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
Forfattere
Helena Aronsson Elly Møller Hansen Ingrid Kaag Thomsen Jian Liu Anne K. Falk Øgaard Hannu Känkänen Barbro UlenSammendrag
This review summarizes current knowledge from the literature and experimental studies on the role of cover crops (CCs) in reducing nitrogen (N) leaching and phosphorus (P) losses to waters under the marine and humid continental climate conditions of southern Scandinavia and Finland. Field leaching studies from 11 sites indicate that undersown ryegrass (Lolium spp.) CCs are robust, with average N uptake in aboveground CC biomass of 7 to 38 kg N ha−1 (6.2 to 34 lb N ac−1). Use of CCs sown at harvest (e.g., crucifers) is restricted to southern Scandinavia for climate reasons. The mean relative reduction in N leaching reported for all CCs investigated was 43%, but it ranged between 62% increase instead of a reduction after a red clover (Trifolium pratense) CC on a clay soil to a reduction of 85% to 89% with a perennial ryegrass CC on sandy soils in Denmark (36 to 51 kg ha−1 [32 to 46 lb ac−1]). The data indicate that CCs do not substantially reduce total P losses by runoff and leaching. The effects of CCs on total P leaching varied between a relative increase of 86% and a decrease of 43%. Climate conditions involving freezing-thawing during winter increased the risk of losses of dissolved P from CC biomass. CCs have been implemented to varying degrees into agri-environmental programs. They are mandatory in Denmark and subsidized in Norway, Sweden, and Finland. CCs are grown on 8% of arable land in Denmark, 5% in Sweden, 1% in Finland, and 0.5% in Norway, but CC area is now increasing dramatically in Finland due to a new subsidy program. In all countries there is a need, and potential, for increased use of CCs, but there are several constraints, particularly reduced interest among farmers. There is a clear need to identify CC systems and develop implementation strategies for appropriate distribution of CCs on different soils and regions with respect to required reductions in N leaching and P losses. For this, more knowledge is required, especially about the effect of CCs on P losses (e.g., the effect of species with different partitioning between shoot and root biomass and the effects of CC systems with harvesting of biomass). There is also a need to devise balanced solutions for maintaining and increasing the frequency of CCs in crop rotations to exploit the possible benefits of CCs in reducing nutrient losses.
Forfattere
Biancha CavicchiSammendrag
Det er ikke registrert sammendrag
Sammendrag
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Sammendrag
The cyanomorph and photosymbiodemes are here reported for the first time for Ricasolia virens (With.) H.H. Blom & Tønsberg comb. nov. (≡ Lobaria virens (With.) J.R. Laundon). The cyanomorph of R. virens is dendriscocauloid. The observed early developmental stages involve (1) a free-living cyanomorph and (2) a photosymbiodeme composed of the cyanomorph supporting small, foliose, chloromorphic lobes. Whereas the chloromorph continues to grow, the cyanomorph decays and disappears leading to the final stage (3), the free-living chloromorph. Secondary cyanomorphs emerging from the chloromorph are not known.
Forfattere
ChoCho Htay Huan Peng Wenkun Huang Lingan Kong Wenting He Ricardo Holgado Deliang PengSammendrag
The root-knot nematode Meloidogyne graminicola is a major constraint in rice production in the world. Using rDNA-ITS sequences data alignments, the genetic variation among twenty-one populations of M. graminicola (sixteen from Myanmar and five from China) was investigated. The results showed that all the populations were clearly separated from other species and that there was a low level of genetic variation among the isolates. A set of species-specific primers was designed to develop a species-specific molecular tool for the precise identification of M. graminicola. The primer reliability, specificity and sensitivity tests showed that the primer set (Mg-F3 and Mg-R2) amplified the expected fragment size of 369 bp from the template DNA of target nematode populations but not from non-target organisms. A duplex PCR test allows for saving diagnostic time and costs by amplifying the species of interest from a nematode mixture. Therefore, this species-specific primer set may be a powerful tool to improve taxonomic identification by non-specialists and the design of successful management practices as well.
Forfattere
Leif Jarle Asheim Julie Føske Johnsen Øystein Havrevoll Cecilie Marie Mejdell Ann Margaret GrøndahlSammendrag
The study examines the economics of different calf rearing systems and considers effects of suckling and milk feeding on production, health and welfare of dairy cows and growth, milk and feed use, health and welfare of calves. The economics of (i) no suckling, (ii) suckling for 3 days, (iii) suckling for 7 weeks, all assuming milk or milk replacer fed until weaning at 13 weeks, was compared with (iv) suckling for 13 weeks and no milk feeding. A linear programming (LP) model, maximizing profit on a dual purpose dairy-beef farm in lowland eastern Norway, was used for the comparison. Details on calf rearing methods, labor, weaning age, intake of milk, and solid feed were gathered for a sample of organic farms and grouped according to the length of the suckling period. The data were coupled with the National Dairy Herd Recording System (NDHRS) using cross-sectional data for the years 2008–2013. The results of the model study showed that suck- ling up to at least 7 weeks and longer than on most farms in the survey, had a positive influence on the farm economics. This was due to the positive influence on calf growth and health as well as lowered costs. Consequently, dual purpose dairy-beef farmers should be careful to sacrifice calf suckling and restrict calf milk feeding. Long suckling until weaning at 13 weeks was, however, unprofitable.
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.
Forfattere
Adam Tomasz Sikora Erlend Nybakk Rajat PanwarSammendrag
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Sammendrag
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