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Organic farming systems with restricted access to animal manure often experience decline in soil P concentrations. Nutrients should be cycled in society to maintain the long-term fertility of agricultural soil. One option for this may be precipitation of struvite (magnesium-ammonium phosphate) from sewage treatment plants, to be Applied as fertiliser. Struvite produced in a Norwegian sewage plant (Hias IKS)significantly increased yield levels and soil P concentrations, when applied in one season (2018) in a long-term experiment comparing two levels of manure application at Tingvoll research farm, NW Norway. Struvite has been proposed by the Expert Group EGTOP to be included in Annex 1, listing permitted fertiliser inputs in organic farming. However, a general allowance for struvite on the European level is by November 2019 still pending, hence hampering also an EU-allowance in organic farming. Several countries, e.g. Norway, allow for use of struvite in agriculture in general

Effects of struvite application on soil and plants: a short‐term field study

The soil P concentration commonly declines over time by organic management, if the farm does not acquire enough fertilisers or other inputs containing P from outside. An interesting source to supply farms with P is struvite (magnesium‐ammonium phosphate). This mineral easily precipitates when the concentrations of these nutrients is high enough, such as in a toilet separating urine. Struvite may be produced in a wastewater treatment plant, as a method to reduce the P concentration in the water reaching the recipient. If struvite is allowed as a mineral fertiliser in the general fertiliser regulation of the European Union,which is currently under revision, this mineral may be allowed also in certified organic agriculture. A wastewater treatment plant in Hamar (south‐eastern Norway), Hedmarken inter‐municipal wastewater corporation (Hias IKS) has developed a patented method to precipitate struvite efficiently. A sample of struvite produced by this process at Hias was sent to Tingvoll (north‐western Norway) to be tested in an experimental field with perennial ley, called “SoilEffects”. This experiment, established in 2011, is used to study the effect on yields and soil characteristics when the slurry from the farm’s herd of organic dairy cows is anaerobically digested to produce biogas before being applied as fertiliser. Non‐digested and digested slurry are compared in two levels of manure application, low and high (30 or 60 tons of slurry per ha and year), and with a control with no manure application. Eight replicates are available of each treatment, and to half of these plots, struvite was applied shortly before the slurry was applied, in the end of April 2018. We applied an amount of struvite corresponding to 40 kg P per ha. Before the application, soil samples had been collected from two depths, to study the effect of struvite on soil characteristics. Yields of ley were recorded in the two cuts, which occurred in June and August. The yield level at the 1st cut was generally low due to drought, but the increase in yield was significant with application of struvite in the plots receiving no manure, and with low manure application. At the 2nd cut, yield levels were generally higher, and again a positive effect of struvite was found in these treatments. On average, the total yield (sum of yields at the 1st and 2nd cut) was 2.4 tons of dry matter (DM) per ha with no application of manure or struvite, and 4.1 with application of struvite. In treatments receiving a low amount of manure, the mean total yield was 5 tons per ha with no struvite, and 6 tons with struvite application. In treatments receiving high amounts of manure, the mean total yield was 6.4 tons per ha without struvite, and 6.2 with struvite. The concentrations of minerals in aboveground plant material from both cuts were analysed, and new soil samples collected after the 2nd cut of ley. Application of struvite increased the P concentrations in plant material and the concentration of AL‐extractable P in soil. Struvite further increased the concentration of magnesium in plant material and soil. Soil pH increased from spring to autumn by application of manure, but the application of struvite reduced this effect. The amount of P being adsorbed to oxides of iron and aluminium in the experimental soil from a solution containing dissolved phosphate was also recorded. The soil has a certain amount of such oxides, and long‐term application of P in manure, as well as application of P in struvite, could possibly reduce the amount of P being adsorbed from the solution. However, no significant differences were found between soils which had received low or high amounts of manure over several years, and we did not find any effect of struvite application on this characteristic in this soil

Spatial fractionation of phosphorus accumulating biofilm: stratification of polyphosphate accumulation and dissimilatory nitrogen metabolism

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Endring av sourcing-strategier for organisasjoner med maritim virksomhet på Sunnmøre : en kvalitativ forskningsstudie

Denne oppgaven tar for seg sourcing-beslutningen organisasjoner må ta når en outsourcingsavtale nærmer seg slutten, eller når partene velger å avslutte kontrakten. Ved en slik oppløsning, har man valget om å 1) beholde den eksisterende outsourcings-tilbyderen, 2) bytte til en annen outsourcings-tilbyder, eller 3) ta aktiviteten tilbake «in-house» gjennom backsourcing. Dette punktet er vår «unit of analysis» og vi ønsker å undersøke hvilke valg man tar, hvilke motiv man legger til grunn i beslutningen, og effekten av strategi-endringen. Studien blir gjennomført som en kvalitativ metode i organisasjoner med maritim virksomhet på Sunnmøre, som har outsourcet deler av produksjonen. Organisasjonene vi undersøker er Tingstad, Fora Form, Fiskerstrand Verft og Kleven Verft. For å belyse problemstillingen starter vi med en begrepsavklaring av de ulike strategiske valgene en organisasjon kan ta, før vi bygger et teoretisk rammeverk for videre analyse. Rammeverket er utledet av transaksjonskostnadsteori, agentteori, strategisk kjerne og kjernekompetanseteori, teori om internasjonal business, «interorganizational relationship theory» og «marketing channelse litterature, og basert på Veltri (2005) sin doktorgradsavhandling om IS-backsourcing. Av disse teoriene får vi frem tre kategorier og tilhørende faktorer; 1) den økonomiske kategorien med faktorene særegne ressurser, kostnadsfordeler og byttekostnader, 2) den strategiske kategorien med faktorene endring av strategisk kjerne, endring av funksjonens rolle, strukturelle endringer, eksterne endringer og tap av kontroll, og 3) den relasjonelle kategorien med faktorene målkonflikt, tilfredshet, servicekvalitet, tillit og kommunikasjon. Funnene viser at kostnadsfordeler er det viktigste motivet i beslutningsprosessen. Andre sentrale motiv er eksterne endringer, endring av strategisk kjerne, byttekostnader, endring av funksjonens rolle, tap av kontroll og målkonflikt. Relasjonelle motiv var nesten fraværende, og kan tyde på at organisasjoner med maritim virksomhet på Sunnmøre er nøye i forberedelsene når man inngår et outsourcingsforhold. Oppgavens bidrag er 1) vi undersøker en liten undersøkt dimensjon av sourcing (tilbakeføring), 2) tidligere forskning har vært fokusert på IT, mens vi ser på produksjon, 3) oppgaven bidrar med et praktisk og relevant rammeverk organisasjoner med maritim virksomhet kan benytte seg av. Vi tilbyr også en oversiktlig begrepsavklaring, og forslår en ny hovedmodell med bakgrunn i våre fire caser

Spatial fractionation of phosphorus accumulating biofilm: stratification of polyphosphate accumulation and dissimilatory nitrogen metabolism

The spatial distribution of microorganisms represents a critical issue in understanding biofilm function. The aim of the current work was to develop a method for biofilm fractionation, facilitating the analysis of individual spatial biofilm layers using metagenomic approaches. Phosphorus accumulating biofilm applied in an enhanced biological phosphorus removal wastewater treatment plant, were fractionated, and analyzed. The fractionated biofilm revealed a surprising spatial distribution of bacteria and genes, where potential polyphosphate accumulating organisms account for ∼ 47% of the inner layer microbiome. A spatial distribution of genes involved in dissimilatory nitrogen reduction was observed, indicating that different layers of the biofilm were metabolically active during the anoxic and aerobic zones of the phosphorus removal process. The physical biofilm separation into individual fractions unveiled functional layers of the biofilm, which will be important for future understanding of the phosphorus removal wastewater process

Spatial fractionation of phosphorus accumulating biofilm: stratification of polyphosphate accumulation and dissimilatory nitrogen metabolism

publishedVersio