Fertilization with digestate and digestate products – availability and demonstration experiments within the project Botnia nutrient recycling

To increase our food security in Västerbotten we will need to become more self-sufficient of both energy, feed and nutrients that are now imported to the region. Biogas production from different waste streams is one solution to this. Biogas is produced using biowaste or sewage sludge as substrate in the major cities Umeå and Skellefteå. Biogas systems offer a range of benefits to society. Biogas production is currently prized for its climate benefits when replacing fossil fuels for the production of heat, electricity and vehicle gas, but at Bothnia Nutrient Recycling we have studied how to use the digestate, i.e. the residual product of production, as fertilizer in agriculture. We have been working to improve profitability for biogas producers and develop sustainable products from recycled nutrients, like phosphorus and nitrogen. Improving the uses for digestate increases self-sufficiency in agriculture and contributes to a circular economy. We conducted three agricultural demonstration experiments in collaboration with agricultural high schools in Finland and Sweden to introduce digestate and digestate products to the future farmers in the regions. We found that it may be possible to replace cattle slurry with compost when growing maize despite the low levels of nitrogen, N, available to plants in the compost. In barley, NPK fertilizers gave the highest yield. Digestate from HEMAB and sludge biochar supplemented with recycled ammonium sulphate gave a smaller yield but higher than unfertilized crop. Digestate from a dry digestion biogas plant in Härnösand was better suited to barley than to grass because in an experiment on grass ley the viscous fertilizer did not penetrate the grass and did not increase the growth of the grass. Fertilizer effects on crop quality were small. There was no increased uptake of heavy metals in barley after fertilization with digestate or digestate products compared to NPK fertilization. These demonstration experiments show that more thorough scientific experimentation is needed as a foundation for recommendations to farmers. The amounts of nitrogen and phosphorous in digestate from Västerbotten that could become used as fertilizer were modelled. It showed that if sewage sludge digestate is used to make sludge biochar and ammonium sulphate and the other available digestates are used directly in agriculture, the entire phosphorous demand but only a small part of the nitrogen demand in the county, could be covered. Thus, to achieve a true circular food production, development and increase of both the waste handling sector and agriculture is needed

Carbon dioxide emissions from reed canary grass during two growing seasons after restoration of an abandoned agricultural peat soil

Reed canary grass (RCG) can be a suitable energy crop on abandoned agricultural peatland as it can be harvested for more than 10 years without re-establishment, and nutrient recycling to rhizomes lowers the fertilizer demand. A field near Mala in Sweden was restored by improving drainage and sowing RCG in 2010. In the first growing season, CO2 emissions from the soil were lower and groundwater level and soil water content higher for the RCG field than for a nearby unrestored field. Possible reasons were peat compaction by agricultural machinery in the restored field and higher transpiration and respiration from vegetation in the unrestored field. In the second growing season, the groundwater level was raised in some restored plots and CO2 emissions and RCG growth were found to be unaffected by this practice

Rörflen - fördjupade studier av sortskillnader

I samarbete med Lantmännen Lantbruk har rörflenssorter under utveckling provats i två försök i Jämtland och ett i Småland. I försöken gjordes också en jämförelse mellan höstskörd och vårskörd. Vårskörd, där fjolårets biomassa får ligga kvar på fältet under vintern, är den etablerade skördemetoden för rörflensodling till fastbränsle. Det nyare sortmaterialet gav goda skördar i alla försöken. En sort har nu gett bra biomasseskörd i tillräckligt många försök för att kunna kommersialiseras, vilket Lantmännen Lantbruk ska göra. Jämförelserna mellan vårskörd och höstskörd visade att det inte finns några skillnader mellan sorter i känslighet för avklippning på våren. Däremot verkar det kunna finnas skillnader mellan sorter i hur mycket av biomassan som förloras under vintern. Andelen fertila skott kunde skilja sig signifikant mellan sorter enstaka år, men det fanns ingen sort som genomgående hade hög andel fertila skott, och inget samband mellan skottmorfologi och skörd av biomassa

Rörflen

Projektet har haft tre delar: Gödslingsförsök på två rörflensfält, där effekten av P, K och rörflensaska har undersökts. På mark i K(AL) klass II och P(AL) klass II eller högre är troligen inte gödsling med P och K nödvändigt för tillväxten av rörflen efter de första åren. För att undvika att markens PK-status minskar kan rörflensaska återföras till odlingen. Inventering av skadeinsekter och svampangrepp i rörflen. Inventeringar gjordes i Västerbotten, Norrbotten, Småland och Värmland. Rörflensgallmyggan Epicalamus phalaridis hittades bara i södra Västerbotten där den var talrikast 2012. En svampsjukdom, Ceratorhiza rhizodes, hittades i norra Västerbotten och Norrbotten. I övrigt har enstaka angrepp av rörflensbladlus och stritar observerats. En studie av jordbearbetningsmetoder vid återetablering av röflensvall med mycket ogräs. Ogräsbekämpning med glyfosat på våren följt av plöjning och harvning gav bäst effekt mot kvickrot, men ingen av metoderna gav tillfredsställande resultat

Miljögifters påverkan på delfiners hälsa och överlevnad

Delfiner är utsatta för många antropogena hot, där en av dessa är miljögifter. Bioackumulering och biomagnifiering uppstår ofta på grund av delfinernas höga position i näringskedjan och miljögifternas persistens, vilket resulterar i höga nivåer av föroreningar i späck. Detta kan i sin tur leda till olika toxiska effekter. Nivåerna i späcket kan byggas upp med åren och de högsta ses ofta hos äldre individer, särskilt de hanliga då de honliga överför mycket av sin toxikologiska börda till avkomman. Andra faktorer som påverkar upplagringen av miljögifter är bland annat den geografiska platsen de befinner sig i, arten och metabolismen. Den här litteraturstudien sammanställer vilka miljögifter som kan påverka delfiners hälsa och överlevnad, i vilken utsträckning samt vilka effekter dessa kan ha på den enskilda individen och på populationen i stort. Substanser som har uppmätts i höga halter hos delfiner är PCB, DDT, PBDE och kvicksilver, medan andra ämnen som PFC, HCH, PAH och kadmium ses i lägre nivåer. Många av dessa verkar ha liknande mekanismer och orsaka samma effekter, av vilka några är immunosuppression, reproduktion- och hormonstörningar, teratogenicitet, carcinogenicitet, neurotoxicitet och vävnadsskada. Ett tydligt och signifikant samband mellan höga koncentrationer av en substans och en viss effekt är svårt att fastställa, många andra faktorer måste has i åtanke, något som gör det här till ett svårt område att studera. Dessutom uppmäts många ämnen samtidigt i ett och samma djur, vilket gör att möjligheten att dessa ämnen interagerar och tillsammans ger upphov till negativa effekter bör beaktas. Att dra grundade slutsatser blir då ännu svårare. Tidstrenden verkar tyda på en nedåtgång av halterna av många av dessa ämnen medan andra, till exempel PCB, fortfarande ses i mycket höga koncentrationer utan tecken på att sjunka inom den närmsta framtiden. De uppmätta halterna tillsammans med möjliga och observerade effekter indikerar på en trolig påverkan av dessa miljögifter, både hos den individuella delfinen och populationen i stort.Dolphins are subject to many anthropogenic threats, one of which is environmental contaminants. Bioaccumulation and biomagnifications often occur due to dolphins’ high trophic level in the food chain and the persistence of many contaminants, resulting in high levels of contaminants in blubber, which in turn can cause toxic effects. Levels in blubber build up over the years and the highest are seen in older dolphins, especially the male ones since the females transfer much of their toxicological burden to their offspring. Other factors that will affect the storage of contaminants are the metabolism, the geographical place and the dolphin species. This study compiles which environmental contaminants that can affect dolphin health status and survival, as well as describes the effects and impact they might have on the dolphin and its population. Contaminants that are measured in high levels include PCB, DDT, PBDE and mercury, while other minor substances are PFC, HCH, PAH and cadmium. Many of these seem to function in similar ways and bring about many of the same effects, some of which are immune suppression, reproductive failure, endocrine disruption, teratogenicity, carcinogenicity, neurotoxicity and tissue damage. A clear cause and effect relationship between high levels of a substance and a certain effect is very hard to come by. There are often many other factors that need to be taken into consideration, which makes this a complicated area to study. Moreover, there are often many contaminants measured in the same animal and the possibility of them interacting and together causing negative effects need to be recognized, which makes it even harder to draw valid conclusions. The time trend seems to point towards a decline in the levels of several of these substances while others, PCB for example, are still observed in very high levels without indication of dropping anytime soon. The levels measured coupled with the possible, as well as seen, effects indicates a probable impact of these environmental contaminants, both on the individual dolphin and on the population as a whole

Effekter av olika växtföljder på rotröta hos klöver

We studied effects of crop rotations with different amounts of grass/clover ley, especially the effect of fodder rape on the development of clover root rot in red clover. Clover plants, one to three and a half years old, with the root-system were collected from a long-term crop rotation experiment in spring and late autumn. Disease severity index (DSI) of clover root rot and the abundance of the clover root rot causal organism Fusarium avenaceum was evaluated. The results showed that development of clover root rot clearly depends on the age of clover plants regardless of the cropping system. Even though there was a higher abundance of F. avenaceum in one year old clover from crop rotations with more ley, this effect did not persist with increasing age of clover. We did not find any robust correlation between the level of DSI and the abundance of F. avenaceum in clover root. In conclusion, the crops and crop rotations used in this long term-experiment were not effective as control of clover root rot and did not increase the longevity of clover in the leys. This project has been financed by The Royal Swedish Academy of Agriculture and Forestry

A Critical Review on the Assumptions of SETI

The Search for Extraterrestrial Intelligence (SETI) makes certain assumptions which guide all current search programs. To illustrate some, this includes (1) that interstellar flight is not possible (2) that the motivations of interstellar cultures are based largely on anthropomorphic understandings of homo sapiens (3) that the Fermi Paradox and the Drake equation are the starting point (axioms) of all reasoning (4) that definitions of 'life' are based largely on our understanding of homeostasis (5) that radio waves are the most likely method of interstellar communications (6) that unknown single event source signatures detected in space are not amenable to scrutiny due to the demands of the scientific method to be reproducible (7) that such anomalous signatures are either astronomical or communications based in type with no consideration for emissions from advanced industrialisation or propulsion and power technology. These assumptions, and others, have guided the SETI community towards a constrained level of thinking that is equivalent to philosophical dogma. In this paper, we unpack these assumptions, and others, and argue that the potential for life and intelligent life in the Cosmos may be much greater than the SETI community currently appears to conclude. It is also argued that more progress in our underanding of our place in the Cosmos can be made, if the separate disciplines of astronomy, interstellar spacecraft design, SETI, biology and philosophy can work together in a complementary way. Presented at the 47th IAA Symposium on the Search for Extraterrestrial Intelligence. SETI and Society.Comment: 14 pages, 7 figures, submitted to Acta Astonautica, 19th December 2018, presented at the 47th IAA Symposium on SETI, Breme