Stores of exchangeable base cations and aluminium in Lysimeters previously treated with sulphuric acid or NPK with and without irrigation

Lysimeters consisting of intact soil cores, including field- and ground-layer vegetation, from a sandy podzol were treated with irrigation water, H₂SO₄ or NPK and combinations thereof. The acid and fertilizer applications corresponded to 100 kg H₂SO₄ per ha annually and a total of 360 kg N per ha, respectively. Precipitation and leachates from the lysimeters were analyzed for main chemical constituents during a 6-year-period. There-after the experiment was terminated and the cores were fractionated into appropriate vegetation and soil strata. Chemical analyses of the soil revealed a significant increase of exchangeable aluminium in the B- and B/C-horizons due to H₂SO₄ application, accompanied by a decrease of magnesium in the same horizons.The fertilizer caused a net depletion of magnesium in the B- and B/C-horizons mainly due to high levels of replacing cations other than magnesium and correspondingly high levels of mobile anions.Budget calc.ulations indicated increased weathering of magnesium and calciu acid treatment. There were also indications of a calcium adsorption from the irrigation water.H⁺ activity estimated from pH measuremetns in 0.001 M CaCl₂, had increased in the A₀-horizon, in lysimeters treated with sulphuric acid, probably an effect of aluminium hydrolysis. There was a slight in activity in the A₀-horizon of the fertilized lysimeters.     

Mobility of heavy metals in pine forest soils as influenced by experimental acidification

The mobility of Pb, Zn, Cd and Cu was examined at two adjacent experimental plots at åmli, southern Norway, B-1 and B-2. Both experiments were established on the same glacifluvial deposits, with forest consisting of uniform stands of Pinus sylvestris L. The forest in B-1 was planted between 1968 and 1970, while B-2 consisted of naturally regenerated trees. The experiments included plots supplied with artificial rain of varying acidity over a period of seven and eight years for B-1 and B-2, respectively, in addition to control plots. In experiment B-1, experimental acidification was carried out both in unlimed plots and in plots applied with three different levels of lime. The two experiments showed distinct differences with respect to effects of the acidification on mobilization of heavy metals from the O horizon. In experiment B-1, the amount of Zn and Cd decreased with decreasing pH in artificial rain, while Pb and Cu were not appreciably affected. The reduction in Zn and Cd concentrations ceased after termination of the acidification experiment. Liming reduced the leachability of Zn, but still appreciable amounts of Zn were obviously leached from the O horizon during the experiment. In experiment B-2 a high retention even of Zn and Cd was observed in the O horizon, probably due to microbial uptake and accumulation.     

Sonication-assisted extraction of chitin from North Atlantic shrimps (Pandalus borealis)

The influence of sonication during extraction of chitin from North Atlantic shrimp (NAS) shells (Pandalus borealis) on chitin yield, purity, and crystallinity was investigated. Shells were peeled, washed, lyophilized, ground, and suspended for 4 h in 0.25 M HCl (1:40) at 40 degrees C followed by ultrasonication at 41 W/cm(2) for 0, 1, and 4 h, respectively. Demineralized shells were lyophilized, resuspended in 0.25 M NaOH (1:40), and ultrasonicated at 41 W/cm(2) for 0, 1, and 4 h to remove proteins. The yield and mineral and protein contents were determined after each processing step. The purity of extracted chitin was determined from the total amount of glucosamine. The crystallinity index and size of crystals were calculated from wide-angle X-ray scattering measurements. Scanning electron microscope images were recorded to evaluate morphological changes in samples. The yield of chitin from NAS decreased from 16.5 to 11.4% for 0 and 1 h sonicated samples, respectively, which was attributed to increased concentrations of depolymerized materials in the wash water. Sonication did not enhance the removal of minerals. The application of ultrasound enhanced the removal of proteins from 39.8 to 10.6, 8.3, and 7.3% after 0, 1, and 4 h of sonication treatments. The crystallinity index of chitin decreased from 87.6 to 79.1 and 78.5% after 1 and 4 h of sonication, yielding chitosans with crystallinity indices of 76.7, 79.5, and 74.8% after deacetylation, respectively. Fourier transform infrared spectroscopy scans indicated that the degree of acetylation of chitins was unaffected by sonication. Comparison of the extraction results of NAS with that from freshwater prawns indicated that more impurities were left in NAS chitin, suggesting that composition and structural arrangement of chitin in shells influence the efficiency of ultrasound-assisted extraction.     

Soil microbial community structure affected by 53 years of nitrogen fertilisation and different organic amendments

The Ultuna long-term soil organic matter experiment in Sweden (59′82° N, 17′65° E) was started in 1956 to study the effects of different N fertilisers and organic amendments on soil properties. In this study, samples were taken from 11 of the treatments, including unfertilised bare fallow and cropped fallow, straw with and without N addition, green manure, peat, farmyard manure, sawdust, sewage sludge, calcium nitrate and ammonium sulphate, with n = 4 for each treatment. Samples were taken from topsoil (0–20 cm) and subsoil (27–40 cm depth) and analysed for concentrations of phospholipid fatty acids (PLFAs), organic C, total N and pH. The results showed that the subsoil samples reflected the total PLFA content of the topsoil, but not the microbial community structure. Total PLFA content was well correlated with total organic C and total N in both topsoil and subsoil. Total PLFA content in topsoil samples was highest in the sewage sludge treatment (89 ± 22 nmol PLFA g dw⁻¹). This contradicts earlier findings on microbial biomass in this sewage sludge-treated soil, which indicated inhibition of microorganisms, probably by heavy metals added with sludge. A switch towards microbial growth and faster decomposition of organic matter occurred around 2000, coinciding with lowered heavy metal content in the sludge. According to the PLFA data, the microbial community in the sewage sludge treatment is now dominated by Gram-positive bacteria. A lack of Gram-negative bacteria was also observed for the ammonium sulphate treatment, obviously caused by a drop in pH to 4.2.     

Examining the importance of consistency in multi-vessel trawl survey design based on the U.S. west coast groundfish bottom trawl survey

Generalized linear mixed-effects models can be used to combine bottom trawl data from multiple vessels, each with a different fishing power, into a single time series of relative abundance. However, how important might it be to have a consistent set of vessels and vessel characteristics from year to year given we can model differences in fishing power among vessels? We demonstrate how changes in the suite of fishing vessels performing the survey can affect the results of the data analysis using sablefish catches in the U.S. west coast groundfish bottom trawl survey from 1998 to 2000. The results do not indicate that one must have a consistent set of vessels over time to provide useful data, but rather that there is benefit to consistency even when the survey data are analyzed using advanced statistical models. Further research should be undertaken to quantify these benefits specifically to aid in contracting and bidding of survey vessels.     

Pigmentation of salmonids — Genetical variation in carotenoid deposition in rainbow trout

Significant differences in the carotenoid, astaxanthin and cantaxanthin levels were observed between full-sib and half-sib of rainbow trout (Salmo gairdneri). The sex did not affect pigment deposition but a weak negative correlation between fish weight and level of carotenoids in the flesh was found.     

Qualitätsprobleme bei der Resistenzzüchtung von Kopf- und Blumenkohl

In judging the value of the varieties and the quality of the edible part one should not forget that the resistance must also be present in other parts of the plant in order to reach the edible portion at all. This is so with diseases of the vascular system in roots, stems and leaves e.g.Fusarium, Plasmodiophora or cabbage fly as the agent of damage. In: Disease resistance in the vegetable crops, III Walker (1964) surveys also the situation in cabbage. Since then our knowledge of the club-root causing fungusPlasmodiophora has risen from 6–7 to at least 16 physiological races.A satisfactory source for club-root resistance in cabbage we only found in plants with pink anthocyanin pigmentation. The inheritance for colour is under complementary genetic control. Sometimes, however, the synthesis of colour is blocked by inhibitors in spite of the presence of a dominant colour gene. We have made use of this breeding pink-free heads.In spite of work on the antocyanin problem in cabbage over the last 20 years, I have been unable to bread white-headed plants which have as good disease resistance as plants with pink colouration in their interiors. In some other plant varieties one can find a similar relationship between disease resistance and anthocyanin colour in particular in the seed. I therefore feel justified to draw attention to the anthocyanin problem. It is also known that the presence of isothiocyanates and similar S-compounds can affect the disease resistance level in the plant. Sulphur containing compounds which co-determined the flavour and odour of the cabbage should be investigated for their influence upon disease resistance before one attempt to change drastically or even reduce them. We also discuss uneveness of the waxy layer in relation to quality and to disease resistance.Attempts were made to crosscauliflower with club-root resistantcabbage in order to obtain better disease resistance in cauliflowerlike plants. Slides are shown which demonstrate the quality problems 12–15 years after crossing, and the difficulties of breeding for cauliflower headlets were often obtained along the stump, but terminal head positions were rare. Quality-wise this cauliflower had more leaves inside the curd than usual. The breeding material segregates also for colour. Better cold — and frost — resistance was observed. If one does not follow up such observations one can lose a lot of disease resistance potential from the breeding material.

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Paper presented at the Congress of the International Association for Quality Research on food Plants (CIQ) held in common with the Deutsche Gesellschaft für Qualitätsforschung (Pflanzliche Nahrungsmittel) (DGQ) in Wädenswil, Switzerland, Oktober 1975.     

When counting cattle is not enough: multiple perspectives in agricultural and veterinary research

A traditional approach in agricultural and veterinary research is focussing on the biological perspective where large cattle-databases are used to analyse the dairy herd. This approach has yielded valuable insights. However, recent research indicates that this knowledge-base can be further increased by examining agricultural and veterinary challenges from other perspectives. In this paper we suggest three perspectives that may supplement the biological perspective in agricultural and veterinary research; the economic-, the managerial-, and the social perspective. We review recent studies applying or combining these perspectives and discuss how multiple perspectives may improve our understanding and ability to handle cattle-health challenges.     

Landscape change patterns in mountains,land use and environmental diversity,Mid-Norway 1960–1993

The Norwegain mountains have had a central role in the subsistence agroecosystems by providing vast biological resources for humans and their livestock since 4000–3500 BP as indicated by paleoecological records. Later with the development of the summer farming system the use of the mountains was intensified. This long-term use of the mountains has shaped a montane cultural landscape by livestock grazing, mowing for hay, fuel collection and a variety of other uses. The result is a significant increase of the grassland areas at the expense of the forest. Those semi-natural grasslands and heathlands with specific biological diversity have until recently dominated the mountains but are today decreasing due to forest invasion – which in turn is a result of changes in human land use. The present paper focuses on changes in landscape pattern and differences in landscape development in two mountain valleys with summer farming activities, in Mid-Norway, over the period 1960s–1990s, and seeks to interpret the changes in relation to differential land use and environmental factors. This study contributes examples from human shaped ecosystems in mountains where the fragmentation of semi-natural habitats is addressed. A set of landscape pattern indices commonly used in landscape ecological studies is also used here, and their ecological relevance in the present context is dealt with. The implications of changed land use for biodiversity conservation in those mountains and the relationships to future sustainable agriculture is also briefly discussed.     

Transport of Babesia venatorum-infected Ixodes ricinus to Norway by northward migrating passerine birds

Background

Bovine babesiosis is regarded as a limited health problem for Norwegian cows, and the incidence has decreased markedly since the 1930s. Rare cases of babesiosis in splenectomised humans from infection with Babesia divergens and B.venatorum have been described. The objective of this study was to determine whether birds can introduce Babesia-infected ticks. There are between 30 and 85 million passerine birds that migrate to Norway every spring.

Methods

Passerine birds were examined for ticks at four bird observatories along the southern Norwegian coast during the spring migrations of 2003, 2004 and 2005. The presence of Babesia was detected in the nymphs of Ixodes ricinus by real-time PCR. Positive samples were confirmed using PCR, cloning and phylogenetic analyses.

Results

Of 512 ticks examined, real-time PCR revealed five to be positive (1.0%). Of these, four generated products that indicated the presence of Babesia spp.; each of these were confirmed to be from Babesia venatorum (EU1). Two of the four B. venatorum-positive ticks were caught from birds having an eastern migratory route (P< 0.001).

Conclusions

Birds transport millions of ticks across the North Sea, the Skagerrak and the Kattegat every year. Thus, even with the low prevalence of Babesia-infected ticks, a substantial number of infected ticks will be transported into Norway each year. Therefore, there is a continuous risk for introduction of new Babesia spp. into areas where I. ricinus can survive.