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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

The aims of this study were: (1) to assess the trends of climatic variables in two contrasting geographical locations: central Poland and northern Norway; and (2) to evaluate the influence of the detected trends on timothy yields. This grass species was selected for its high importance for forage production in Norway as well as in Poland. For the assessment of climate trends, historical meteorological data, which cover time series from 1985 onwards, were used. Trends of various climate condition indicators were investigated. Data on timothy yields were collected beginning in the 1990s for Brody in Poland from cultivar testing experiments and Holt in Norway by the national cultivar-testing program. The results indicated that in central Poland air temperature in specific months significantly decrease the annual yield of timothy while in northern Norway many climatic variables, such as earlier start and prolonged length of growing season, may have a slightly positive impact on timothy productivity.

Abstract

The growing season is longer than earlier and especially autumn temperatures have increased during the last 30 years (Hanssen‐Bauer et al 2015). A longer growing season increases the potential for forage production as an earlier spring, and warmer autumn implies that farmers can take more cuts with larger yields than earlier. Nevertheless, a warmer autumn can promote considerable regrowth after the last cut, and farmers report that they are uncertain if this regrowth should be harvested. The cost of harvesting forage is high, and feed quality of late harvested forage may be sub‐optimal. Changing precipitation patterns where there may be more episodes of heavy rains during autumn, late harvesting of grass swards can increase the risk of soil compaction and damage plant cover. This was the background to a study where we examine how different harvest time in autumn affects overwintering and yields the following year. We have established randomized block field experiments with 3 replicates in established leys dominated by timothy (Phleum pratense L.) at two sites in Norway in 2015; Kvithamar 63o29’N, 10o53’E, and Holt 69o38’N, 18o57’E. In the Kvithamar field, the main harvests were made June 30 and August 10. Thereafter, in one treatment, plots were left unharvested till next spring, while in other treatments plots were cut 4, 6, 8 or 10 weeks after the second main harvest. At Holt, the first harvest was made July 7, and the second harvest either August 11 or August 27. The regrowth after these treatments were either left uncut or harvested 4, 6 or 8 weeks after the last main cut in August 10, or 6 weeks after the cut in August 28. Dry matter yields were measured from all cuts. The results were analysed using ANOVA with MiniTab. No significant differences in yields were found between the different cutting treatments at either site, even though temperatures were between 2.2‐ 2.5oC higher than normal (1961‐1990) in September and between 1.1‐1.6 warmer than normal in October. Global radiation decreases rapidly from September onwards, and is a limiting factor for the growth potential of timothy‐dominated leys. In spring, we will measure winter survival and growth rate and yields in all treatments. The results from these measurements will be presented at the conference.

Abstract

Grasslands are significant as a source of forage for animal production, but are also important in many ecological functions. To be able to analyse changes in environmental conditions of grasslands, monitoring of grassland areas using remote sensing is an important task. Studying changes in environmental condition over time and space in grasslands has been the subject of research at different scales. Such an example is the Polish-Norwegian Research Project FINEGRASS „Effect of climatic changes on grassland growth, its water conditions and biomass’. In situ measured soil-vegetation parameters and satellite observations have been combined and analysed to quantify the spatial and temporal variability of grassland conditions, as reflected in variations of vegetation surface temperature, soil moisture, and biomass. Results show a significant trend of increasing grassland surface temperature in Poland, based on AVHRR satellite data; a positive significant relationship between the (April-September) standardized precipitation evapotranspiration index (SPEI) and grass yields in Poland; northern Norway has shown trends towards warmer springs and autumns since 1991, and significant trends towards earlier snowmelt and green-up on test fields in northern Norway.