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.
2010
Sammendrag
Store drensvannvannprøver (5-15 l) ble tatt ut før og etter passering av et leca (Filtralite-P) filter og sedimentet ble oppkonsentrert før det ble tørket og sendt til tynnslippreparering. Mikroskopstudier av disse sedimentene fra drensvann tatt ut før og etter passering av lecafilter viser at filteret holder tilbake partikler større enn leirfraksjonen, mens finfordelt leir har fulgt drensvannet gjennom filteret. Andelen av leir var for alle tidspunkter høyest i utprøven og prøver tatt av filtermaterialet viser at det er avsatt orientert leir på og mellom lecakulene. Vannprøver tatt ut ved utløp av filteret klarner raskere enn vann tatt ut ved innløpet når det står til sedimentasjon, noe som trolig kommer av en homogenisering av partikkelstørrelsen og en økning av innholdet av ioner i vannet etter at det har passert filteret.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Tatsiana Espevig Michelle DaCosta Chenping Xu Lindsey Hoffman Trygve S. Aamlid Anne Marte Tronsmo Bruce B. Clarke Bingru HuangSammendrag
Freezing tolerance is a major component of winter hardiness of perennial grasses. Velvet bentgrass showed the same freezing tolerance as creeping bentgrass. Acclimation at temperatures above 0 ºC was associated with accumulation of nonstructural carbohydrates and enhanced plant survival after freezing. Acclimation at 2 ºC for 4 wk was more effective than for 2 wk and resulted in higher concentrations of fructans. Additional subzero acclimation at -2 ºC resulted in a reduction in fructans and higher concentration of reducing sugars; however, there was no additional improvement in freezing tolerance. Protein analysis was performed using 2-D polyacrylamide gel electrophoresis. Nineteen protein spots were responsive to acclimation. Thirteen proteins were identified. Identified proteins belonged to metabolism, energy, disease/defence, and secondary metabolism functional groups.
Forfattere
Tatsiana Espevig Michelle DaCosta Trygve S. Aamlid Anne Marte Tronsmo Bruce B. Clarke Bingru HuangSammendrag
Cold acclimation plays a decisive role in turfgrass winter survival. This study was performed in collaboration with Rutgers University and University of Massachusetts (USA) to examine changes in carbohydrate levels in crown tissues during the first and second phases of cold acclimation in velvet bentgrass (Agrostis canina L.) and creeping bentgrass (A. stolonifera L.), and their association with freezing tolerance.. Four treatments representing different phases of cold acclimation were compared: (i) nonacclimated plants maintained at 18 °C/12 °C (day/night); (ii) plants acclimated at 2 °C for 2 wk and 250 μmol m-2 s-1 for 12 h photoperiod ; (iii) as treatment (ii) but for 4 wk; and (iv) as treatment (iii) plus additional sub-zero acclimation in the dark at -2 °C for 2 wk. Velvet bentgrass and creeping bentgrass showed no difference in lethal temperatures for 50% of the test population (LT50) as estimated by whole plant survival. Acclimation at 2 °C for 2 and 4 weeks resulted in accumulation of sucrose and fructans, and significantly lowered LT50 as compared with nonacclimated plants. Subzero acclimation resulted in less fructans, no difference in sucrose, and higher concentration of reducing sugars, but LT50 was not lower than after acclimation at 2 °C for 4 weeks.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Gedrime Kusliene Trond Olav Pettersen Tatsiana Espevig Trygve S. Aamlid Anne A. SteensohnSammendrag
High fertilizers rates, especially of nitrogen (N) and phosphorus (P), are commonly used for turfgrass grow-in on sand-based soils. The United States Golf Association recommends preplant applications of up to 1.0 kg P and 0.5 kg N per 100 m2 followed by applications of up to 0.3 kg N/100 m2 every fifth day until plant cover is complete. Such high rates of N and P, given before roots have developed, incur a great risk for nutrient leaching. Irrigation several times per day to keep the seedbed constantly moist also contributes to this leaching potential. iSeed® is a seed coat patented by Yara International ASA and used for grass seed marketed by DLF Trifolium. The coat contains both fast-acting and slow-release fertilizers, in total 10% N and 2% P of coated seed weight. The objective of this research was to determine the effect of iSeed® on turf quality and nitrogen and phosphorus leaching during turfgrass grow-in on two sand-based rootzones. A two-factorial experiment was carried out in the field lysimeter facility at Bioforsk Øst Landvik, South East Norway (58o34"N, 8o52"E) from 22 June to 26 July 2010. The rootzone was maid up of either straight sand, SS, or Green Mix®, GM, (Høst AS, Grimstad Norway), the latter being SS amended with 20% (v/v) mature garden compost. The 2 m2 lysimeter plots were seeded with either iSeed® or uncoated seed of the same seed lot of perennial ryegrass (Lolium perenne L.) ‘Berlioz 1", the sowing rate in both cases corresponding to 20 g/m2 pure seed. Use of uncoated seed was combined with preplant applications of 4 g N (as calcium ammonium nitrate, 27% N) and 0.8 g P (as superphosphate, 8% P) per m2, i.e. the same amount of total nitrogen and phosphorus as in the iSeed® coating. One treatment included additional applications of 5 g N (as calcium nitrate, 15.5% N) and 1.0 g P (as superphosphate, 8% P) on day no. 10 and 21 after sowing. The experiment was irrigated heavily, especially during the first ten days after sowing. Observations were made over the 35 day period. The results revealed significant effects of rootzone composition (SS vs. GM) and/or seed type/additional fertilizer application on turfgrass ground cover, overall impression, colour, surface traction and root development. For all these characters, the GM rootzone showed significant benefits compared with the SS rootzone; however, total nitrogen leaching was 21 % higher and total phosphorus leaching 11 times higher from the GM than from the SS rootzone. Plots seeded with iSeed® usually performed slightly better than plots seeded with uncoated seed, but the visual effects were mostly insignificant and small compared to those of additional fertilizer applications on day no 10 and 21 after sowing. Use of iSeed® reduced nitrate and total nitrogen leaching by approximately 50% during the first 10 days after sowing, but caused no significant reduction during the following 25 days; these effects probably reflect the slow-release properties of 82% of the nitrogen contained in iSeed®. Leaching of phosphorus was not affected by either seed type or additional fertilizer application. Interactions between rootzone and seed type/additional fertilizer applications were mostly not significant. We conclude that iSeed® has the potential to reduce nitrogen leaching during turfgrass establishment on sand-based rootzones. However, as iSeed® does not eliminate the need for additional fertilizer inputs about two weeks after sowing, the environmental benefit seems to be of relatively short duration when growing in perennial ryegrass on athletic fields. The advantages of iSeed® may perhaps be more significant when growing in forage or amenity grasslands over a longer period and with less fertilizer inputs.
Sammendrag
The results from two field trials (Landvik and Apelsvoll) showed that the use of a proper combination of nitrogen rate and topdressing level is very important for thatch control. In coastal areas with ample rainfall, velvet bentgrass should be dusted with find sand every week or at least every other week, totalling around 10-14 mm per season. Nitrogen rate should be held at a level just to get an acceptable color. Weekly grooming, monthly verticutting and spiking twice a year are also needed to control thatch on velvet bentgrass greens, but heavy mechanical treatments should be avoided due to slow recuperative capacity of velvet bentgrass.
Sammendrag
No significant differences in frost tolerance between velvet bentgrass and creeping bentgrass was observed when freezing occurred directly after acclimation. Acclimation under natural conditions was more effective than under controlled conditions. The quantitative and qualitative composition of nonstructural carbohydrates, particularly fructans, varied among bentgrass species, but did not correlate with frost tolerance. The accumulation of fructans may play a role in other aspects of winter hardiness. Subfreezing acclimation increased the frost tolerance of velvet bentgrass and creeping bentgrass.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Vinteren i år gledet skifolket med mye snø og stabil kulde. Men var den lange og stabile vinteren bra for gresset? I forskingsanlegget på Landvik har vi for en gangs skyld sett en del spennende vinterskader!