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.
2025
Authors
Karin Juul Hesselsøe Anne Friederike Borchert Trond Olav Pettersen Kristoffer Herland Hellton Trygve S. AamlidAbstract
Abstract Ice encasement (IE) is one of the big challenges in winter stress management on golf course putting greens in Northern Scandinavia. The turfgrass is damaged due to lack of oxygen (hypoxia or anoxia) and accumulation of toxic by‐products of anaerobic respiration. Breeding IE‐tolerant turfgrass species and varieties is the best defense against these challenges. A method to simulate ice encasement was tested to screen selected varieties of winter‐hardy bentgrass species and red fescue subspecies. Note that 32 varieties were chosen from the SCANGREEN trial seeded at NIBIO Landvik, Norway, in 2019. Samples were taken in December 2020, 2021, and 2022, vacuum sealed in plastic, and stored in darkness at 0.5°C for up to 77 days to test them for their tolerance to simulated ice encasement (SIE). Samples were incubated at different intervals; plants were potted, and tiller survival was tested after 4 weeks of regrowth. Lethal duration of ice encasement (LD 50 ) that is, the number of days under anoxia that kills 50% of the plant population for each species and variety was calculated. The results showed that the ranking of cool season turfgrass species for tolerance to SIE was velvet bentgrass > Chewings fescue > slender creeping red fescue = colonial bentgrass > creeping bentgrass. This ranking does not fully reflect the ranking found in field tests where velvet bentgrass was superior together with creeping bentgrass. SIE caused a more rapid development of anoxia than IE in the field, and we hypothesize that creeping bentgrass is less tolerant to these conditions compared to the other species tested. To make the SIE method more representative for IE in field, it should be further adapted with incubation at lower temperatures, and with acclimation conditions to be standardized prior to sampling. Within species, the best tolerance to IE was found in velvet bentgrass Nordlys, creeping bentgrass Penncross, Chewings fescue Lykke, and slender creeping red fescue Cezanne.
Abstract
Abstract The primary benefits of turfgrass sod include rapid greenery and soil coverage, but its production causes concerns about soil losses at production sites. Soil adheres to the grass root system during harvesting and is removed from the sod farm, which in the long run might lead to soil degradation on the sod farm. In this study, we investigated sod thickness and the removal of organic and mineral matter when harvesting 24 fields representing 12 Norwegian sod farms in 2022 and 2023. On each field, 10 sod strips were randomly chosen, and five sod plugs were collected from each strip. Sod thickness was measured using a sliding gauge. Sod mineral matter (SMM: soil and thatch mineral matter) and sod organic matter (SOM: soil and thatch organic matter) contents were quantified by loss on ignition at 550°C. Management and field properties were also documented. Results showed an average amount of mineral matter in the sod strips of 36 Mg ha −1 for all fields but with significant variation among fields ( p < 0.001). The average SOM content was 10 Mg ha −1 . Mean sod thickness was 15.4 mm and had a strong correlation with SOM ( r = 0.8) but only a moderate correlation with SMM ( r = 0.6). Soil water content and surface hardness at harvest affected sod thickness and SMM only slightly. Sod harvesters with twin heads harvested significantly thicker sod strips and removed more mineral matter than harvesters with single cutting heads. Soil texture did not have a significant impact on sod thickness or mineral matter removal.
Authors
Siv Mari AurdalAbstract
This paper is a historical review of scientific progress on horticultural growing media, with particular attention to the role of peat and the recurring search for sustainable alternatives. It is well established that peat became the cornerstone of horticultural growing media because it offered a unique combination of nutrient control, pH buffering, water retention, absence of harmful microorganisms, and structural stability. Equally evident are the environmental concerns and sustainability goals that have driven the search for alternative materials since the 1980s. This historical review traces the evolution of growing media from the early 20th century to the mid-2020s, focusing on how peat came to dominate and why its substitution has proven so difficult. Drawing on a wide range of literature, including peer-reviewed experimental studies, historical sources, symposia proceedings, institutional reports, and synthesis articles, the historical development of growing media science and practice across each decade is outlined. Attention is given to various composts, coir, wood fiber, bark, and biochar and challenges with these materials related to product standardization for end-user reliability. While many alternatives show potential, particularly as partial components or as stand-alone media under certain conditions, no single material currently offers a fully viable replacement for peat. Instead, the most promising direction appears to be peat-reduced mixtures optimized for both functionality and sustainability. By understanding how growing media science has evolved and where it has struggled, this paper identifies lessons critical to navigating the ongoing transition toward more sustainable and functional systems.
Authors
Abel Gizaw Seid Dimitar Dimitrov Catherine Aloyce Masao Felly Mugizi Tusiime Tigist Woldimu Ahmed Abdikadir Abdi, Desalegn Chala Galina Gusarova virginia Mirré Mulugeta Kebede Rosalia Pineiro Mary Namaganda Pilar Catalan Manuel Pimentel Pierre Taberlet Hans Peter Linder Magnus Popp Gerald Eilu Pantaleo Munishi Geoffrey Mwachala Sileshi Nemomissa Christian BrochmannAbstract
No abstract has been registered
Authors
Juan Manuel Gorospe Eliska Zaveska Desalegn Chala Abel Gizaw Seid Felly Mugizi Tusiime Lovisa Gustafsson Lubomir Pialek Filip Kolář Christian Brochmann Roswitha SchmicklAbstract
No abstract has been registered
Authors
Lucía D. Moreyra Cristina Roquet Alfonso Susanna Siri Birkeland Carme Blanco‐Gavaldà Christian Brochmann Desalegn Chala Mercè Galbany‐Casals Abel Gizaw Seid Juan Antonio CallejaAbstract
ABSTRACT Aim We investigated the biogeographic history and diversification dynamics of Afrocarduus , an Afromontane–Afroalpine genus endemic to eastern Africa. We aimed to assess the roles of geographic isolation, habitat transitions, and ecological speciation in shaping current diversity. Location The Afromontane and Afroalpine regions of East Africa and Ethiopia are situated along the Great Rift Valley system. Taxon Afrocarduus (Compositae: Carduinae), a genus comprising 18 endemic species. Methods We conducted a comprehensive taxonomic and geographic sampling of Afrocarduus , generating data from 489 nuclear loci. Phylogenomic and biogeographic ancestral estimation analyses were performed to infer the evolutionary history and historical biogeography of the genus. Results Afrocarduus originated in the Afromontane zone of eastern Africa during the Late Miocene (~10.7 Ma), with major diversification events occurring in the Early Pleistocene (~2.3 Ma). Most dispersal events occurred between neighbouring massifs, though occasional long‐distance dispersal between disjunct mountain systems was detected. The Turkana Depression and the Great Rift Valley have acted as major biogeographic barriers. Phylogenetic structure shows distinct clades occupying different regions. Ecological divergence between Afromontane and Afroalpine environments contributed to speciation, with at least six independent adaptations to Afroalpine conditions and multiple cases of ecological reversal. Stem loss, a trait associated with alpine habitats, evolved convergently in two clades. Closely related species often segregate by elevation or microhabitat within the same massif. Main Conclusions The diversification of Afrocarduus has been shaped by a combination of historical climate change, geographic isolation, and ecological adaptation. Our results emphasise the importance of ecological speciation and habitat transitions in Afrotemperate plant evolution and highlight the need for further research on understudied Afromontane taxa, especially under the threat of ongoing climate change.
Authors
Lucía D. Moreyra Juan Antonio Calleja Cristina Roquet Siri Birkeland Carme Blanco‐Gavaldà Mercè Galbany‐Casals Abel Gizaw Seid Frederik Leliaert Christian Brochmann Alfonso SusannaAbstract
Abstract Accurate species delimitation is crucial for biodiversity research, as it significantly impacts taxonomy, ecology, and conservation. Recent advances in molecular phylogenetics and integrative taxonomy have improved classifications and resolved long‐standing taxonomic uncertainties. Here, we use Hyb‐Seq (489 nuclear loci) and phylogenomic approaches to investigate Afrocarduus , a genus endemic to tropical Afromontane and Afroalpine regions. Our analyses reveal 16 evolutionary lineages within this relatively young genus (crown age 2.3 Mya), with new morphological data strongly supporting the recognition of each lineage as a distinct species. We demonstrate that the stemless habit evolved independently in species from the Ethiopian Highlands and the East African Rift System (EARS). Notably, we show that the concept of the stemless Afrocarduus schimperi adopted by the Flora of Tropical East Africa, in fact, comprises seven clearly recognizable species, which we formally reinstate. Unexpectedly, the stemmed Afrocarduus nyassanus was recovered as paraphyletic with Afrocarduus ruwenzoriensis nested within it, probably due to incomplete lineage sorting or hybridization. Additionally, the stemmed Afrocarduus keniensis may represent a complex of cryptic species, and we describe a new stemmed species from southern Ethiopia, Afrocarduus kazmi sp. nov. We expand the number of accepted species in Afrocarduus from eight, as recognized in the Flora of Tropical East Africa, to 18 (including two species for which we were not able to obtain molecular data). Our study thus highlights a substantial prior underestimation of the diversity of Afrocarduus in Afromontane and Afroalpine habitats.
Abstract
This study evaluates the effectiveness of various peat-free and peat-reduced growing media on the growth and yield of tomatoes and carrots, with the aim to develop sustainable alternatives to traditional peat-based substrates in horticulture. Thirty different growing media mixtures were tested, incorporating materials such as wood fiber, compost, biochar, bio-ash, and struvite, with the goal of identifying viable alternatives to peat. The experiments were conducted in greenhouse conditions, and the performance of these mixtures was assessed based on yield and overall vitality of tomato and carrot plants. The results revealed that fully peat-free mixtures generally underperformed compared to peat-based references. However, some peat-reduced mixtures with 30% peat in combination with wood fiber, compost, struvite or bio-ash demonstrated promising results. Bio-ash and struvite were evaluated as phosphorus sources, with findings suggesting that both materials can enhance substrate fertility when combined with appropriate nitrogen fertilizers. The effect of biochar was not very pronounced in general. Moreover, the addition of biochar was associated with a disappearance of plant-available nitrogen from the growing media, which likely contributed to its limited effectiveness in improving crop performance. The study underscores the continual challenge of completely phasing out peat in growing media for horticulture but highlights the potential of reducing it greatly and integrating more sustainable materials such as wood fiber and recycled materials such as compost, bio-ash and struvite. The results suggest that with further refinement, specific combinations of these materials could be developed into optimized substrate mixtures for sustainable horticultural practices without compromising productivity.
Abstract
Jordens fysiske egenskaper ble studert på to golfbaner der enten små, lette robotklippere eller store, tunge tradisjonelle gressklippere hadde vært brukt i fire til fem år. På begge banene var jorda mindre komprimert der det var brukt robotklippere sammenlignet med der de store maskinene var brukt, men fordi innledende målinger manglet, kan det ikke konkluderes definitivt om forskjellene skyldtes bruk av robotklippere eller tradisjonelle gressklippere.
Abstract
In this study the effects of growing annual and perennial plant species in five growing media blends; one peat-based, two peat-reduced and two peat-free. Three main components were used in the blends: sphagnum peat (P-Soil (PS), Wood fiber substrate (WFS), Peat reduced blend (PRB)), coarse wood fiber (Fibergrow®) of Norway spruce (Picea abiens) (WFS, PRB, Circle soil (Circle), PFB) and garden/park waste-based compost (Circle, PRB, PFB). The peat-based reference (P-Soil) contained 10 vol.% composted bark in addition to sphagnum peat. pH in the blends ranged from 5.1 to 6.4. Both annual and perennial plants were tested in the five blends, and large differences in growth and vitality of plants grown in the different blends were observed. The performance of most plant species grown in Circle, PRB and PFB was characterized as satisfactory, while P-Soil gave the best results and was used as reference as it is commonly used in the plant nursery. Plants grown in WFS showed generally weak growth and the plant growth was characterized as unsatisfactory. However, WFS and PRB performed satisfactory to seedlings of Rhododentron uniflorum, while Circle and PFB failed to give satisfactory growth of rhododendron seedlings. Although all blends were basic fertilized with different types of compound mineral fertilizers, chemical analyses showed significantly lower concentrations of CAT-soluble plant nutrients in WFS compared to the other blends. N-immobilization during storage in plastic bags may have occurred for WFS, which has very high C/N-ratio. In the blends with compost and Fibergrow® the expected levels of mineral N were found, and no N-immobilization occurred. In the blends with compost almost all mineral N was present as nitrate-N, while ammonium-N dominated in P-Soil. There were no large differences in root development between the five blends, and the root growth in WFS was good despite significantly smaller plants than in the other blends.