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.
2023
Sammendrag
Cover crops are used to increase carbon sequestration in soils. However, an increase of organic matter in soils not only increases carbon stocks but also affects nitrogen availability. This can trigger N2O emissions, particularly during wintertime, when standing plant biomass from cover crops decays. N2O emissions associated with cover crops could potentially cancel out the carbon gain. In this study, N2O emissions were measured over two years in a field experiment in SE Norway with barley and various cover crops (perennial and Italian ryegrass, oilseed radish, summer and winter vetch, phacelia and a mixture of different herbs) and compared with controls without cover crops. Manual chambers were used in summer during the growth of the main crop, while winter emissions were measured more frequently by a field robot to capture freeze-thaw induced emission peaks. Both winters had poor snow cover and the highest N2O emissions were measured during freeze-thaw cycles in early spring. Nitrogen-rich cover crops with poor overwintering (oilseed radish) increased wintertime emissions, whereas perennial cover crops with good overwintering (perennial ryegrass and herb mixture) tended to reduce N2O emissions compared to controls. This suggests that the overall climate effect of cover crops in hemiboreal cereal production depends on cover crop species and winter conditions.
Sammendrag
The use of cover crops in cereal production as a climate smart agricultural practice is generally used to increase carbon sequestration in soils. However, increased plant biomass in wintertime can trigger N2O emissions due to decay during freeze-thaw cycles. So far little is known about N2O winter emissions from cover crops which, in the worst case, could cancel out the carbon gain by cover crops. Here we report N2O emissions from a two-year field experiment in SE Norway with barley and various cover crops (perennial and Italian ryegrass, oilseed radish, summer and winter vetch, phacelia and a mixture of different herbs) measured against controls without cover crops. A field robot was used for measuring N2O emissions at high temporal resolution during off-season, i.e., the period from cereal crop harvest to cereal crop sowing. During the first winter, the snow cover was poor and the significantly higher N2O emissions were measured from oilseed radish during spring thaw whereas perennial ryegrass reduced emissions. A second winter is measured and N2O emissions from both years will be presented. In addition, continuous measurements are needed to assess the effect of diurnal freeze-thaw cycles on N2O emissions before scaling up to annual N2O emission fluxes and comparing with C sequestration.
Forfattere
Emily FollettSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Ellen ElverlandSammendrag
Det er ikke registrert sammendrag
Forfattere
Ellen ElverlandSammendrag
Det er ikke registrert sammendrag
Forfattere
Cristina Micheloni Frank Willem Oudshoorn María Isabel Blanco Penedo Sari Autio Andrea Beste Jacopo Goracci Matthias Koesling Ursula Kretzschmar Eligio Malusá Bernhard Speiser Jan van der Blom Felix WäckersSammendrag
The Expert Group for Technical Advice on Organic Production (EGTOP) was requested to advise on the use of several substances with plant protection effects in organic production. The Group discussed whether the use of these substances and methods is in line with the objectives and principles of organic production, and whether they should be included in Reg. (EU) 2021/1165. With respect to Annex I to Reg. (EU) 2021/1165, the Group recommends the following: • Entry ‘Pheromones and other semiochemicals’: The present restriction ‘only in traps and dispensers’ should be complemented with the following text: ‘microcapsules shall be biodegradable and shall not be applied to edible parts of the crop’. • The introductions to Annex I and to the sub-chapters of Annex I refer to the authorization of pesticides pursuant to Regulation (EC) No 1107/2009. The Group recommends minor editorial amendments to clarify that these references apply only when pesticides are used within the EU.