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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.

2018

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Abstract

Acid deposition arising from sulphur (S) and nitrogen (N) emissions from fossil fuel combustion and agriculture has contributed to the acidification of terrestrial ecosys- tems in many regions globally. However, in Europe and North America, S deposition has greatly decreased in recent decades due to emissions controls. In this study, we assessed the response of soil solution chemistry in mineral horizons of European forests to these changes. Trends in pH, acid neutralizing capacity (ANC), major ions, total aluminium (Al tot ) and dissolved organic carbon were determined for the period 1995–2012. Plots with at least 10 years of observations from the ICP Forests moni- toring network were used. Trends were assessed for the upper mineral soil (10– 20 cm, 104 plots) and subsoil (40–80 cm, 162 plots). There was a large decrease in the concentration of sulphate (SO 2 4 ) in soil solution; over a 10-year period (2000– 2010), SO 2 4 decreased by 52% at 10–20 cm and 40% at 40–80 cm. Nitrate was unchanged at 10–20 cm but decreased at 40–80 cm. The decrease in acid anions was accompanied by a large and significant decrease in the concentration of the nutrient base cations: calcium, magnesium and potassium (Bc = Ca 2+ + Mg 2+ + K + ) and Al tot over the entire dataset. The response of soil solution acidity was nonuni- form. At 10–20 cm, ANC increased in acid-sensitive soils (base saturation ≤10%) indicating a recovery, but ANC decreased in soils with base saturation >10%. At 40–80 cm, ANC remained unchanged in acid-sensitive soils (base saturation ≤20%, pH CaCl 2 ≤ 4.5) and decreased in better-buffered soils (base saturation >20%, pH CaCl 2 > 4.5). In addition, the molar ratio of Bc to Al tot either did not change or decreased. The results suggest a long-time lag between emission abatement and changes in soil solution acidity and underline the importance of long-term monitor- ing in evaluating ecosystem response to decreases in deposition.

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Abstract

The aim of this study was to contribute to the development of pelleted compound recycling fertilizerswith favourable handling and spreading characteristics and balanced nutrient ratios by combiningnitrogen (N)- and phosphorus (P)-rich waste resources (meat bone meal, fish sludge or food waste)with potassium (K)-rich bottom wood ash. Pelleted compound recycling fertilizers with gooddurability and low dusting tendency were produced by roll-pelleting preheated waste resources at asuitable moisture content. However, the nutrient ratios in the final products were insufficientlybalanced, with too low N concentrations relative to P and K to meet crop demands. In a bioassayusing barley ( Hordeum vulgare) and a nutrient-deficient sand/peat mixture, the relative agronomiceffectiveness (RAE) of pelleted compound recycling fertilizers and reference recycling fertilizers was22–42% of that of mineral compound fertilizer. Growth limitation was due to reduced N availability(mineral fertilizer equivalent - MFE = 35–57%) or reduced P availability (MFE = 20–115%), with thegreatest P fertilizer value obtained for digestate based on dairy manure and fish sludge. Availability ofK in bottom wood ash was masked by the experimental soil.

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Abstract

Impacts of nutrient supply and different cultivars (genotypes) on actual yield levels have been studied before, but the long-term response of yield trends is hardly known. We present the effects of 24 different fertilizer treatments on long-term yield trends (1953–2009) of winter wheat, winter rye, sugar beet and potato, with improved cultivars changing gradually over time. Data was obtained from the crop rotation within the long-term fertilization experiment at Dikopshof, Germany. Yield trends were derived as the slope regression estimates between adjusted yield means and polynomials of the first year of cultivation of each tested cultivar, when tested for more than two years. A linear trend fitted best all data and crops. Yields in highly fertilized treatments increased linearly, exceeding 0.08 t ha−1 a−1 for both, winter wheat and winter rye, and ≥0.30 and ≥0.20 t ha−1 a−1 for sugar beet and potato fresh matter yields. Yield trends of winter cereals and sugar beet increased over time at N rates ≥40 kg ha−1 a−1, being 0.04–0.10 t ha−1 a−1 for cereals and 0.26–0.34 t ha−1 a−1 for sugar beet, although N rates >80 kg ha−1 a−1 produced a stronger effect. Nitrogen was the most influential nutrient for realisation of the genetic yield potential. Additional supply of P and K had an effect on yield trends for rye and sugar beet, when N fertilization was also sufficient; high K rates benefited potato yield trends. We highlight the importance of adequate nutrient supply for maintaining yield progress to actually achieve the crop genetic yield potentials. The explicit consideration of the interaction between crop fertilization and genetic progress on a long-term basis is critical for understanding past and projecting future yield trends. Long-term fertilization experiments provide a suitable data source for such studies.

Abstract

Previous studies estimating TFP and its components have been criticized for not considering farm heterogeneity in their model. Moreover, the studies focused on the technical evaluation of a sector. However, the technical evaluation alone reveals how well farmers use the physical production process. There is a need to closely examine the cost efficiency of the farmers. In this study, we used a cost function (dual) approach to facilitating the decomposition and estimation of TFP components. Using a translog stochastic cost function, we estimated the level and source of productivity and profitability change for crop producing family firms in Norway. We used the true random effect to account for farm heterogeneity. The analysis is based on 23 years unbalanced panel data (1991-2013) from 455 crop- producing firms with a total of 3885 observations. The result indicates that average annual productivity growth rate in grain and forage production was - 0.11 % per annum during the period 1991-2013. The profit change was 0.14 % per annum.

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Abstract

Effects of climatic factors and material properties on the development of surface mould growth on wooden claddings were investigated in a laboratory experiment. Specimens of aspen (Populus tremula), Siberian larch (Larix Sibirica), American white oak (Querqus alba), Scots pine (Pinus sylvestris), Norway spruce (Picea abies) and thermally modified pine were incubated in eight climatic chambers at specified wetting periods (2 or 4 h per day), relative humidity (58–86%) and temperature conditions (10–27°C). Surface mould growth was assessed weekly for 13 weeks, and the results were evaluated statistically using Generalized Estimating Equations logistic regression models. All tested climatic factors had significant effects on the mould growth, and there were significant differences between the materials. The ranking of the materials varied with temperature and over time. Aspen, pine sapwood and oak were overall most susceptible to mould growth, and thermally modified pine least susceptible. There were significant differences between sapwood and heartwood for pine and spruce. The effect of density was tested on the spruce heartwood material, but was not found to be significant. The results can be used to further develop prediction models for mould growth on wooden claddings.