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.
2021
Sammendrag
Current forage production on tile drained peat soil is challenged by low drainage efficiency and large GHG emissions. Alternative methods need to be evaluated to sustain agricultural usage while protecting peat C and N stocks. Peat inversion is a valid method when the peat layer is less than 1.5 m deep and lies on top of a self-draining mineral soil. The peat body is covered by the underlying mineral soil while maintaining connectivity to the self-draining subsoil through tilted mineral soil layers. We studied the effect of inversion of previously tile drained peat with forage production on dry matter yield (DMY), methane (CH4) and nitrous oxide (N2O) emissions and peat degradation. The field experiment was carried out in adjacent fields with inverted and tile drained nutrient poor peat in Western Norway during 2014-2018. At both fields the surface was slightly graded towards open ditches surrounding the field. The thickness of the mineral cover layer of the inverted peat varied between 80-100 cm on top of the graded surface (upper site) and 40-50 cm closer to the ditches (lower site). Coarse silt and fine sand dominated the texture of the cover layer and content of organic matter was very low (0.5 % tot. C). The texture was finer (higher content of silt and clay) at the lower site compared to the upper site. Mean DMY for 4 ley years at the inverted (upper site) and tile drained peat was 12.2 and 10.3 t ha-1 y-1, respectively. Mean methane emissions in tile drained peat were 200, 140, 209 and 55 kg CH4-C ha-1 in 2015, 2016, 2017 and 2018, respectively, whereas the CH4 exchange in inverted peat was small. In inverted peat, we found up to 50 vol% CH4 in the soil air close to the buried peat, which strongly decreased towards the soil surface at both inverted sites. Nitrous oxide emissions in fertilized tile drained peat were 4.3, 9.5, 9.8 and 5.3 kg N2O-N ha-1 in 2015-2018, respectively. In inverted peat (upper site) N2O emissions were 3.6, 3.6, 8.5 and 2.7 kg N2O-N ha-1 these years. In lower site, measured in 2017 and 2018, the emissions were 10.3 and 4.5 kg N2O-N ha-1, respectively for the two years. N2O-emissions were small in unfertilized plots both at tile drained and inverted peat. Depth profiles of N2O in soil air indicated that N2O is produced in the mineral layer and not in the buried peat. Continuously monitored O2 profiles showed O2-concentrations of 0-5 vol% in the top of the buried peat and much higher concentrations (5-20 vol %) in the tile drained peat. Dark chamber measurements in 2018 showed a CO2-flux of 1.43, 1.49 and 2.35 kg ha-1 h-1 CO2-C after 1.st cut and 1.4, 1.25 and 2.01 kg ha-1 h-1 CO2-C after 2.cut in inverted upper site, inverted lower site and tile drained peat, respectively. The larger respiration measured at tile drained peat most probably derives from larger heterotrophic respiration, as the mass of roots was lower in tile drained than in inverted peat. Results from this field experiment suggest that inversion of tile drained peat reduces the CH4 emissions and degradation of the peat. N2O emissions is fertilizer induced in both tile drained and inverted nutrient poor peat, and is determined by soil and weather conditions at the time of fertilization. The large variation in emissions between years can be explained by different weather conditions. 2017 was a wet year and 2018 a very dry year.
Sammendrag
Formålet med denne rapporten er å beregne investeringsbehovet i melkeproduksjonen som følger av næringens omlegging fra båsfjøs til løsdrift. I 2019 var 60 prosent av besetningene fremdeles i båsfjøs og 37 prosent av melka ble produsert i båsfjøs. I overkant av 4 500 produsenter med båsfjøs vil ha krav om å legge om driften til løsdrift innen 2034. Norsk Landbruksrådgiving har på oppdrag for denne rapporten utarbeidet investeringskalkyler for løsdriftsfjøs til ulike besetningsstørrelser. Kalkylene viser at kostnaden for nye løsdriftsfjøs med 50 prosent påsett varierer fra kr 202 000 per kuplass til kr 386 000 per kuplass avhengig størrelsen på besetningen. Faktorer som størrelsen på besetningen, muligheter for ombygging/påbygging til eksisterende driftsbygning og grad av påsett av ungdyr vil påvirke kostnadene i stor grad. For bygninger med 35 prosent påsett er det lavere kostnader per kuplass. Det totale investeringsbehovet er beregnet til å være mellom 18 og 22,8 milliarder kroner.
Forfattere
Liang Wang Alba Dieguez-Alonso Maria Nicte Polanco Olsen Alice Budai Daniel Rasse Øyvind SkreibergSammendrag
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Forfattere
Liang Wang Alba Dieguez-Alonso Maria Nicte Polanco Olsen Alice Budai Daniel Rasse Ondřej Mašek Øyvind SkreibergSammendrag
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Forfattere
Jorunn BørveSammendrag
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Forfattere
Ingunn ØvsthusSammendrag
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