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
Authors
Paul Eric AspholmAbstract
No abstract has been registered
Abstract
The dynamic interactions between soil, weather and crop management have considerable influences on crop yield within a region, and should be considered in optimizing nitrogen (N) management. The objectives of this study were to determine the influence of soil type, weather conditions and planting density on economic optimal N rate (EONR), and to evaluate the potential benefits of site-specific N management strategies for maize production. The experiments were conducted in two soil types (black and aeolian sandy soils) from 2015 to 2017, involving different N rates (0 to 300 kg ha−1) with three planting densities (55,000, 70,000, and 85,000 plant ha−1) in Northeast China. The results showed that the average EONR was higher in black soil (265 kg ha−1) than in aeolian sandy soil (186 kg ha−1). Conversely, EONR showed higher variability in aeolian sandy soil (coefficient of variation (CV) = 30%) than in black soil (CV = 10%) across different weather conditions and planting densities. Compared with farmer N rate (FNR), applying soil-specific EONR (SS-EONR), soil- and year-specific EONR (SYS-EONR) and soil-, year-, and planting density-specific EONR (SYDS-EONR) would significantly reduce N rate by 25%, 30% and 38%, increase net return (NR) by 155 $ ha−1, 176 $ ha−1, and 163 $ ha−1, and improve N use efficiency (NUE) by 37–42%, 52%, and 67–71% across site-years, respectively. Compared with regional optimal N rate (RONR), applying SS-EONR, SYS-EONR and SYDS-EONR would significantly reduce N application rate by 6%, 12%, and 22%, while increasing NUE by 7–8%, 16–19% and 28–34% without significantly affecting yield or NR, respectively. It is concluded that soil-specific N management has the potential to improve maize NUE compared with both farmer practice and regional optimal N management in Northeast China, especially when each year’s weather condition and planting density information is also considered. More studies are needed to develop practical in-season soil (site)-specific N management strategies using crop sensing and modeling technologies to better account for soil, weather and planting density variation under diverse on-farm conditions.
Authors
Habtamu AlemAbstract
The objective of this paper is to examine the economic performance of crop-producing farms accounting for unobserved heterogeneity,environmental variables, and regions. The empirical analysis was based on a translog cost function and unbalanced farm-level panel data for 1991–2013 from the 455 crop-producing farms with 3,885 observations (1,004observations from the central region and 2,881 observations from the eastern region). We found that the mean minimum costs were about 93% and 92% of the actual costs for crop farms in the central and eastern regions, respectively.The marginal effects of crop rotation, land tenure, off-farm activity, direct government support, and experience were positively associated with crop farm economic performance. The marginal contribution of these variables on economic performance increased in the years 2000–2013 compared with the years 1991–1999 in both regions.
Authors
Paul Eric AspholmAbstract
No abstract has been registered
Abstract
Remediation using nanoparticles depends on proper documentation of safety aspects, one of which is their ecotoxicology. Ecotoxicology of nanoparticles has some special features: while traditional ecotoxicology aims at measuring possible negative effects of more or less soluble chemicals or dissolved elements, nanoecotoxicology aims at measuring the toxicity of particles, and its main focus is on effects that are unique to nano-sized particles, as compared to larger particles or solutes. One of the main challenges when testing the ecotoxicity of nanoparticles lies in maintaining stable and reproducible exposure conditions, and adapt these to selected test organisms and endpoints. Another challenge is to use test media that are relevant to the matrices to be treated. Testing of nanoparticles used for remediation, particularly red-ox-active Fe-based nanoparticles, should also make sure to exclude confounding effects of altered red-ox potential which are not nanoparticle-specific. Yet another unique aspect of nanoparticles used for remediation is considerations of ageing of nanoparticles in soil or water, leading to reduced toxicity over field-relevant time scales. This review discusses these and other aspects of how to design and interpret appropriate tests and use these in hazard descriptions for subsequent risk assessments.
Authors
Hilde Karine WamAbstract
In this educational tool kit, your pupils will learn about the amazing and sometimes odd ways animals have adapted to living, especially in polar extreme environments. This is part 1 of a series of three tool kits on the topic. Part 1 gives an introduction and explains principles of evolutionary adaptations in view of climate change. Part 2 is about animals in the taiga, while part 3 is about animals on the tundra.
Authors
Hilde Karine WamAbstract
In this educational tool kit, your pupils will learn about why and where there is a region called Fennoscandia. We explore cultures for the outdoors that are shared between all the countries of the region. In role play, pupils will explore how one, by learning about another’s culture, one can more easily accept it even when one does not like it.
Authors
Hilde Karine WamAbstract
Do you know what happens when an exotic species comes to a new place, where it does not belong? Can the planet be completely invaded by exotic species? What exactly is an exotic species? In this learning package, we look at how invasive species are a growing problem and how they can affect the environment, other species and even the entire global bioeconomy.
Authors
Hilde Karine WamAbstract
The taiga is the deep boreal forests of the north. Where the wolves roam, brown bears pick berries, and capercaillies sing. The biodiversity is huge, and in the taiga ecosystem, all the species are wondrously linked to each other. What happens here when the climate is changing?
Abstract
Forskningsformidling til ungdom 13-19 år. Et nettbasert undervisningstilbud som bruker naturforskning til å fremme ungdoms miljøbevissthet og interesse for vitenskap.