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
No abstract has been registered
Abstract
Large population increases of Arctic-breeding waterfowls over recent decades have intensified the conflict with agricultural interests in both Eurasia and North America. In the spring-staging region Vesterålen in sub-Arctic Norway, sheep, dairy and meat farmers have reported reduced agricultural grassland yields due to pink-footed geese Anser brachyrhynchus and barnacle geese Branta leucopsis that rest and forage in the region for 3–4 weeks in spring on their way to their breeding grounds on Svalbard. Here, we report from an experimental exclosure design where goose access to plots at three grassland fields in Vesterålen was prevented. The experiment was conducted over 3 years between 2012 and 2014. Goose abundance varied greatly between fields and years as a function of variable spring weather and forage quantity, facilitating evaluation of longer-term impacts under contrasting grazing intensities. First and second harvest yields across fields and years were 20% and 19% higher in exclosures than in plots open for grazing, while total yields (sum of first and second harvests) were on average 27% higher. Within-year effects on harvest yields varied substantially, primarily due to highly contrasting sward development during the spring-staging periods. Cool weather (2012) led to slow sward development and little or no effects on harvest yields, warmer weather (2013) resulted in generally large effects, while variable weather (2014) led to treatment effects varying across fields, with one field experiencing 61% higher yields in exclosures while there were no significant impacts on first-harvest yields at the two other fields. Goose grazing did not increase dry weight-based proportions of weeds. Overall, the farmers' reports on yield-loss due to goose grazing were confirmed, although impacts varied substantially between years. A novel finding is that second-harvest yields were also reduced. For the most affected farmers, it is unlikely that the current subsidy scheme is sufficient to cover all the their losses.
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
No abstract has been registered
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No abstract has been registered
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
No abstract has been registered
Abstract
No abstract has been registered
Authors
Wendy Marie Waalen Trygve S. Aamlid Pia Heltoft Thomsen Tatsiana Espevig Marte Skattebu Jan TangsveenAbstract
No abstract has been registered
Abstract
Self-sufficiency with feed (SSF) is a basic principle in organic animal production. The current regulations do not impose strict requirements for SSF at farm level, but further restrictions are expected in future. The aim of the present work was to quantify SSF on a range of organic dairy farms in Norway and study farmers’ strategies to produce milk with a high degree of SSF. Nine farms were selected for interview and data collection. On farm level, the proportion of SSF varied between 66 and 99 %. SSF increased to 88-100 % when expressed on national level. Land area is among the limiting factors for famers to reach higher SSF while maintaining the milk production level. A lower proportion of concentrates in the diet seems to have as strong impact on SSF as using own cereals and protein crops as feed, but milk production per total feed production area was highest for the latter. The farmers’ goals and actions are important driving forces to develop more SSF in dairy production systems.