Browsing by Subject "Magisterprogrammet i lantbruksvetenskaper"

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  • Määttänen, Satu (Helsingin yliopisto, 2020)
    Agroforestry, a widespread land-use in tropics and especially in tropical drylands, is gaining increasing attention due its carbon sequestration and storage potential. Majority of African countries acknowledge agroforestry as a national climate change mitigation and adaptation strategy. Despite the large extent of African drylands and the commonness and importance of agroforestry systems to dryland livelihoods, these systems are scarcely studied and research on dryland African agroforestry carbon stocks are few. The aim of the study was to compare carbon stocks of three land-uses: Vitellaria paradoxa dominated parkland (PL), improved agroforestry system (IA) and, as a control, abandoned land (AL), to study carbon allocation between and within the land-uses and to examine the variability of biomass estimates of different allometric equations used in carbon inventory in West African Sahel. Study was conducted in two villages in Yorosso, Southern Mali. Carbon stocks accounted were woody above- and belowground biomass, litter and top-soil organic carbon. Allometric equations and root-to-shoot ratios were used for woody biomass measurement. Comparison of biomass estimations of different allometric equations and root-to-shoot-ratios was conducted by using multiple equations for the dataset. Total system carbon stocks were 24.7 MgC haˉ¹, 29.9 MgC haˉ¹ and 42.2 MgC haˉ¹, for PL, AL and IA, respectively, with statistically significant difference between PL and IA. Top-soil organic carbon (SOC) was important carbon pool, accounting 34.8 % of total system carbon in PL and IA, and 49.6 % in AL. There were no statistically significant differences on the SOC/biomass C ratios between the land-uses. PL had lower SOC stocks than IA or AL, difference being statistically significant. The reason for lower SOC stock of PL could not be explained in this study. IA had larger woody biomass carbon stocks (27.0 MgC haˉ¹) than PL (15.5 MgC haˉ¹ ) and AL (14.4 MgC haˉ¹), but the difference was not statistically significant due to the similar density of large mature trees in all of the land-uses and partly due to the large woody biomass variation within the land-uses. In all of the land-uses, most of biomass carbon was stored in large mature trees and in two species: V. paradoxa and Parkia biglobosa. Large woody individuals had major impact on the land-use level carbon stocks. For carbon conservation, these individuals should be preserved and spared even during land-use change. Despite relatively large density, young trees and shrubs stored diminutive amount of carbon compared to mature trees. As the currently young planted trees in IA will grow and mature in the future, the woody biomass carbon stocks of the system will increase significantly. Lack of regeneration observed in PL threatens the sustainability of the system and its carbon stocks. Future carbon storage potential of AL depends on the regeneration potential of large tree species. Comparison of different allometric equations for tree biomass estimation revealed substantial variation. The choice of allometric equation used affects the obtained results, hampering the comparison of studies using different equations. Commonly used root-to-shoot ratios vary on their estimations, and most probably by underestimating root biomass. There is a clear need for specialised and standard carbon inventory methods for drylands and agroforestry systems.
  • McPartlin, Maria (Helsingin yliopisto, 2020)
    Cellular agriculture is a novel food production technology that utilizes tissue engineering techniques to culture muscle cells to make cultured meat, or microbes and fermenting to create proteins such as casein, albumin and collagen which can be processed to products similar to milk and egg white for example. This thesis aims to explore the challenges that cellular agriculture faces in terms of policy, politics and the society mainly in a Finnish context, but also observing EU regulations. These challenges were investigated by interviewing altogether 15 representatives of stakeholder groups, which are political parties, government administration, organizations of policy executioners, NGO’s, food-tech companies, -funds and research centres. The data from the interviews was transcribed and processed in Atlas.ti-software using the analysis of qualitative content -method. The processed data was then analysed using the analysis of a specialist interview -method. The study revealed that specialists agree that cellular agriculture products will follow EU Novel Food regulations, but that cellular agriculture might have to overcome some regulation-related challenges. Challenges might also arise from markets, consumers and competing with conventionally produced food. Some believed cellular agriculture to have a negative impact on the Finnish society in the form of eroding rural livelihoods, and that the production will be in the hands of large corporations. Many stated that they do not believe cellular agriculture will surpass conventional agriculture, but that it will become just another food innovation. Some believed cellular agriculture offers great possibilities in the form of more sustainable food production. Many of the statements of the interviewees reflected current events already underway in the cellular agriculture and alternative protein field. The challenges cellular agriculture will face are multifaceted, and more information is still needed, especially on the societal effects of cellular agriculture.
  • Valdebenito Alamar, Nerea (Helsingin yliopisto, 2021)
    Despite their immobile nature, their ability for adaptation allows plants to face harmful conditions from the environment to successfully survive and reproduce. Plant cells sense and integrate signals from the environment and activate response mechanisms. Participants in these mechanisms are the receptor-like protein kinases (RLKs) and a subgroup of RLKs, the cysteine-rich receptor-like kinases (CRKs). Members of this family have been associated with functions related to environmental stress responses in plants. CRK2 is one interesting member of the CRK clade of RLKs. While roles of CRK2 in the response to biotic and abiotic stimuli have been recently described, many aspects of the diverse functions of CRK2 remain elusive. The reduced size of the crk2 mutant suggests that developmental processes are affected by the absence of the protein. One of the objectives of this work was to analyse potential reasons for the smaller size of crk2. The difference in plant size could be due to a reduced number of cells. Results from the analysis of young cotyledons showed that the smaller plant size is not due to a reduced cell number in leaves when compared to Arabidopsis thaliana (Arabidopsis) ecotype Columbia (Col-0). Another way to understand the processes in which a protein is involved is to target possible interaction partners. Therefore, genotyping and analysis of growth phenotypes of T-DNA insertion mutant lines for candidate interaction partners for CRK2 was performed. The results revealed smaller phenotype for a nitrate transporter (NRT1.7) mutant in fresh weight and rosette area whereas for a protein kinase (QSK1) mutant, higher fresh weight but reduced rosette area was observed compared to Col-0. Generation of constructs for fusion protein expression and purification revealed the possibility of expressing tagged cytoplasmic regions of these proteins for further analysis of protein-protein interaction through kinase assays due to the kinase activity of CRK2. Generation of fluorescent-tagged proteins from the candidate interaction partners allowed for localization studies via confocal microscopy to determine the co-localization to the plasma membrane of these proteins with CRK2, which is located to plasma membrane under standard growth conditions. The co-localization results suggest that the proteins NRT1.7 and QSK1 colocalize with CRK2, which is a step forward in the verification of their possible interaction in planta. The smaller size of the nrt1.7 and qsk1 mutants indicates that the lack of these proteins affects plant development.
  • Qin, Kaiyue Jr (Helsingin yliopisto, 2020)
    Strawberries (Fragaria sp.) are perennial plants that belong to Rosaceae family. According to flowering habit, strawberries are classified as seasonal flowering and perpetual flowering strawberries. Environmental factors regulate flowering in plants. Among them, photoperiod and temperature are two important cues to affect flowering in strawberries. Besides, FT is a general flowering activator in many plant species. This thesis explored the flowering habits and FT expression level of two diploid strawberries F. bucharica and F. nilgerrensis under short and long day at cool temperature at 11 °C. The results were compared with F. vesca which has been studied earlier. After 2, 4 and 6 weeks of cool temperature (11 °C) treatment, all F. vesca and the majority of F. bucharica flowered regardless of photoperiod. As for F. nilgerrensis, there was no floral induction under SD and 20 % flowering rate after 6 weeks of LD treatment. After 4 weeks of the treatment, the expression of FT was down-regulated in F. vesca and F. bucharica compared with control groups under long day at 20 °C. In conclusion, the cool temperature at 11 °C induced flowering both in F. vesca and F. bucharica. The photoperiod affected flowering in F. vesca, while not in F. bucharica. As for F. nilgerrensis, the treatments were not strongly inductive for flowering. It may need more time for floral induction. The FT1 expression was down regulated after 4-week cool temperature treatments in F. vesca and F. bucharica, which was negatively correlated with flower induction. The photoperiod and temperature significantly affect branch crown formation in F. nilgerrensis, while the temperature had significant effects on runner formation and leaf formation in these three species.
  • Zhao, Chuanhui (Helsingin yliopisto, 2020)
    The research of this thesis was focused on anaerobic digestion of cow manure mixed with different types of biowaste, especially those material that are available in Finland. The research was conducted by search, collection, and analysis of different data in literature. Topic of the thesis was predetermined by the Co-Creation Lab project of Helsinki Institute of Sustainability Science (HELSUS), which was seeking solution to achieve carbon neutral cow milk production. The solution was co-approached by three participants conducting thesis from technological, economical, and legislative points of view, in which I was responsible for writing mainly the technological part, and general findings in economic efficiency and legislative terms by the other two co-creators were also included in this thesis. The research was mainly related with the whole cycle of biogas production, including basics about anaerobic digestion (AD), applications of the biogas and digestate as a product and by-product of AD. Substrates for AD were researched with a focus to find the best combination of cow manure (CM) and biowaste in regard with methane yield outcome, especially a mixture of CM and silage waste that suits the cow farming situation in Finland. Methane yields for mono-digestion of various types of biowaste and co-digestion of CM with different biomass were collected and analyzed. Premises for biogas plant establishment were researched briefly, including facility composition, and consideration of feasibility and raw material availability. CM with grass containing 75% timothy and 25% meadow fescue grass at 70%:30% mixing ratio could be the best combination of CM: grass co-digestion, followed by 0.5:0.5 mixed CM and perennial ryegrass. Furthermore, CM mixed with food waste at 52:48% ratio could be the best combination among co-digestion of CM with biowaste other than grass, followed by CM and food waste mixed with 68%:32% ratio, and CM with oat straw mixed at 1:2 ratio could be a considerable combination of CM and crop waste.
  • Huhdanmäki, Tuukka (Helsingin yliopisto, 2021)
    CRISPR-Cas9 is one variant of newly emerging technologies utilizing targeted mutagenesis based on Cas family proteins and guide RNA that enable binding and modifying selected target sequence. The aim of the master’s thesis was to compare different methods of CRISPR-Cas9 induced gene editing in the genus Nicotiana and other secondary protocols necessary to identify successful mutations. PDS1 and PDS2 genes coding phytoene desaturase in plants were selected as target genes as mutant genotype produce visually identifiable photobleaching phenotype. CRISPR-Cas9 ribonucleoprotein complex mediated transformation uses separately produced Cas9 protein and guide RNA that when combined perform transient gene editing in cell. This method was planned to be used but Cas9 protein was challenging to produce in soluble form and final transformation was not achieved. This study suggests that acquiring ready-to-use Cas9 protein might be preferable choice when targeting only few transformations with CRISPR-Cas9 RNP-complex. Agrotransformation is well established method for genus Nicotiana and using Single Transcriptional Unit CRISPR-Cas9 system it is straightforward procedure from plasmid design to transformation. Successfully transformed plants were redeemed from transient agroinfiltration and stable agrotransformation experiments. Off-target mutations are possible and selective outbreeding may be needed. This method lacks the several advantages of CRISPR-Cas9 RNP-complex such as instant gene editing in cell, avoiding RNA interference and transformation over species boundaries, but is simple and functional in genus Nicotiana. Successful mutations were detected using commercial T7E1 and with natural CEL I endonuclease from celery extract. Celery extract can be used as cost-effective alternative to T7E1 for verifying or replicating previously confirmed results.
  • Mäkinen, Arttu Tapio (Helsingin yliopisto, 2021)
    Crop monitoring in commercial indoor farming is a commonly used method in assessing the general productivity of the cultivated plants. This assessment practice is typically conducted manually by greenhouse workers and is sometimes supplemented by certain hand-held or stationary devices. An interesting example of novel device-assisted crop monitoring technologies utilizes digital imaging devices and computer-driven image analysis algorithms that have been prominently employed within the field of plant phenotyping. In the context of botanical studies, they have been used in e.g. characterizing various complex interactions between the genotypes of important food crops and their agronomic traits in specific prevailing environmental conditions. Additionally, image-based data acquisition technologies also present very interesting prospects for precision agriculture management practices. They could be harnessed to scan entire greenhouse compartments continuously and acquire massive amounts of data on multiple morphological and physiological aspects of crop growth and development in a non-destructive fashion. The acquired data could be implemented into mathematical greenhouse control models and utilized in a plethora of useful applications, including e.g. estimating and predicting biomass production and yield, detecting and localizing potential abiotic/biotic stress symptoms at an early stage, and ultimately enhancing overall crop production efficiency. In this thesis, these imaging technologies were explored in practice by designing and constructing a growth chamber embedded with automatic climate control and a low-cost multispectral imaging subsystem. The final assembly was tested by conducting a simple experiment involving drought-stressed sweet basil plants (Ocimum basilicum L. cv. ‘Genovese’) to determine how early drought-stress related symptoms could be detected purely from multispectral images. While the system carried out the tasks of automated climate control and continuous image capture adequately, the implemented approach in drought-stress detection was deemed unsuccessful. Significant differences between drought-stressed plants and their respective controls were not observed until visible symptoms were present. This was assumed to be due to incompatibility of the camera module’s spectral sensitivity in detecting changes in water content in plant tissue.
  • Sarvela, Konsta (Helsingin yliopisto, 2020)
    The purpose of this thesis was to design, build and test a system, which is capable of measuring in real time simple quantities influencing on tire-soil contact of agricultural tractors mobility. The measuring equipment is based on acceleration and distance sensors connected to the Arduino Uno microcontroller. The tractor’s CAN bus was logged and the data was saved using a CAN bus card connected to a Raspberry Pi minicomputer. The sensors were calibrated, and their sensitivity checked before performing the experiments while driving in the field. Accelerometers were placed on top of the rear axle of the tractor at both ends in housings printed for them and distance sensors were mounted behind the rear axle. All sensors were logged by using Raspberry's Raspbian operating system with a python program. The Raspberry was chosen as a computer because of its demanding low space, low cost, and versatility of interfaces. The properties of the field were monitored by monthly penetrometer measurements as well as SoilScout sensors embedded in the ground, which indicated the moisture and temperature of the ground at that depth in real time. The purpose of this was to find out the changes in the field during the growing season, which would also affect the tractor's mobility. The measurement were carried out successfully and the result were considered to be reliable and provide many other opportunities for the future. The results clearly indicated the factors influencing the tractor’s mobility and the different stages of the tillage could be recognized. Future challenges remain the filtering of large amounts of data and the application of measuring equipment in further research. The measurement equipment developed in the work is well suited for its purpose in terms of measurement accuracy and economical affordability. In the future, better accuracy could be achieved with more accurate measuring devices as well as data obtained from this work.
  • Qiu, Yachen (Helsingin yliopisto, 2021)
    Onion (Allium cepa L.) is an important vegetable, which provides major nutritional benefits. In Finland, basal rot caused by Fusarium fungal species (FBR) has become the most destructive disease of onion in recent years. It causes damping off and stunted growth on onion seedlings and root death and abscission and bulb rot on mature onions. The average onion crop loss caused by basal rot has been up to 10% in conventional farming and as high as 30% in organic farming. In this study, a seedling assay was conducted to test the virulence of different Fusarium isolates on a commercial onion cultivar. The study goals were, primarily, to find out which of the Fusarium isolates, originating from onion and crop rotation plants grown in Finland, are pathogenic, and secondly, to compare the virulence of different isolates. Altogether 115 Fusarium isolates were tested for virulence on onion seedlings in a greenhouse. Fifty-five of the tested isolates of F. oxysporum, F. proliferatum and F. redolens were more or less virulent. 19.4% of F. oxysporum isolates, 35.3% of F. proliferatum isolates and 18.2% of F. redolens isolates showed high virulence. Among the aggressive pathogens isolated from onion samples, F. oxysporum f.sp. cepae is still the dominant onion pathogen, F. proliferatum is a new pathogen on onion in Finland, and relatively more aggressive than F. oxysporum. The F. solani and F. tricinctum isolates tested did not have any detrimental effects on the onion seedling health or growth. In order to control FBR in Finland, avoiding planting onion in the infested soils, growing onions from local seedlings to avoid new contamination and storing onions at cold temperatures are recommended.
  • Saha, Sani (Helsingin yliopisto, 2021)
    Immunodeficiency in neonatal piglet is one of the major causes of pre-weaning mortality. Colostrum supply cytokines to newborn piglets, which play an important role in formation of their immune mechanism. This study aims to identify the relationship between sow’s blood and colostrum cytokines, and effect of resin acid-enriched composition (RAC) in sow’s blood and colostrum cytokines concentration. RAC is a plant extract of coniferous tree, and it is composed of resin acids and fatty acids which exert immunomodulatory function. Two experiments were conducted in two different farms where RAC was supplemented in the diet of late gestation sows, starting from one week before of expected farrowing date till farrowing. Multiplex immunoassay was used to determine the interferon alpha (IFN-α), interferon gamma (IFN-ɣ), interleukin 1 (IL-1), interleukin 10 (IL-10), interleukin 4 (IL-4), interleukin 6 (IL-6), interleukin 8 (IL-8), tumor necrosis factor alpha (TNF-α) and interleukin 12p40 (IL-12p40) cytokines concentration in blood and colostrum of sow collected within 2 hours of the birth of first piglets. There were significant (p < 0.05) positive correlations between sow’s blood and colostrum cytokines concentration. RAC-fed sows had significantly (p < 0.05) higher level of IL-1 and showed positive tendency (p = 0.1) to increase TNF-α cytokine level in blood. Colostrum level of IFN- ɣ, IL-1 and IL-12p40 had also positive tendency (p = 0.1) to rise in RAC supplemented sow. On this basis, it is proposed that application of RAC in late gestation sow diet enhance the cytokine production in sow’s blood, and blood cytokines levels are positively correlated with colostrum cytokines.
  • Norrback, Josefin (Helsingin yliopisto, 2021)
    Gastrointestinal parasites (GIP) and resistance against anthelmintics are and will be one of the biggest challenges for the sheep husbandry. Research within this area is very important today and it is important to figure out new methods to identify individuals with high burden of parasites and to treat just these individuals. The aim of the study was to investigate the effects of GIP on activity patterns and weight gain in first season grazing lambs. A sub-study accompanied with the aim was to see if the manually made behavioural observations supported data from the sensors. The study took place at the Swedish University of Agricultural Sciences (SLU) during the summer of 2019. The study was divided into two experimental periods. In the first experimental period 30 ewes and their 60 twins were used. Of those, 58 lambs continued to the second experimental period. Two groups were dewormed with ivermectin (high group) and two groups were untreated (low group). All lambs were fitted with sensors, and the data was downloaded once a week, at the same time with the weighting of animals. Individual faecal samples were collected four times. The pasture where the lambs grazed was a first-year pasture. Sward height was measured, and herbage samples were collected three times during the experiment. Herbage samples were analysed for nutritional and mineral content. The manual behavioural observations were made two days a week during five weeks. The high group had higher weight (28.9 kg) in the beginning of the experiment, compared with the low group (28.1 kg). On the contrary, the high group had lower weight (42.7 kg), compared with the low group (44.8 kg) at the end of the experiment. According to data from the sensors there were differences in lying time and motion index (MI) during the 7-10 first days after weaning. The low group laid down more, compared with the high group. The low group had higher MI compared with the high group. During the whole experiment there were no differences in lying time, lying bouts or MI. The manual behavioural observations showed that “standing still” had significantly more registrations for the high group compared to the low group. It is possible to see differences in behaviour with sensors at an early stage of parasitic infection, even with low levels of parasites. This means, that there is a potential to use automatic behaviour observations as a diagnostics tool during infection of GIP.
  • von Konow, Helena (Helsingin yliopisto, 2020)
    The feeding behavior of beef cattle is complex and varies depending on different factors such as the nutritive value of the feed, the individual and the environment. By optimizing and improving the feed efficiency, the economics of the production increases. Knowledge of feed intake and feeding behavior can be used to optimize the production and the health and well-being of the animals. The aim of this study was to determine how the cut of grass silage affects the feeding behaviour of bulls and thereby how to optimize the use of silage for animal growth. Simmental bulls got three different silage cuts. The first cut was taken on 25th June (ES1), the second cut on 11th August (ES2) and the third cut on 3rd October (ES3). The feeding was given as total mixed ration (TMR) ad libitum. Each TMR group had 15 bulls (TES1, TES2, TES3). Each TMR group had a diet based on grass silage (550 g/kg DM), the only difference being if the silage was of the first, second or third cut. That way the nutritive value differed among the TMR. Individual information about duration, when, and how much the bulls ate was recorded by the Growsafesystem. The average for the bulls in the feeding groups was calculated based on the individual data. This Master´s thesis researched feed intake, feeding frequency, time for head down, time for feed intake and feed intake rate during one month when the body weight of the bulls was on average 546 kg in the beginning and 607 kg at the end of the study. The dry matter for the three cuts was 201 g/kg for ES1, 298 g/kg for ES2 and 354 g/kg for ES3. D-value was 719, 685 and 739 g/kg DM, respectively. The bulls that ate ES3 had higher dry matter intake (12,1 kg DM/d) and eating rate (94,9 g DM/min) than the two other groups. The bulls that ate ES1 and ES2 had the same feed utilization, which was better than the feed utuilization of the bulls that were given ES3. Feeding frequency was about 15 times per day for all groups. The second cut had the lowest digestibility and the bulls eating the second cut had the longest feed intake time. The bulls that ate the third cut had the highest dry matter intake, but the lowest feed utilization. The study indicates that the D-value of the grass silage used in TMR has a clear impact on dry matter intake of the TMR and eating time and eating rate of the animal.
  • Salakka, Anna (Helsingin yliopisto, 2019)
    The objective of the experiment was to study how different additives effect on fermentation quality and aerobic stability of maize silage. Three additives and two maturity stages were used in the labo-ratory scale experiment. Maize silage preserved with different additives was compared to control with no additives. The maize (Pioneer, P7326) used in the study was cultivated at the research farm of the Univer-sity of Helsinki in Viikki on growing season 2018. First silages were made on 21st of August 2018 and after 50 days the second silages were made on 10th of October 2018 92 and 142 days after sowing. The treatments were 1) control 2) formic acid 3) mixture of formic acid, sodium formate, propionic acid and sorbic acid 4) mixture of sodium benzoate and potassium sorbate. Chemical com-positon and buffering capacity of the pre-ensiling maize were determined. Fermentation quality of the silages was also determined. In addition aerobic stability of silages was determined by monitoring the temperature change of silages for 12 days with data loggers. Composition of the maize varied by the maturity stage. Dry matter content in the first maturity stage was 211 g/kg and in the second it was 327 g/kg. Content of water soluble carbohydrates (su-gars) was higher in the first maturity stage. Starch content increased in the second maturity stage considerably. Feed preservation succeeded mainly well and pH of silages in both maturity stages were below four. Sugar content of silages treated with formic acid and mixture of acids was very high in the first maturity stage. Lactic acid content of the control and Na-benzoate and K-sorbate silages was higher than other treatments. Na-benzoate and K-sorbate silage in late maturity stage had noticeably higher acetic acid content. In the silages, there were mainly low content of volatile fatty acids (VFA) and butyric acid was not observed. The silages contained lactic acid as well as acetic acid and only low amount of propionic acid. Silages were aerobically stable except silages of two formic acid silos in the first maturity stage and control silos in the second maturity stage. Temperature started to rise in formic acid silages after 10 days and in control silages after five days from exposure to air. Other silages were aerobically stable during the testing period. The maturity stage affected maize composition and thus ensiling characteristics. Composition differences of maize in different maturity stages cause different challenges in terms of preservation. Different preservation treatments affected the intensity of lactic acid fermentation and silage sugar content and the differences were higher in the first maturity stage. Intensity differences of fermenta-tion and differences in acetic acid content may affect aerobic stability. The use of additives tended to improve aerobic stability of the silages at the late stage of maturity.
  • Lipping, Sanna (Helsingin yliopisto, 2021)
    Kaivannaisfosfori on merkittävin fosfaattilannoitteiden lähde maailman maataloudessa. Fosforia on kuitenkin rajallinen määrä maapallolla ja kaivannaisfosforin varannot uhkaavat ehtyä 50-500 vuoden aikana. Maailman maatalous joutuu sopeutumaan tulevaisuudessa kaivannaisfosforin vähenemiseen, jolloin fosforin talteen saaminen erilaisin kierrätysmenetelmin tulee olemaan merkittävä kiertotalouden osa. Kierrätyslannoitteiden mahdollisuuksia on yleisesti tutkittu viime aikoina paljon, mutta niiden vaikutusta kauran fosforin ottoon on tutkittu melko vähän. Tämän tutkimuksen tarkastelun kohteena oli kauran (Avena sativa. L Obelix) fosforin otto vuosina 2017 ja 2018 Uudellamaalla sijaitsevalla koelohkolla. Tutkittavina kierrätyslannoitteina olivat lihaluujauho, matokomposti, mädätejäännös ja ammoniumsulfaatti. Kontrollina tutkimuksessa olivat väkilannoiteruutu sekä lannoittamaton ruutu. Koepellon lannoitushistoria oli suomalaisittain tyypillinen ja pellon fosforitaso oli tutkimuksen alkuvaiheessa luokiteltu hyväksi tai korkeaksi. Vuoden 2017 kasvukausi oli pitkäaikaiseen keskiarvoon (1981-2010) nähden kylmä ja sateinen, kun taas vuosi 2018 oli erityisen lämmin ja kuiva. Tämän tutkimuksen perusteella näillä kierrätyslannoitteilla ei ollut merkitsevää eroa kauran fosforin ottoon kumpanakaan vuonna verrattuna väkilannoitteeseen tai lannoittamattomaan käsittelyyn. Merkitsevä ero näkyi kuitenkin vuoden 2017 fosforin otossa lihaluujauhon ja mädätejäännöksen välillä (p=0,0159 vertailussa lannoittamattoman käsittelyn ja p=0,0206 vertailussa väkilannoitekäsittelyn kanssa). Maaperän fosforitaseissa ei havaittu merkitseviä eroja käsittelyiden välillä. Kierrätyslannoitekäsittelyiden välillä havaittiin merkitsevä ero niiden vaikutuksessa maaperän pH-arvoon (p=0,045 vertailussa lannoittamattoman ruudun ja p=0,036 vertailussa väkilannoitekäsittelyn kanssa) vuonna 2018. Tukeyn HSD-testissä ei kuitenkaan tapahtunut jakaantumista eri alajoukkoihin. Koepellon ennestään hyvä ravinnetilanne on voinut vaikuttaa kokeessa tasaamalla eroja eri käsittelyiden välillä.
  • Salovaara, Anna-Kaisa (Helsingin yliopisto, 2019)
    Jääsalaattia (Lactuca sativa var. crispa L.) tuotetaan ympärivuotisesti kasvihuoneessa ja se on kuluttajien keskuudessa suosittu lehtivihannes. Jääsalaatti kerää monien muiden lehtivihannesten tapaan nitraattia ja sen nitraattipitoisuudet voivat nousta melko suuriksikin. Jääsalaatin nitraattipitoisuuteen vaikuttavat useat eri tekijät, kuten laji, lajike, lannoitustaso ja valon intensiteetti. Tehokkailla nitraattipitoisuuden hallintakeinoilla voidaan parantaa tuottajan mahdollisuuksia vaikuttaa sadon laatuun. Valtaosa ravinnon mukana saatavasta nitraatista on peräisin lehtivihanneksista. Euroopan unioni on asettanut katteen alla kasvatetun salaatin nitraattipitoisuudelle talvi- ja kesäkauden raja-arvot. Nitraatti on ihmisen terveydelle haitallinen yhdiste, sillä osa siitä muuttuu elimistössä nitriitiksi, mikä kasvattaa etenkin pienten lasten methemoglobinemian riskiä. Glysiinibetaiini on osmolyytti ja solun metabolian kanssa yhteensopiva yhdiste. Monet viljelykasvit syntetisoivat glysiinibetaiinia vasteena abioottisille stresseille ja se parantaa kasvien stressinkestävyyttä myös eksogeenisesti annettuna. Glysiinibetaiinia saadaan ravinnon mukana esimerkiksi viljatuotteissa ja se on ihmisille turvallinen yhdiste, jota voidaan käyttää myös ravintolisänä. Glysiinibetaiinia eristetään muun muassa sokerijuurikkaan melassista ja sitä voidaan käyttää orgaanisena lannoitteena tai kasvunedistäjänä kasvintuotannossa. Tämän tutkimuksen tavoitteena oli selvittää glysiinibetaiinin käyttömahdollisuuksia jääsalaatin tuotannon edistäjänä. Kasvihuonekokeessa seitsemän vuorokautta kestänyt glysiinibetaiinikäsittely aloitettiin jääsalaattien ollessa 29 vuorokauden ikäisiä. Glysiinibetaiinikäsittelyjen pitoisuudet olivat 0, 1, 7,5 ja 15 mM. Jääsalaatin nitraattipitoisuus, glysiinibetaiinipitoisuus sekä tuore- ja kuivamassa määritettiin 24, 29, 36, 41 ja 49 vuorokauden ikäisistä kasveista. Tutkimus toteutettiin kiertovesiviljelyjärjestelmässä ja glysiinibetaiinikäsittely annettiin ravinneliuoksessa. Jääsalaatit ottivat eksogeenisesti annettua glysiinibetaiinia. Glysiinibetaiinikäsittely pienensi jääsalaatin nitraattipitoisuutta seitsemän vuorokauden käsittelyn jälkeen merkitsevästi kontrolliin verrattuna ja alenema oli suoraan verrannollinen käsittelyn pitoisuuteen. Lisäksi glysiinibetaiinikäsittely pienensi jääsalaatin tuorepainoa ja suurensi kuiva-ainepitoisuutta. Määrityksissä myös jääsalaatin glysiinibetaiinipitoisuuden havaittiin olevan suoraan verrannollinen käsittelyn pitoisuuteen.
  • Linnainmaa, Eeva (Helsingin yliopisto, 2021)
    Dairy cattle breeding has been driven by economics since the 1930s. For a longer period, the costeffectiveness of dairy farming has been poor, and the farmers have been forced to look for all possible ways to improve economics, through either reducing costs or increasing profit. Finland had in 2018 6250 dairy farms, which all differ from each other by size, economics and production environment. Finland participates to Nordic Cattle Genetic Evaluation (NAV) and uses Nordic Total Merit (NTM) as a joint total merit index for Finland, Denmark and Sweden. It has not been published, whether Finnish dairy farms would need more farm specific total merit indices. Breeding goal preferences do differ not only between farms but also between production types, since organic farmers tend to put more emphasis on production, compared to conventional. The aim of this study was to study whether economic values on breeding goal traits differ between farms and production types. Herd specific economic values were counted for ten breeding goal traits. The study was fulfilled with seven dairy herds, who differed from each other by herd size and production environment. Two of the herds were organic. The calculation of economic values was based on a bioeconomic model SimHerd. It is a stochastic simulation model, which simulates the herd in weekly steps, taking all events in a cow’s life into account. Traits analyzed in this study were chosen according to hypotheses of their economic values. Traits analyzed were ECM yield, mastitis, conception rate of cows, conception rate of heifers, cow mortality, calf mortality, claw and leg diseases, feed efficiency, body weight and other culling. Prices and variable costs as well as the phenotypic data of the farms was collected from the year 2018. Finnish milk production is highly dependent of subsidies, but due to their complexity, only direct subsidies for milk were considered in this study. Relations between traits were cut off from the model before simulation. The maximum number of cows for each farm was set to 1000 to improve the reliability of the simulations. Each trait was simulated three times: with the phenotypic data and then twice with changing the parameter. According to the results, the relative economic value of ECM yield was the highest for all farms. The highest economic values differ between farms, but on average the next highest economic values were for body weight, conception rate of cows and cow mortality. These economic values were in the same range for both conventional and organic farms. When relative economic values are presented as percentages of the sum of standardized economic values, traits affecting longevity cover together the greatest percentage. With improved longevity the cows have more productive years, which means greater lifetime milk yield, less replacement cots and smaller environmental impact. When results were compared between farms, they showed no need for farm specific TMI. A different TMI for organic production would need a further research.
  • Vaahtera, Maria (Helsingin yliopisto, 2021)
    Tarhaomenapuu (Malus domestica Borkh.) on tärkein Suomessa viljelty hedelmäpuulaji. Omenapuiden jalostus on Suomessa vähäistä ja viljelijät ovat uusien lajikkeiden suhteen pitkälti ulkomaisen jalostuksen varassa. Jos uuden lajikkeen kylmänkestävyyttä pystyttäisiin arvioimaan luotettavasti laboratoriomenetelmin, uusista lajikkeista saataisiin tietoa nopeammin ja edullisemmin kuin kenttäkokeissa, ja viljelijän riski viljelyn epäonnistumisesta pienenisi. Tavoitteena oli selvittää, voidaanko karaistumisen aikana omenan hiilihydraattipitoisuuksissa tapahtuvien muutosten avulla ennustaa lajikkeen kylmänkestävyyttä. Lisäksi tutkittiin silmämääräisen tarkastelun ja ionivuototestin kykyä kuvata lajikkeiden välisiä eroja kylmänkestävyydessä kontrolloidun pakkasaltistuksen jälkeen. Tutkimukseen valittiin etukäteistiedon perusteella kylmänkestävyydeltään neljä erilaista lajiketta: ’Aroma’, ’Lobo’, ’Pirja’ ja ’Santana’. Liukoisten hiilihydraattien kertyminen karaistumisen aikana ei selittänyt lajikkeiden tai kasvinosien välisiä eroja kylmänkestävyydessä. Tärkkelyksen pitoisuus oli sekä versoissa että silmuissa suurempi herkiksi tiedetyillä lajikkeilla ’Aromalla’ ja ’Santanalla’ kuin kestävämmillä lajikkeilla ’Pirjalla’ ja ’Lobolla’. Omenalla suuri tärkkelyspitoisuus karaistumisen aikana saattaa selittää lajikkeiden välisiä eroja kylmänkestävyydessä. Silmämääräinen tarkastelu kontrolloidun pakkasaltistuksen jälkeen kuvasi lajikkeiden välisiä eroja kylmänkestävyydessä sekä versoissa että silmuissa karaistumisen alkuvaihetta lukuun ottamatta. Ionivuototestin erottelukyky versoissa oli heikko. Silmuissa ionivuotesti erotteli lajikkeet syvän karaistumisen aikana. Lisää tutkimusta tarvitaan kasvissa karaistumisen aikana tapahtuvien muutosten tuntemiseksi ja menetelmien kehittämiseksi kylmänkestävyyden mittaamiseen.
  • Toratti, Sanni (Helsingin yliopisto, 2018)
    The quantity and quality of buckwheat yield are highly dependent on insect mediated cross-pollination. While buckwheat flowers are visited by a diverse pollinator guild, honey bees are often considered to be their most important pollinators. This study describes the effect of pollination by honey bees and wild pollinators on buckwheat yield quantity and quality (1000 seed weight, harvest index and proportion of empty achenes). The composition of the pollinator guild was also monitored. The study was conducted in Southern Finland, 2017. Pollination cages with four pollination treatments were used to study insect pollination. The treatments were as follows: closed cage with honey bee colony, closed cage (excluding all pollinators), open cage and free pollination. The open cage and free pollination treatments were accessible to both honey bees and wild pollinators. The experiment was conducted as a randomized complete block design with four blocks. A honey bee colony was placed next to the research field to carry out free pollination. Pollinator composition was surveyed by transect walks, with special attention paid to the beginning of flowering, which is when the main yield is formed. The highest yields were obtained in the free pollination (822 kg/ha) and open cage (718 kg/ha) treatments. The yield of plants pollinated exclusively by honey bees was 427 kg/ha. The lowest yield was obtained from closed cages (37 kg/ha). The difference in yield was significant for all treatments except open cage and free pollination. The treatments did not affect the 1000 seed weight. The absence of insect pollination decreased the harvest index by approximately 92% and the proportion of filled seeds by approximately 30 percentage points. At the beginning of flowering, honey bees were the dominant pollinators. Insect pollination is essential for the quantity and quality of buckwheat yield. Pollination service by honey bees increases the yield, but is not solely sufficient. The highest yield was obtained when both honey bees and wild pollinators were present. This study focused on honey bees, but the role and efficiency of specific wild pollinators as pollinators of buckwheat should also be studied.
  • Sahra, Mia (Helsingin yliopisto, 2019)
    Kivennäis- ja hivenaineet ovat lypsylehmälle välttämättömiä elintoimintojen ja tuotannon ylläpitoon. Härkäpavun siementä voidaan käyttää valkuaisen lähteenä ja koko kasvustoa säilörehuna, mutta niiden hivenainekoostumusta ei tunneta yhtä hyvin kuin rypsirouheen ja nurmisäilörehun. Tutkimuksessa verrattiin lypsylehmän kivennäis- ja hivenaineiden saantia ja sulavuutta härkäpapusäilörehusta ja härkäpavun siemenestä nurmisäilörehuun ja rypsirouheeseen. Tutkielmassa tarkasteltiin kahta koetta, jotka oli tehty Viikin opetus- ja tutkimustilalla vuosina 2014 ja 2015. Molemmissa kokeissa oli 8 Ayrshire-rotuista lypsylehmää. Kokeet toteutettiin kaksinkertaisina 4x4 latinalaisina neliöinä, joissa oli neljä ruokintaa neljänä kolmen viikon jaksona. Koeasetelmat olivat 2x2 faktoriaalisia. Ensimmäisessä kokeessa faktoreina olivat säilörehun kasvilaji (nurmi tai 1:1 nurmi+härkäpapu-kevätvehnä) ja väkirehun raakavalkuaispitoisuus (175 tai 200 g/kg ka). Toisessa kokeessa faktoreina olivat valkuaistäydennys eri lähteistä (rypsirouhe tai härkäpapu), sekä näiden osittainen korvaaminen Spirulina platensis mikrolevällä. Kokeen 2 koeruokinnat olivat isonitrogeenisiä valkuaisrehujen suhteen. Kokeessa 2 kaikissa koeruokinnoissa oli sama pitoisuus kaupallista kivennäisrehua ja kokeessa 1 kivennäislisä oli täysrehuissa. Härkäpapusäilörehuseos sisälsi enemmän kivennäisaineita, mutta vähemmän hivenaineita kuin nurmisäilörehu. Härkäpavun siemen sisälsi 70 % enemmän kuparia kuin rypsirouhe. Härkäpapusäilörehuseos lisäsi eri kivennäisaineiden saantia 1-6 %, mutta vähensi hivenaineiden, kuten raudan ja mangaanin saantia 5-7 % verrattuna nurmisäilörehuun. Härkäpavun siemen lisäsi kuparin saantia 9 %, mutta pienensi magnesiumin, rikin, raudan, mangaanin ja seleenin saanteja 2-14 % verrattuna rypsirouheeseen. Härkäpavun lisääminen ruokintaan kokoviljasäilörehuna tai kokonaisena siemenenä ei vaikuttanut kivennäis- tai hivenaineiden sulavuuteen. Härkäpapusäilörehu tai härkäpavun siemen eivät eronneet merkittävästi nurmirehusta tai rypsistä hivenaineiden lähteinä. Härkäpapu ei sisältänyt mitään kivennäis- tai hivenainetta haitallisen suurta tai hälyttävän pientä määrää.
  • Haarala, Jaakko (Helsingin yliopisto, 2020)
    Ilmastonmuutos tuo mukanaan Suomeen äärioloja, jotka lisäävät typen huuhtoutumista, mutta myös mahdollisuuksia pidempinä ja lämpimimpinä kasvukausina. Viimeisen kahdenkymmenen vuoden aikana lajikejalostus ei ole kuitenkaan lisännyt käytännön satotasoja, vaan sadot ovat jopa taantuneet. Laskeneet satotasot eivät selity pelkästään laskeneilla typpilannoitustasoilla, ja satokuilua onkin lähdetty ratkaisemaan monimuotoisemmalla viljelykierrolla, joihin sisältyy esimerkiksi härkäpapua. Tutkimuksen tavoitteena oli selvittää esikasvina toimineen härkäpavun (Vicia faba L.) vaikutusta maaperän liukoisiin typpivaroihin ja seuraavien viljelykasvustojen typpidynamiikkaan. Tutkimus toteutettiin Haltialan pellolla satunnaistettuna täydellisten lohkojen kerrannekokeena, jossa käsittelynä oli yhteensä kuusi kasvia ja neljä lannoitustasoa. Kasvustoista mitattiin lehtivihreäpitoisuus, lehtialaindeksi (LAI) sekä määritettiin kuiva-aineen kehittyminen ja koeruuduista otettiin maanäytteet vähintään viidesti kasvukauden aikana. Biomassamääritysten pohjalta analysoitiin kasvinosien typpipitoisuudet ja laskettiin typpisadot. Maanäytteet uutettiin (2M KCl) NH4+- ja NO3--N-pitoisuuksien määrittämiseksi. Kasvustojen typpidynamiikkaa (NUE, UPE, UTE, NHI), typpisatoja ja koeruutujen mineralisaatiota sekä mineraalityppipitoisuuksia vertailtiin lannoitus ja esikasvi taustatekijöinä. Lämmin ja kuiva kasvukausi viivästytti kasvustojen sulkeutumista ja epätasaisuus vaikutti tuloksiin enemmän kuin esikasvi tai lannoitus. Lannoittamattomat kasvustot eivät eronneet tilastollisesti biomassaltaan tai typenotoltaan lannoitetuista. Kasvien typenotto vaikutti enemmän maaperän NO3--N kuin NH4+-N-pitoisuuksiin. Härkäpapuesikasvi lisäsi kauran lehtialan kestoa (LAD). Laskennallinen mineralisaatio oli suurin nollalannoitusruuduissa, keskimäärin 127 N kg ha-1. Kasvustojen UPE, UTE ja NUE jäivät pieniksi maan pintahorisontin ollessa lakastumisrajalla koko kesän. Härkäpavulla on hyvin todennäköisesti vaikutusta maan typpivaroihin, mutta tarkemmat arviot vaativat syvemmälle maahan ulottuvia mittauksia ja edullisemman kasvukauden.