Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2018
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Abstract
In cold-temperate climate with high soil water content in spring, the farmer often faces the choice between topsoil compaction during seedbed preparation and delayed sowing, both of which may reduce attainable cereal yield. The objective of this study was to explore whether future climate change with increasing precipitation would aggravate this dilemma. We generated weather based on historical and projected future climate in Southeastern and Central Norway. Using this weather data as input, we simulated spring workability, attainable yield, timeliness costs, and mechanization management with a workability model and a mechanization model. The projected climate changes resulted in improved workability for spring fieldwork and higher attainable yield in South-eastern Norway, and either positive or negative changes in Central Norway compared to historical conditions. We observed a general increase in variability of workability and attainable yield, and a larger risk of extremely unfavourable years in the most unfavourable scenarios in Central Norway. Changes in profitability and mechanization management were small, but followed the same pattern. The negative effects in the most unfavourable climate scenarios in Central Norway were in contrast to positive effects in earlier studies. We explained discrepancies by differences in research methods and purpose. However, simulated sowing dates of annual crops should consider workability of the soil, in terms of water content. Under worst-case conditions, in need of a certain time window to complete their spring fieldwork, farmers might adapt to impaired spring workability by working the soil at higher water content than simulated in our study. The consequence would be a larger loss of attainable yield and less profitability in the future. We anticipate that negative effects may also be expected in other northern cold-temperate regions with high soil water content in spring.
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Authors
Celine Rebours Inga Marie Aasen Ana Karina Carvajal Jan Emblemsvåg Karina Gajardo Jon Halfdanarson Erlend Indergård Alexander Jaramillo Torres Trond Moxness Kortner Åshild Krogdahl Tom Ståle Nordtvedt Hélène Marfaing Annik Fet Magerholm Ronan Pierre Michael Roleda Ingrid Sandbakken Jorunn Skjermo Rasa Slizyte Håvard Steinshamn Pierrick Francois Denis Stévant Wenche Uksnoy Per WaldeAbstract
No abstract has been registered
2017
Authors
Caroline Brophy John A. Finn Andreas Lüscher Matthias Suter Laura Kirwan Maria-Teresa Sebastià Áslaug Helgadóttir Ole Hans Baadshaug Gilles Bélanger Alistair Black Rosemary P. Collins Jure Čop Sigridur Dalmannsdottir Ignacio Delgado Anjo Elgersma Michael Fothergill Bodil E. Frankow-Lindberg An Ghesquiere Barbara Golinska Piotr Golinski Philippe Grieu Anne-Maj Gustavsson Mats Höglind Olivier Huguenin-Elie Marit Jørgensen Zydre Kadziuliene Päivi Kurki Rosa Llurba Tor Lunnan Claudio Porqueddu Ulrich Thumm John ConnollyAbstract
1. Increased species diversity promotes ecosystem function; however, the dynamics of multi-speciesgrassland systems over time and their role in sustaining higher yields generated by increased diver-sity are still poorly understood. We investigated the development of species’ relative abundances ingrassland mixtures over 3 years to identify drivers of diversity change and their links to yield diver-sity effects.2. A continental-scale field experiment was conducted at 31 sites using 11 different four-speci esmixtures each sown at two seed abundances. The four species consisted of two grasses and two legumes, of which one was fast establishing and the other temporally persistent. We modelledthe dynamics of the four-species mixtures, and tested associations with diversity effects on yield.3. We found that species’ dynamics were primarily driven by differences in the relative growth rates(RGRs) of competing species, and secondarily by density dependence and climate. The temporallypersistent grass species typically had the highest RGRs and hence became dominant over time. Den-sity dependence sometimes induced stabilising processes on the dominant species and inhibitedshifts to monoculture. Legumes persisted at most sites at low or medium abundances and persistencewas improved at sites with higher annual minimum temperature.4. Significant diver sity effects were present at the majority of sites in all years and the strength ofdiversity effects was improved with higher legume abundance in the previous year. Observed diver-sity effects, when legumes had declined, may be due to (i) important effects of legumes even at lowabundance, (ii) interaction between the two grass species or (iii) a store of N because of previouspresence of legumes.5. Synthesis. Alongside major compositional changes driven by RGR differences , diversity effectswere observed at most sites, albeit at reduced strength as legumes declined. This evidence stronglysupports the sowing of multi-species mixtures that include legumes over the long-standing practiceof sowing grass monocultures. Careful and strategic selection of the identity of the species used inmixtures is suggested to facilitate the maintenance of species diversity and especially persistence oflegumes over tim e, and to preser ve the strength of yield increases associated with diversity.
Authors
John Connolly Maria-Teresa Sebastià Laura Kirwan John Anthony Finn Rosa Llurba Matthias Suter Rosemary P. Collins Claudio Porqueddu Áslaug Helgadóttir Ole Hans Baadshaug Gilles Bélanger Alistair Black Caroline Brophy Jure Čop Sigridur Dalmannsdottir Delgado Ignacio Anjo Elgersma Michael Fothergill Bodil E. Frankow-Lindberg Ghesquiere An Piotr Golinski Philippe Grieu Gustavsson Anne-Maj Mats Höglind Olivier Huguenin-Elie Marit Jørgensen Zydre Kadziuliene Tor Lunnan Paivi Nykanen-Kurki Angela Ribas Friedhelm Taube Ulrich Thumm Alex De Vliegher Andreas LüscherAbstract
1. Grassland diversity can support sustainable intensification of grassland production through increased yields, reduced inputs and limited weed invasion. We report the effects of diversity on weed suppression from 3 years of a 31-site continental-scale field experiment. 2. At each site, 15 grassland communities comprising four monocultures and 11 four-species mixtures based on a wide range of species' proportions were sown at two densities and managed by cutting. Forage species were selected according to two crossed functional traits, “method of nitrogen acquisition” and “pattern of temporal development”. 3. Across sites, years and sown densities, annual weed biomass in mixtures and monocultures was 0.5 and 2.0 t DM ha−1 (7% and 33% of total biomass respectively). Over 95% of mixtures had weed biomass lower than the average of monocultures, and in two-thirds of cases, lower than in the most suppressive monoculture (transgressive suppression). Suppression was significantly transgressive for 58% of site-years. Transgressive suppression by mixtures was maintained across years, independent of site productivity. 4. Based on models, average weed biomass in mixture over the whole experiment was 52% less (95% confidence interval: 30%–75%) than in the most suppressive monoculture. Transgressive suppression of weed biomass was significant at each year across all mixtures and for each mixture. 5. Weed biomass was consistently low across all mixtures and years and was in some cases significantly but not largely different from that in the equiproportional mixture. The average variability (standard deviation) of annual weed biomass within a site was much lower for mixtures (0.42) than for monocultures (1.77). 6. Synthesis and applications. Weed invasion can be diminished through a combination of forage species selected for complementarity and persistence traits in systems designed to reduce reliance on fertiliser nitrogen. In this study, effects of diversity on weed suppression were consistently strong across mixtures varying widely in species' proportions and over time. The level of weed biomass did not vary greatly across mixtures varying widely in proportions of sown species. These diversity benefits in intensively managed grasslands are relevant for the sustainable intensification of agriculture and, importantly, are achievable through practical farm-scale actions.
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No abstract has been registered
Abstract
In Scandinavia, pasture for dairy herds with automatic milking (AM) is frequently offered purely for exercise and recreation, rather than as a feed-source. In the present study, cows in an AM-system with 12 h nightly outdoor-access from summer solstice until mid-September were offered either fresh production pasture (treatment P; ≥15 kg dry matter (DM) cow‑1 nightly, combined with 6 kg DM grass silage daytime) or exercise pasture (treatment E; <1 kg DM cow‑1 combined with ad libitum silage allowance day and night). Treatment showed a significant effect on milk yield (P:31.3, E:33.0 kg, P=0.05), and a tendency for milking frequency (P:2.25, E: 2.37 milkings × day‑1, P=0.06). Group P spent more time outdoors than E, 4.0 and 3.2 h, respectively (P<0.001). Cows in P grazed approximately 2.5 h throughout the season, while E grazed less overall, 0.6 h (P<0.001) and decreased their time spent grazing over the season (1.0 to 0.3 h). In conclusion, night-time pasture is poorly exploited by cows, irrespective of the quantity of both of pasture and silage that are available.