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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.

2022

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Abstract

Purpose: Due to environmental concerns, there is a demand to reduce the use of peat as a growing medium for horticultural crops. Simultaneously, there is an interest to recycle organic waste materials in the form of compost. This study aimed to document effects on growth, yield, and fruit quality of tomato plants when cultivated in a sewage digestate-based compost in a subirrigation container system. Materials and methods: The compost used in this experiment consisted of 30% hygienised sewage digestate from biogas extraction and 70% garden waste. The treatments were 100% compost, a peat mix and mixtures of the two in 25/75, 50/50 and 75/25 ratios. Results and conclusion: Considering the contrast in chemical and physical properties of the treatments, variations in growth, yield and quality were expected. The plants differed in leaf area and number of leaves, but there were no differences in yield or quality of the tomato fruits. It is assumed that this is in great part due to the remediating effects of subirrigation with an ideal nutrient solution, and the use of pre-established plants. Further research should focus on benefits of this cultivation system for use in sustainable horticulture in combination with recycled organic waste.

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Abstract

This paper presents results from a container experiment and a real-scale study in road environments for evaluating the performance of soil mixtures and herbaceous perennials for use in rain gardens. The container experiment included 12 soil mixtures and 4 perennial species. The plants were exposed to three flooding events and one drought period, and their overall vitality was recorded after the floodings. The containers were stored outdoors the following winter and plant survival was observed in spring. Amsonia orientalis did not survive the winter after being exposed to flooding in the growing season and was replaced by Hosta ‘Francee’ in the real-scale study, which was established in Drammen (Norway) in a soil mixture based on optimisation of the best mixtures in the container experiment. Luzula sylvatica performed well in the container study and survived the winter; however, in the field study, individuals of this species that were located close to the road died due to de-icing salt. Eurybia divaricata showed some mortality in both studies, and total mortality occurred in individuals that were close to the road, due to de-icing salt. Hemerocallis cvv. performed well in both experiments and appeared to be useful in all rain garden positions in the cold climate road environment. H. ‘Francee’ developed well in the road environment, except when exposed to splashes of road water. The study highlights considerable differences between species’ adaption to roadside rain gardens in cold climates, and the need for further field investigations.

Abstract

Denne rapporten gir resultater fra andre år (2021) i prosjektet"ROBO-GOLF: Bedre gresskvalitet, redusert gjødselkostnad og mindre bruk av fossil energi ved bruk av robotklippere på fairway og semi-rough". Arbeidspakke (WP1) omfatter forsøk med sammenlikning av robotklipper og manuell klipper (sylinder-klipper på fairway, 15 mm klippehøyde; rotorklipper på semirough, 35 mm klippehøyde) til ulike grasarter. Resultatene viste forskjeller mellom robotklipping og manuell klipping, som for det meste ble sett på semi-rough når det gjelder sykdommer, ugress (hvitkløver) og jordpakking. En tendens til lavere sykdomsforekomst med robotklipping ble sett spesielt på semi-rough i alle arter på sensommeren/høsten, men også i Agrostis capillaris på fairway. Mer hvitkløver på de robotklippede ruter med Lolium perenne i semi-rough resulterte i et lavere helhetsinntrykk. I arbeidspakke 2 (WP2) ble nitrogen (N) gjødseleffekten av retur av klipp med robot- vs. manuell klipping studert på fairway etablert i en blanding bestående av Poa pratensis, Agrostis capillaris og Festuca rubra. Årlige N-rater på 0, 30, 60, 90 og 120 kg/ha/år, hver delt inn i 6 like tilførsler, ble brukt over sesongen. Innsamling av klipp én gang per måned viste at tilbakeføring av klipp både for manuell og robotklipping økte gressveksten sammenlignet med når klippet ble fjernet. Samtidig var N-konsentrasjonen i klippet høyere om våren og forsommeren, men ikke på sensommeren og høsten. Helhetsinntrykket av gresset viste samme høye vurdering for robot- og manuell klipp. I WP3 ble demonstrasjonsforsøk med robotklippere sammenlignet med sylinderklippere på fairway og rotorklippere på semi-rough videreført fra 2020 på fem golfbaner i Norden. Helhetsinntrykk, dekning av ugress og sykdommer og energibruk ble registrert månedlig fra mai til september. Helhetsinntrykk i robotklippede ruter var stort sett lik manuelt klippede ruter på fairway og semi-rough. På noen datoer resulterte robotklipping i signifikant høyere helhetsinntrykk enn manuell klipping.

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Abstract

Large areas of forests are annually damaged or destroyed by outbreaking insect pests. Understanding the factors that trigger and terminate such population eruptions has become crucially important, as plants, plant-feeding insects, and their natural enemies may respond differentially to the ongoing changes in the global climate. In northernmost Europe, climate-driven range expansions of the geometrid moths Epirrita autumnata and Operophtera brumata have resulted in overlapping and increasingly severe outbreaks. Delayed density-dependent responses of parasitoids are a plausible explanation for the 10-year population cycles of these moth species, but the impact of parasitoids on geometrid outbreak dynamics is unclear due to a lack of knowledge on the host ranges and prevalences of parasitoids attacking the moths in nature. To overcome these problems, we reviewed the literature on parasitism in the focal geometrid species in their outbreak range and then constructed a DNA barcode reference library for all relevant parasitoid species based on reared specimens and sequences obtained from public databases. The combined recorded parasitoid community of E. autumnata and O. brumata consists of 32 hymenopteran species, all of which can be reliably identified based on their barcode sequences. The curated barcode library presented here opens up new opportunities for estimating the abundance and community composition of parasitoids across populations and ecosystems based on mass barcoding and metabarcoding approaches. Such information can be used for elucidating the role of parasitoids in moth population control, possibly also for devising methods for reducing the extent, intensity, and duration of outbreaks.