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.
2016
Abstract
Large areas of cultivated grassland are annually abandoned and no longer used for production in Norway. Such areas will over time be encroached by shrubs and trees, which is regarded as undesirable. We assessed plant community development, pasture production, herbage quality and pasture utilization by sheep and heifers of a grassland that has been unmanaged for 12 years. e experiment was run for two consecutive years. Sheep grazed the whole area for one month in spring and autumn. During the summer, the area was assigned to three replicated treatments: (1) control with no management; (2) grazing heifers; and (3) grazing sheep with offspring. The stocking rate was 1.8 LU ha-1, in both b and c, for a duration of one month. The area was left resting for a month aer treatment and before autumn sheep grazing. Pasture production and herbage intake was estimated using grazing exclosure cages. Herbage consumed during summer period was on average 211 g DM m-2 and the pasture utilization was 55%. The annual consumption and utilization was 336 g DM m-2 and 62% in the grazed treatments and 28 g DM m-2 and 15% in the control, respectively. Total annual pasture production was on average 72% higher in the grazed treatments compared to the control. Tere was no difference between the grazed treatments on annual production, herbage intake or pasture utilization. Grazing stimulated herbage production, and such abandoned grasslands are valuable forage resources.
Abstract
Large areas of cultivated grassland are annually abandoned and no longer used for production in Norway. Such areas will over time be encroached by shrubs and trees, which is regarded as undesirable. We assessed plant community development, pasture production, herbage quality and pasture utilization by sheep and heifers of a grassland that has been unmanaged for 12 years. e experiment was run for two consecutive years. Sheep grazed the whole area for one month in spring and autumn. During the summer, the area was assigned to three replicated treatments: (1) control with no management; (2) grazing heifers; and (3) grazing sheep with offspring. The stocking rate was 1.8 LU ha-1, in both b and c, for a duration of one month. The area was left resting for a month aer treatment and before autumn sheep grazing. Pasture production and herbage intake was estimated using grazing exclosure cages. Herbage consumed during summer period was on average 211 g DM m-2 and the pasture utilization was 55%. The annual consumption and utilization was 336 g DM m-2 and 62% in the grazed treatments and 28 g DM m-2 and 15% in the control, respectively. Total annual pasture production was on average 72% higher in the grazed treatments compared to the control. Tere was no difference between the grazed treatments on annual production, herbage intake or pasture utilization. Grazing stimulated herbage production, and such abandoned grasslands are valuable forage resources.
Abstract
No abstract has been registered
Authors
Håvard Steinshamn Steffen Adler Randi Berland Frøseth Tor Lunnan Torfinn Torp Anne Kjersti BakkenAbstract
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.
Abstract
No abstract has been registered
Authors
Gudni Thorvaldsson Liv Østrem Linda Öhlund Toroddur Sveinsson Sigridur Dalmannsdottir Rolvur Djurhuus Kenneth Høegh Thordis Anna KristjansdottirAbstract
Eight experiments with cultivars (cvs.) of grass and clover species were established in the Faroe Islands, Greenland, Iceland, Norway and Sweden to evaluate important forage species and cvs. in terms of yield potential, persistence and adaptation to variable climate in the West Nordic countries. Timothy had on average the highest spring cover after three years of trial together with smooth meadow grass (cv. Knut), whereas perennial ryegrass had the lowest spring cover after three years. On average cocksfoot (cv. Laban) and timothy (Grindstad related cvs.) gave the highest yield, 8.85 and 8.71 t ha-1, respectively, and smooth meadow grass and common bent grass the lower yields, 7.52 and 7.30 t ha-1, respectively. The results from these experiments show that we have a wide range of species and cultivars usable in the West Nordic areas. We can meet an increase in temperature to a certain level by moving the more southern species and cvs. farther north, however, our most winter hardy cvs. are still important to maintain.
Abstract
Process-based grassland models (PBMs) simulate growth and development of vegetation over time. The models tend to have a large number of parameters that represent properties of the plants. To simulate different cultivars of the same species, different parameter values are required. Parameter differences may be interpreted as genetic variation for plant traits. Despite this natural connection between PBMs and plant genetics, there are only few examples of successful use of PBMs in plant breeding. Here we present a new procedure by which PBMs can help design ideotypes, i.e. virtual cultivars that optimally combine properties of existing cultivars. Ideotypes constitute selection targets for breeding. The procedure consists of four steps: (1) Bayesian calibration of model parameters using data from cultivar trials, (2) Estimating genetic variation for parameters from the combination of cultivar-specific calibrated parameter distributions, (3) Identifying parameter combinations that meet breeding objectives, (4) Translating model results to practice, i.e. interpreting parameters in terms of practical selection criteria. We show an application of the procedure to timothy (Phleum pratense L.) as grown in different regions of Norway.
Abstract
No abstract has been registered
Authors
Z. Kruma L. Tomsone T. Kince R. Galoburda S. Senhofa M. Sabovics E. Straumite Ievina SturiteAbstract
No abstract has been registered
Abstract
No abstract has been registered