Browsing by master's degree program "Master's Programme in Agricultural Sciences"

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.

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.

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.

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.

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.

In agricultural soils, Nitrogen (N) is an essential nutrient in crop production, and its supply comes from various pools. Understanding the N pools in soil could help farmers make better decisions about N fertilisation, increase productivity, reduce costs, and decrease environmental impacts. N is a challenging element to track in soil due to its seven oxidation states that are large-ly cycled and intermediated by soil organisms between various organic, mineral, and gaseous forms. This thesis aims to find whether C farming practices accumulate N in soil through investi-gating the size of soil N pools and how they relate to each other through a literature survey and data from a four-year carbon (C) farming experiment. The thesis also investigates whether meas-uring the fast-cycling N pools and including them in fertilisation recommendation calculations results in financial savings from N fertiliser cuts. Twenty different Finnish farms were investigated, split between six C farming practices: subsoil-ing, undersown cover crops, ley farming, soil organic amendments, planned grazing, diverse grasses lay. Soil samples were collected at two different depths (0-17 and 17-30 cm) and ana-lysed for total N and C (Total N, Total C), mineral N, Illinois Soil N Test (ISNT N), autoclave citrate extractable protein N (ACE-Protein N), water extractable organic N and C (WSON and WSOC), and microbial activity derived N (PMN) from CO2 burst after rewetting of dry soil (Resp C).The analysis recovered on average 25% of total N, while 75% remained in the non-recovered pool. Clay%, C% and C:Clay explained the variation in Total N (r2=0.90), ISNT N (r2=0.90), pro-tein N (r2=0.93) and the non-recovered N (r2=0.83), but it did not for WSON (r2=0.50), PMN (r2=0.21) and inorganic N (r2=0.20). Four-year C farming management did not result in statisti-cally significant differences in the N pools, even though PMN and WSON were 19% and 11.6% higher in treatment than in control, respectively. The variation was high for both (SD=48 and 42), explaining the non-significance. Strong correlations (Spearman rho, ρ) were observed between Total N - ISNT N, Residual N, and WSON, indicating their predictive capability for total N, while protein N showed weaker correlations. PMN correlated strongly with bacterial respiration C (ρ = 0.94) and WSON (ρ = 0.75) and had a negative strong correlation with the WSOC:WSON ratio (ρ = -0.73). In conclusion, soil's non-recovered N fraction, likely associated with the mineral surfaces and undecomposed particulate organic matter (POM), is the largest portion of total N. Clay%, C% and C:Clay explains the variation in the slow-cycling N pools but not in the fast-cycling ones. The quality of soil organic matter (SOM) is better assessed using WSON, PMN, and the WSOC:WSON ratio. Utilising PMN as a predictor of N release from SOM results in lower N ferti-liser recommendations, leading to cost savings for farmers. This research shows that four years of C farming do not increase the N stock in soil. Further research is needed to determine if C farming practices in a long-term experiment would increase the soil N stocks, significantly affect soil N pool relationships and result in financial savings for farmers.

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.

Reproduction traits are economically important features in pig production. Inbreeding has negative effect on fitness and fertility of the animals. In pig production, the increase of inbreeding reduces litter sizes and increases piglet mortality. The aim of this study was to examine the effect of parents inbreeding to number of piglets born alive, stillbirths and weaned piglets in Finnish Landrace pig population. An additional goal was to estimate heritability of the studied traits. The data used in the thesis was received from Figen Oy including pedigree and reproduction information. R and DMU programs were used for data management and statistical analyses. The number piglets born alive and weaned piglets increased during the years 2012 and 2021. At the same time number of stillborn piglets also increased. The average inbreeding rate of the boars was 0,104 and of sows 0,102. The annual average inbreeding rate of boars and sows increased significantly in the reviewed period. Heritability of investigated traits varied between 0,05 (number of stillborn and weaned piglets in litter) and 0,10 (number of piglets born alive). The inbreeding rate of the boar had statistically significant effect on the number of piglets born alive and weaned; 10 % unit increase in inbreeding coefficient decreased piglets born alive by 0,35 and the number of weaned piglets by 0,24. A negative dependency between increased inbreeding value of sow and litter size was also found in study but these results were not statistically significant. Inbreeding of either of the parents did not have statistically significant effect on the number of stillborn piglets. In the future there should be paid more attention to the increasing level of inbreeding in the Finnish Landrace population.

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.

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.