Sammendrag

Lengre vekstsesong og høyere temperaturer om høsten gir spørsmål om de anbefalte høstetidspunktene for eng fortsatt er gyldige og om ettervekst etter hovedslåtter bør høstes eller kan få stå. Vi har undersøkt effekt av tidspunkt for høsting og antall slåtter på mengde og kvalitet av etterveksten, og konsekvenser for overvintring og avling neste år av å enten la etterveksten stå, eller høste den med jevne mellomrom utover høsten mot vekstavslutning. I forsøk i eng dominert av timotei (Phleum pratense L.) på Holt (Tromsø), Løken (Øystre Slidre), samt flere steder i Troms og Finnmark har vi undersøkt ettervekst etter tidlig og sein 2. slått. På Kvithamar (Stjørdal) og Fureneset (Fjaler) har vi målt gjenvekst etter to eller tre slåtter i timoteidominert eng, samt gjenvekst etter 3. slått i flerårig raigras (Lolium perenne L.). Etterveksten er generelt lav sjøl om høsttemperaturene er blitt høyere. Dette skyldes antakelig svært lav lysinnstråling i høstmånedene, noe som forsterkes dess lengre nord en kommer. Fôrkvaliteten er god. Det hadde ingen negative konsekvenser å la etterveksten stå. Høsting av ettervekst bidro til mindre timotei det påfølgende året, spesielt i nord. I raigras hadde høsting av ettervekst negativ effekt både på avling i 1. slått og total avling det påfølgende året.

Sammendrag

Spredning av husdyrgjødsel er regulert med faste datoer for første og siste spredetidspunkt. Disse datoene er satt for store deler av landet, og det er ingen geografisk differensiering etter lengde på vekstsesongen. Farsund ligger i et område med milde vintre og lang vekstsesong, og kommunen ønsket derfor å utrede mulighetene og konsekvensene av å justere spredetidspunktet innen og mellom år ut fra værforholdene i faktisk vekstsesong. Utredningen er gjennomført med utgangspunkt i lokale forhold, samt tilgjengelige varslingstjenester og værdata, først og fremst med tanke på fare for tap av næringsstoffer til miljøet.....

Sammendrag

The aim of the study was to explore whether and how intensification would contribute to more environmentally friendly dairy production in Norway. Three typical farms were envisaged, representing intensive production strategies with regard to milk yield both per cow and per hectare in the three most important regions for dairy production in Norway. The scores on six impact categories for produced milk and meat were compared with corresponding scores obtained with a medium production intensity at a base case farm. Further, six scenario farms were derived from the base case. They were either intensified or made more extensive with regard to management practices that were likely to be varied and implemented under northern temperate conditions. The practices covered the proportion and composition of concentrates in animal diets and the production and feeding of forages with different energy concentration. Processes from cradle to farm gate were incorporated in the assessments, including on-farm activities, capital goods, machinery and production inputs. Compared to milk produced in a base case with an annual yield of 7250 kg energy corrected milk (ECM) per cow, milk from farms with yields of 9000 kg ECM or higher, scored better in terms of global warming potential (GWP). The milk from intensive farms scored more favourably also for terrestrial acidification (TA), fossil depletion (FD) and freshwater eutrophication (FE). However, this was not in all cases directly related to animal yield, but rather to lower burden from forage production. Production of high yields of energy-rich forage contributed substantially to the better scores on farms with higher-yielding animals. The ranking of farms according to score on agricultural land occupation (ALO) depended upon assumptions set for land use in the production of concentrate ingredients. When the Ecoinvent procedure of weighting according to the length of the cropping period was applied, milk and meat produced on diets with a high proportion of concentrates, scored better than milk and meat based on a diet dominated by forages. With regards to terrestrial ecotoxicity (TE), the score was mainly a function of the amount of concentrates fed per functional unit produced, and not of animal yield per se. Overall, the results indicated that an intensification of dairy production by means of higher yields per animal would contribute to more environment-friendly production. For GWP this was also the case when higher yields per head also resulted in higher milk yields and higher N inputs per area of land.

Sammendrag

Forbruket av økologisk mat har økt jevnt i Norge fra 2011 til 2016, mens det økologiske arealet har blitt redusert i samme periode. NIBIO som er en viktig leverandør for kunnskap om økologisk landbruk fikk i Statsbudsjettet for 2016 tildelt kunnskapsutviklingsmidler fra Landbruks- og matdepartementet som var øremerka til å "videreutvikle forskningsbasert kunnskap om økologisk landbruk". Arbeidet med å kartlegge status, flaskehalser og kunnskapsbehovet i de ulike produksjonene er basert på en gjennomgang av relevante prosjekter, rapporter og intervjuer med fagpersoner. De foreslåtte temaene for FoU-aktiviteter må anses som veiledende, og er ment som inspirasjon ved utvikling av nye prosjekter innen økologisk landbruk......

Sammendrag

Jordpakking er blitt et problem i moderne engdyrking pga av endra klima og stadig større og tyngre maskiner. I masteroppgaven, som er en del av forskningsprosjektet Agropro, har det blitt undersøkt om mekanisk jordløsning i etablert eng kan bidra til å øke avlingene ved å forbedre jordstrukturen. Det ble anlagt to forsøksfelt med jordløsning, et i Orkdal i Sør-Trøndelag og et i Nærbø på Jæren, der virkning på jordfysiske egenskaper og grasavling ble undersøkt.

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Stem elongation and flower bud emergence in response to photoperiod (16 and 20 h) and temperature (10, 14 and 18 °C) were characterized in three Norwegian (Lea, Nordi, Reipo) and one Swiss (Fregata) red clover variety. The Norwegian varieties were slower in generative development than Fregata, and were, unlike Fregata, responsive to an increase in photoperiod from 16 to 20 h. Lea was later than Reipo, while Nordi was intermediate. Across all varieties, the earliness of stem elongation in response to temperature was saturated at 14 °C, whereas earliness of flower bud emergence also responded to an increase from 14 to 18 °C. Photoperiod and temperature had additive effects on timing of development prior to stem elongation and complementary effects on timing of development prior to flower bud emergence. Developmental rates calculated on a thermal time basis varied between temperature treatments.

Sammendrag

Grassland and the associated ruminant livestock production is the backbone of Norwegian agriculture, as ruminant products contribute nearly 50% of the gross income of the agricultural sector. About 2/3 of the agricultural area is used for temporary and permanent grassland, and a large proportion (40%) of the arable land is used for producing cereals that are included in concentrate mixtures fed to ruminants. The huge variation in climatic conditions, caused by the wide range in both latitude and altitude as well as in the distance to the coast, determines the land use and choice of species and varieties used in grassland. However, the dominating ley grassland species used in in almost all parts of the country are timothy (Phleum pratense L.), meadow fescue (Festuca pratensis Huds.) and red clover (Trifolium pratense L.). The use of perennial ryegrass (Lolium perenne L.) is increasing, particularly in the southwestern parts of the country. The grassland yields and forage feed quality have remained very much the same during the last decade, while the intensity in ruminant production, e.g. milk yield per cow, has increased considerably. Factors that have contributed to grassland yield stagnation are probably the increasing proportion of rented farmland by larger farm units, the increasing price ratio between livestock products and feed concentrates and the increasing cost of producing forage relative to the price of concentrates

Sammendrag

Grassland and the associated ruminant livestock production is the backbone of Norwegian agriculture, as ruminant products contribute nearly 50% of the gross income of the agricultural sector. About 2/3 of the agricultural area is used for temporary and permanent grassland, and a large proportion (40%) of the arable land is used for producing cereals that are included in concentrate mixtures fed to ruminants. The huge variation in climatic conditions, caused by the wide range in both latitude and altitude as well as in the distance to the coast, determines the land use and choice of species and varieties used in grassland. However, the dominating ley grassland species used in in almost all parts of the country are timothy (Phleum pratense L.), meadow fescue (Festuca pratensis Huds.) and red clover (Trifolium pratense L.). The use of perennial ryegrass (Lolium perenne L.) is increasing, particularly in the southwestern parts of the country. The grassland yields and forage feed quality have remained very much the same during the last decade, while the intensity in ruminant production, e.g. milk yield per cow, has increased considerably. Factors that have contributed to grassland yield stagnation are probably the increasing proportion of rented farmland by larger farm units, the increasing price ratio between livestock products and feed concentrates and the increasing cost of producing forage relative to the price of concentrates

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Effects of wilting rate and fermentation stimulators and inhibitors on protein characteristics of forages typ- ical for organic production were assessed using tradi- tional analytical methods and a gas production in vitro assay. The hypotheses were that the proportion of the crude protein (CP) fraction that was soluble would be lowest, and the protein feed value highest, under rapid wilting and restricted fermentation. The solubil- ity of the CP fraction varied according to treatments and between a first and a second cut, with moderate and high content of clover respectively. It was, how- ever, of minor importance for the protein value, both calculated as amino acids absorbed in the small intes- tine (AAT 20 ) and estimated as effective utilizable crude protein (uCP 04 ) by the in vitro assay. In ensiled her- bage, AAT 20 was highest in rapidly wilted and restrict- edly fermented silages made from a first cut dominated by highly digestible grasses. Silages from the second cut dominated by red clover were far lower in AAT 20 . The in vitro assay did not separate silages according to herbage composition or wilting rate, but ranked restrictedly fermented above extensively fer- mented with regard to protein supply. The assay might still have caught the characteristics that determine the true protein value in vivo.

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

A meta-analysis based on experiments in organically cultivated grasslands in Norway was conducted to quantify the effects of management factors on herbage yield and feed quality. A dataset was collected that included 496 treatment means from experiments in five studies carried out at eight locations with the latitude range of 58.8 to 69.6 N between 1993 and 2010. We tested the effect of harvesting system (two vs. Three cuts annually), plant developmental stage at the first cut, growth period (temperature sum) and the herbage clover proportion. Plant maturity at the first cut and herbage clover proportion explained to a large extent herbage yield and quality of the first cut and annual yield. The timing of the first cut influenced also the yield and herbage quality of the second cut. The analysis confirmed the importance of legumes performance for herbage yield and quality from grasslands in organic production. Estimated annual herbage DM yield harvested at standardized plant development stage and at average clover proportion was 9%higher in the two—compared to the three-cut system. The crude protein concentration and in vitro dry matter digestibility was 17 and 3 % higher and the NDF concentration 7 % lower in the annual herbage from the three-cut than from the twocut system, respectively. The empirical equations developed in this study may be applied to explore different options for grassland management as basis for ration and production planning and in scenario analysis of economic performance of individual and model farms. The equations do also reveal in numeric terms the tradeoffs in management practice between high yields, yield digestibility, NDF and crude protein content in organic forage production relying on red clover N2 fixation as the engine in the system.

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The dataset comprises detailed mappings of two communities of interacting populations of white clover (Trifolium repens L.) and grass species under differing experimental treatments over 4-5 years. Information fromdigital photographs acquired two times per season has been processed into gridded data and documents the temporal and spatial dynamics of the species that followed from a wide range of spatial configurations that arose during the study period. The data contribute a unique basis for validation and further development of previously published models for the dynamics and population oscillations in grass-white clover swards. They will be well suited for estimating parameters in spatially explicit versions of these models, like neighborhood based models that incorporate both the dispersal and the local nature of plant-plant interactions.

Sammendrag

På oppdrag frå Statens Landbruksforvaltning har Bioforsk foreslått avlingar av grovfôr hausta frå fleirårig eng i eit vêrmessig normalår i fire grupper av kommunar i Norge. Dette skulle tene som grunnlag for å endre forskrifta som regulerer utrekning av erstatning for avlingssvikt. Dei foreslåtte normavlingane er baserte på modellsimulerte potensielle avlingar som stegvis har vorte justerte ned til forventa praksisavlingar. Simuleringane vart gjort på grunnlag av historiske klimadata frå Bioforsk-stasjonar, og alle norske kommunar vart så grupperte rundt og med utgangspunkt i resultat for desse stasjonane.

Sammendrag

The spring and the summer growth of an organic grass-clover sward were preserved as extensively and restrictedly fermented silages in laboratory silos.The aim was to develop and test the hypothesis that such crops contribute complementary energy and protein qualities that can be exploited in mixed rations. The summer growth, containing 76% red clover, contributed more, and more stable crude protein than the spring growth, which was dominated by grasses. Nevertheless, when preserved as silage, summer growth supplied less metabolizable protein and net energy lactation because of its lower digestibility. Lower feed value remains to be validated in feeding experiments, and the quality of regrowth silages may also be improved by more frequent or appropriate timing of harvests. Restricted fermentation obtained by application of formic acid improved energy and protein preservation.

Sammendrag

Råproteininnhaldet var høgare og proteinet var meir stabilt under konservering i raudkløverdominert gjenvekst enn i grasdominert vårvekst. Likevel vart proteinverdien lågare i gjenvekstsurfôret, spesielt dersom ein la til rette for sterk gjæring. Tilsetjing av maursyrehaldige ensileringsmiddel for å hemme nedbryting av lettomsetjelege karbohydrat vil vere eit godt tiltak for god proteinkonservering. både i vårvekst og gjenvekst.

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The fauna of surface-active spiders was studied in 12 cereal fields, with two types of subcrop, and in four young (17 months old) perennial leys (grass/clover). The fields were located in the southeastern (A), central (B) and western (C) parts of Norway. In total, 3945 spiders were caught from May to September 2004, using pitfall traps. Linyphidae was the most numerous family, with Erigone atra Blackwall 1833 representing 56% of all trapped individuals. The total numbers of spider species and individuals were significantly higher in leys than in barley at sites where both crops were present (sites A and B), with on average 11 species and 93 specimens in barley, and 20 species and 393 specimens in leys. Thus, young perennial leys appeared to provide a better habitat for spiders than did cereal fields, as has previously been documented for older perennial leys. The use of multi-species crops instead of a single crop species undersown in cereals, tended to result in higher spider species diversity, but it did not influence the total number of specimens. An ordination (DCA) showed a clustering of the spider fauna from the same site, but no clear separation between main crop types (ley vs. barley) was apparent. The main crops, subcrops, and the surrounding environs of the cropped field seem to affect the diversity and abundance of spiders.

Sammendrag

Implications Mulching of GM herbage can increase cereal yields compared to its removal. However, the same GM herbage removed for biogas production will provide biogas residue that can be used as spring fertilizer to cereals. This will improve N-recovery and reduce the risk for N pollution. Cooperation with existing biogas plants will be more efficient, as building small biogas plants are costly and challenging.

Sammendrag

The present report outlines the processes and lists the data invented in a Life Cycle Assessment (LCA) of milk and meat produced at three modeled Norwegian dairy farms. The modeled farms represents typical dairy farms of average size and production intensity located in the three most important milk and beef production counties of Norway, i.e. Rogaland, Nord-Trøndelag and Oppland. Information on management and yields was collected from available statistics, results from recent research as well as informal interviews of farmers and supervisors in farmers extension services. Descriptions and data on buildings, machinery and equipment, consumption of diesel and oil, fertilizer, lime, seeds, pesticides, fences, polyethylene and additives for silage production, detergents, medicines, sawdust, cow matrasses, forages, concentrates and mineral supplement are given. Transport distances of major inputs (i.e. fertilizers, lime, feed concentrates, sawdust, and health care service) to the farm are also included. All data presented are on an annual basis at farm

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Motivasjonen for prosjektet var å legge grunnlag for en kommersiell satsing på å bruke spillvarme i en bærekraftig dyrking og prosessering av andemat i Midt-Norge, for bruk i kommersielle fiske- og dyrefôr samt å initiere et Midt-norsk og blå-grønt samarbeid mellom industri og FoU. Sunndal Energi arbeider for å finne gode prosjekter som kan utnytte spillvarme kommersielt. Formålet var derfor å legge grunnlag for en kommersiell satsing på å bruke spillvarme i en bærekraftig dyrking og prosessering av andemat i Midt-Norge, for bruk i kommersielle fiske- og dyrefôr. Rapporten tar for seg faglige vurderinger av alternative dyrkingsmetoder, næringsinnhold i andemat, husdyrgjødsel og biorest som næringsmedium, og metoder for avvanning og tørking. I tillegg blir det foretatt en vurdering av lønnsomhet. Rapporten konkluderer med at en helårsproduksjon av andemat vil kreve investeringer i dyrkingsfasiliteter og energi til lys og klimaregulering, og at dette kan bli kostbart. Utfra næringssammensetning kan andemat brukes som relevant råvare dersom tilstrekkelig kvantum er tilgjengelig. For å dyrke andemat kan en kombinasjon av fiskeslam fra ferskvannsbaserte anlegg og blautgjødsel fra storfe være gunstig for andemat, siden dette vil øke innholdet av P, som ser til å kunne bli det begrensende næringsstoffet hvis kun husdyrgjødsel brukes som næringskilde. Fiskeslam fra saltvannsbasert oppdrett er for salt. Andemat krever mye avvanning. Mekanisk avvanning etterfulgt av et tørkesystem basert på mekanisk fluidisering under tørkeprosessen (paddeltørke), eventuelt et ringtørke- system vil trolig bli den mest effektive metoden. De økonomiske analysene viser at det er utfordrende å oppnå lønnsomhet i dyrking og prosessering av andemat til fôrformål.

Sammendrag

I forsøk med ulik grønngjødselhåndtering fant vi en betydelig positiv avlingseffekt på påfølgende byggavling av å la grønnmassen bli liggende etter hver slått sammenlignet med å fjerne den. Biorest fra anaerobt fermentert grønnmasse ga samme avlingsnivå og bedre nitrogenutnytting enn å la grønnmassen bli liggende på stubben for å råtne etter hver slått.

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Denne rapporten er en utredning av kompetansegrunnlaget for bedre agronomi for å møte landbrukets klimautfordringer. Utredningen er gjort på oppdrag for Norges forskningsråd av Bioforsk, UMB og Høyskolen i Hedmark. Utredningen omhandler hvilke agronomiske muligheter og utfordringer jordbruket står overfor for å nå målene om lavere utslipp av klimagasser. Den tar også opp agronomiske utfordringer knyttet til effekter av endret klima og jordbrukets tilpasningsmulighter og behov for tiltak. Den gir en oversikt over hvor det er behov for målrettet FoU-innsats, og kommer med forslag til hvordan man kan sikre et godt utdanningstilbud og forskerrekruttering innen land-bruksteknikk og andre viktige områder av agronomien der studenttilgangen nå er for lav. Se utvidet sammendrag.

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The relative effects of using light (2-3 Mg) versus heavier (5-7 Mg) tractors, shallow (15 cm) versus deeper (25 cm) ploughing and on-land versus in-furrow wheel placement during ploughing were investigated from 2003 to 2006 in organic rotations (wheat or barley, green manure, oats with peas) and conventionally fertilized barley. Trials were located on loam soil in south-eastern Norway and silty clay loam in central Norway. Ploughing was performed in spring, when the topsoil moisture content was at or below field capacity, using single furrow ploughs that allowed alternative wheel placement and resulted in complete coverage of the surface by wheels each year (ca. 3 times the normal coverage during ploughing). Low tyre inflation pressures (:<= 80 kPa) were used throughout. The use of a heavy tractor increased topsoil bulk density slightly in the loam soil, and, in combination with in-furrow wheeling, it reduced air-filled pore space and air permeability at 18-22 cm. On the silty clay loam, the use of a heavy tractor did not increase bulk density, but it reduced air-filled pore space throughout the topsoil. In-furrow wheeling reduced air-filled pore space in this soil also, compared to on-land wheeling. Penetration resistance was in this soil always greater at 15-25 cm depth after shallow than after deep ploughing, especially with in-furrow rather than on-land wheeling. Shallow ploughing led on both soils to marked increases in perennial weed biomass compared to deep ploughing. Earthworms were hardly affected by the treatments, but in the loam in 2006 a higher number of individuals were found where the light rather than the heavy tractor had been used. Few significant treatment effects were found on grain yield and quality. Deep ploughing with a light tractor gave the highest wheat yield and protein content in 2 years on the loam soil, and on the silty clay loam the yield of conventionally fertilized barley was higher after deep than after shallow ploughing. In summary, limited evidence was found to support the use of on-land rather than in-furrow wheeling when ploughing is performed at favourable soil moisture and with tractor weights < 5 Mg. There is, however, reason to be wary of using heavy tractors (> 5 Mg), even under such conditions. With regard to ploughing depth in organic rotations dominated by cereals, the need to combat perennial weeds by deep ploughing weighs probably more heavily than any possible beneficial effect of shallow ploughing on stimulating nutrient turnover. (C) 2008 Elsevier B.V. All rights reserved.

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I blandingseng av timotei, engsvingel og rødkløver på lokaliteter i Stjørdal, Øystre Slidre og Klepp har en fastliggende over fire år prøvd ut ulike to-, tre- og fireslåttsystem på to nitrogengjødslingsnivå. Førsteslått har blitt tatt fra sein stengelstrekking til full skyting hos timotei, og påfølgende slåtter har blitt fastsatt etter akkumulert varmesum eller tatt på fast dato. Avling, kvalitet, fenologisk utviklingstrinn og botanisk sammensetning har blitt registrert i alle slåtter, til dels også artsvis.

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I blandingseng av kvitkløver og engrapp på lokaliteter i Stjørdal og Øystre Slidre, samt av kvitkløver og flerårig raigras i Klepp, har en fastliggende over fire år prøvd ut ulike tre- og fireslåttsystem på to nitrogengjødslingsnivå. Tidligste førsteslått har blitt tatt ved stengelstrekking hos engrapp/raigras, og påfølgende slåtter har blitt fastsatt etter akkumulert varmesum eller tatt på fast dato. Avling, kvalitet, fenologisk utviklingstrinn og botanisk sammensetning har blitt registrert i alle slåtter.

Sammendrag

Akkumulert varmesum kan berre delvis brukast som rettesnor for kvalitetsutvikling i gjenvekst. Ein må også ta omsyn til utviklingstrinnet hos graset slåtten før, artar og sortar i enga og om tørke eller næringstilgang kan ha begrensa veksten. Energiinnhaldet i andreslåttane på tjue undersøkte bruk i 2007 var høgt ut frå at dei fleste vart hausta lenge etter at førsteslåtten vart tatt.

Sammendrag

Effekter av traktorvekt, pløyedybde og kjøremåte under pløying ble undersøkt på to jordarter i et økologisk vekstskifte. Forsøksbehandlingene hadde relativt liten effekt på avling, men djup pløying var ofte best bl.a. fordi det reduserte mengden rotugras. Både pløying med hjulene i fåra og bruk av tyngre traktorer hadde uheldige virkninger på jordstrukturen. Dekkdimensjoner, hjulbelastning og dekktrykk bør kombineres på en slik måte at jordpakking unngås i dypere jordlag. En metode for å vurdere dette ble nylig lansert på internett i Danmark.

Sammendrag

In order to improve the basis for utilising nitrogen (N) fixed by white clover (Trifolium repens L.) in northern agriculture, we studied how defoliation stress affected the N contents of major plant organs in late autumn, N losses during the winter and N accumulation in the following spring. Plants were established from stolon cuttings and transplanted to pots that were dug into the field at Apelsvoll Research Centre (60 degrees 42'N, 10 degrees 51' E) and at Holt Research Centre (69 degrees 40' N, 18 degrees 56' E) in spring 2001 and 2002. During the first growing season, the plants were totally stripped of leaves down to the stolon basis, cut at 4 cm height or left undisturbed. The plants were sampled destructively in late autumn, early spring the second year and after 6 weeks of new spring growth. The plant material was sorted into leaves, stolons and roots. Defoliation regime did not influence the total amount of leaf N harvested during and at the end of the first growing season. However, for intensively defoliated plants, the repeated leaf removal and subsequent regrowth occurred at the expense of stolon and root development and resulted in a 61-85% reduction in the total plant N present in late autumn and a 21-59% reduction in total accumulation of plant N (plant N present in autumn + previously harvested leaf N). During the winter, the net N loss from leaf tissue (N not recovered in living nor dead leaves in the spring) ranged from 57% to 74% of the N present in living leaves in the autumn, while N stored in stolons and roots was much better conserved. However, the winter loss of stolon N from severely defoliated plants (19%) was significantly larger than from leniently defoliated (12%) and non-defoliated plants (6%). Moreover, the fraction of stolon N determined as dead in the spring was 63% for severely defoliated as compared to 14% for non-defoliated plants. Accumulation in absolute terms of new leaf N during the spring was highly correlated to total plant N in early spring (R-2 = 0.86), but the growth rates relative to plant N present in early spring were not and, consequently, were similar for all treatments. The amount of inorganic N in the soil after snowmelt and the N uptake in plant root simulator probes (PRS (TM)) during the spring were small, suggesting that microbial immobilisation, leaching and gas emissions may have been important pathways for N lost from plant tissue.

Sammendrag

Temporal changes in the scores of selected soil fertility indices were studied over six years in three different cases of organic crop rotation located in southern, eastern and central Norway. The cropping history and the initial scores of fertility indices prior to conversion to organic cropping differed between the sites. Crop yields, regarded as an overall, integrating fertility indicator, were in all rotations highly variable with few consistent temporal trends following the first year after conversion. On the site in eastern Norway, where conversion followed several years of all-arable crop rotations, earthworm number and biomass and soil physical properties improved, whereas the system was apparently degrading with regard to P and K trade balances and contents in soil. On the other two sites, the picture was less clear. On the southern site, which had a relatively fertile soil before conversion, the contents of soil organic matter and K decreased during the six-year period, but the scores of other fertility indices showed no trends. On the site in central Norway, there were positive trends for earthworm-related indices such as worm biomass and tubular biopores, and negative trends for soil porosity. The results, especially those from the eastern site, illustrate the general difficulty in drawing conclusions about overall fertility or sustainability when partial indicators show divergent trends. Consequently, the study gave no unambiguous support to the initial working hypothesis that organic farming increases inherent overall soil fertility, but rather showed that the effect varied among indicators and depended on status of the cases at conversion. It is concluded that indicators are probably better used as tools to learn about and improve system components than as absolute measures of sustainability.

Sammendrag

The three organic cropping systems Landvik (in Grimstad), Voll (at Ås) and Kvithamar (in Stjørdal) were established in 1993 on previously conventionally farmed soils of marine origin. The six-year crop rotation at Landvik was designed for an organic stockless farm producing cash crops. These crops were fertilized with composted organic household waste from the nearby community (maximum 100 kg N ha-1) and composted waste from the system itself. The rotation at Voll was designed for an arable farm withbeef production from suckling cows (0.9 animal units ha-1), and the rotation at Kvithamar was designed for a dairy cattle farm (1.0 animal unit ha-1). During the first six years of organic farming, the soil reserves of K were slightly depleted. The nutrient balance was –250 kg K ha-1 at Voll and –420 kg K ha-1 at Landvik, and the content of easily soluble K in the plough layer decreased at these sites. At Kvithamar, however, where the K balance for six years was –380 kg ha-1, no changes in soil content of K were recorded. For P, the six-year balance was positive at Landvik, where altogether 120 kg P ha-1 was supplied from composted household waste. The P balance was negative (-40 kg ha-1) at Voll and Kvithamar, and at Voll the content of easily soluble P in the plough layer was lower in 1999 than in 1993. In the study period, the yields were variable both within and between the systems. We have not identified any trends or variations in yields that might have been directly caused by changesin soil nutrient status or other soil quality components. At Voll and Kvithamar, however, the number of earthworm and the soil macroporosity increased from 1993 to 1999, with a concurrent slight increase in the yields of leys (Voll) and grain crops and swedes (Kvithamar). In the system at Landvik the yields of potatos and carrots were higher the first two than the last four years. At this site the soil structure was good, and the porosity and earthworm activity high, during the whole study period.

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Kostnadseffektiv grovfôrproduksjon


Legitimiteten og lønnsemda i norske drøvtyggarproduksjonar er utfordra av høge og stadig stigande grovfôrkostnader. Prisen per fôreining grovfôr er på mange bruk høgare enn for innkjøpt kraftfôr, og investeringar i maskiner, teknisk utstyr og infrastruktur utgjer ein stor del av kostnadene. For å snu denne trenden, trengst kunnskap om korleis ein kan auke utbyttet og redusere kostnader, og ikkje minst korleis tiltak med dette som mål skal vegast opp mot kvarandre når det er aktuelt.

Aktiv Sist oppdatert: 14.12.2017
Slutt: jan 2020
Start: feb 2016
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Division of Food Production and Society

SolarFarm


SolarFarm - Exploring solar on-farm energy production combined with a fleet of electrical vehicles and precision agriculture for reduced GHG-emissions

Norway is working towards a low-emission society and its agriculture is in demand to contribute by reducing greenhouse gas emissions from food and feed production. There are two areas which may be considered as «low-hanging fruits»: the reduction of emissions from diesel-driven tractor work and from inefficient use of nitrogen fertilizer. The SolarFarm project has been awarded a 4-year funding to address these areas by developing a concept of innovative technical solutions and methodologies, being applicable on most Norwegian farms.

Aktiv Sist oppdatert: 30.05.2018
Slutt: feb 2022
Start: mars 2018