dharmaraj Divya Johan Johansen Shubing ZhangAbstract
There is a stable growth in aquaculture production to avoid seafood scarcity. The usage of eco-friendly feed additives is not only associated with aquatic animal health but also reduces the risk of deleterious effects to the environment and consumers. Aquaculture researchers are seeking dietary solutions to improve the growth performance and yield of target organisms. A wide range of naturally derived compounds such as probiotics, prebiotics, synbiotics, complex carbohydrates, nutritional factors, herbs, hormones, vitamins, and cytokines was utilized as immunostimulants in aquaculture. The use of polysaccharides derived from natural resources, such as alginate, agar, laminarin, carrageenan, fucoidan, chitin, and chitosan, as supplementary feed in aquaculture species has been reported. Polysaccharides are prebiotic substances which are enhancing the immunity, disease resistance and growth of aquatic animals. Further, chitin (CT), chitosan (CTS) and chitooligosaccharides (COS) were recognized for their biodegradable properties and unique biological functions. The dietary effects of CT, CTS and COS at different inclusion levels on growth performance, immune response and gut microbiota in aquaculture species has been reviewed. The safety regulations, challenges and future outlooks of CT, CTS and COS in aquatic animals have been discussed in this review.
Abstract
To compensate for higher production costs in winter, tomato cultivars with better taste and flavor characteristics and higher selling price are often cultivated. Tomato taste and flavor is reduced during cold storage, however the reduction is often cultivar dependent. Little is known how postharvest storage conditions affect flavor and taste quality of tomatoes cultivated in greenhouses during wintertime at high latitudes. This study was aimed to analyze how postharvest storage conditions affect composition of flavor-related volatile organic compounds (VOCs) and taste quality of tomato fruits. Tomato cultivars ‘Brioso’, ‘Flavance’, ‘Piccolo’, ‘Sweetelle’, ‘Sweeterno’ were grown in greenhouses with artificial lightning in southwestern Norway during wintertime and were collected ripe. Experimental set up was simulating shortest postharvest chain for southwestern Norway, including harvest day (18°C for one day, in darkness), packaging and transport (12°C for 3 days, in darkness), retail (18°C for 2 days, with light) and consumer storage in either a refrigerator (4°C for 4 days, in darkness) or a kitchen counter (20°C for 4 days, with light). VOC composition of tomato fruits was analyzed using HS-SPME-GC-MS. Fruit quality parameters including sugars, titratable acidity (TA), dry matter content, firmness and pigments were analyzed. Laboratory results were compared to responses from a taste panel. Firmness and TA were lower for fruits after storage at both conditions compared to fresh fruits. Relative concentrations of the most flavor-related VOCs were lowest for fruits after storage at both conditions. The reduction was higher when fruits were stored at 4°C. Fruits from cultivars ‘Sweeterno’ and ‘Piccolo’ showed the lowest difference in relative VOC concentration at 4°C. Perceived overall tomato taste generally decreased after storage. Overall, storage at 20°C is favorable for preserving flavor of most winter-produced tomato cultivars, but disadvantageous for maintaining their firmness and TA.
Abstract
Appropriate weed control measures during the renewal phase of temporary grasslands are critical to ensure high yields during the whole grassland lifecycle. The aim of this study was to determine which integrated grassland renewal strategy can most effectively control annual weeds in the sowing year and delay perennial weed re-establishment. Four split-plot trials were established at three sites dominated by Rumex spp. along a south-north gradient in Norway. The annual and perennial weed abundance was recorded during the sowing year and two or three production years. Main plots tested seven renewal strategies: 1. Spring plowing, 2. Spring plowing+companion crop (CC), 3. Summer cut+plowing, 4. Summer glyphosate+plowing, 5. Summer glyphosate+harrowing, 6. Late spring glyphosate+plowing, 7. Fall glyphosate+spring plowing+CC. Strategies 1–4 were tested in all four trials, strategy 5 in three trials, strategy 6 in two trials and strategy 7 in one trial. Plowing was performed at 20–25 cm depth, rotary harrowing at 15 cm depth, and glyphosate was applied at 2160 g a.i. ha-1. CC was spring barley (Hordeum vulgare). Subplots tested selective herbicide spraying (yes/no) in the sowing year. Results showed that effects of renewal strategies were often site-specific and differed between the sowing year and production years. Spring renewal resulted in higher perennial weed abundance than summer renewal in two out of four trials (by 3 and 12 percentage points, over all production years), and glyphosate followed by harrowing drastically increased Rumex spp. in one out of three trials (by 18 percentage points over all production years). CCs only significantly reduced perennial weed abundance in one trial (by 8 percentage points over all production years). In comparison, the selective herbicides had a strong effect on annual and perennial weeds in the sowing year in all trials. Selective herbicides reduced the weed cover from 32% to 7% cover, and averaged over the production years and sites, the perennial weed biomass fraction was 6 percentage points lower where herbicides had been applied. We conclude that while the tested renewal strategies provided variable and site-specific perennial weed control, selective herbicides were effective at controlling Rumex spp. and other perennial dicot weeds in the first two production years.
Authors
Quentin Lardy Mohammad Ramin Vibeke Lind Grete H. M. Jørgensen Mats Höglind Emma Matilda Ternman Mårten HettaAbstract
This study compared animal performance and enteric methane (CH4) emissions from dairy cows in a part-time grazing (PTG) system in northern Sweden. Twenty-four Nordic Red dairy cows were allocated to one of two treatments: DAY (10 h daytime pasture access) or NIGHT (12 h night-time pasture access). The cows in each treatment received the same ad libitum partial mixed ration (PMR) indoors and ad libitum herbage allowance. Methane was recorded using two linked GreenFeedTM emissions monitoring (GEM) units, on pasture and indoors. Day or night grazing showed no statistical differences in estimated grass or PMR intake, milk production or daily enteric CH4 emissions. There was a rapid decrease in diurnal CH4 emissions (28%) when the cows were moved from indoors to pasture in both grazing treatments. Using two GEM units (indoor, outdoor) in combination improved the diurnal assessment of enteric CH4 emissions during PTG conditions in the mixed feeding system.
Abstract
No abstract has been registered