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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.

2016

Sammendrag

A future wetter climate in Northern Europe may increase soil compaction from traffic of heavy machinery. This study investigated the impact of tractor traffic on grassland yield, soil physical properties and penetration resistance in three experimental field trials in Norway; on medium sand at Tjøtta, Nordland, on silty medium sand at Fureneset, Sogn og Fjordane and on silt at Løken, Oppland. The experiments were conducted in a split-plot design with three levels of two wheel-by-wheel passes with tractor traffic after each cut: no traffic, light tractor or heavy tractor on large plots, and three different seed mixtures on small plots. The yield reduction by tractor traffic was 26% at Løken, 4% at Fureneset and 1% at Tjøtta. There was a positive correlation between soil moisture content and yield reduction by traffic. Tractor traffic reduced pore volume and air capacity and increased bulk density, compaction degree and penetration resistance with the largest effect at Løken and the smallest at Tjøtta. There were no statistically significant differences in yield or soil physical properties between light and heavy tractor. The study shows that soil texture and soil moisture content are major factors explaining traffic effects on soil physical properties and grassland yield.

Sammendrag

The effects of cutting frequency, silage fermentation pattern and legume performance in grass-clover ley on use of inputs and profitability in an organic dairy system in Mid-Norway were examined. A whole-farm linear programming model was developed to compare a three-cut and a two-cut system, either with restricted silage fermentation through acidification or untreated at low or high red clover (Trifolium pratense L) proportion in the ley. Input-output relations incorporated into the model were derived from a meta-analysis of organic grassland field trials in Norway, silage fermentation experiments, and with feed intakes and milk yields from simulations with the NorFor feed evaluation system. The model maximised total gross margin of farms with 250,000 l milk quota, and housing capacity for 45 cows. Farmland availability was allowed to vary with 40 ha as the basis. High proportion of legumes in the leys was far more important for profitability than the score on the other variables considered. With little land available, the costs of preservatives were higher than their benefits. At higher land areas applying preservatives was more profitable. Cutting systems producing silages that result in an increased intake of silage per cow, generally three-cut systems, performed relatively better at higher land availabilities.

Sammendrag

The effects of cutting frequency, silage fermentation pattern and legume performance in grass-clover ley on use of inputs and profitability in an organic dairy system in Mid-Norway were examined. A whole-farm linear programming model was developed to compare a three-cut and a two-cut system, either with restricted silage fermentation through acidification or untreated at low or high red clover (Trifolium pratense L) proportion in the ley. Input-output relations incorporated into the model were derived from a meta-analysis of organic grassland field trials in Norway, silage fermentation experiments, and with feed intakes and milk yields from simulations with the NorFor feed evaluation system. The model maximised total gross margin of farms with 250,000 l milk quota, and housing capacity for 45 cows. Farmland availability was allowed to vary with 40 ha as the basis. High proportion of legumes in the leys was far more important for profitability than the score on the other variables considered. With little land available, the costs of preservatives were higher than their benefits. At higher land areas applying preservatives was more profitable. Cutting systems producing silages that result in an increased intake of silage per cow, generally three-cut systems, performed relatively better at higher land availabilities.

Sammendrag

Dagens produksjonsmetode av veksthusgrønnsaker gir betydelig utslipp av næringsstoffer. Det er en situasjon som er uønsket og kan føre til forurensing av nærmiljøet, bruk av for mye næringsstoffer og økonomisk tap for produsenter. Registreringer viser at avrenningsprosenter kan variere mellom 30 og 40 % i tomat og agurk. Tapet av næringsstoffer ble estimert. Det ble påvist at det er mulig å begrense mengde avrenningsvann ved å tilpasse vanningsteknikk. Men bruk av denne vanningsteknikken forutsetter at vanntilførselen er 100% nøyaktig. Avvik vil ha store konsekvenser for avling og/eller kvalitet av produktene og dermed for økonomien for den enkelte produsent, og er dermed enda ikke forsvarlig. Resirkulering av avrenningsvann er teknisk mulig. Det vil redusere avrenningen med tilnærmet 100%. Desinfeksjon av avrenningsvann er helt nødvendige for å unngå spredning av sykdommer. Det er god erfaring med gode teknikker fra utlandet, og teknikkene er beskrevet i rapporten. Resirkulering vil kreve en investering i bl.a. oppsamlingstanker, rensesystemer og en ny gjødselblander. Denne investeringen vil øke produksjonskostnader for gartnerier med et gjennomsnittsareal på 1000-3000 m2 med ca 25 %. Besparelsen av utgifter for gjødsling og vann er estimert på 0,10 til 0,15 nok/kg. Rapporten konkluderer at det er pr i dag for de fleste bedrifter ulønnsom å investere i et slikt vanningssystem.

Sammendrag

LEgislation in Sweden and Norway requires that Dairy cattle have outdoor acess in summertime. PAsture utilization can be challenging with high-yielding cattle abd karge herd-sizes. Tehrefore, many farmers choose to offer their cows Access to an exercise- and recreation area only, rather than a full Production pasture. However, is an exercise paddoc as attractive as Production pasture for the cow? We compared part-time production and exercise grazing in an automated milking system, with outdoor acess in the morning (4.5 h) and the evening (4 h). The Production pasture group (P)was offered fresh Production pasture daily and given a Limited silage ration night-time. The exercise pasture group (E) was given Access to a small exercise paddoc and were fed silage ad libitum 24 hours. Milk yield dit not differ significantly: 36.1 kg for P and 36.0 kg for E. However, behaviour differed, with 5.5 (P) and 2.6 h(E) spent outdoors, and 3.7 h (P) and 0.6 h (E) grazing time. In conclusion, while milk-yields were similar between the Groups, lower ammounts of supplementary feed were needed for cows on treatment P, who also spent longer hours putdoors and grazing.

Sammendrag

Legislation in Sweden and Norway requires that Dairy cattle have outdoor acess in summertime. Pasture utilization can be challenging with high-yielding cattle abd karge herd-sizes. Tehrefore, many farmers choose to offer their cows Access to an exercise- and recreation area only, rather than a full Production pasture. However, is an exercise paddoc as attractive as Production pasture for the cow? We compared part-time production and exercise grazing in an automated milking system, with outdoor acess in the morning (4.5 h) and the evening (4 h). The Production pasture group (P)was offered fresh Production pasture daily and given a Limited silage ration night-time. The exercise pasture group (E) was given Access to a small exercise paddoc and were fed silage ad libitum 24 hours. Milk yield dit not differ significantly: 36.1 kg for P and 36.0 kg for E. However, behaviour differed, with 5.5 (P) and 2.6 h(E) spent outdoors, and 3.7 h (P) and 0.6 h (E) grazing time. In conclusion, while milk-yields were similar between the Groups, lower ammounts of supplementary feed were needed for cows on treatment P, who also spent longer hours putdoors and grazing.