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
Abstract
Podzol development was investigated in a chronosequence on sandy beach sediments, the ages of the soils ranging from 2,400 to 8,500 years. All soil properties investigated-the organic matter content of the B horizons, clay content, Fe-o, Al-o, Si-o, Fe-o/Fe-d and Fe-d/Fe-t - tend to increase with advancing podzolization, and are strongly correlated with soil age. Topsoil pH values decrease with age. The characteristic Bh and Bs horizons had developed after approximately 4,000 years.
Authors
Isabelle Schülli-Maurer Daniela Sauer Karl Stahr Ragnhild Sperstad Rolf SørensenAbstract
We investigated the development of Albeluvisols and Podzols with time in southern Norway. The Vestfold region at the western shore of the Oslofjord was chosen because it is characterized by continuous glacio-isostatic uplift for the last 12,000 years. Due to the permanent elevation process, no distinct marine terraces have been built, and the age of the sediments continuously increases with distance from the modern coastline. Albeluvisol development was assessed in a soil chronosequence on loamy marine sediments with ages ranging from approximately 1,800 to 10,200 years. The most obvious change during soil development was that after 4,500 - 5,000 years light tongues intruded from the E horizon into the B horizon, and became more pronounced with time. The combined thickness of the A and E-horizons was constant at 40 ± 3 cm in 9 of the 12 profiles and did not change with age. The organic matter content of the A-horizons, the fine silt to coarse silt ratio of the Btg horizons and the Feo/Fed ratio all decreased with soil age, whereas the thickness of the organic surface horizon and B horizon, as well as the Fed/Fet ratio all increased. Podzol development was investigated in a chronosequence on sandy beach sediments, the ages of the soils ranging from 2,400 to 8,500 years. All soil properties investigated - the organic matter content of the B horizons, clay content, Feo, Alo, Sio, Feo/Fed and Fed/Fet - tend to increase with advancing podzolization, and are strongly correlated with soil age. Topsoil pH values decrease with age. The characteristic Bh and Bs horizons had developed after approximately 4,000 years.
Authors
Roshan M. Bajracharya Bishal K. Sitaula Subodh Sharma Alhaji S. JengAbstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Mehreteab TesfaiAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Peder GjerdrumAbstract
Predicting the yield and quality of sawn timber continues to be a challenging task, influenced by several stochastic processes: Log dimension and shape under bark varies, accuracy of sawing is not perfect, etc. This work presents an annotated model based on an approach successfully applied in the industry through a couple of decades. A number of important timber yield predictors are identified, and the following models give unbiased yield estimates. Being in need of adjustment before transferring to new locations, the approach might be considered a powerful tool to analyse and improve the operation, rather than a complete model in itself. Nevertheless, the notional, purely geometric, models might be superior for analysing unfamiliar sawing patterns, even if they tend to overestimate the yield. Thus, the two methods should preferably be used in combination, rather than one replacing the other. Finally, the everyday use of such models is illustrated and a procedure for associating sawn timber with suitable logs is outlined.
Authors
Trond Henriksen Audun Korsæth Tor Arvid Breland Bo Stenberg Lars Stoumann Jensen Sander Bruun Jon Gudmundsson Fridrik Palmason Anders Pedersen Tapio SaloAbstract
Mechanistic, multi-compartment decomposition models require that carbon (C) and nitrogen (N) in plant material be distributed among pools of different degradability. For this purpose, measured concentrations of C and N in fractions obtained through stepwise chemical digestion (SCD) and values predicted from near-infrared (NIR) spectra or total plant N concentration were compared. Seventysix cash, forage, green manure and cover crop plant materials representing a wide range in biological origin and chemical quality were incubated in a sandy soil at 15 degrees C and -10 kPa water potential for 217 d. A mechanistic decomposition model was calibrated with data from soil without plant material and initialised by data on amounts of C and N in fractions obtained from SCD directly or C and N in SCD fractions as predicted from NIR spectroscopy or plant N concentration. All model parameters describing C and N flows from plant material were kept at default values as defined in previous, independent works with the same model. When results from SCD were used directly to initialise the decomposition model, C and N mineralisation dynamics were predicted well (r(2) = 0.76 and 0.70 for C mineralisation rates and accumulation of inorganic N, respectively). When a NIR calibration was used to predict the SCD data, this resulted in nearly equally good model performance (r(2) = 0.76 and 0.69 for C and N mineralisation, respectively). This was also the case when SCD data were predicted from plant material N concentration (r(2) = 0.76 and 0.69 for C and N). We conclude that the combined use of a mechanistic decomposition model and quality data from SCD is a highly adequate basis for an a priori description of the mineralisation of both C and N from common agricultural plant materials, and that both NIR spectroscopy and measurement of total N concentration offer good and cost-effective alternatives if they are calibrated with SCD data. (C) 2007 Elsevier Ltd. All rights reserved.
Abstract
To study physiological and biochemical effects of demethylation inhibitor (DMI) fungicides on non-target insects, larvae of the cabbage moth, Mamestra brassicae L., were exposed orally to propiconazole, (R,S)-1-[2-(2,4-diclophenyl)-4-propyl-1,3-dioolan-2-ylmetyl]-1H-1,2,4-triazole (100, 200 and 600 mg L−1) and fenpropimorph, (±)-cis-4-[3-(4-tert-butylphenyl)-2-methylpropyl] 2,6-dimethylmorpholinc (10, 100, 200 and 600 mg L−1) in a semi-synthetic diet. Ten mg L−1 of fenpropimorph reduced larval weight and induced in vitro glutathione S-transferase activity. Reduced larval and pupal growth rate, reduced survival, prolonged developmental time, and altered patterns of larval survival and adult emergence were found for one or both fungicides in at least one of the concentrations tested. The results suggest, that although the use of agricultural fungicides is generally regarded as of minor ecotoxicological consequence for insects, feeding on DMI-treated crops may influence insect fitness, and may also leave them susceptible to pesticide treatments or to residues of pesticides and other pollutants in their food. Standard methods to detect such effects should be developed for use in the environmental risk assessment of these products.