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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.

2020

Abstract

Coccidiosis is a serious disease caused by Eimeria spp. in young lambs in Norway. Re-sistance against anticoccidial chemicals has been demonstrated in conventional sheep farm-ing. In organic farming we are looking for natural plant sources to increase animal health and welfare. Condensed tannins (CT) have showed effect against coccidia in several trials. Extract from Norwegian spruce bark (Picea abies), a waste product from the wood industry, was shown to contain CT in a Norwegian study. In our trial we tested the effect of bark extract from Norwegian spruce against Eimeria spp in young lambs. The extract was prepared by hot water extraction followed by evaporation and freeze drying. 24 naïve lambs were randomly grouped, 16 of them were inoculated with 100 000 Eimeria oocysts each for three days at 3 weeks of age, and eight of the 16 were treated with bark extract for 12 successive days post infection. The CTg per lamb per day correspond to 0.05% BMW. A control group of eight lambs was not infected or treated. Individually faeces samples were collected and analysed for faecal score and oocysts. Clinically observations and weight gain were measured. In this trial the bark extract was found to have a significant effect on the development of Eime-ria spp. oocysts in the lambs (p<0,001). The extract was given by a stomach tube, and had a negative effect on the lambs appetite as long as it was administered.

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Abstract

To respect the Paris agreement targeting a limitation of global warming below 2°C by 2100, and possibly below 1.5 °C, drastic reductions of greenhouse gas emissions are mandatory but not sufficient. Large‐scale deployment of other climate mitigation strategies are also necessary. Among these, increasing soil organic carbon (SOC) stocks is an important lever because carbon in soils can be stored for long periods and land management options to achieve this already exist and have been widely tested. However, agricultural soils are also an important source of nitrous oxide (N2O), a powerful greenhouse gas, and increasing SOC may influence N2O emissions, likely causing an increase in many cases, thus tending to offset the climate change benefit from increased SOC storage. Here, we review the main agricultural management options for increasing SOC stocks. We evaluate the amount of SOC that can be stored as well as resulting changes in N2O emissions to better estimate the climate benefits of these management options. Based on quantitative data obtained from published meta‐analyses and from our current level of understanding, we conclude that the climate mitigation induced by increased SOC storage is generally overestimated if associated N2O emissions are not considered but, with the exception of reduced tillage, is never fully offset. Some options (e.g, biochar or non‐pyrogenic C amendment application) may even decrease N2O emissions.

Abstract

Perennial versus short term (<3 years) grass vegetation cover is likely to have considerable differences in root density and thus carbon (C) inputs to soil. Carbon inputs are important to maintain soil organic carbon (SOC) and may even increase it. In Norway and Scandinavia, the SOC content in soil is often higher than in other parts of Europe, due to the cold climate and high precipitation (i.e. slower turnover rates for soil organic matter) and a dominance of animal production systems with a large amount of grassland. Here we aimed to evaluate differences in SOC content, down to 60 cm depth, of a long-term grassland (without ploughing for decades) and a short-term grassland (frequently renewed by ploughing) under contrasting climate, soil and management conditions. Quantification of SOC was carried out on three long-term experimental sites on an extended latitude gradient in West and North Norway. The samples were taken from 4 depth increments (0-5, 5-20, 20-40 and 40-60 cm) in treatments that have not been ploughed for at least 43 years, and in treatments that were ploughed every third year until 2011. Preliminary results suggest that there is no significant difference in SOC storage down to 60 cm between long-term and short-term grasslands.

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Abstract

In the Nordic countries, permanent outdoor housing of horses in winter is gaining popularity. This practice will expose the horses to harsh weather conditions. However, horses that are kept indoors at night and turned out in the cold during daytime also experience thermoregulatory challenges. With emphasis on the special challenges in a Nordic climate, this paper aims to increase the understanding of thermoregulation in horses, and ultimately to improve management practices. First, factors related to the environment and the mechanisms of heat exchange are summarised, thereafter the factors related to the horse, such as anatomy and physiological mechanisms which are important for balancing heat gain and heat loss. Human utility of horses and management practices such as clipping, the use of rugs, and provision of shelter are discussed in the light of thermoregulation in horses. The management and care for horses should take into account the principles of thermoregulation and mechanisms of heat loss and gain, and horses should be given a freedom of choice to cope with changing weather conditions. This should include space for movement, protection from sunshine, precipitation and wind, dry bedding, and appropriate feeding. Several studies indicate that the combination of cold rain and wind is a very demanding weather type, not just very low ambient temperatures. A shelter offers the horse protection from wind, precipitation and radiation which it can use when needed, and is therefore a more flexible management solution than a rug, especially when weather conditions change rapidly. In inclement weather, a rug may be a useful supplement. Too many horse owners clip their horse, which often necessitates the use of rugs on a regular basis. More knowledge is needed on how to best manage sport horses, especially when being sweaty after exercise in winter, to ensure good welfare.

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Abstract

In the future, the world is expected to rely increasingly on renewable biomass resources for food, fodder, fibre and fuel. The sustainability of this transition to bioeconomy for our water systems depends to a large extent on how we manage our land resources. Changes in land use together with climate change will affect water quantity and quality, which again will have implications for the ecosystem services provided by water resources. These are the main topics of this Ambio special issue on ‘‘Environmental effects of a green bio-economy’’. This paper offers a summary of the eleven papers included in this issue and, at the same time, outlines an approach to quantify and mitigate the impacts of bioeconomy on water resources and their ecosystem services, with indications of useful tools and knowledge needs.

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Abstract

In Norway, strawberry producers use cereal straw mulching to prevent berries from contacting the soil and to control weeds. We hypothesized that organic matter such as straw mulch also favors the maintenance of predatory mites which visit strawberry plants at nighttime. We compared mite diversity in cereal straw exposed for different periods in strawberry fields and evaluated their possible migration to plants in two experiments with potted plants in 2019. An ‘Early season’ experiment compared no mulching (T1), oat straw mulch exposed in field since 2018 (T2), or 2017 (T3), while a ‘Mid-season’ experiment compared no mulching (T1), barley straw mulch from 2018 (T2), or a mix from 2017 and 2018 (T3). To provide edaphic predatory mites with a potential source of food, all plants were infested with two-spotted spider mite (Tetranychus urticae Koch). Results suggested that straw mulch facilitates the prevalence of predatory mites in strawberry fields. Most predatory mite visits were at night, confirming our initial hypothesis. Predominant nocturnal mites on leaves belonged to Melicharidae (Proctolaelaps sp.) (‘Early season’, T2), Blattisociidae (Lasioseius sp.) (‘Early and Mid-season’, T3) and Phytoseiidae (‘Mid-season’, T2). Parasitus consanguineus Oudemans & Voigts was the predominant species (‘Early season’, T3) at the base of plants. Anystidae were diurnal visitors only (‘Mid-season’, T2). Future studies should evaluate the predation potential of Proctolaelaps sp. and Lasioseius sp. on two-spotted spider mite and other strawberry pests.