Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2018
Forfattere
Panu Korhonen Taru Palosuo Tomas Persson Mats Höglind Guillaume Jégo Marcel Van Oijen Anne-Maj Gustavsson Gilles Bélanger Perttu VirkajärviSammendrag
During the past few years, several studies have compared the performance of crop simulation models to assess the uncertainties in model-based climate change impact assessments and other modelling studies. Many of these studies have concentrated on cereal crops, while fewer model comparisons have been conducted for grasses. We compared the predictions for timothy grass (Phleum pratense L.) yields for first and second cuts along with the dynamics of above-ground biomass for the grass simulation models BASGRA and CATIMO, and the soil-crop model STICS. The models were calibrated and evaluated using field data from seven sites across Northern Europe and Canada with different climates, soil conditions and management practices. Altogether the models were compared using data on timothy grass from 33 combinations of sites, cultivars and management regimes. Model performances with two calibration approaches, cultivar-specific and generic calibrations, were compared. All the models studied estimated the dynamics of above-ground biomass and the leaf area index satisfactorily, but tended to underestimate the first cut yield. Cultivar-specific calibration resulted in more accurate first cut yield predictions than the generic calibration achieving root mean square errors approximately one third lower for the cultivar-specific calibration. For the second cut, the difference between the calibration methods was small. The results indicate that detailed soil process descriptions improved the overall model performance and the model responses to management, such as nitrogen applications. The results also suggest that taking the genetic variability into account between cultivars of timothy grass also improves the yield estimates. Calibrations using both spring and summer growth data simultaneously revealed that processes determining the growth in these two periods require further attention in model development.
Forfattere
O. Janne Kjønaas Sunil Mundra Teresa Gómez de la Bárcena Mette Hansen Gro Hylen Håvard KauserudSammendrag
Tree species change has been suggested as one of the government policies to mitigate climate change in Nor-way with the aim to increase the annual uptake of CO2 and the long-term storage of carbon (C) in forests. The strategy includes replacing native, deciduous species with fast-growing species, mainly Norway spruce. A shift in tree species is expected to affect the pools and fluxes of C in the stand as well as the microbial community. As part of the BalanC project, we assess C storage related to shift in tree species cover in western Norway and whether a corresponding shift in soil microbial communities are happening. The study aim at integrating results on soil respiration, C mineralization, soil stability, diversity of bacteria, fungi and micro-eukaryotes, soil nutrient pools, litter inputs and edaphic factors at the stand level in order to identify key drivers for changes in the soil C stocks. Fifteen paired plots of native birch and planted Norway spruce at five locations were sampled. Prelimi-nary results suggests a redistribution of C from the mineral soil to the forest floor in the spruce stands, with minor changes in the total soil C pools over the 45-60 years since the tree species change. The in situ soil respi-ration and heterothropic respiration, as well as C mineralization rates, were higher in birch than in spruce stands. Differences in C mineralization rates attenuate with depth between forest types. The microbial com-munities of the three organismal groups were all strongly structured along the vertical depth.
Sammendrag
The boreal forest is a key ecosystem for global C sequestration and storage. Microorganisms in soil have crucial functions in regulating these processes. Fungi are typically sharply structured with soil depth, but we largely lack such information for other microorganism, including bacteria and other micro-eukaryotes. To improve our knowledge of how different microorganisms are structured vertically and how they might interact, we investi-gated the communities of bacteria, fungi and micro-eukaryotes in four different soil horizons in natural birch forests in Western Norway. The communities of all three organismal groups were strongly structured along the vertical depth. Our results support the hypothesis that natural decrease in nutrient availability and pH differ-ences between organic and mineral horizons affect the distribution of soil microorganisms. Proteobacteria, Actinobacteria and Planctomycetes dominated in the uppermost organic layer while Acidobacteria and Firmicu-tes in mineral layers. Proportionally, fungi dominated in mineral layers whereas other micro-eukaryotes (Meta-zoa, Apicomplexa, Conosa, Ochrophyta and Chlorophyta) in organic layers. Ascomycota were relatively more abundant in mineral layers compared to Basidiomycota and Cryptomycota. Nematoda, Annelida and Arthropo-da showed decreasing trends with depth. Furthermore, different optima in the depth distribution of ectomy-corrhizal and saprotrophic genera was observed, supporting the view that different genera are adapted to different niches along the soil depth gradient. Network analyses will be used to infer tentative biotic interac-tions between the microbial groups and how this varies with soil depth.
Forfattere
Krishna Reddy Kakumanu Yella Reddy Kaluvai Sekhar Udaya Nagothu Narayan Reddy Lati Gurava Reddy Kotapati Sunitha KaranamSammendrag
Climate change characterized by global warming has become a hotspot of research in recent years for water resources, agriculture,ecology and other disciplines. In India, studies have shown an increasing trend in surface temperature, with decreasing trends inrainfall. Farmers are also more affected by the climate variability which has a serious influence on their production and income.The climate change and adaptation (ClimaAdapt) programme was implemented from 2012 to 2016 to build farm-level capacitiesand enhance the adaptive capacity of the agricultural and water sectors in the Krishna basin of Andhra Pradesh and Telanganastates. Water-saving interventions such as direct seeded rice, a modified system of rice intensification and alternate wetting anddrying (AWD) of rice were implemented in a cluster approach and enhanced water productivity. The training and implementationprogrammes increased the adaptation and awareness of farmers. Water measurements were carried out by usingflumes andultrasonic sensors. The area under direct seeded rice has increased to 64% in the study district and 77% of the trained farmersare adopting the practice. Capacity building, implementation and science–policy linkages are the key pillars of the programmeto improve the adaptive capacity and scaling-up of water management practices.
Forfattere
Leonardo Ciaccheri Lorenza Tuccio Andrea A. Mencaglia Anna G. Mignani Ewelina Hallmann Kalina Sikorska-Zimny Stanislaw Kaniszewski Michel Verheul Giovanni AgatiSammendrag
Non-destructive tools for evaluating the lycopene content in tomatoes are of great interest to the entire fruit chain because of an increasing demand for beneficial health products. With the aim of developing compact low-cost reflectance sensors for lycopene determination, we compared Partial Least Squares (PLS) prediction models by using either directional or total reflectance in the 500–750 nm range. Directional reflectance at 45° with respect to the LED lighting direction was acquired by means of a compact spectrometer sensor. Total reflectance was acquired through a 50-mm integrating sphere connected to a spectrometer. The analysis was conducted on two hydroponic greenhouse cultivated red tomato varieties, namely the large round ‘Dometica’ (average diameter: 57 mm) and the small cherry ‘Juanita’ (average diameter: 26 mm). For both varieties, the spectral variance of directional reflectance was well correlated to that of total reflectance. The performances of the PLS prediction models were also similar, with R2 of cross-validation between 0.73 and 0.81. The prediction error, relative to the mean lycopene content of full ripe tomatoes, was similar: i.e. around 16–17% for both varieties and sensors. Our results showed that directional reflectance measured by means of portable, low-cost and compact LED-based sensors can be used with an adequate precision for the non-destructive assessment of lycopene in tomatoes.
Forfattere
Ravishankar Narayana Judith Fliegmann Ivan Paponov Massimo E. MaffeiSammendrag
Det er ikke registrert sammendrag
Forfattere
Hege UlfengSammendrag
Det er ikke registrert sammendrag
Forfattere
Anne Falk Øgaard Lasse Vråle Martin MengedeSammendrag
Sewage sludge is a significant phosphorus resource that should be better utilized in the plant production than today. However, phosphorus in sludge produced after precipitation with aluminium and iron coagulants have low plant availability. This article presents results from plant growth experiments where plant available phosphorus in lime precipitated sewage sludge from Bokerøya and Skådevika wastewater treatment plants was studied. Both wastewater treatment plants normally use iron as coagulant aid, but Skådevika produced in addition a sludge to the experiments without using iron. The growth experiments included a pot experiment in greenhouse with three harvests of Italian ryegrass (Lolium multiflorum) and a two-year field experiment in cereals in Southeast Norway. The results showed that precipitation with lime gives a sludge with higher plant availability of phosphorus than what is earlier found for aluminium/ iron precipitated sludge. This was special the case with moderate use of iron as coagulant aid.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Erling MeisingsetSammendrag
Det er ikke registrert sammendrag