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Utvärdering av skogens sammansättning efter betesskador i unga tallbestånd
Get PDFSince the early 2000s browsing damage to Scots pine (Pinus Sylvestris) in the Götaland
region of Sweden has been consistently estimated to be 15% per year, peaking at around
25% between 2009-2016, the highest of any region in the country.
The Swedish Forest Agency has set a goal of achieving pine damage levels below 5%
on average in the long-term, even if higher levels can be accepted in an individual year.
Damage levels are influenced by a range of factors e.g., Scots pine density, moose density,
tree species composition and forest stand management decisions. Scots pine monocultures
planted for production forestry purposes are at risk of being replaced by competing species
when browsing damage from moose (Alces alces) occurs.
The aim of this study was to evaluate if intentional Scots pine plantations can be a future
pine forest, or if browsing damage may be too severe to reach the goals of the investment.
Fieldwork was carried out in 22 young stands located in Götaland which were regenerated
with the planting of Scots pine between 2016-2018, on sites managed by forest owner
association Södra Skogsägarna – who have raised the issue of what will become of Scots
pine plantations. In addition, forest owners were interviewed regarding their aim with the
regenerations and what they think about the possibility to combine Scots pine plantations
with the population of moose.
Results from the fieldwork indicated that the average damage level of Scots pine across
all 22 stands was 25% and that Scots pine faces strong competition from regenerating
Norway spruce (Picea abies), birch (Betula spp.) and other broadleaved species. Scenario
analyses employed to determine the future dominant tree in stands revealed that targeted
thinning may be necessary of competing trees to ensure Scots pine plantations are realised
in the future. Results from the forest owner questionnaire indicated that forest owners’
management decisions are affected by browsing damage to Scots pine and that additional
guidance from forest owner associations and financial support from relevant authorities to
implement additional browsing deterrents is welcomed.Sedan början av 2000-talet bedöms betesskador på tall (Pinus Sylvestris) i Götaland
(Sverige) ligga på 15 % per men ännu högre, runt 25 % mellan 2008–2016, högst av alla
regioner i landet.
Skogsstyrelsen har satt upp ett mål att betesskadorna på tall ska ligga under 5 % i
genomsnitt på lång sikt, även om högre betesskador nivåer kan accepteras under ett enskilt
år. Betesskador påverkas av ett flertal faktorer till exempel, förekomst av tallskog,
älgtäthet, trädslag i bestånden och skogsskötsel. Planterade tallföryngringar riskerar att
utvecklas till skogar med andra trädslag på grund av betesskador från älg (Alces alces).
Målet med den här uppsatsen var att utvärdera om tallmonokulturer kan utvecklas till
de bestånd som var det tänkta, eller om betesskador gör att markägaren inte kan nå målet.
Inventering gjordes i 22 föryngringar i Götaland med planterad tall mellan 2016–2018.
Möjliga utfall efter röjning utvärderades i scenarier med och utan hänsyn till betesskadorna.
Vidare, skogsägarna intervjuades gällande deras mål med föryngringen och vad de tror om
möjligheterna att kombinera tallföryngringar med närvaron av höga älgstammar.
Resultaten från inventeringen visade att medelvärdet av betesskador för de 22 bestånden
var 25 % och att tall möter stark konkurrens från gran (Picea abies), björk (Betula spp.)
och andra lövträd. Röjningsscenarierna visade att riktad röjning krävs för att försäkra att
de framtida bestånden blir talldominerade i framtiden. Resultaten från skogägarenkäten
visade att deras skogsskötsel-beslut påverkas av betesskador på tall samt att ytterligare
vägledning från skogliga rådgivare och riktade stöd för skydd mot betesskador välkomnas
In contact with the bank : credit analysis of agricultural enterprises from a gender perspective
Get PDFSveriges lantbruksföretag blir allt färre och en underrepresentation av kvinnliga lantbrukare råder. För att ha möjlighet att bedriva lantbruk är tillgång till extern finansiering nödvändigt, och banker tillhör den vanligaste kreditformen.
Syftet med studien var att undersöka på vilka bedömningsgrunder kreditbeslut fattas och om genusstrukturer påverkar bedömningen vid kreditgivning. Åtta respondenter som representerat fyra banker har intervjuats för djupare förståelse för kreditbedömningen. Studien bygger på en tematisk analys av empiri och teori samt 5C-modellen ur ett genusperspektiv.
Studien visar att kreditbedömarna eftersträvar objektivitet. Men förutsättningar som modellen grundas på ger olika förutsättningar för kvinnor och män. Till följd av genusstrukturer premieras faktorer där kvinnor är underrepresenterade och jämlik möjlighet att söka kredit saknas.In Sweden agricultural enterprises has continuous decrease, and have an underrepresentation of female owned farms. To have the possibility to run a farm external financing is a must, and bank loan is the most common form of financing.
This research aimed to study agricultural financing from a gender perspective, and see if credit assessment criteria affect the lending decisions. The study is based on qualitative empirical data with thematic analysis from eight interviews with a similar number of respondents representing four different Swedish banks. The theoretical framework is based on 5C-model from a gender perspective.
The study shows that the creditors strive after equal conditions and that the model is gender neutral. However different factors of the model including collateral and capital having a negative impact on female prerequisites. The 5C-model is both intuitive and open for meanings of their own
Value flows and transaction costs in the potential market for meadow biomass
Get PDFThere is an urgency for agricultural firms to increase profitability in order to keep larger areas of meadows under maintenance. The alternative use of meadow biomass is a business opportunity for agricultural firms to increase revenue streams. However, there is a knowledge gap regarding the potential value flows created by firms, as well as the obstacles impeding firms’ development in the market for meadow biomass.
The purpose of this thesis is to create an understanding of how values might be created by agricultural firms through the market for alternative use of meadow biomass. The purpose also includes to create an understanding of the possible obstacles impeding firms’ ability to develop in the market. To achieve the purpose of this thesis the Sustainable Business Model archetype “Create value from waste” and transaction cost theory will act as the theoretical lenses. Based on the aim and research questions, the study was performed with qualitative research methods. With a multiple case study design and semi-structured interviews, four agricultural firms participated in the study. The empirical findings were categorised through open coding and analysed through a within- and cross-case analysis.
The results showed how incorporation of economic, environmental, and social aspects in the Sustainable Business model archetype can create value flows in the potential market for meadow biomass. Moreover, the result also displays possible transaction costs impeding firms’ development in the market
Upplevda transaktionskostnader för jordägare och arrendatorer
Get PDFOmkring 40 % av all jordbruksmark arrenderas i Sverige idag, där den vanligaste typen är sidoarrenden. Det gör att arrenden är en transaktion som många lantbrukare och jordägare ställs inför och måste hantera. Varje transaktion påverkas dock av transaktionskostnader, till följd av att marknaden är komplex och ineffektiv. Transaktionskostnader innebär att resurser behöver spenderas på transaktionen för att den ska komma till stånd. Transaktionskostnadernas upplevda storlek avgörs i sin tur av en rad faktorer som analyseras i denna studie. Därigenom kan faktorerna få betydelse för transaktionens design och genomförande.
Således är syftet med denna studie att utforska huruvida transaktionskostnaderna påverkar inställningen till sidoarrenden utifrån jordägares respektive arrendatorers synvinkel i områdena Götalands södra slättbygder och nedre Norrland. Genom kvalitativ forskningsmetod, och en mul-tipel fallstudiedesign utfördes studien. Tre jordägare och tre arrendatorer från båda områdena intervjuades på ett semi-strukturerat sätt för att ge flexibilitet till att få en djupare förståelse för respondenternas kontext.
Studiens resultat visar att det finns både likheter och skillnader i hur transaktionskostnaderna påverkar inställningen till sidoarrenden. Skillnaderna identifierades framförallt mellan områdesindelningarna. Förutsättningarna mellan områdena är olika och således anpassar sig parterna till det område som de är verksamma inom. Därigenom finns det både likheter och skillnader mellan områdena gällande hur vissa faktorer upplevs öka, vara oförändrade eller minska transaktionskostnaderna, och sedermera påverka inställningen till sidoarrenden. Samtidigt kan individers egna preferenser vara avgörande för om en faktor får en viss effekt för den specifika individen.Today almost 40% of all agricultural land in Sweden is leased, these leases are predominately side leases. Side leases are a common transaction for farmers and landowners, which means that it is a transaction that happens on a regular basis. However, each transaction is different, due to a complex and inefficient market, this means that transaction costs will vary, and farmers will be affected differently. Transaction costs are defined as resources needed to be spent on the transaction for fulfillment. The perceived size of transaction costs can be determined by a number of different factors. The authors of this study will assess and evaluate these factors in order to aid in the design and execution of future transactions.
Thus, the purpose of this study is to explore whether transaction costs can affect the attitude towards side leases from the perspectives of landowners and tenant farmers in the areas of Götalands södra slättbygder and nedre Norrland in Sweden. The study will employ a qualitative research method and a multiple case study design in order to achieve an in depth understanding of the areas in question. Three landowners and three tenant farmers from each of the two areas were interviewed using semi-structured interviews.
The results of this study show that there are both similarities and differences in how the transaction costs affect parties and their attitude towards side leases. The primary differences have been identified as differences in areas of operation and their unique agricultural conditions. The conditions for the two operational areas are different, and therefore the involved parties must adapt to the conditions in their geographical area. As a result, there are both similarities and differences in how certain factors are perceived between the two areas, and how these variances effect the perception of transaction costs. Furthermore, individual characteristics play a role in the attitude toward the varying factors and the impact they have on the overall attitude toward transaction costs
Ko och kalv tillsammans i mjölkproduktion
Get PDFSyftet med den här studien var att undersöka hur kalvar inom ekologisk produktion som tillåts dia
sin mor ökar i vikt under diperioden. Vidare studerades kornas mjölkproduktion och celltal under
och efter diperioden.
Försökskalvarna hölls med korna under dagtid och separerades nattetid. Under sommaren hölls de
utomhus och under vintern inne i ladugården. Försöksgruppen jämfördes med kontrollgrupper där
kalvarna skiljdes av från kon något dygn efter födseln och därefter utfodrades manuellt eller via
kalvamma. Kontrollkalvarna utfodrades med 9-10 liter mjölk 3 gånger om dagen. Mammorna till
kontrollkalvarna användes som kontrollgrupp för de kor som ingick i försöket. Totalt inkluderades
38 ko-kalvpar på 2 gårdar, varav 18 par i försöksgruppen och 20 par i kontrollgruppen. Samtliga
kalvar vägdes eller så mättes bröstomfånget en gång i veckan under hela diperioden, totalt 13 veckor.
Bröstomfångsmätningarna omvandlades sedan till en vikt i kg genom en formel. Data från mjölkningsenheten gällande mjölkproduktion och celltal samlades in från samtliga mjölkningstillfällen
under laktationsdag 0 till 130.
Försökskalvarna ökade i vikt med i genomsnitt 9,49 ± 1,06 kg per vecka, och kontrollkalvarna med
7,04 ± 1,52 kg per vecka. Försökskalvarna ökade i genomsnitt 35 % mer i vikt än vad kontrollkalvarna gjorde. Vid analys kunde statistiskt signifikant skillnad påvisas mellan grupperna oavsett gård.
Studiepopulationen var relativt liten och bröstomfångsomvandlingen ger endast en ungefärlig vikt
vilket gör det svårt att dra slutsatser om hela populationen.
Försökskorna gav i genomsnitt 14,5 ± 3,8 kg mindre mjölk per dag än kontrollkorna under diperioden, och i genomsnitt 3,0 kg mindre mjölk per dag efter avvänjning. Statistiskt signifikant
skillnad i mjölkavkastning kunde påvisas mellan grupperna och på båda gårdarna. Mellan kontrolloch försöksgruppen efter avvänjning kunde dock endast statistiskt signifikant skillnad påvisa på en
av gårdarna.
Vid analys av celltal noterades en stor variation, medianvärdet var 120 000 celler/ml för båda
försöksgrupperna och 76 000 respektive 177 000 celler/ml för kontrollgrupperna. Statistiskt signifikant skillnad kunde påvisas mellan grupperna och på båda gårdarna. På den ena gården hade försöksgruppen lägre celltal än kontrollgruppen medan det rådde omvända förhållanden på den andra
gården, vilket gör det svårt att dra slutsatser om digivningens påverkan på celltal. Vidare studier
med större studiepopulationer och fler gårdar skulle behövas för att dra säkra slutsatser om hur
digivning påverkar mjölkproduktion och juverhälsa.The purpose of this study was to investigate how calves in organic production gain weight when
they are allowed to suckle during the first 3 months of life. Furthermore, the cows' milk production
and cell count were studied during and after the suckling period.
The test calves were kept with the cows during the daytime and separated at night. During the
summer they were kept outdoors and during the winter inside the barn. The test group was compared
with a control group where the calves were separated from the cow a few days after birth and then
fed manually or via an automatic feeder. The control calves were fed 9-10 liters of milk 3 times a
day. The mothers of the control calves were used as a control group for the cows included in the
study. A total of 38 cow-calf pairs were included on 2 farms, including 18 pairs in the trial group
and 20 pairs in the control group. All calves were weighed, or the chest circumference was measured
once a week throughout the suckling period, a total of 13 weeks. The chest circumference data was
then converted to a weight in kg through an equation. Data from the milking unit on milk production
and cell count were collected from all milking sessions during lactation day 0 to 130.
The test calves gained an average of 9.49 ± 1.06 kg per week, and the control calves an average of
7.04 ± 1.52 kg per week. The test calves increased an average of 35% more in weight than the control
calves did. When analyzed, statistically significant difference could be demonstrated between the
groups regardless of farm. The study population was relatively small, and the chest circumference
gives only an approximate weight when calculated, making it difficult to draw conclusions about
the entire population.
The test cows produced an average of 14.5 kg less milk per day than the control cows during the
suckling period, and on average 3.0 kg less milk per day after weaning. Statistically significant
difference in milk yields could be demonstrated between the trial and control groups. However,
between the control and trial group after weaning, no statistically significant difference could be
demonstrated on one of the farms.
When analyzing cell counts, a large variation was noted, the median value was 120,000 cells/ml for
both test groups and 76,000 and 177,000 cells/ml, respectively, for the control groups. The cell
counts were compared at farm level only. Statistically significant differences could be demonstrated
between the groups. On one farm, the test group had lower cell numbers than the control group while
there were reverse conditions on the other farm, making it difficult to draw conclusions about the
impact of suckling on cell count. Further studies with larger study populations and more farms would
be needed to draw firm conclusions about how suckling affects milk production and udder health
Gait screening using a mobile phone application
Get PDFOrthopaedic disorders are the most common reason for unplanned rest in the performing horse
population. Locomotor disorders which slowly build up to clear lameness might be avoidable with
easy access objective motion measurement devices. An early detection of a disorder affecting the
locomotor apparatus will lead to an early diagnosis and directed treatment to avoid chronic, irreversible damages to the tissues, often caused by long drawn inflammation.
During the last 30 years, biomechanical researchers have established and refined sensitive objective
measures of lameness. Decreased loading of a painful front- or hind limb leads to a vertical motion
asymmetry of the head or pelvis respectively at the trot. These asymmetries can be detected with
high precision and accuracy, but the relevance of small amplitude asymmetries is not fully elucidated
and clear thresholds for where an asymmetry is likely to reflect a painful condition are lacking.
Several studies have investigated the prevalence of motion asymmetries in different horse
populations, revealing that asymmetries above clinically used thresholds are very common, ranging
from 73-90% in mature riding horses, youngsters, endurance horses, standardbred trotters and polo
horses. These high prevalence numbers and the sensitive measurement devices available have raised
the question whether these asymmetries are caused by pain or if it is a question of biological variation of the gait pattern. In the search for the relevance of mild and moderate motion asymmetries,
the relation to a high performing locomotor system is of particular interest. Therefore, studying
horses that are judges to be “fit to compete” for high level events could provide insight.
The aim of this study was to describe vertical movement symmetry of head and pelvis in eventing
horses as they trotted up during the horse inspection before and during an international FEI long
format eventing competition. The asymmetry was described for horses that passed and did not pass
the inspection. We investigated how the horses responded to the strenuous cross-country section of
the competition by studying if the symmetry changed from the first to the second horse inspection
(before and after cross country). In addition to the description of asymmetries on a group level, we
also evaluated the usability of the mobile phone gait analysis tool, Sleip AI, which was used during
the study.
In total, 58 horses were recorded using a computer vision tool for gait analysis at the horse
inspections at one FEI long format eventing competition. At the first horse inspection, 36% of the
horses showed asymmetry of mild type or more, on one leg or more. In spite of the high exercise
load during the cross country, 52% of the 44 horses presented at the second horse inspection (after
the cross country) improved their total asymmetry, 36% had a worsening/increased total asymmetry
and 11% remained unchanged in their total asymmetry level. No significant difference on a population level was found (p =0.77) using a paired non-parametric test (Wilcoxon signed rank test),
when looking at all the groups, first compared to the second horse inspection. The level of measured
movement asymmetry using the gait analysis app was higher in the horses which were given a nonpass (sent to holding) compared to the ones that were subjectively judged to be fit to compete and
were given a “pass”, but this was not statistically tested due to the low number of horses sent to
holding. Horses that got a straight away “pass” at the first horse inspection (n =53) had a median
asymmetry score of 0.95 for total asymmetry. The runs that generated a “holding” decision (n =5),
had the median score of 2.1 for total asymmetry at the first horse inspection. At the second horse inspection the “pass” (n =42) had a median score of 1.05 and the “holding” (n =2) a median score
of 1.75. Some horses with high degree of asymmetry slipped through the “pass”. Objective gait
analysis can be useful in order to pick these horses out for a second control. We observed that many
of the outliers with a high degree of asymmetry were white/grey-coloured horses. When looking at
the total asymmetry and the outliers in the “pass”-group at the first and second horse inspection 3/5
and 3/3 horses were white coloured. This might indicate white horses are visually more difficult to
assess. A mean of 11.8 trot strides were recorded for the front limbs during the first horse inspection
and 7.4 trot strides for the hind limbs. During the second horse inspection a mean of 12.2 trot strides
were measured for the front limbs and 8.5 for the hind limbs. In order to render a more reliable
interpretation of the gait analysis, more trot steps should be recorded. This could be made possible
if the trot up was longer.
To conclude, around one third of the eventers studied showed mild or more accentuated motion
asymmetry at the day of the competition and surprisingly, the majority of this group of eventers
improved their total motion asymmetry after the cross country. The mobile phone gait analysis
application seemed to be a useful decision-tool for gait screening, but the horses should be trotted
more strides in order to improve the reliability of the motion analysis
Young consumer perceptions of wooden multistorey construction
Get PDFIn a time when many institutions call for climate action, the housing shortage in Sweden continues to increase and therefore also the need for increased construction. Traditional construction methods that use concrete and steel emit large amounts of greenhouse gases and many call for better construction methods to meet the demand of more sustainable practices. Wooden multistorey construction is believed to be a sustainable alternative to traditional methods that could provide society with sustainably constructed housing that would still fulfill the demands of the modern consumer. Projects that make use of this method have already been implemented both in Sweden and globally but there is a need for more research concerning consumer perceptions, preferences, and behavior regarding the use of wood in multistorey construction, especially among the younger population.
This study aimed to explore young consumer perceptions of wood as a construction material in multistorey apartment buildings as well as perceptions and preferences for conventional apartment buildings. These findings were then used to give suggestions to improve marketing of said buildings and supplement research in the area. 21 young respondents living in Uppsala, Sweden were interviewed using a laddering technique. By using Means End Theory and Personal Value Theory, attributes, consequences, and values that influenced perceptions and preferences were identified in the group of respondents.
The results showed that price and location were the most important attributes for consumers considering a conventional apartment and that the material used in construction did not have an impact on their perception of said apartments. Respondents mainly perceived WMC-apartments as aesthetically appealing, and they connected those attributes with the value of well-being. WMC-apartments were also considered to be environmentally sustainable, an attribute many respondents connected to reducing climate impact and the value of universalism
Funktionell analys av effektorer från Blumeria graminis och deras effect på växters microbiom
Get PDFWith an expected population of 10 billion by the next century, agricultural production has to increase at the same pace to match such demand. One of the main obstacles to achieving this are the pathogenic microorganisms that reduce food quality and yields every year. Understanding the interactions between these microbes and their hosts is essential for shaping proper control strategies.
Phytopathogenic fungi utilize effectors, a class of small and diverse proteins, to interact with and supress the defences of the plants they infect. More recently, interest has been growing in the potential for alternative roles for these proteins, such as the interaction with other microbes in the environment and how they may be used to shape the local microbiome.
Here, eight proteins from a family of effector genes produced by Blumeria graminis f.sp. tritici, selected based RNA expression profiles showing increased expression during coinfections, were studied using heterologous protein production. Stable transformation of Pichia pastoris and transient expression in Nicotiana benthamiana through homologous recombination and Agroinfiltration respectively was used to perform assays testing the proteins for antimicrobial and phytotoxic activity. While no phytotoxic effects could be observed, three effectors displayed indications of antifungal activity and one in particular displayed both antifungal and antibacterial potential. Additional verification and optimization of the assays used here should be performed to improve the reliability of the results and potentially allow the protocols to be used for characterization of other effectors of obligate biotrophic plant pathogens
Assessment of future climate and land use changes on streamflow and phosphorus transport in a Swedish agricultural catchment
Get PDFDespite efforts to reduce nutrient excess in surface waters in the last decades, eutrophication continues to be an important environmental problem in Europe. The presence of excess phosphorus (P) in waters, together with nitrogen (N), is one of its main causes. It is crucial to understand how P may respond to future environmental change to adopt adequate management strategies to fight this problem in the long term. The present study explored this direction of research by testing the effects of future climate, weather and land use on streamflow and total P using hydrologic and water quality modelling in Sävjaån catchment (722km2), central Sweden. The scenarios represented future changes in the period 2071-2100
derived from representative concentration pathway (RCP) emission scenarios, changes in extreme precipitation patterns and land use changes. Results showed higher maximum P loads when more extreme precipitation events were combined with high emission scenarios (RCP 4.5 and 8.5). Besides, extreme precipitation increase caused significant differences between maximum and minimum annual P loads, suggesting an increased uncertainty in future projections. Lastly, results indicated a shift in the seasonal distribution in loads, with decreases in winter and spring loads associated with less snowfall and increases in autumn and especially summer loads
Växt-elicitorers påverkan på ammoniak oxiderande mikrobsamhällen från höstvetes rötter och rhizosfär
Get PDFNitrogen is one of the essential nutrients for plants. Nitrogen is taken up as ammonium (NH4+) or nitrate (NO3-) from roots. If not taken up by the plants, nitrate can be lost to the atmosphere by denitrification which contributes to the global warming. Nitrate can leach out in aquatic systems, this can cause eutrophication, thus it’s important to save the nitrogen in soil. Nitrate can be added as fertilizer or produced by a microbial process called nitrification. The first step of nitrification is the oxidation of ammonia, done by ammonia oxidizing archaea, ammonia oxidizing bacteria and comammox (Nitrospira). This first step is also the rate limiting step of this process.
Plant elicitors such as cis-jasmone, methyl jasmonate and methyl salicylate are used in pest management but there are also indications that they trigger the production of secondary metabolites that can be found in root exudates and inhibit ammonia oxidizers. However, our knowledge on their effect on soil microbes remains limited.
The hypothesis was that treating winter wheat with elicitors will alter the soil ammonia-oxidizing communities without negatively affecting plant performance. The first aim was to determine the abundance, composition and activity of the ammonia oxidizing root and rhizosphere communities. The second aim was to measure plant traits both above- and below ground. The third aim was to assess effects of ammonium availability of the elicitor treated plants.
The elicitor treatments showed most effects in the fertilized pots. The elicitors had most significant effects on the ammonia-oxidizing root communities compared to the rhizosphere communities. Methyl jasmonate showed most significant effects and methyl salicylate showed second most significant effects of both decreased microbial abundance and changed community composition. In both cases the plant traits were positively affected except for the shoot biomass. However, it is possible that this effect is temporary and that a longer growth period would allow an increase in the shoot biomass. Cis-jasmone showed no significant effect on microbial abundance but a trend of changed composition. Cis-jasmone positively affected below-ground plant performance.
Methyl jasmonate seems to be the most promising elicitor and methyl salicylate is the second promising elicitor. Cis-jasmone is still interesting, showing positive effects on plant performance although limited effect on microbial abundance. Fertilizer as ammonium chloride increase the effects of the elicitor treatments limited to the roots microbial community. We should continue use cis-jasmone, methyl jasmonate and methyl salicylate to see how they can be used in practical agriculture and in different crops.Kväve är ett essentiellt näringsämne för växter. Kväve tas upp som ammonium (NH4+) eller nitrat (NO3-) genom växtrötterna. Nitrat är lättrörligt i jorden, om nitrat inte utnyttjas av växter kan det försvinna till atmosfären genom denitrifikationen, detta bidrar till den globala uppvärmningen. Nitrat kan också läcka ut till vattendrag och orsakar övergödning, det är därför viktigt att spara kvävet i marken. Nitrat kan tillföras genom gödsel eller bildas genom mikrobiella processer i marken via nitrifikationen. Ammoniakoxideringen är det första steget i nitrifikationen vilket bestämmer hasigheten av nitrifikationen. Ammoniak oxideras av ammoniak oxiderande arkéer, ammoniak oxiderande bakterier eller comammox (Nitrospira). Växt-elicitorer som cis-jasmonsyra, metyljasmonsyra och metylsalicylsyra inducerar försvarsmekanismer mot herbivorer och patogener. Det finns indikationer om att elicitorer kan också trigga syntes av sekundära metaboliter i rotexudatet som inhiberar ammoniakoxiderande mikrober i jorden. Kunskapen om effekten på jordmikrober är dock minimal.
Hypotesen var att elicitorer påverkar det ammoniakoxiderande mikrobsamhället som är kopplat till höstvete, utan negativ påverkan på växtens tillväxt. Det första syftet var att mäta rot- och rhizosfärsamhällets storlek, komposition och aktivitet. Det andra syftet var att mäta växtens ovan- och underjordiska delar för att undersöka växtens tillväxt av behandlingarna. Det tredje syftet var att bedöma eventuella effekter från ammoniumgödsling på elicitorbehandlade plantor.
Elicitorbehandlingarna visade mest signifikant effekt i de gödslade leden. Rotmikrobsamhället visade fler signifikanta effekter jämfört med rhizosfärmikrobsamhället.
Metyljasmonsyra visade flest signifikanta effekter och därefter metylsalicylsyra. Dessa reducerade storleken på rotmikrobsamhället, förändrade samhällets komposition, samt hade positiv påverkan på växtens tillväxt förutom skottbiomassa. Det är dock möjligt att denna effekten är temporär och efter en längre tillväxtperiod ökar skottbiomassan. Cis-jasmonsyra visade inga signifikant skillnader på mikrobsamhällets storlek, men en trend på förändrad komposition. Cis-jasmonsyra visade ändå positiv påverkan på rottillväxten.
Metyljasmonsyra är den mest lovande elicitoren och metylsalicylsyra den näst lovande elicitoren. Cis-jasmonsyra är fortfarande intressant då den visade ha positiv inverkan på växtens tillväxt men begränsad påverkan på mikrobsamhällets storlek. Gödsel som ammoniumklorid visade sig ge en förstärkt effekt på elicitorbehnadlingarna, begränsad till rotmikrobsamhället. Vi bör fortsätta använda cis-jasmonsyra, metyljasmonsyra och metylsalicylsyra för att se hur de kan användas i praktiskt jordbruk och vilken effekt de har i oliak grödor