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.
2021
Abstract
Predicting N mineralization from green manure in different soil types during the cold season is instrumental for improving crop management with higher N use efficiency and reduced risks of N losses in a cool and humid climate. The objective of our work was to study the effects of low temperatures and soil type on the net nitrogen (N) mineralization and the relationship between N and carbon (C) mineralization from N-rich plant material. A silty clay loam and a sandy loam were incubated with or without clover leaves for 80 days at 0, 4, 8.5 or 15 ◦C. The results showed a substantial mineralization of N in clover leaves (7% of N added), unaffected by temperature, already on 3rd day. This was followed by net N immobilization for about 4 weeks in the clay soil, with similar tendencies in the sandy soil, and more severely at the higher than the lower temperatures. After 80 days of incubation, net N mineralization was only 13–22% of total N in clover leaves. The ratio of net mineralized N to C was higher at lower temperatures, and higher in the sandy than in the clay soil. After the immobilization period, the N mineralization increased, positively related to temperature, and the ratio of net mineralized N to C became constant. In conclusion, low temperature during the initial phase of mineralization altered the ratio between net N and C mineralization from easily decomposable plant material, and the net N mineralization occurred more rapidly in the sandy soil. The change in stoichiometry at low temperatures, as well as the modifying effect of soil type, should be considered when predicting N mineralization of N-rich plant material.
Authors
Randi Berland FrøsethAbstract
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Abstract
For a 100% organic value chain, we need more varieties suitable for organic cultivation. Varieties bred for organic growing is a challenge in small markets. Many breeding goals are equal for organic and conventional cereals. Hence, accessions failing qualification as commercial varieties may perform well in organic growing. A field experiment over two years was performed at two growing sites to compare 25 accessions of spring wheat, ranging from old heritage varieties to modern breeding lines. We assessed yield and agronomic characteristics, artisan bread baking quality and sensory characteristics. Modern accessions gave best yields. Old varieties had smaller kernels, less grain filling, lower falling numbers and SDS-sedimentation volumes, but higher concentrations of minerals, although the growing site has a strong effect. Bread from modern accessions performed best in a baking test. Several sensory characteristics such as juiciness, chew resistance, firmness, acid taste and vinegar odor varied between varieties. Heritage varieties have an important cultural value, and many consumers are willing to pay a significant premium price for such products. A premium price is required, since yield levels are often considerably lower.
Abstract
Norwegian pear (Pyrus communis L.) production has been in decline for the last 25 years. This was mainly because of old cultivars, with low yields and poor consumer appeal, could not compete against strong competition from imported pears, mainly ‘Conference’. Since 1994, the Norwegian breeding company, Graminor Ltd., has released several new pear cultivars, which have been evaluated at NIBIO Ullensvang, western Norway. The first trial was planted in 1999 and included the Graminor Ltd. cultivars: ‘Ingeborg’, ‘Fritjof’ and ‘Anna’, which were bred by the Norwegian University of Life Sciences. In 2002, a second trial was planted including Graminor Ltd. cultivars: ‘Kristina’, ‘Ingrid’ and ‘Celina’ and these were compared against a control, ‘Clara Frijs’. All scion cultivars were grafted on the semi-vigorous rootstock ‘Brokmal’ and grown for 8 years. In both trials, full bloom (~80% of flowers open) took place between 7 May + 3 days and 15 May + 4 days. Flowering was however, completed within a 7-day period in any one year, ensuring adequate overlap in flowering time between all cultivars. Over the final 4-year period all cultivars were evaluated, ‘Anna’, ‘Fritjof’, ‘Kristina’ and ‘Ingeborg’ all had moderate cumulative yields (64.7, 66.2, 36.1, and 30.4 kg·tree-1, respectively). Fruit weight (212 to 183g) and quality of all these cultivars was acceptable (11.2% ≤ TSS ≤ 11.8%; 0.16% ≤ acidity ≤ 0.22%). However, ‘Fritjof’ had many misshapen fruit and exhibited pre-harvest shriveling in several instances making it unacceptable for commercial plantings. ‘Clara Frijs’ and ‘Celina’ cumulative yields were low (12.5 and 21.2 kg per tree, respectively) and fruit were also small (172 to 161 g, respectively). However, due to the attractive cerise-blush ‘Celina’ (trademarked QTee®) pear is now widely planted in Norway and abroad and grafted on Quince rootstocks.
Abstract
A key issue in food governance and public administration is achieving coordinated implementation of policies. This study addressed this issue by systematically comparing the governance of animal welfare in Norway and Sweden, using published papers, reports, and legal and other public information, combined with survey and interview data generated in a larger research project (ANIWEL). Governing animal welfare includes a number of issues that are relevant across different sectors and policy areas, such as ethical aspects, choice of legal tools, compliance mechanisms and achieving uniform control. Based on the challenges identified in coordinating animal welfare in Norway and Sweden, relevant organisational preconditions for achieving uniform and consistent compliance were assessed. The results showed that Sweden’s organisation may need more horizontal coordination, since its animal welfare management is divided between multiple organisational units (Swedish Board of Agriculture, National Food Agency and 21 regional County Administration Boards). Coordination in Norway is managed solely by the governmental agency Norwegian Food Safety Authority (NFSA), which has the full responsibility for inspection and control of food safety, animal health, plant health, as well as animal welfare. Thus, Norway has better preconditions than Sweden for achieving uniformity in animal welfare administration. However, in Norway, the safeguards for the rule of law might be an issue, due to NFSA acting as de facto “inspector”, “prosecutor” and “judge”.
Abstract
Performance of the Quince rootstocks ‘Adams’, ‘C’ and ‘Eline®’, all grafted with pear cultivars ’Celina’, ‘Ingeborg’ and ‘Kristina’, were compared at the experimental farm of NIBIO Ullensvang, western Norway. Tree vigour, yield, fruit size and fruit quality were evaluated annually for the first seven years. No severe winter damage was observed during these years and none of the trees died. After seven years there were no significant differences in tree size in ‘Celina’ and ‘Ingeborg’ grafted on the different rootstocks, while trunk diameter increase of ‘Kristina’ was significantly larger on ‘Eline®’ than on ‘C’ and intermediate on ‘Adams’. Flower development and fruit set were not affected by rootstocks in any of the three scion cultivars. On average, mature fruit were picked during mid to end September and the trees began producing a small crop in the third season. No alternate bearing pattern was identified. For ‘Celina’ and ‘Kristina’ yield was similar for trees on all three rootstocks. Cumulative yields for the first five cropping years were 31.3 kg tree‑1 for ‘Celina’, 25.9 kg tree‑1 for ‘Kristina’ and 19.4 kg tree‑1 for ‘Ingeborg’. ‘Celina’ produced the highest total number of fruit when grafted on ‘Adams’ or ‘C’. Trees on ‘Eline®’ produced a significantly lower number of fruit in both ‘Celina’ and ‘Ingeborg’. On average for all cultivars, no significant effect of rootstock was observed on average fruit weight during these 5 production years. ‘Eline®’ on average yielded fruit of 165 g for all cultivars while for ‘Adams’ and ‘C’ it was 162 g. Soluble solids concentration was high (11.2% on average) but was not significantly affected by rootstocks. Fruit acidity was similar for all quince rootstocks (0.19-0.21%). The fruit development period between full bloom and harvest showed a clear inverse linear relationship with the average daily temperature. In conclusion, because the trees have not reached their full production none of these quince rootstocks can yet be recommended as the preferred rootstock for pear growing in a cool, mesic northern climate.
Abstract
The Norwegian newly bred pear cultivar, ‘Celina/QTee®’, which was launched in 2010, has been released from the Norwegian breeding program. It derived from the combination ‘Colourée de Juillet’ × ‘Williams’. In Norway the flowering is medium to late in May and it ripens in the beginning of September. It has large attractive fruits with red blush and good fruit quality, storability and shelf life. Significant areas of ‘Celina’ cultivars are planted in other countries, mainly Europe. Generally, unfavourable environmental conditions for pear pollination during the Nordic spring can have a very negative effect on the yields in Norwegian pear orchards. Therefore, it is of considerable importance to interplant multiple suitable pollinizer genotypes together with the main cultivar. In order to find the right pollinizers besides following biology of fertilization, pollinizing efficacy using microsatellites were studied at NIBIO Ullensvang, western Norway. In this study, during 2017, seeds from fruits of the pear cultivar ‘Celina’ were extracted. The fruits were randomly harvested from five different orchards located in Ullensvang including NIBIO. Alongside the seeds, leaves were taken from the mother cultivar (‘Celina’) and five pear pollinizer cultivars presented in the orchards (‘Fritjof’, ‘Kristina’, ‘Clara Frijs’, ‘Herzogine Elsa’ and ‘Anna’). Using 11 microsatellite markers, a genetic characterization was conducted on both the seeds and the leaves. The obtained SSR profiles were used for gene assignment analyses. The results of the genetic analyses indicate a very heterogeneous situation regarding pollination. In conclusion, ‘Fritjof’, ‘Kristina’, ‘Clara Frijs’, ‘Herzogine Elsa’ and ‘Anna’ pears had different pollen contributions as pollinizers to ‘Celina’ depending on the investigated orchard. Only one cultivar (‘Herzogine Else’) could be singled out as a major pollen contributor in more than two orchards. Genetic analyses will be repeated in the same orchards, during an additional season, after which more conclusive results will be available.
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Abstract
No abstract has been registered