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NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.

2024

Sammendrag

Parasittmidler er viktige for å ivareta god dyrehelse, men økt resistens gjør at virkningen av midlene avtar. I tillegg er parasittmiddel-rester i dyremøkk skadelig både for insekter som lever av møkk, og for mange former for jordliv. Redusert bruk av parasittmidler og riktig håndtering av gjødsla kan bremse resistensutviklingen og bedre situasjonen for gjødselbiller og jordliv.

Sammendrag

Since the 1950s, the use of plastics in agriculture has helped solving many challenges related to food production, while its persistence and mismanagement has led to the plastic pollution we face today. Soils are no exception and concentrations of polyethylene mulch debris up to 380 kg/ha have been reported in Chinese agricultural soils. A variety of biodegradable plastic products have thus been developed and marketed, with the aim to solve plastic pollution through complete degradation after use. But the environmental conditions for rapid and complete degradation are not always fulfilled, and the risk that biodegradable plastics could also contribute to plastic pollution must be evaluated. In this presentation, we want to share the knowledge gained through research projects on biodegradable plastics in agricultural soil, where we both studied the degradation of biodegradable mulch under Nordic soil conditions, and the fate of other biodegradable plastics in soil amendments such as compost and biogas digestate. A two-year field experiment with biodegradable mulch (PBAT-starch and PBAT-PLA) buried in soil in mesh bags showed that also under colder climatic conditions does degradation occur, involving fragmentation already after 2 months, but that complete degradation may take 3 to 9 years, depending on soil temperature and soil organic matter content (both correlate positively with degradation rate). Accumulation is therefore likely to happen when biodegradable mulch is repeatedly used every year. A full-scale experiment with compostable plastic cups (PLA) at an industrial composting plant, where we followed their fate and conducted metagenomic analysis over 13 weeks, demonstrated the major role played by fungi for a successful degradation of PLA. However, the successful management of biodegradable plastic products largely depends on existing waste management infrastructure. Most biodegradable plastic bags, labelled as compostable and used for food waste collection do not end up in industrial composting plants in Norway, but in biogas production plants. Here, we showed that these plastic bags (Mater-Bi®) are only marginally degraded (maximum 21-33 % mass loss) during biogas production, and likely to end up in biogas digestate and then in agricultural soils, unless digestate is treated to remove plastic residues.

Sammendrag

Since the 1950s, the use of plastics in agriculture has helped solving many challenges related to food production, while its persistence and mismanagement has led to the plastic pollution we face today. Soils are no exception and concentrations of polyethylene mulch debris up to 380 kg/ha have been reported in Chinese agricultural soils. A variety of biodegradable plastic products have thus been developed and marketed, with the aim to solve plastic pollution through complete degradation after use. But the environmental conditions for rapid and complete degradation are not always fulfilled, and the risk that biodegradable plastics could also contribute to plastic pollution must be evaluated. In this presentation, we want to share the knowledge gained through research projects on biodegradable plastics in agricultural soil, where we both studied the degradation of biodegradable mulch under Nordic soil conditions, and the fate of biodegradable plastics in two major soil amendments: compost and biogas digestate. A two-year field experiment with biodegradable mulch (PBAT-starch and PBAT-PLA) buried in soil in mesh bags showed that also under colder climatic conditions does degradation occur, involving fragmentation already after 2 months, but that complete degradation may take 3 to 9 years, depending on soil temperature and soil organic matter content (both correlate positively with degradation rate). Accumulation is therefore likely to happen when biodegradable mulch is repeatedly used every year. A full-scale experiment with compostable plastic cups (PLA) at an industrial composting plant, where we followed their fate and conducted metagenomic analysis over 13 weeks, demonstrated the major role played by fungi for a successful degradation of PLA. However, the successful management of biodegradable plastic products largely depends on existing waste management infrastructure. Most biodegradable plastic bags, labelled as compostable and used for food waste collection do not end up in industrial composting plants in Norway, but in biogas production plants. Here, we showed that these plastic bags (starch-based polymer) are only marginally degraded (maximum 21-33 % mass loss) during biogas production, and likely to end up in biogas digestate and then in agricultural soils, unless digestate is treated to remove plastic residues.

Sammendrag

By the time they enter soils, engineered nanomaterials (ENM) have undergone physicochemical transformations and may no longer resemble the pristine materials which have been thoroughly investigated during two decades of nanotoxicology research. Is the behavior of environmentally relevant chemical forms of ENM different from that of other metallic species present in soils? Are they more available to soil organisms than their naturally occurring counterparts? The present study aimed at answering these questions, through the use of isotopically enriched ENMs, which could be traced at low concentrations in soil microcosms, despite high natural metallic background. The relevance of the chemical forms was ensured by introducing isotopically enriched 109Ag, 68ZnO and 46TiO2 ENM to a wastewater treatment plant and using the resulting sewage sludge (final sink for most ENM) as amendment in soil microcosms with earthworms. The sludge application rate to soil was similar to that used in agriculture and the experiment lasted for a month. Protocols using inductively coupled plasma mass spectrometry were developed for determination of isotope ratios in complex matrixes, such as soil and organisms. For 109Ag ENM, the dissolved fraction in soil (i.e. the most easily accumulated in organisms) was extremely low and comparable to that of Ag naturally present in soil, and transfer factors to earthworms were similar to those of natural Ag. For 46TiO2 ENM, the transfer to earthworms was negligible, similarly to what was observed for natural Ti. While no difference in behavior and bioavailability was observed between ENM and their naturally occurring counterparts for Ag and Ti, different results were obtained for Zn. The dissolved fraction for 68ZnO ENM was 3-5 times higher than for Zn forms naturally present in soil, and transfer factors to earthworms twice those of natural Zn. Overcoming long-standing challenges related to environmental relevance of chemical forms and concentrations in nanotechnology studies, the approach provides valuable insight into behavior and impacts of environmentally relevant forms of ENM in soils.