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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.

2022

Abstract

Microplastics ending up in nature as a result of end-of-life processes for plastic packaging is a serious environmental concern, and was addressed in the Packnoplast project through sampling at three sites: one biogas facility in Norway and two thermoplastic recycling plants, one in Norway and one in The Netherlands. The amounts of microplastics ending up in soil from biogas digestate was estimated to represent 0.4-2 mg/kg soil per year if 6 t/daa of biogas digestate is used as fertilizer. Food packaging is estimated to represent 75% of this. The amounts of microplastics measured are significant, but too small to affect soil properties even on a time-scale of decades. The risk of adverse effects on soil quality, plant growth or soil organisms seem very low at the current predicted rates of plastic inputs to soil. Since plastics are virtually non-degradable, they are still prone to accumulate in soil, and waste streams recycled to soil need to address and prevent plastic contamination even better than today. Thermoplastic recycling plants are handling large amounts of plastic, and during processes in the plant, microplastics are generated. Concentrations of microplastic particles varied from 7 to 51 particles per lite rin the effluent water from the two plants. Discharges of effluent water are often through the sewer system and/or into a water body. Today regulations regarding discharges of microplastics are missing. Sand filter treatment of the effluent water was a promising treatment technique to remove the microplastics. Background concentrations of microplastics, comparable to pristine areas, were found in blue mussels sampled outside the thermoplastic recycling plant in Norway. Knowledge about the risk imposed by microplastics to the aquatic environment is today not known.

Abstract

Book of Abstracts p. 225: Perennial sow-thistle (Sonchus arvensis L.) is a problematic weed in arable crops in northern Europe. To control S. arvensis, strategies which reduce both seeds and creeping root production are essential. Inducing repeated sprouting should result in depleting root reserves and reduction in the subsequent shoot emergence. Earlier studies of S. arvensis in the northern European countries have shown a restricted sprouting ability from July/August/ September to October/November. To better understand the sprouting patterns, we conducted joint outdoor pot experiments from March 2020 until July 2021 in three northern European regions: Northern Germany, Norway, and Finland. In each pot, root pieces of 5 cm from local plant material were planted at 5cm depth. Above-ground plants were cut at the soil surface in the growing season of 2020 at 1) flower-bud stage, 2) first visible open flowers, 3) start of seed production, and 4) withering stage. Shoots were counted monthly in 2020 and 2021. In the year 2020, in Germany, sprouting, flowering, seed-set, and withering started earlier than at the other two sites. Significantly more shoots showed up at the flower-bud stage in Germany and Finland compared to Norway. In Finland, significantly more shoots were observed at the later cutting stages compared to the first counts at the flower bud stage. As a subsequent effect, fewest shoots showed up in 2021 at the German and Finnish sites after cutting at flower bud and early flowering stage. The lowest emerged shoot number in 2021 for Norway tended to occur after cutting at the flower bud stage and the start of seed production. Accordingly, cutting at the flower-bud stage decreases the ability to produce shoots in the next year. Keywords: Perennial sow-thistle, sprouting, cutting, shoots Acknowledgements: This research was part of the project “AC/DC-weeds” which is funded by ERA-Net Cofund SusCrop/EU Horizon 2020, Grant no. 771134