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Browsing by study line "Växtproduktionsvetenskap"

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  • Pärssinen, Jonna (2022)
    This study investigated the frost hardiness of cranberry (Vaccinium macrocarpon Ait.) in four cultivars (’Early Black’, ’Howes’, ’Pilgrim’ and ’Stevens’), focusing especially on the frost hardiness of roots in soilless cultivation. Plants for the study were forced in a greenhouse from cuttings of mother plants. The cuttings were rooted in pots diameter of 10 cm x 10 cm in forest peat. Plants were set to grow in the high tunnel over the growing season. Two experiments were conducted during winter 2020–2021. In the experiments, whole plants with pots were exposed to freezing treatments in a controlled freeze chamber at the temperatures of -10, -15, -20 and -30 °C. Control plants were exposed to cooling at +2 °C for an equal time. In the first experiment, plants were exposed to freezing treatment in November straight from the high tunnel. The second experiment took place in January, and plants were overwintered outside until the experiment. After the freezing treatment one upright in each plant was cut, set in a glass tube containing distilled water, and forced in the greenhouse for 14 days. The vitality of the buds, leafs and stems in the cuttings was observed with a stereomicroscope. After the freezing treatment the vegetative growth of the plants grown in pots was cut off exluding the main shoot, which was cut 5 cm above the soil surface. Thereafter plants were forced in the greenhouse over 10 weeks (the light period of 18/6 h, temperature +20 °C). The vitality of the roots was determined by measuring the amount of the new vegetative growth. All the plants tolerated -10 ° C freeze in November and -15 ° C in January, respectively without injury. Some new growth was observed in plants exposed to freezing treatments of -5 ° C below the temperature mentioned above, but frost damage occurred, and the re-growth was decreased compared to control plants. Cultivar Stevens was more tolerant than the others in both experiments conducted. It maintained its growth potential after -15 °C freezing treatment in November, and -20 °C in January respectively. Frost hardiness (LT50) of buds ranged in November from -19 °C to -27 °C. In January ’Stevens’ buds had the highest frost hardiness (LT50 =-36 °C) and ’Pilgrim’ buds had the lowest (LT50 =-27 °C). The environmental conditions throughout the whole growing season may affect frost hardiness, thus, this experiment should be repeated for verifying the results obtained. Also the potential impact of dormancy in the experiment conducted in November cannot be ignored.
  • Freudenthal, Ines (2022)
    The objective of the thesis is to review and characterize (i) typical agroforestry systems in the temperate zone, (ii) levels of soil organic carbon (SOC) in agroforestry and control plots, and (iii) identify the conditions under which agroforestry farming is most likely to enhance SOC. A meta-analysis was conducted to investigate the impact of agroforestry farming systems on SOC stocks at soil depths of 0 – 20, 0 – 40 and 0 – 100 cm. Data was collected from 15 published studies and all sites are located in temperate climates. Studies had to report at least measurements on SOC concentration or stock for an agroforestry plot and a control plot (arable land, grassland, forest). Investigated treatment variables were soil depth, agroforestry system type, soil type, tree species and age. The results have shown significantly higher SOC stocks under agroforestry in comparison to controls in all three soil depth datasets. The largest amount of SOC in agroforestry was found in the first 20 cm of topsoil and at a soil depth of 60 – 100 cm. There were no significant differences found between alley cropping, silvopasture and shelterbelt systems. The most popular tree species in temperate agroforestry were Populus spp., M.domestica, Juglans regia and Picea. But no significant differences in C sequestration could be observed between tree species across all datasets. The assumption that systems with older trees have higher stocks of SOC could not be confirmed. Most common soil types of temperate agroforestry systems were Luvisol, Fluvisol and Chernozem. The meta-analysis did not verify results of other studies, which have shown that clay contents in the soil promote C sequestration. The wide variability and diversity of agroforestry systems has shown to be problematic in conducting a meta-analysis, indicated by a high heterogeneity. Furthermore, different types of study designs, lack of standardized sampling procedures and explanatory variables may have influenced the results. However, the study showed that agroforestry can be a promising carbon dioxide (CO2) mitigation option, also for the temperate climate zone.
  • Kopakkala, Topi (2022)
    In order to achieve carbon neutrality and slow down climate change, it is necessary not only to curb greenhouse gas emissions but also to remove carbon from the atmosphere. In agricultural sector, adding biochars to soils has proven to be one of the most effective methods to sequester carbon. Using biochars in urban planting soils could be simple and effective way to create carbon sinks also in urban environment. Wood based biochars are already available in the market and their viability as soil amendment is supported by an extensive body of research. Despite large evidence from agricultural and greenhouse sectors, research focused on biochars in planting soils for urban trees is scarce. To assess and demonstrate viability of biochars as component of urban planting soils, an experiment was established in 2019-2020 in Hyväntoivonpuisto-park in Helsinki. The experiment consists of four tree species and nine different planting soils, seven of which include biochars. Three of the planting soils were structural soils installed below a sealed surface. Tree growth in planting soils was followed and biomass accumulation was estimated with allometric equations. Planting soil nutrient composition was analysed at the time of soil application and nine months later after first growing season. Pyrogenic carbon fractions were analysed by BPCA analysis. Planting soil physical and hydrological properties were analysed by water retention curves with pF range of 0 – 4.2. After two growing seasons, biochars had increased tree growth in two planting soils compared to the control while in other planting soils with biochar, the growth was similar to control. In structural soils biochars had improved growth, but there were no statistically significant pairwise differences between treatments. Biochars increased the macroporosity of planting soils, indicating they could improve aeration and water conductivity in planting soils. Effects to total porosity and water retention capacity were mixed, but highest total porosity and water retention capacity was observed in planting soil with the highest amount of biochar. Planting soil nutrient composition varied a lot due to different raw materials, limiting the possibilities of making mechanistic analysis of effects of biochars. These results indicate that biochars are viable and safe constituent for planting soils which may increase tree growth by improving soil physical properties and improve carbon sinks in urban infrastructure.
  • Shehata, Reham (2022)
    Cell walls (CWs) are the safeguards of plant cells and have a crucial role in controlling cell integrity and plant-environment interactions. Perception of cell wall damage (CWD) results in activation of signaling pathways leading to activation of plant defiance responses. Previous research utilizing murus1 GDP-L-fucose deficient mutant has shown the role of GDP-L-fucose biosynthesis in controlling the structure and integrity of the CWs. Here, we investigated whether phenotypical consequences provoked by the lack of GDP-L-fucose, observed in mutants lacking MURUS1 can be suppressed by blocking signal transduction pathways involving THESEUS1 (THE1) receptor-like kinase or WALL-ASSOCIATED KINASE 2 (WAK2)- MAP KINASE 6 (MPK6) signaling module involved in CWD responses. For this, mur1 the1 and mur1 mpk6 double mutants were generated and analyzed. We found that the phenotypes of double mutants closely resemble that of mur1 mutants, indicating that the morphological consequences of GDP-L-fucose deficiency develop independently of THE1 and MPK6 signaling. Further, we aimed to investigate whether GDP-4-keto-6-deoxymannose-3,5-epimerase-4-reductases GER1 and GER2 controlling the final step of GDP-L-fucose synthesis are functionally redundant. Due to the inability of generating ger1 ger2 double mutants, we have applied the artificial microRNA (amiRNA) strategy to generate ger1 ger2 amiRNA knockdown plants. We found that these knockdown plants exhibit severe developmental growth defects similar to those observed in plants impaired in import of GDP-L-fucose into the Golgi apparatus and these growth defects exceeded those observed in plants lacking MUR1. Therefore, we have concluded that GER1 and GER2 are functionally redundant.
  • LU, Jinghong (2022)
    Inflorescence meristem development in plants generally falls into two types: one is the indeterminate type when the main axis keep growing and new flowers are initiated on its flank; while the other is the determinate type when the main axis terminates as a flower and growth continues sympodially. The Asteraceae plant family harbors a unique type of inflorescence, called the flower head. It combines up to hundreds of individual florets into a single structure, but its infloresecence meristem has a determinate fate and can only produce a certain number of florets before getting consumed. The genetic regulation of such determinacy has been recently brought into attention in Gerbera hybrida, a model system used for studying inflorescence and flower development in Asteraceae. So far, several genetic regulators have been identified regulating the determinacy of inflorescence meristem in Gerbera. This thesis aims to characterize new Gerbera transgenic lines to study the function of the Gerbera homolog of TERMINAL FLOWER 1 (GhTFL1). In Arabidopsis and other species, TFL1 is known to counteract with the flower meristem identity genes and maintain the indeterminacy of the inflorescence meristem. Previous results by overexpressing GhTFL1 under constitutive 35S promoter in Gerbera convert the determinate fate of inflorescence meristem into indeterminate. To better study the GhTFL1 function, an inducible overexpression system pOpON2-pOp6/LhGR-N was introduced, and the transgenic lines have been made for GhTFL1. In this this thesis, in total of 19 candidate lines were screened with GUS staining assay and RT-PCR. Two promising lines (TR4 and TR7) with strongest responses in GUS staining and high expression of the target gene were identified. Further treatment of dexamethasone was conducted in these two lines to the growing rosette; however, no clear phenotypes was observed in these lines. The treatment results suggested that further optimization should be made, in particular, the timing of treatment shall be the determining factor for a successful treatment.
  • Bubolz, Jéssica (2022)
    Late blight, caused by Phytophthora infestans (Mont.) de Bary, is considered the most devastating disease in potato (Solanum tuberosum L.) production worldwide. Control methods involve mostly the use of fungicides, which are costly and are under political pressure for reduction in Europe. Potatoes from the major potato cultivar in Sweden, King Edward, previously stacked with three resistance (R) genes (RB, Rpi-blb2 and Rpi-vnt1.1) were tested in a local Swedish field, with spontaneous P. infestans infection over three seasons to evaluate the effectiveness and stability of the resistance on leaves. In addition, testing of resistance was done in both in leaves and tubers. Field results demonstrated that the 3R stacked into the cultivar King Edward, showed practically full resistance to infections of P. infestans, with no difference to fungicide use. Moreover, the resistance was effective in both leaves and tubers. The results reveal the 3R potatoes offer a functional field resistance, that could, alone, reduce the total use of fungicides in agriculture by several percent in Sweden, in an event of modifications in the EU legislation.
  • Laugel, Henri (2022)
    Faba bean (Vicia faba L.) is an annual herbaceous cool-season food legume widely cultivated worldwide, especially for its high seed protein content. However, its major limitation in being used as food and feed, is the presence of antinutritional factors in its seeds, especially vicine and convicine (VC), two related compounds, which may be harmful to livestock and G6PD-deficient humans. To remove VC, the most sustainable method is breeding for low-VC faba bean cultivars. To improve the efficiency and speed of breeding programs, breeders use marker-assisted selection (MAS). The identification of genes responsible for VC content allows the development of reliable DNA markers and a better understanding of the molecular basis of this trait. The major-effect QTL controlling VC content named “VC1”, was identified in faba bean chromosome 1, and a few minor-effect QTLs were detected in previous studies. Hence, a total of 165 RILs from the cross Mélodie/2 (low-VC) x ILB 938/2 (high-VC) were genotyped and evaluated for VC content. Composite interval mapping was run on R/qtl software with accurate phenotypic data associated with a high-density SNP-based genetic map. Results revealed two minor-effect QTLs in addition to VC1. One was on chromosome 4 and had about 15% effect on convicine content. The other was on chromosome 5 and had 15% effect on vicine and total VC content. This research also reports candidate genes for the newly detected minor-effect QTLs through comparative genomics with the Medicago truncatula genome. Hypotheses were proposed on the role of these candidate genes on the VC biosynthetic pathway or transportation into the embryo beans for further testing.
  • Pietikäinen, Laura; Pietikäinen, Laura (2021)
    Fragaria x ananassa is a widely appreciated berry with its production growing all around the world. Thus, there will be a huge demand for strawberry breeding in the future especially since the climate change is casting an extra shadow upon the growing conditions which is also why there is a need for better understanding of different cultivar types. There are everbearing and seasonally flowering cultivars of both Fragaria x ananassa and Fragaria vesca. The seasonally flowering types such as ʻHapilʼ flower once during the growing season whereas everbearing types such as ʻCalypsoʼ flower for a longer period. The gene behind the change in the flowering habit has been tracked to the photoperiodic pathway of F. vesca although the gene behind the trait in F x ananassa remains unknown. The aim of this project was to compare flowering and vegetative responses of in vitro propagated everbearing F x ananassa cultivar ʻCalypsoʼ and seasonally flowering ʻHapilʼ in long and short day photoperiodic conditions in order to find out differences between everbearing and seasonally flowering cultivars. This was done by collecting data from phenotype observations linked to the vegetative and generative stages of the development of strawberries. The phenotype data was then combined with gene expression data of FaSOC1, FaTFL1, FaGA20ox4 and FaAP1 which are genes known to work on the photoperiodic pathway that regulates the switch between the vegetative and generative development of both F x ananassa and F. vesca. In addition, the expression of an everbearing phenotype associated gene FaFT2 was analysed. This study was a part of a larger project aimed to find out the genetic basis for the everbearing habit of F x ananassa. Part of the ʻCalypsoʼ plants were induced to flower already during the acclimatization period and the rest at the very beginning of the treatment period which then caused differential flowering times between the ʻCalypsoʼ groups. Short day grown ʻHapilʼ was induced to flower between weeks three and six whereas long day grown ʻHapilsʼ remained vegetative. Phenotypic observations were also backed up by the expression of FaTFL1 and FaAP1. Instead the FaSOC1 expression was repressed in short day conditions more than in the long days regardless of the cultivar type. ‘Calypsos’ were capable of producing runners regardless of photoperiod or flower induction. Consequently the runner production seemed to be regulated by factors outside of the photoperiodic pathway. However, the expression of runnering associated FaGA20ox4 was low and variable due to the sampling strategy. Interestingly most of the axillary meristems of short day grown ‘Hapils’ remained dormant for an unknown reason. Expression of FaFT2 was low on the apical meristems and further support for the role of the gene in everbearing phenotype was not found.
  • Omran, Mohammad (2022)
    Strawberry breeding in Finland began 60 years ago and has largely relied on traditional breeding methods. The geography of Finland, as well as local consumer preferences for darker-coloured strawberries, have been the main focus of selection in all implemented Finnish breeding programs. With several successful and popular cultivars have been released, the current focus is on increasing yield and disease resistance while maintaining the excellent fruit quality of breeders' selections. A panel of 175 garden strawberry accessions was created and trialled at the Natural Resources Institute Finland (Luke) as part of a Nordic-Baltic pre-breeding collaboration between the institute and the Norwegian breeding company Graminor AS. A medium-density, genome-wide scan for 50K SNPs has been performed on each individual of the panel. This panel represents the genetic diversity present and typical for cultivated strawberry in the Nordic-Baltic region, and it is expected to provide Nordic breeders with markers tailored to their plant material diversity, supporting their future selection decisions and accelerating their breeding cycles. In this study, symptom severities of two strawberry leaf diseases (leaf spot caused by Mycosphaerella fragariae and leaf scorch caused by Diplocarpon earlianum) and seven fruit quality traits (berry weight, skin colour, flesh colour, evenness of flesh colour, basket appearance, predominant berry shape and tip type) were scored in the panel. GAPIT and statgenGWAS statistical packages in R were used to run five different GWAS models: Significant SNP-trait associations were found using single-locus (GLM and MLM) and multi-locus (FarmCPU and BLINK) association mapping analyses. The study had shed a light on the importance of considering several statistical models and parameters for a maximum benefit of association mapping studies. Among significant SNP-trait associations for fruit weight, fruit skin colour and fruit flesh colour, four were partially characterized by inspecting their allelic effects. On chromosome Fvb6-1, appearance of consensus, significant signals from the flesh colour trait of secondary-position berries is discussed. Nine significant SNP-marker associations were detected for berry weight.
  • Bour, Charlotte (2022)
    Bilberry is a soft fruit, growing wild in the forests of Europe, and especially Nordic and East European countries. Its demand is growing on the market, thanks to its heath beneficial components like anthocyanins, present in both skin and flesh of the berry. It however has a very short shelf-life. The goal of this study was to identify pectinase genes, with a focus on two subfamilies, polygalacturonase (PG) and pectate lyase (PL). The main interest was to study those that are expressed during bilberry’s ripening, to get a better understanding of this process. Bioinformatics were used to identify the annotated genes from the bilberry genome, and point out candidates, from which transcripts are found during ripening, with BLAST searches within a transcriptome of ripening bilberry fruit. The expression of the PL candidates was then studied with qPCR analysis. The study identified 70 PG-coding genes and 25 PL-coding genes, of which 35 and 12, respectively, were found in the ripening berry. The expression of five PL genes was increased during ripening, suggesting a role in the softening of the fruit. Two of those had a notably higher relative increase, making them prime candidates for further study.
  • Ndah, Renata (2022)
    Aluminum (Al3+) toxicity is a major limiting factor in acidic soils when pH<5.5 and faba bean experiences yield decreases in these conditions. The multidrug and toxic compound extrusion (MATE) family plays a vital role in Al3+ tolerance across species. This study searched for an ortholog of MtMATE66, a gene involved in Al3+ resistance in barrel medic, in faba bean and quantified the ortholog’s relative expression in 4 faba bean genotypes (GPID_0022, GPID_0153, GPID_0178 and GPID_0191). pBLAST of MtMATE66 in the faba bean unpublished genome identified the ortholog jg20333.t1, with 88.6 % identity, e-value 0.0 and bit score 880. InterPro Scan and NCBI CDD conserved domain queries classified jg20333.t1 as a MATE in the DinF subfamily. MEME Suite identified the 50-amino acid citrate exuding motif characteristic to MATEs exuding citrate in Al3+ tolerance while a multiple sequence alignment and phylogenetic analysis clustered jg20333.t1 with Al3+ -tolerant citrate exuding MATEs. The SWISS Model 3D structure and DeepTMHMM predicted an α-helical, twelve-transmembrane protein topology. The plasma membrane was predicted as the subcellular localisation of jg20333.t1 by ProtComp, WoLFSPORT and YLoc, however SignalP identified no signal peptides. The molecular weight 54.57kDa, theoretical isoelectric point 8.60 and grand average of hydropathicity 0.67 of jg20333.t1 were calculated by ProtParam. EMBOSS Needle and GSDS aligned 13 exons. Four biological replicates of faba bean plants were set up for 3 different treatments: acidic of pH 3.81 (Ac), acidic of pH 3.81 plus Al3+ (Al) and neutral of pH 6.01 (N) in a greenhouse and root tip samples were collected 45 days after transplanting in peat media for RNA extraction. The relative expression of jg20333.t1 was determined by RT-qPCR of jg20333.t1 as target gene, Vfactin as reference gene and N as internal calibrator. The Cq values generated were analysed using the 2-ΔΔCq method and showed high relative fold change in both Ac and Al. The upregulation in Al confirmed the implication of jg20333.t1 in faba bean tolerance to Al3+. The upregulation in Ac suggests upstream regulation by STOP transcription factor. The four genotypes had no significant difference in fold change. Based on these results, it is concluded that jg20333.t1 is a faba bean MATE gene, VfMATE, implicated in Al3+ tolerance by citrate exudation.
  • Jyakhwa, Sarkal (2022)
    Turnip mosaic virus (TuMV) is an economically important plant RNA virus causing huge damage to wide range of arable and vegetable crops. A study was conducted in Nicotiana benthamiana to know if a TuMV mutant carrying a mutation in a thoroughly conserved WD-domain interacting motif and WG motif in HCPro protein can be mechanically transmitted to a healthy plant or not. HCPRoWD is a mutation in “AELPR” motif where glutamic acid and arginine are replaced by alanine. This mutated virus is here referred as TuMVWD. Similarly, in TuMVAG the tryptophan residue in the WG pair is changed to alanine and this mutated HCPro is called as TuMVAG. Four treatments, TuMVWT (positive control), Mock (negative control), TuMVWD and TuMVAG were made. Three plants per treatment were agroinfiltrated and five plants per treatment were used for mechanical inoculation experiment. Green fluorescent protein (GFP), a quantitative reporter of gene expression, was measured followed by qPCR for quantification of vRNA (viral RNA) accumulation. In agroinfiltrated plants, newly emerged leaves showed strong fluorescence in TuMVWT and TuMVAG by 14 dpi (days post inoculation), but TuMVWD showed poor GFP as compared to TuMVWT. During mechanical inoculation experiment, none of the treatments developed GFP in systemic leaves by six dpi but by 14 dpi GFP accumulation in the upper leaves of TuMVWT and TuMVAG was increased. TuMVWD was not used for 2nd mechanical experiment as it did not cause systemic infection during 1st mechanical inoculation experiment even by 14 dpi. Results from vRNA accumulation showed that mechanical transmission of virus was reduced with TuMVAG and not possible with TuMVWD. However, mutations had negative effect on vRNA accumulation.
  • Lehti, Jasmin (2022)
    Couch grass is one of the most common perennial weeds that cause significant yield losses in temperate regions. In conventional farming, glyphosate has been commonly used to control couch grass. As attitudes and regulations are tightening towards the use of herbicides, it is necessary to find effective alternatives to replace herbicides, especially glyphosate. This master’s thesis aimed to examine the efficacy of different mechanical methods to control couch grass. The second aim was to study how these methods affect the spring cereal yield and its quality. The hypothesis was that with mechanical control methods couch grass can be controlled as effectively as with glyphosate. Data was collected from two field trials located in Inkoo and Ruukki in 2020-2021. The study plan included seven treatments: direct drilling, ploughing (in two treatments), tine cultivation, a combination of tine cultivation and ploughing, Kvickfinn cultivator, and fallowing. The coverage of couch grass was visually estimated before tillage and before harvest. Field trials were photographed with drones before harvest. The density of couch grass was defined from direct drilling plots before sowing. Biomass samples of couch grass and barley were collected from every plot for one square meter in Ruukki at harvest timing. Spring barley was harvested, and grain yield and its quality were analyzed. The coverage of couch grass was lower with Kvickfinn and fallowing than with direct drilling in Inkoo. There was no difference in yield and quality between mechanical control methods and direct drilling. In Ruukki the infestation of couch grass was more abundant and more even than in Inkoo. The coverage and biomass of couch grass were highest in direct drilled plots in Ruukki. The yield and quality of spring barley were the lowest and poorest in direct drilled plots. Couch grass was almost totally controlled with fallowing. It has to be taken into account that the results base on the data of only one growing season. Therefore, the long-term effects or the effects of weather are still uncertain. Based on the data, it is possible to conclude that fallowing is the most effective method to control couch grass. It seems that with mechanical control methods, couch grass can be controlled as effectively as with glyphosate. With mechanical control methods the spring cereal yield and quality were better than with direct drilling. It is important to control couch grass because it limits crop growth and yield formation.
  • Tarpio, Ximenna Alexandra (2021)
    Tiivistelmä - Referat – Abstract Acid sulfate soils are formed from sediment deposits containing sulfides, in which sulfur is present in the form of iron sulfides. In contact with air, the sulfur layer initiates a long-chain of biochemical and chemical reactions that increase the acidity of the soil and the amount of sulfate. Excessive acidity restricts plant development and growth. In acid soil, the aluminum solubility reaches a high level of toxicity for roots and slows down the microbiological degradation of organic matters, resulting in a reduction of nitrogen mineralization. Previous research results have shown that important liming has the potential to raise the pH of sulphate soils, and thereby reduce its acidity. With a high pH, the concentrations of ammonium and nitrate in the soil increase, facilitating nitrogen uptake and thereby also improving the efficiency of nitrogen uptake by plants. It has been speculated that, by increasing the nitrogen uptake efficiency and nitrogen utilization in plants, it will improve nitrogen use efficiency and so will reduce denitrification in sulphate soils and the resulting N2O emissions. However, to date, the studies on the effect of liming on plant nitrogen uptake (UPE) and utilization efficiency (UTE) and, consequently, on plant nitrogen utilization efficiency (NUE) have been minimal. The purpose of this study is to investigate how liming affects the yield formation and nitrogen uptake efficiency for barley (Hordeum vulgare L.) in unfertilized and fertilized acid sulfate soils. The field trial was established in Viikki, Helsinki, in the spring 2018. It followed split-plot design, in which the main plots were combinations of plant and nitrogen fertilization treatments (0 or 100 kg of nitrogen per hectare of fertilized barley (Kaarle) or unfertilized fallow) and lime treatments (0; 7,7; 15,3 t/ha) in four replicates. Liming raised the soil pH as expected and also increased nitrogen mineralization during the growing season, which is reflected in the nitrogen uptake. The effect of liming and fertilization on crop formation was small for barley biomass, yield component and grain yield. On the other hand, the liming effect reduced the nitrogen absorption efficiency and the nitrogen utilization efficiency and thereby the efficiency of nitrogen use. Fertilization also increased nitrogen uptake, but also decreased nitrogen utilization efficiency and nitrogen harvest index. The combined effect of liming and fertilization increased nitrogen mineralization. Liming treatment clearly increased nitrogen mineralization more in unfertilized soils than fertilized (there was no difference between liming levels). The drought in June and the low moisture limited the mobilization of nitrogen released from fertilizer in the soil, which would explain the effect of the nitrogen fertilizer treatment remaining relatively small. The drought also limited the development of the roots and thus the uptake of nitrogen and other nutrients. Lime treatment did not change NUE, UPE and UTE, but increased nitrogen mineralization and nitrogen uptake during the growing season, suggesting that under more favorable conditions the liming treatment could improve the efficiency and therefore improve the profitability and ecology of the barley crop. Further studies are needed as the results of studies performed elsewhere may not be valid under boreal conditions.
  • Nummi, Iida (2022)
    Maissi (Zea mays L.) on yksi maailman yleisimmistä viljelykasveista. Maissia hyödynnetään maailmanlaajuisesti esimerkiksi ihmisravinnoksi, bioenergian tuotannossa sekä nautakarjan karkearehussa. Rehuna käytetään tuleentunut jyväsato tai koko kasvusto tuleentumattoman korjattuna. Tuleentumattomasta maissisadosta saadaan yhdellä korjuukerralla suurempi kuiva-ainesato kuin muista yksivuotisista rehukasveista tai säilörehunurmista. Runsas yhdellä korjuukerralla korjattava sato on lisännyt viljelijöiden kiinnostusta rehumaissinviljelyä kohtaan. Maissi voidaan kylvää muovista tai muusta katekalvomateriaalista valmistetun katteen alle. Katekalvo luo kasvulle kasvihuonemaiset olosuhteet ja nopeuttaa itämistä ja kasvuunlähtöä. Maissinviljelyä on tutkittu Suomen olosuhteissa vain vähän, joten lisää tutkimusta maissin viljelymenetelmistä tarvitaan. Tämän maisteritutkielman tavoitteena oli selvittää, miten katekalvon käyttö vaikuttaa rehumaissisadon määrään ja laatuun. Kenttäkoe tehtiin Helsingissä kasvukaudella 2018. Koe oli osaruutukoe, jossa pääruututekijä oli kolme korjuuajankohtaa ja osaruututekijänä oli katekalvo (katekalvo, ei katekalvoa). Katekalvon käyttö lisäsi tuore- ja kuiva-ainesadon määrää verrattuna katekalvottomaan käsittelyyn. Katekalvon käyttö lisäsi rehumaissista saatua tuoresatoa keskimäärin 5 tn/ha ja kuiva-ainesatoa (KA-sato) 2,2 tn/ha. Laatuominaisuuksista katekalvon käyttö vaikutti ainoastaan tärkkelyspitoisuuteen. Katekalvon käyttö lisäsi tärkkelyspitoisuutta 40 g/kg KA verrattuna katekalvottomaan. Katekalvon käyttö vaikutti odotetusti sadon määrään mutta ei laatuun. Johtopäätöksenä voidaan todeta, että katekalvon käyttö mahdollistaa runsaamman tuore- ja KA-sadon kuin ilman katekalvoa. Tämän tutkimuksen perusteella katekalvoa voidaan käyttää Suomen olosuhteissa kasvattamaan sadon määrää.
  • Yli-Puntari, Sanni (2022)
    The advantages of foliar fertilizers are to provide the necessary plant nutrients to the crop at the optimal time of growth and the miscibility of foliar fertilizers with plant protection products in the same tank mix, thus avoiding additional costs. The aim of this experiment was to determine whether the foliar fertilizers which are most commonly used by sugar beet farmers can be safely mixed with standard Conviso® One herbicide tank mixture without mixing problems or without phytotoxic symptoms on Smart KWS sugar beet (Beta vulgaris subsp. vulgaris Altissima-Group). There was no previous study about the compatibility of foliar fertilizers in the standard Conviso® One tank mix and the result of this experiment were believed to provide significant information for the cultivation of Smart sugar beet. Two subtests were performed; a field trial for phytotoxic symptoms and a miscibility and 24 -hour standing test to determine the effect of hard and soft water on miscibility. The field test was organized at the one trial site of Sugar Beet Research Center in Meltola, Paimio and the mixing and standing trial was performed indoors in the same location. In both experiments, 11 different foliar fertilizers were tested. During the experiment visual mixing and application evaluations of sugar beet were performed. Sugar beet leaf and root samples were collected from the experiment area and one row of sugar beet was harvested for yield and quality analysis. There were two hypotheses; the miscibility of the standard Conviso® One tank mix together with foliar fertilizers doesn`t show any miscibility problems during the mixing or spraying, and the tank mixture doesn`t decrease the yield or quality of Smart sugar beet. The conclusion of this experiment was that the tested foliar fertilizers can be safely mixed into the basic Conviso® One tank mix without any miscibility problems during the mixing, spaying or after 24-hour standstill period. Miscibility problems were not observed with either water type (hard or soft) during mixing or after 24-hour standing time. The tank mixture didn`t have negative effect to Smart sugar beet yield but the treatments showed a difference in the potassium content of the root, which is one of the factors determining the quality of the sugar beet.
  • Manka, Veera (2022)
    Eight active farms participated in the OSMO-project between years 2015 and 2018. Each farm had unique soil health related challenges. The aim of this work was to identify factors related to soil manganese concentration and mobility and develop tools and materials to help farmers better to understand manganese related soil health issues. Manganese cycling and mobility in soils was analysed through soil structure, electric conductivity (EC), SOM, pH and soil iron concentration. Soil manganese concentration was evaluated with three indicators: pH-corrected acid ammonium acetate + EDTA extractable manganese, acid ammonium acetate + EDTA extractable manganese and the amount of manganese available to plants based on the volume of soil available for root growth. Foliar fluorescence measurement to evaluate manganese deficiency in plant tissues is shortly discussed. Soil manganese concentrations and mobility in soil profiles varied because of soil chemical and biological properties but also because of farming practices and changes in physical soil properties. To improve manganese availability in arable farming, soil health analysis through multiple indicators together with consistent soil health improvement and crop rotation is recommended for all active farms. When using fluorescence measurements to evaluate the need for foliar manganese fertilisation, the use of control solution is necessary for reliable results. More research is needed on manganese efficient crops and crop rotation and its effects on manganese cycle and availability in soils. To improve scientific understanding on soil processes, more research is needed about soil redox-reactions, electric conductivity, pH and how the dynamic change in soil Eh-pH environment relates to soil health.
  • Söderholm-Emas, Annika (2022)
    Grain legumes are grown on less than 2% of the arable area of Europe, while large quantities of soybean and soymeal are imported for feed for pigs and poultry. Crop rotations need diversifying by adding grain legumes for soil health and for the break-crop effect, lowering pest, disease and weed pressures in the subsequent crop. The economic effects are of interest from adding legumes to crop rotations and can be evaluated by modelling crop rotations and comparing the means of the gross margins (GM) from the rotations. In Finland, cereal-based crop rotations dominate the important crop growing areas of Southwestern Finland. The most common rotation during a five-year-period can consist of a cereal monoculture with two or more cereal species. The largest potential for diversification in crop rotations can be found on pig, poultry, and cereal farms. Modelling of grain legumes in crop rotations has previously been done for Västra Götaland in Sweden, Brandenburg in Germany, Calabria Italy, eastern Scotland in the United Kingdom, and Sud-Muntenia i Romania. The aim of this work was to create modelled crop rotations for Southwestern Finland to evaluate the gross margin, NO3-N-leaching, and N2O-emissions of the crop rotations. Yields were modelled for a ten-year period following actual yield fluctuations. They were analysed and there were no significant differences in gross margin detected in the crop rotations, whether they were a legume or an all-cereal rotation. Significant differences were found in N2O-emissions between the crop rotations
  • Kulmala, Noora (2022)
    Domesticity and the highest possible degree of domestication of food have attracted more and more people over the last couple of years. The protein solvency ratio is only 15% in Finland. Legumes are an important part of feeding in domestic animal production, but the use as a human food is also increasing. Because of the increasing use of protein, it would be important to take a note of the amount of sulfur in fertilizers. The sulfur affects plant growth directly through photosynthesis and the amount of chlorophyll. Plant growth, in turn, affects crop formation. The purpose of this thesis was to research the effect of sulfur on the yield formation of peas (Pisum sativum L.) and thereby on the yield level using an organic fertilizer or a mineral fertilizer. The study was conducted as field experiment during summer 2020 in Southwest Finland in cooperation with Biolan's contract farms and HKScan. In the field experiment, peas were cultivated, fertilized with either organic Novarbon Arvo 3-1-15-5 granular fertilizer made from chicken manure, or YaraMila Y3 (23-3-8-3) mineral fertilizer prepared by Yara. Novarbo Arvo is designed as a protein crop fertilizer due to the addition of potassium sulphate as well as YaraMila Y3. During the growing season, the SPAD value of the crops was measured and the dry matter (%), moisture content (%), biomass, nitrogen and sulfur content and yield components were determined six times. In addition, the protein content, moisture content (%), dry matter (%) and fresh weight were determined from a sample taken from the seeds in the yield. Protein crops need sulfur for their growth and for the formation of crop components. The results showed that sulfur affects the SPAD value, the sulfur content of the plant, and the nitrogen content in the crops during the growing season. The decrease in the sulfur content in the crop affects the decrease in the SPAD value and the nitrogen content. The SPAD value correlates with photosynthesis and nitrogen content. The organic fertilizer released nutrients more slowly than the mineral fertilizer, which was reflected in more steady growth of organic fertilized crops. In addition, the higher sulfur content of the organic fertilizer increased the SPAD value, sulfur content, and nitrogen content during the growing season. The amount of fertilizer sulfur can affect the sulfur content of pea crops. The higher sulfur content during the growing season resulted in a higher protein content in the seeds. The yield of peas with the organic fertilizer was slightly lower than the mineral fertilizer, but the protein content of the seeds was higher. The organic fertilizer granules proved to be a viable fertilizer alternative alongside the mineral fertilizer.
  • Kaipainen, Ruska (2022)
    Maatalouden vaikutus vesistöjen rehevöitymiseen on ollut pinnalla useita vuosia. Kalkitus on ikivanha metodi, mutta se on pitänyt pintansa maanparannuskeinona erityisesti Suomessa, jossa peltomaat ovat luontaisesti happamia. Kalkituksen päätarkoitus onkin neutraloida peltomaan happamuutta ja näin parantaa ravinteiden saatavuutta sekä vähentää haitallisten aineiden liukoisuutta viljelykasveille, mikä nostaa viljelykasvin satoa. Kuitenkin erityisesti rakennekalkkien on havaittu stabiloivan savimaan rakennetta tehokkaasti, mikä vähentää mahdollisesti pintamaasta eroosion kautta tapahtuvaa fosforikuormitusta vesistöihin. Rakennekalkituksen vaikutuksista viljelykasvien satoihin puuttuu vielä yksityiskohtaista tieteellistä tietoa viljelykasveittain ja maalajeittain erityisesti Suomen olosuhteissa. Esimerkiksi Ruotsissa tehdyissä rakennekalkituskokeissa on saatu ristiriitaisia tuloksia sen vaikutuksista viljelykasveihin eri pelto-olosuhteissa, eri vuosina. Tämän tutkielman tavoitteena oli selvittää eri rakennekalkitustasojen (0, 8 ja 12 Mg ha-1) vaikutusta vehnän Triticum aestivum L. ’Amaretto’ sadonmuodostukseen korkean (pH(H2O)=6,5) ja matalan (pH(H2O=5.2)) lähtö-pH:n omaavilla savipelloilla. Tutkimus toteutettiin peltokokeina kasvukautena 2020 Sokerijuurikkaan Tutkimuskeskuksella, Hevonpäässä, Varsinais-Suomessa. Koeasetelmana oli sovellettu osaruutukoe, jossa pääruudun osatekijä oli pellon pH ja osaruutuina rakennekalkkikäsittely. Rakennekalkkina käytettiin kalsiumoksidia 19,5 %:a sisältävää tuotetta ja se levitettiin syksyllä 2019. Korkean pH:n lohkolle vehnä kylvettiin 1.5.2020 ja matalan pH:n lohkolle se kylvettiin 26.5.2020. Rakennekalkitusta seuraavana vuotena, etenkin alemman pH:n olosuhteissa, rakennekalkitus paransi vehnän satoja vain hyvin suureella 12 Mg ha-1 käsittelyllä. Päinvastoin korkeamman pH:n olosuhteissa rakennekalkitus ei lisännyt vehnän satoa, vaan aiheutti jopa sadon laskua. Jyvien kokonaistypenotto selitti sadon kasvua, sillä se lisääntyi myös erityisesti alhaisen pH:n sekä suurimman kalkkikäsittelyn olosuhteissa. Rakennekalkitus vaikutti myös ravinteiden kuten kaliumin sekä mangaanin pitoisuuksiin lehdissä ja korsissa sekä tähkien magnesiuminpitoisuuteen molemmilla lohkoilla. Toisaalta rakennekalkituksella ei ollut juurikaan vaikutusta satokomponentteihin eikä sadon laatuun. Kesäkuu 2020 oli kuiva ja aikaisemmin kylvetty lohko kärsi todennäköisesti kuivuudesta, mikä vaikutti todennäköisesti satotuloksiin etenkin korkeamman lähtö-pH:n omaavalla lohkolla, joka kylvettiin aikaisemmin. Tulosten perusteella ei voida tehdä vielä laajempia johtopäätöksiä rakennekalkin vaikutuksista vehnän satoon, vaan tarvitaan myös pitkän aikavälin tutkimusta sekä liittyen satoon, että maaperän ominaisuuksiin.