Yield effects of soil compaction after different wheeling intensities on a silt soil in Norway

Climate change with a higher amount of rain during harvesting increases the need for efficient harvesting and transport which leads to use of more effective and heavier machinery with an enhanced risk for compaction. Soil compaction is known to reduce the production capacity of a soil and can have severe negative ecological consequences and may reduce the production capacity of soils. Heavy loads can enhance subsoil compaction which is considered to be irreversible. The effect of contrasting wheeling frequency (1x; 10x) and different wheel loads on the bearing capacity of a silt soil was studied in cooperation project between NIBIO (Norway), Christian- Albrecht- Universität Kiel (Germany) and Norwegian University of Life Sciences (Norway). Furthermore it is examining the influence of the use of typical (Norwegian) transport equipment (cereals, potatoes) with differing loads (12Mg; 16Mg total weight) and inflation pressure on soil physical parameters and yields under the climatic conditions of SE Norway. Field measurements and sampling took place at Kongsvinger (60.25° N and 11.08° E) in SE Norway in June 2015. The soil is characterized as silt soil with 82% silt in the topsoil, overlying silt (84%). Unloaded reference plots and loaded wheel tracks were sampled by taking undisturbed and disturbed soil samples (20, 40, 60 cm depth) to determine soil physical parameters. Soil bearing capacity was measured by determining precompression (PC). Stress propagation during wheeling was measured with a Stress-state and displacement stress transducer systems (SST, DTS). Yields of barley yields were monitored on unwheeled and wheeled plots two years after compaction. We will present both the results from the soil physical analyses and use of the compaction verification tool (CVT) in addition to the results from the SST/ DTS measurements. The yield effect of compaction will be illustrated by showing the yield data (barley) for wheeled and unwheeled plots for the 2 years after the compaction. First results show that the compaction had significant effects on the yields, but may have a positive yield effect under certain condition

Regenerationswirkung im Unterboden eines Ackerstandortes in Südnorwegen fünf Jahre nach der Belastung

Im Jahr 2011 wurden Befahrungsversuche mit zwei unterschiedlich schweren Gespannen, bestehend aus Ackerschlepper und Güllefass, in Südnorwegen nahe der Stadt Sarpsborg durchgeführt. Neben unterschiedlichen Gewichten wurden zwei Befahrungshäufigkeiten (einfach und zehnfach Befahrung) und zwei Bodenbearbeitungsverfahren (konventionelle und konservierende Bodenbearbeitung) untersucht. Mit dem Compaction Verification Tool (CVT) wurde außerdem eine potenziell schadhafte Unterbodenverdichtung bewertet. An den in drei Tiefen (20 cm, 40 cm und 60 cm) entnommenen Zylinderproben wurden folgende Parameter analysiert: Luftkapazität, Gesamtporenvolumen, Trockenrohdichte, Vorbelastung, gesättigte Wasserleitfähigkeit und Luftleitfähigkeit. Die Ergebnisse zeigen, dass durch die Befahrung eine Zunahme der schadhaften CVT-Klasse IV bei beiden Varianten unabhängig von der Bodenbearbeitung beobachtet werde konnte. Nach einer fünf jährigen Regenerationsphase wurden für ausgewählten Varianten erneut Proben auf einer bereits in 2011 zusätzlich angelegten Fläche genommen. Die erhobenen Daten wurden mit den Ergebnissen aus 2011 verglichen und lassen auf einen Regenerationseffekt schließen. Die Ergebnisse verdeutlichen aber auch, dass viele Parameter ihren unbelasteten Ursprungszustand nicht wieder erreichen

Axonopathy in the central nervous system is the hallmark of mice with a novel intragenic null mutation of dystonin.

Dystonia musculorum is a neurodegenerative disorder caused by a mutation in the dystonin gene. It has been described in mice and humans where it is called hereditary sensory autonomic neuropathy. Mutated mice show severe movement disorders and die at the age of 3-4 weeks. This study describes the discovery and molecular, clinical, as well as pathological characterization of a new spontaneously occurring mutation in the dystonin gene in C57BL/6N mice. The mutation represents a 40-kb intragenic deletion allele of the dystonin gene on chromosome 1 with exactly defined deletion borders. It was demonstrated by Western blot, mass spectrometry, and immunohistology that mice with a homozygous mutation were entirely devoid of the dystonin protein. Pathomorphological lesions were restricted to the brain stem and spinal cord and consisted of swollen, argyrophilic axons and dilated myelin sheaths in the white matter and, less frequently, total chromatolysis of neurons in the gray matter. Axonal damage was detected by amyloid precursor protein and nonphosphorylated neurofilament immunohistology. Axonopathy in the central nervous system (CNS) represents the hallmark of this disease. Mice with the dystonin mutation also showed suppurative inflammation in the respiratory tract, presumably due to brain stem lesion-associated food aspiration, whereas skeletal muscles showed no pathomorphological changes. This study describes a novel mutation in the dystonin gene in mice leading to axonopathy in the CNS. In further studies, this model may provide new insights into the pathogenesis of neurodegenerative diseases and may elucidate the complex interactions of dystonin with various other cellular proteins especially in the CNS

Reduced risk of oat grain contamination with fusarium langsethiae and HT-2 and T-2 toxins with increasing tillage intensity

Frequent occurrences of high levels of Fusarium mycotoxins have been recorded in Norwegian oat grain. To elucidate the influence of tillage operations on the development of Fusarium and mycotoxins in oat grain, we conducted tillage trials with continuous oats at two locations in southeast Norway. We have previously presented the content of Fusarium DNA detected in straw residues and air samples from these fields. Grain harvested from ploughed plots had lower levels of Fusarium langsethiae DNA and HT-2 and T-2 toxins (HT2 + T2) compared to grain from harrowed plots. Our results indicate that the risk of F. langsethiae and HT2 + T2 contamination of oats is reduced with increasing tillage intensity. No distinct influence of tillage on the DNA concentration of Fusarium graminearum and Fusarium avenaceum in the harvested grain was observed. In contrast to F. graminearum and F. avenaceum, only limited contents of F. langsethiae DNA were observed in straw residues and air samples. Still, considerable concentrations of F. langsethiae DNA and HT2 + T2 were recorded in oat grain harvested from these fields. We speculate that the life cycle of F. langsethiae differs from those of F. graminearum and F. avenaceum with regard to survival, inoculum production and dispersal

Influenza A (H10N7) virus causes respiratory tract disease in harbor seals and ferrets

Avian influenza viruses sporadically cross the species barrier to mammals, including humans, in which they may cause epidemic disease. Recently such an epidemic occurred due to the emergence of avian influenza virus of the subtype H10N7 (Seal/H10N7) in harbor seals (Phoca vitulina). This epidemic caused high mortality in seals along the north-west coast of Europe and represented a potential risk for human health. To characterize the spectrum of lesions and to identify the target cells and viral distribution, findings in 16 harbor seals spontaneously infected with Seal/H10N7 are described. The seals had respiratory tract inflammation extending from the nasal cavity to bronchi associated with intralesional virus antigen in respiratory epithelial cells. Virus infection was restricted to the respiratory tract. The fatal outcome of the viral infection in seals was most likely caused by secondary bacterial infections. To investigate the pathogenic potential of H10N7 infection for humans, we inoculated the seal virus intratracheally into six ferrets and performed pathological and virological analyses at 3 and 7 days post inoculation. These experimentally inoculated ferrets displayed mild clinical signs, virus excretion from the pharynx and respiratory tract inflammation extending from bronchi to alveoli that was associated with virus antigen expression exclusively in the respiratory epithelium. Virus was isolated only from the respiratory tract. In conclusion, Seal/H10N7 infection in naturally infected harbor seals and experimentally infected ferrets shows that respiratory epithelial cells are the permissive cells for viral replication. Fatal outcome in seals was caused by secondary bacterial pneumonia similar to that in fatal human cases during influenza pandemics. Productive infection of ferrets indicates that seal/H10N7 may possess a zoonotic potential. This outbreak of LPAI from wild birds to seals demonstrates the risk of such occasions for mammals and thus humans

Residue cover, soil structure, weed infestation and spring cereal yields as affected by tillage and straw management on three soils in Norway

Four field trials (spring wheat and oats) were conducted (one on clay soil, one on loam soil and two on silt soil) for three years in important cereal growing districts, to investigate the influence of tillage regimes (ploughing versus reduced tillage in either autumn or spring) and straw management (removed and retained) on plant residue amounts, weed populations, soil structural parameters and cereal yields. The effect of tillage on soil structure varied, mainly due to the short trial period. In general, the amount of small soil aggregates increased with tillage intensity. Reduced soil tillage, and in some cases spring ploughing, gave significantly higher aggregate stability than autumn ploughing, thus providing protection against erosion. However, decreasing tillage intensity increased the amounts of weeds, particularly of Poa annua on silt soil. Straw treatment only slightly affected yields, while effects of tillage varied between both year and location. Reduced tillage, compared to ploughing, gave only small yield differences on loam soil, while it was superior on clay soil and inferior on silt soil. Our results suggest that shallow spring ploughing is a good alternative to autumn ploughing, since it gave comparable yields, better protection against erosion and was nearly as effective against weeds