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.
2024
Authors
Nina SvartedalAbstract
No abstract has been registered
Abstract
Cultivation of microalgae has gained significant interest as an alternative protein source, potentially becoming a target commodity recovered from microalgae-based wastewater treatment. This study examined a semi-continuous cultivation strategy to optimize protein accumulation of the indigenous freshwater chlorophytes, Lobochlamys segnis and Klebsormidium flaccidum, and simultaneously remove nutrients from wastewater efficiently. A strain-specific regime was made based on a fixed biomass concentration at the start of 24-h cultivation cycle, i.e., a constant initial cell density, which regulated harvesting and fresh medium supply volume according to the dilution rate. Six cultivation cycles were conducted in lab-scale 1L reactors with a synthetic municipal wastewater. Lobochlamys segnis and K. flaccidum grew exponentially in all cycles. The biomass productivity was 573 and 580 mg L–1 day–1, in which the total protein consisted of 62 and 45% of dry cell weight (dw), respectively. When a culture medium deficient in nitrogen and phosphorus was used, protein level was significantly reduced. L. segnis consumed all NH4+ and PO43– supplied by the medium replacement, giving the removal rate of 9.2 and 5.2 mg L–1 day–1. Whereas K. flaccidum removed 13.8 mg L–1 day–1 NH4+ without completing PO43– removal. The amino acid profile of both strains was characterized by glutamic acids content (4–5% dw). We concluded that the designed cultivation regime would support a constant biomass production with stable and high protein content, along with an efficient removal of nutrient from the wastewater.
Abstract
Large clear-cut areas as a consequence of drought and bark beetle infestations necessitate extensive replanting efforts in German forests, leading to an increased interest in efficient planting systems. In addition to manual planting, mechanized and semi-mechanized systems utilizing surplus forest machine capacities available after completion of salvage logging operations are likely required for timely reforestation of the clear-cut areas. A semi-mechanized system utilizing a standard forwarder with a grapple-actuated soil borer for both, the transport of planting material and the preparation of planting pits, combined with two workers carrying out manual planting, was investigated in a time-and-motion study. The frequency method was used after video recording of a planting operation that covered an area of approximately 1.2 hectares. A total of 815 alder saplings (Alnus glutinosa L.) with heights of 1.2–1.5 m were planted. Observed productivity was 93 saplings per system work hour (SWH). With additional placement of stakes for stabilizing the plants, the productivity decreased to 42 saplings per SWH. While directly comparable results were not found in the literature, available productivity figures of purely manual planting systems do not suggest an increased productivity of this semi-mechanized system. Considering ergonomics, however, forwarder utilization provides reduced workload not only in plant hole preparation but also with material transport and clearing of planting spots. Both the ergonomic aspects of the system and, in particular, the suitability of the soil borer for different soil textures should be further investigated.
Abstract
Semi-natural hay meadows are among the most species-rich habitats in Norway as well as in Europe. To maintain the biodiversity of hay meadows, it is important to understand local management regimes and the land use history that has shaped them and their biodiversity. There is however a general erosion of Traditional Ecological Knowledge (TEK), related to hay meadows and other semi-natural habitats. This review aims to examine historical and written sources of land use practices related to hay meadows and to discuss the implications of a re-introduction of TEK in present and future management practices. Traditional land use practices and TEK obtained from written sources from four Norwegian regions and for the country as a whole are compared with present management practices. Written sources show that hay meadows have been managed in a complex but flexible way. Today's management regimes of hay meadows in Norway are streamlined and strongly simplified, most often involving only one late mowing and in some cases grazing. This simplification may result in loss of biodiversity. The potential to include more variety of management practices in hay meadows, by utilizing knowledge from written sources more systematically in combination with farmers’ experienced knowledge (TEK) should be better utilized. Such an approach may secure both the biodiversity in hay meadows and TEK for the future. Former and present landscape ecological contexts in the infield-outlying land system show that management should be done for larger landscapes rather than small, isolated hay meadows, to optimize biodiversity conservation. For this study, we conducted a Norwegian literature review, based on ethnographical and ethnobotanical sources, as well as historical and present agricultural statistics, historical maps, results from research projects, and other sources. Our findings are discussed with similar European studies focusing on the historical management of hay meadows.
Abstract
No abstract has been registered
Abstract
Ultraviolet (UV) irradiation below 300 nm may control powdery mildew in numerous crops. Depending on disease pressure, wavelength, and crop growth stage, one to three applications of 100–200 J/m2 per week at night are as effective or better than the best fungicides. Higher doses may harm the plants and reduce yields. Although red light alone or in combination with UV has a suppressive effect on powdery mildew, concomitant or subsequent exposure to blue light or UV-A strongly reduces the efficacy of UV treatments. To be effective, direct exposure of the pathogen/infection sites to UV/red light is important, but there are clear indications for the involvement of induced resistance in the host. Other pathogens and pests are susceptible to UV, but the effective dose may be phytotoxic. Although there are certain limitations, this technology is gradually becoming more used in both protected and open-field commercial production systems.
Abstract
In high latitude regions, variability in weather and climate conditions during the winter season cause a considerable variation in forage grass productivity and animal feed supply between years and locations. Tools to estimate or predict winter survival and yield, such as ground registrations, satellite image analysis and process-based simulation models, can be combined in decision support for grassland management. In this study, we simulated grassland winter survival using the BAsic GRAssland (BASGRA) model. The model was initialized after the last cut in the autumn. Its performance to simulate ground coverage in the early spring, either assessed by on-site ground registrations or from Sentinel-2 satellite images, was evaluated. Grass fields at Malangen and Målselv in Northern Norway were simulated for the winter seasons 2020–2021 and 2021–2022. Model input including daily air temperature, precipitation, relative humidity and wind speed data were obtained from weather stations nearby the grass fields. The initial values of biomass, leaf area and tiller density in the autumn were based on ground registration in October. Preliminary results show considerable variation in both simulated winter survival and prediction accuracy of observed spring ground coverage between the locations and two winter seasons.
Abstract
No abstract has been registered
Authors
Trygve S. AamlidAbstract
No abstract has been registered
Abstract
The birth process in animals, much like in humans, can encounter complications that pose significant risks to both offspring and mothers. Monitoring these events can provide essential nursing support, but human monitoring is expensive. Although there are commercial monitoring systems for large ruminants, there are no effective solutions for small ruminants, despite various attempts documented in the literature. Inertial sensors are very convenient given their low cost, low impact on animal life, and their flexibility for monitoring animal behavior. This study offers a systematic review of the literature on detecting parturition in small ruminants using inertial sensors. The review analyzed the specifics of published research, including data management and monitoring processes, behaviors indicative of parturition, processing techniques, detection algorithms, and the main results achieved in each study. The results indicated that some methods for detecting birth concentrate on classifying unique animal behaviors, employing diverse processing techniques, and developing detection algorithms. Furthermore, this study emphasized that employing techniques that include analyzing animal activity peaks, specifically recurrent lying down and getting up occurrences, could result in improved detection precision. Although none of the studies provided a completely valid detection algorithm, most results were promising, showing significant behavioral changes in the hours preceding delivery.