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.
2007
Authors
Zhihui Yang Bal Ram Singh Sissel Hansen Zhengyi Hu Hugh RileyAbstract
Understanding soil sulfur pools and associated aggregates S fractions can provide a platform for monitoring S dynamics in soils. A long-term experiment established in 1922 on an Aquic Eutrocryepts in South-eastern Norway was chosen to investigate the effects of long-term fertilization on S fractions in bulk soil and those associated with aggregates. Chloroform fumigation-extraction was used to determine Microbial biomass S (MBS) and the wet chemical analysis method was used to fractionate soil S into ester S (hydriodic acid reducible S), carbon-bonded S (Raney nickel reducible S) and residual S (Raney nickel non-reducible S). High farmyard manure (FYM) application resulted in higher MBS in bulk soil than nitrogen + potassium (NK) application, but it did not differ significantly from the control. Application of FYM at 60 Mg ha(-1) resulted into accumulation of total S, total organic S and carbon-bonded Sin bulk soils, while mineral fertilizer (nitrogen+phosphorus+potassium+sulfur [NPKS] and NK) and the medium rate of FYM did not increase the accumulation of total S and organic S fractions. The macroaggregate sizes (> 2 and 1-2 mm) and the finest aggregate size (< 0.106 mm) showed significantly greater total S concentration than other aggregate sizes. Ester S and residual S were predominant organic S fractions and they accounted for 39 to 52% and 38 to 51% of the organic S, respectively. The macroaggregate sizes (> 2 and 1-2 mm) contained the highest ester S, but microaggregates (< 0.106 mm) exhibited higher carbon-bonded S and residual S than other aggregates. In conclusion, the accumulation of S was dependent on fertilizer type, the rate of FYM application and aggregate sizes.
Authors
Alhaji S. Jeng Roshan Bajracharya Bishal K. Sitaula Bed Mani Dahal Subodh ShermaAbstract
No abstract has been registered
Authors
Daniela Sauer Isabelle Schülli-Maurer Ragnhild Sperstad Rolf Sørensen Karl StahrAbstract
The coastal areas of Scandinavia provide suitable conditions for studying soil development with time, due to glacio-isostatic uplift. Our study area is located along both sides of the Oslofjord (Vestfold and stfold). The climate in this area is rather mild although it is located between 59 and 59 40 latitude. The mean annual temperature ranges from 5.4 to 6. 0 C. Precipitation is 9751094 mm year1 in Vestfold and 751829 mm year1 in stfold. Due to the steadiness of the uplift, no separate terraces were formed in the study area, but soils continuously get older from the coast inland. We established two soil chronosequences comprising six pedons each, one in Vestfold (1650 9000 years) and one in stfold (300011050 years). The ages were estimated by use of several sea level curves established for various locations in the area, based on calibrated radiocarbon datings. The parent material is loamy marine sediment. The geological basement below the sediment consists of basic magmatite (monzonite, latite) in Vestfold and predominantly acid magmatite (granite) in stfold. Higher precipitation in Vestfold leads to earlier beginning of clay illuviation. Clay coatings are perceptible in Vestfold already in the 1650 years old soil. In stfold they become visible for the first time in the 3500 years old soil. The E horizon becomes lighter with age, but its thickness stays constantly around 40 cm in both areas. The development of the characteristic albeluvic tonguing starts after 4000 to 5000 years. The tongues initially develop mainly along intersections of cracks. Due to ongoing leaching they increase in length and width, progressively consuming the prisms in between the cracks in the upper part of the Bt horizon. Base saturation in the upper 25 cm exhibits a decrease with time which can be best described by an exponential model, while pH (water) stays constantly at pH 4.4 0.4 in all soils covering a range of 1650 to 11050 years in age. These findings indicate that the soil pH is buffered by protonation of surface charges occupied by exchangeable base cations over a time span of more than 9000 years. The Fed/Fet ratio shows an increase with time which can be described by both, a linear or potential model, reflecting progressive iron release from mineral weathering. The Feo/Fed ratio shows a linear decrease indicating increasing degree of iron oxide crystallization.
Abstract
No abstract has been registered
Authors
Guro Ådnegard Skarstad Laura Terragni Hanne TorjusenAbstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Carl Gunnar FossdalAbstract
In collaboration with the NARC platform at Ås, we have taken the Norway spruce phytochrome and PaChi4 promoters and introduced them into Arabidopsis using GFP and YFP expression vectors in order to study their effect on expression under long and short day treatment. Said in other words we use of GFP and YFP as reporters and Arabidopsis as a host for the Norway spruce promoters in order to study their possible regulation by day-length in this model plant system. In completely separate experiments in collaboration with the NARC platform at Ås, we have introduced the Norway spruce glycohydrolase PaChi4 into Arabidopsis to examine what effect this might have on the response to wounding and to pathogens. The PaChi4 enzyme is produced at very high levels in tissues with high level of host cell death (PCD) following fungal infections and it might be a marker for or directly involved in PCD. We have obtained transgenic plants and the first examination for any day-length dependent expression of the GFP and YFP reporters in the transgenic Arabidopsis lines is currently being pursued while the examination of the PAChi4 enzyme overexpressing lines are yet to be initiated.
Abstract
The study aims to estimate the effects on the sheep farm economy of reducing grazing levels necessitated due to possible overgrazing by sheep on two important mountainous range pastures in southwest Norway. The pasture range in Setesdal Vesthei is grazed by sheep from distant farms located at Jæren (south of Stavanger), while south-western Hardangervidda is grazed by sheep from local farms and distant farms located along the coast. Farmers utilizing the pasture areas combine sheep with dairy cows, off farm work or businesses, while the local farms combine it with orchards. A Linear Programming (LP) model for specialized sheep farms based on farm records has been developed to study effects of reaching various grazing capacity levels. Reducing the number of sheep in Setesdal Vesthei by 10 percent would lower farm income per breeding stock animal with € 15 to € 119 and with € 35 to € 211 for Hardangervidda. The decrease in annual income will range from € 15,00 to € 119,00 in total for the farms using Setesdal Vesthei. The economic effects depend much on meat production per ewe. Replacing unilateral sheep grazing with a mixed system involving suckling goats and heifers is discussed to deal with the problems of encroachment and increasing elevation of the alpine tree-line.
Abstract
It is generally recommended that solutions for the treatment of wastewater and toilet waste is based on a detailed knowledge of the local physical and natural conditions as well as socio-economical factors and socio-cultural factors. Based on experience from previous comparable projects the following components are recommended: " The systems should be build as large as possible based on local natural/financial resources " Infiltration systems are preferred if local soil is usable and local water resources are protected " A combination with pre-treatment, compact filtering and extensive filtering in wetlands or peat filters Based on experience from previous comparable projects the following components might also be recommended given a local acceptance: " Urine separating toilets without water/low water consumption " Separate collection of urine in tanks to be stored and reused or safely disposed off " Toilet solid waste to be stored in separate tanks and co-treated with other organic waste fractions " Separate treatment of greywater and urine in extensive infiltration or filter systems These systems makes it possible to a safe, odour free and recycling waste and wastewater treatment without creating unacceptable loads on the environment or risks to human health. Infiltration systems depend on local soils and previous use of ground water.