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.

2021

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Abstract

Seed mixtures with a nurse grass that germinates quickly at low soil temperatures can be an option for faster establishment of Agrostis stolonifera (AS) putting greens after winter damage. From 2015 to 2018 Poa trivialis (PT) ‘Dark Horse’ and Lolium perenne (LP) ‘Chardin’ were evaluated as nurse grasses in comparison with pure AS ‘Independence’ at two experimental sites in each of the two major climatic zones of the Nordic countries. Poa annua (PA) ‘Two‐Putt’ was also included as a nurse grass in the northern zone. As an overall trend, establishment was faster with AS+LP than with AS+PT and AS+PA, which in turn had faster establishment than pure AS. In the northern zone, AS+PT produced better turf quality than pure AS in the seeding year and year after and tended to be superior even on average for the entire trial period (mean value 6.0 vs. 5.8 for pure AS, 5.3 for AS+LP, and 4.6 for AS+PA; scale 1–9 where 9 is the highest quality). In the same zone, AS+PT also suffered less overall winter damage than the other combinations and was less infected with microdochium patch than pure AS. In the southern zone, PT and especially LP were far more persistent than in the northern zone and compromised turfgrass quality compared with pure AS. In conclusion, we recommend PT as a nurse grass for faster establishment of AS putting in the northern zone, but not in the southern zone where AS should rather be seeded in a pure stand.

Abstract

Leaf blotch diseases (LBD), such as Septoria nodorum bloch (Parastagnospora nodorum), Septoria tritici blotch (Zymoseptoria tritici) and Tan spot (Pyrenophora tritici-repentis) can cause severe yield losses (up to 50%) in Norwegian spring wheat (Triticum aestivum) and are mainly controlled by fungicide applications. A forecasting model to predict disease risk can be an important tool to optimize disease control. The association between specific weather variables and the development of LBD differs between wheat growth stages. In this study, a mathematical model to estimate phenological development of spring wheat was derived based on sowing date, air temperature and photoperiod. Weather factors associated with LBD severity were then identified for selected phenological growth stages by a correlation study of LBD severity data (17 years). Although information regarding host resistance and previous crop were added to the identified weather factors, two purely weather-based risk prediction models (CART, classification and regression tree algorithm) and one black box model (KNN, based on K nearest neighbor algorithm) were most accurate to predict moderate to high LBD severity (>5% infection). The predictive accuracy of these models (76–83%) was compared to that of two existing models used in Norway and Denmark (60 and 61% accuracy, respectively). The newly developed models performed better than the existing models, but still had the tendency to overestimate disease risk. Specificity of the new models varied between 49 and 74% compared to 40 and 37% for the existing models. These new models are promising decision tools to improve integrated LBD management of spring wheat in Norway.

2020

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Abstract

To achieve a complete organic value chain, we need organic seed from cultivars adapted to organic growing. A separate breeding for organic growing is difficult to achieve in small markets. Many breeding goals are equal for organic and conventional cereals, and cultivars failing to qualify as a commercial variety for conventional growing may possibly perform well in organic growing, with different regimes of fertilisation and plant protection. A field trial was conducted over 2 years to compare 25 cultivars of spring wheat, ranging from one land race and some old varieties released between 1940 and 1967, to modern market varieties and breeding lines. Grain yield, agronomic characteristics and grain and flour quality, including mineral content, were recorded. The performance of the 20 most interesting cultivars in artisan bread baking was measured, as were sensory attributes in sourdough bread from six cultivars. Modern varieties and breeding lines gave higher yields and had larger kernels, better grain filling, higher falling numbers and higher SDS-sedimentation volumes compared with old cultivars. The old cultivars, on average, had higher concentrations of minerals, although the growing site had a strong effect on mineral concentrations. Bread from modern cultivars performed best in a baking test. Several sensory attributes such as juiciness, chew resistance, firmness, acid taste and vinegar odour varied significantly between the six tested cultivars. Land races and old varieties have an important cultural value, and many consumers are willing to pay a premium price for such products. This will be required since yield levels are often considerably lower, especially with humid weather conditions at harvest.

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Abstract

Microbes are central drivers of soil processes and in-depth knowledge on how agricultural management practices effects the soil microbiome is essential in the development of sustainable food production systems. Our objective was therefore to explore the long-term effects of organic and conventional cropping systems on soil bacterial and fungal quantity, their community structures and their combined function. To do so, we sampled soil from a long-term experiment in Southeast Norway in 2014, 25 years after the experiment was established, and performed a range of microbial analyses on the samples. The experiment consists of six cropping systems with differences in crop rotations, soil tillage, and with nutrient application regimes covering inorganic fertilizers, cattle slurry (both separately and combined with inorganic fertilizers) and biogas residues from digested household biowaste. The quantity of soil microbes was assessed by extraction of microbial C and N and by analysis of soil DNA (bacterial 16S rRNA, and fungal rRNA internal transcribed spacer region). The structures of the microbial communities were determined and assessment of relatedness of bacterial and fungal communities was done by the unweighted pair group method. Estimates of richness and diversity were based on numbers of unique operational taxonomic units from DNA sequencing and the function of the microbial assembly was measured by means of enzyme assays. Our results showed that production systems including leys had higher microbial biomass and higher numbers of bacterial and fungal gene copies than did systems with cash crops only. A cropping system which appeared to be particularly unfavourable was a reference-system where stubble, roots and exudates were the single source of organic material. Production system significantly affected both bacterial and fungal community structures in the soil. Systems including leys and organic fertilization had higher enzyme activities than did systems with cash crops only. An inclusion of ley in the rotation did not, however, increase either microbial richness or microbial diversity. In fact, the otherwise suboptimal reference-system appeared to have a richness and diversity of both bacteria and fungi at levels similar to those of the other cropping systems, indicating that the microbial function is largely maintained under less favourable agricultural treatments because of the general resilience of soil microorganisms to various stresses. Neither disturbance through tillage nor the use of chemical fertilizer or chemical plant protection measures seemed as such to influence soil microbial communities. Thus, no differences between conventional and organic farming practices as such were found. We conclude that the choice of agricultural management determines the actual microbial community structure, but that biodiversity in general is almost unaffected by cropping system over many years. Adequate addition of organic material is essential to ensure a properly functioning microbial ensemble and, thus, to secure soil structure and fertility over time.

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Abstract

Many Norwegian consumers eat more red meat than is recommended by the Government. Of the protein currently consumed, 75% is of animal origin. Natural conditions in Norway favour the production of meat, dairy and seafood but high-protein plants can also be grown in the country. This study analysed the environmental impact of growing turnip rapeseed (Brassica rapa) and rapeseed (Brassica napus) and the processing of rapeseed into dietary oil and press cake. The results were then compared with some common animal protein food sources. Impacts were calculated for 24 impact indicators. The climate impact of dried seeds was 1.19 kg CO2-eq/kg, for rape oil—3.0 kg CO2-eq/kg and for rapeseed press cake—0.72 kg CO2-eq/kg. The environmental impact of rapeseed production is higher than in most other countries, predominantly due to lower yields. Press cake from rapeseed could be a valuable source of protein in foods. In Norway, the environmental impacts of this material (climate impact—2.5 kg CO2-eq/kg protein) are at the same level as other plant protein sources, but far lower than some of the most common animal protein sources (climate impact—16–35 kg CO2-eq/kg protein). When comparing the impacts while taking nutrient content into account, these differences remained the same. Improvements in the environmental performance of oilseed and its products can be achieved both by improving yields through better agronomic practices and increasing the proportion of winter rapeseed.

Abstract

Optimizing phosphorus (P) application to agricultural soils is fundamental to crop production and water quality protection. We sought to relate soil P tests and P sorption characteristics to both crop yield response to P application and environmentally critical soil P status. Barley (Hordeum vulgare L.) was grown in pot experiments with 45 soils of different P status. Half the pots were fertilized at 20 kg P ha−1, and half received no P. Soils were extracted with ammonium lactate, sodium bicarbonate (Olsen P), dilute salt (0.0025 M CaCl2), and diffusive gradient in thin films. Soil adsorption coefficients were determined using the Freundlich isotherm equation, and the degree of P saturation was determined from both oxalate and ammonium lactate extracted Fe, Al, and P. All soil P analyses showed a nonlinear and significant relationship with yield response to P application, and all analyses manifested a threshold value above which no P response was observed. For the commonly used ammonium lactate test, inclusion of Al and Fe improved prediction of plant‐available soil P. The threshold for yield response coincided with the environmentally critical values determined from the degree of P saturation. Results support the conclusion that soil P levels for which no P application is needed also have elevated risk of P loss to runoff.

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Abstract

SCANTURF is a joint Nordic programme for turfgrass variety testing, set up in 2005 and funded by variety entrance fees only. It replaced and simplified the former government‐funded national evaluation programmes in Finland, Sweden, Denmark and Norway. The programme includes testing of all cool‐season grasses on lawn/fairways at 15–20 mm mowing height (“lawn trials”) and optional testing of Poa pratensis L. and Lolium perenne L. on simulated football pitches with wear, mowed at 30 mm (“wear trials”). Since 2013, the program has regarded the Nordic countries as one trial zone with three test sites: Tystofte Denmark (55°15′ N, 11°20′ E), Landvik, Norway (58°21’ N, 8°32’ E) and Ylistaro, Finland (62°57′ N, 22°31’ E). Wear trials are carried out at the intermediate location Landvik only. Candidate varieties are tested against two reference varieties of the same species or subspecies. In the lawn trials, candidate varieties are evaluated for visual merit (overall turfgrass quality), winter damage, winter color, diseases and daily height growth at all three locations and for tiller density, fineness of leaves, in‐season (genetic) color, at Landvik only. Based on the results from the SCANTURF trials in 2014–2016 and 2016–2018, the candidate varieties Fabian, Tetrastar, Annecy, and Monroe (Lolium perenne), Becca, Harmonie, Traction, and Markus (Poa pratensis) and Lystig, Greenmile, and Humboldt (Festuca rubra ssp. commutata) were recommended for lawns in the Nordic countries, while Eurocordus, Columbine, Monroe, and Annecy (Lolium perenne) and Harmonie (Poa pratensis) were recommended for sports grounds. More use of the recommended varieties will have a positive effect on quality of lawns and sport grounds in the Nordic countries. Less winter injury and increasing relative performance with increasing latitude of the tetraploid perennial ryegrass variety Fabian in the lawn trials may possibly lead to more use of perennial ryegrass in the northern and more continental parts of the region.

Abstract

To mitigate the risk of erosion and nutrient runoff, reduced tillage has become more prevalent in Norway. Within within recent decades, there have been some years with relatively high occurrence of Fusarium head blight and mycotoxins in Norwegian cereal grain. This is thought to have been caused by an increased inoculum potential (IP) of Fusarium spp. due to larger amount of crop residues remaining on the soil surface, in combination with weather conditions promoting fungal growth and infection of cereal plants. The objective of this work was to elucidate the influence of different tillage practices on the IP of Fusarium spp. and the subsequent Fusarium-infection and mycotoxin contamination of spring wheat grain at harvest. Tillage trials were conducted at two locations in southeast Norway (Solør and Toten) over three years, 2010-2012. Residues of wheat from the previous year were collected in spring. Fusarium avenaceum and Fusarium graminearum were the most common Fusarium species recorded on wheat straw residues. IP was calculated as the percentage of the residues infested with Fusarium spp. multiplied by the proportion of the soil surface covered with residues. The IP of Fusarium spp. was lower in ploughed plots compared to those tilled with harrowing only. Ploughing in spring resulted in a similarly low IP as autumn ploughing. In contrast, harrowing in autumn generally reduced IP more than did spring harrowing. The mycotoxin levels in the harvested wheat were generally low, except for deoxynivalenol at high levels in Solør 2011. Despite a lower IP of ploughed versus harrowed plots, this was not reflected in the content of Fusarium and mycotoxins in harvested grain. The Fusarium species that dominated in the residues examined in this study were the same as those detected in the harvested grain, supporting the finding that residues are an important source of inoculum.