Closing nutrient loops through decentralized anaerobic digestion of organic residues in agricultural regions: A multi-dimensional sustainability assessment

Decentralized anaerobic digestion (AD) of manure and organic residues is a possible strategy to improve carbon and nutrient cycling within agricultural regions, meanwhile generating renewable energy. To date, there has been limited adoption of decentralized AD technology in industrialized countries owing to low profitability for plant operators. There remains a need to demonstrate the wider sustainability of small-scale, decentralized AD in order to justify policy support for such a strategy. This study applies a multi-dimensional assessment of the environmental, economic and social sustainability of two scenarios of decentralized, farm-scale AD of pig slurry and organic residues in Southern Sweden. The environmental dimension was assessed by means of an expanded boundary life cycle assessment, in which trade-offs between fertilizer replacement, soil organic carbon accumulation, digestate/manure storage and application, transport and soil emissions were evaluated. The economic dimension was assessed through modelling of the net present value and internal rate of return. Finally, the social dimension was assessed by means of a stakeholder perception inquiry among key stakeholders in the field. It was concluded that the overall environmental balance of decentralized AD was favorable, while also the net present value could be positive. Fertilizer replacement, soil organic carbon and digestate storage effects were identified as important factors that should be accounted for in future life cycle assessments. A key issue for interviewed stakeholders was product quality assurance. Wider application of multi-dimensional sustainability assessment, capturing important nutrient cycling effects, could provide an evidence base for policy to support sustainable deployment of decentralized AD

Statement on a conceptual framework for the risk assessment of certain food additives re-evaluated under Commission Regulation (EU) No 257/2010

The Panel on Food Additives and Nutrient Sources added to Food (ANS) provides a scientific statement presenting a conceptual framework for the risk assessment of certain food additives re-evaluated under Commission Regulation (EU) No 257/2010. This framework will be used in the evaluation made by the Panel, but the expert judgement of the scientific background, on a case-by-case basis, remains essential to reach a final conclusion. The outcome of the re-evaluation of food additives taking into account all available information is presented in the document, as well as the exposure assessment scenarios to be carried out by the Panel considering the use levels set in the legislation and the availability of adequate usage or analytical data

Physiological integration and morphological plasticity in extensive clonal plants

Clonal plants show a large variation in physiological integration, i.e. the translocation of resources among ramets within the clone. As resource transport is costly, we hypothesized that plants from poor sites should be more highly integrated than plants from rich sites and that plants would benefit if they were plastic in their degree of integration. Tracers were used to study the transport of water, mineral nutrients and carbohydrates in plants from contrasting habitats using field or green house experiments. As opposed to our hypothesis, plants from poor habitats changed their patterns of physiological integration in response to resource availability, while plants from rich sites maintained the same pattern. The number of integrated ramets did not change in response to nutrient level, but the absolute distance of translocation, the amounts that were shared between ramets and the direction of translocation was affected. Proposed costs of physical connections between ramets are high risks of pathogen spread and a lower morphological plasticity in integrated ramets, resulting in a less efficient foraging strategy. Extensive rhizome growth was an efficient strategy to escape soil-borne pathogens. Although morphological plasticity was similar in the two Carex species (C. arenaria and C. disticha), one species was more integrated than the other. I propose that the responses in the patterns of physiological integration provide clues to understand the evolution from the ancestral, fully integrated ramets to the derived trait of ramet independence found in many present-day species

Origin matters for level of resource sharing in the clonal herb Aegopodium podagraria

Resource sharing in heterogeneous environments has been shown to increase growth and survival of clonal plants. In addition, plants in harsh climates have been suggested to have higher levels of resource sharing than plants in milder climates. We experimentally investigated the level of resource sharing in plants from garden and forest habitats from two regions with contrasting climates. The clonal herb Aegopodium podagraria reaches its northern distribution limit in central Sweden. South of that it grows in both patchy and dynamic light climate, as a natural component of deciduous forest, as well as in more homogeneous light climates as a garden weed. Since heterogeneity and habitat harshness have both been suggested to increase resource sharing, we hypothesized (1) integration and sharing of resources to be higher in plants from forest than in plants from garden habitats and (2) integration and sharing of resources to be higher in plants from the northern region that encounter a harsher climate than in plants from the southern region. Clonal fragments of A. podagraria were collected and multiplied in the greenhouse. Ramet pairs were then planted in adjacent pots, with one ramet shaded. Rhizome connection was either left intact or severed to prevent resources sharing. Plants from forest habitats were more negatively affected by the severance treatment than plants from garden habitats. Although region alone had no significant effect on biomass, the interaction between rhizome severing, shading and regional origin was close to significance. We conclude that A. podagraria from forests are more dependent on resource sharing than those from gardens. These results concur with previous studies that suggest that local adaptation for different degrees of resource sharing can occur in clonal plants

Naturvårdshänsyn vid miljöriskbedömning av genmodifierade grödor. : Långsiktiga effekter och effekter på icke-målorganismer.

Naturvårdsverket har i regleringsbrevet för år 2009 fått i uppdrag av regeringen att redovisa vilka uppgifter som verket bedömer behövs i miljöriskbedömning-en av genmodifierade (GM) grödor för att kunna ta naturvårdshänsyn till lång-siktiga effekter och effekter på icke-målorganismer. Denna rapport utgör redo-visningen av uppdraget.Utveckling och användning av genetiskt modifierade organismer (GMO) är förknippat med potentiella risker. En genomgång har gjorts av de grödor som i dagsläget är intressanta för svenska förhållanden (raps, sockerbeta, potatis och majs), vilka genmodifieringar som finns för varje gröda, och vilka potentiella effekter dessa genmodifierade grödor kan ha. Målen har varit att identifiera potentiella risker vid kommersiell odling och försöksodling av de aktuella grö-dorna, definiera vilka uppgifter som behövs för att kunna utföra en miljörisk-bedömning och undersöka kunskapsläget för dessa uppgifter. Enligt gällande EU-lagstiftning och inom vetenskaplig litteratur framhålls att miljöriskbedömningar ska genomföras baserat på ett fall till fall-förfarande. Nya transgena egenskaper utvecklas dock ständigt och det råder stor variation mel-lan medlemsländerna exempelvis avseende förekomst av icke-målorganismer och frööverlevnad. Detta innebär att det i praktiken är sällan som tillräckliga kunskaper finns om den aktuella grödan och miljön där den är tänkt att odlas kommersiellt, för att fullständigt kunna utvärdera de eventuella negativa effek-terna i det specifika fallet. Här måste en rimlighetsavvägning göras av vilka upp-gifter som anses nödvändiga mot bakgrund av de identifierade riskerna.Jordbruksverkets beslut avseende försöksodling av genmodifierade grödor visar att merparten av försöksodlingarna gäller potatis, raps och sockerbeta, medan försöksodling av majs har förekommit två gånger. Genflödesproblemati-ken skiljer sig mellan grödorna. Majs har inga vilda släktingar som den kan korsa sig med i Sverige och potatis korsar sig inte med de befintliga svenska vilda släktingarna, medan sockerbeta och raps har vilda släktingar till vilka genspridning kan ske. För att kunna genomföra miljöriskbedömningar av genmodifierade grödor med hänsyn till långsiktiga effekter och effekter på icke-målorganismer anser Natur-vårdsverket att det finns ett behov av ytterligare kunskap avseende odling av GM-grödor under svenska förhållanden. Med utgångspunkt från de identifierade riskernas storlek anser Naturvårdsverket att det är särskilt angeläget att öka kunskaperna kring effekter på icke-målorganismer vid odling av herbicidtole-ranta och insektsresistenta grödor, liksom kring resistensutveckling hos ogräs och spillplantor vid odling av herbicidtoleranta grödor. För detta krävs obero-ende vetenskapliga studier