Hopp til hovedinnholdet

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.

2025

Til dokument

Sammendrag

Thirty-seven turfgrass samples expressing dollar spot symptoms were collected in summer 2020 on golf courses in Sweden, Denmark, United Kingdom, Germany, Portugal, and Spain. The fungi were isolated at Norwegian Institute of Bioeconomy Research (NIBIO) Turfgrass Laboratory (Norway) and sent for molecular identification using sequencing of regions of ITS (internal transcribed regions of the ribosomal DNA) and calmodulin. Clarireedia homoeocarpa was identified in four turfgrass samples and Clarireedia jacksonii was identified in 11 turfgrass samples. From seven turfgrass samples, the isolated fungi were not Clarireedia spp., but Waitea circinata, Fusarium culmorum, and Fusarium oxysporum. This suggests dollar spot is not always accurately identified from foliar symptoms in the field.

Til dokument

Sammendrag

In recent years, biochar loaded with urea has been proposed as a promising N-rich fertilizer with both high-N capacity and slow release. Understanding the interaction between urea and biochar at the molecular level is key to product design. Solid-state NMR (SSNMR) spectroscopy is a particularly powerful method to probe molecular composition and interactions within the bulk of materials. The objective of this work was to identify molecular structures and interactions when urea is loaded into and released from biochar. To do so, we carried out SSNMR investigations of biochar loaded with 13C and 15N isotopically enriched urea. Biochar-urea composites were prepared both with a saturated aqueous urea solution (BUs) and with molten urea (BUm). SSNMR analysis revealed that urea is predominantly in a paracrystalline form on the biochar surface or physically entrapped within biochar pores. In BUm, products of the thermal degradation of urea were also detected, mainly in the form of biuret. Water-immersion experiments showed that 78 and 64% of the urea contained in BUs and BUm is released, respectively, after 24 h, demonstrating substantial retention of urea. The residual urea is mainly physically confined in the biochar pores. In the case of BUm, urea thermal degradation species are also partially retained.

Til dokument

Sammendrag

Ice encasement is a major concern for turfgrass managers in cold climates; however, there is a lack of data about both which turfgrasses are best suited for survival under these conditions and the reasons behind the superior recovery of some grasses from long-term ice encasement. In this study, we encased golf course putting greens-height field plots of creeping bentgrass (Agrostis stolonifera L.), velvet bentgrass (Agrostis canina L.), annual bluegrass (Poa annua L. var. reptans Hausskn.), Chewings fescue (Festuca. rubra L. ssp. commutata Gaudin), and slender creeping red fescue (F. rubra L. ssp. littoralis (G. Mey.) Auquier) with ice for 90–120 days with the inclusion of CO2, O2, and temperature sensors at 2.5 and 12.5 cm depth to better understand environmental conditions under ice and factors related to winterkill. Velvet bentgrass had the best overall performance and recovery, while annual bluegrass did not survive. Differences in recovery among turfgrass taxa may have been affected by the length of the ice encasement period, higher CO2 levels (>40,000 ppm), and lower O2 values, particularly in the second experimental run. During the recovery period in both years, photochemical efficiency values began increasing 5–10 days before percent green cover, suggesting that visual performance of the turf surface is a lagging indicator of recovery. Overall, recovery from ice encasement was annual bluegrass < Chewings fescue < creeping bentgrass = slender creeping red fescue = velvet bentgrass. These results can guide turfgrass managers in making species selection decisions in areas where long-duration ice encasement is a risk. Plain Language Summary Turfgrasses on golf course greens in cold climates can be severely damaged or even die from ice encasement. Little is known about this stress, including why certain grasses can survive longer. As a first step to learn more about this problem, we tested five different turfgrasses for their ability to survive under ice. The study was done during two separate winters in Minnesota under field conditions, resulting in 98 days of ice in 2021–2022 and 112 days of ice cover in 2022–2023. Annual bluegrass died completely during both experimental runs, while Chewings fescue suffered some injury in the first year and did poorly in the second year. Velvet bentgrass was the best grass in both years. Under the longer duration of ice cover in the second year, carbon dioxide levels were very high, while oxygen gas levels slowly declined over the course of the ice encasement period.