8 resultados para viljojen siementuotanto


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Maisterin tutkielman tavoitteena oli kartoittaa kevätviljojen siemenviljelyn edellytyksiä Kmaatalouden sopimusviljelytiloilla. Erityisesti oltiin kiinnostuneita kansallisen siementuotantotuen poistumisen vaikutuksesta viljeltävien lajikkeiden lukumäärään ja viljelyaloihin. Tutkielman teoriaosassa tarkasteltiin viljojen siemenviljelyä, sen erityispiirteitä Suomessa ja siihen liittyvää lainsäädäntöä, asetuksia ja maatalouspolitiikkaa. Siemenviljelyä tarkasteltiin paitsi huoltovarmuuden näkökulmasta myös viljelyn taloudellisuuden näkökulmasta. Lisäksi esitettiin sertifioidun ja tilan oman siemenen käyttöön ja laajuuteen vaikuttavia tekijöitä ja siemenen sertifiointiprosessi. Tutkimuksen aineisto perustui maaliskuussa 2010 tehtyyn lomakekyselyyn, joka lähetettiin 119 K-maatalouden sopimussiemenviljelijälle. Kyselyyn vastasi 71 viljelijää, jolloin vastausprosentiksi muodostui 60. Tutkimusmenetelminä aineiston analysoinnissa käytettiin frekvenssijakaumia, keskiarvotestejä ja Kruskall-Wallisin testiä. Tutkimustulosten mukaan kansallisen siementuotannon tuen poistuminen vuoden 2011 alussa ei näyttänyt vaikuttavan siemenviljelyn jatkuvuuteen tai jatkohalukkuuteen. Siementuotannon tukea pidettiin varsin alhaisena, joten sen vaikutus viljelyyn osoittautui vähäiseksi. Huomattavasti enemmän siemenviljelyyn näytti vaikuttavan yleinen maatalouden ja etenkin viljanviljelyn alhainen kannattavuus. Siemenviljelijät katsoivat, etteivät esimerkiksi siementuotannon tuki tai tuen poistuminen korvaa riittävästi tuotannosta aiheutunutta lisätyötä. Toisaalta harva siemenviljelijä aikoi lopettaa tuotannon, vaikka pitivät viljanviljelyä huonosti kannattavana. Tällaiseen näkemykseen saattoi olla syynä se, että viljelijöillä oli siemententuotantoon soveltuva kalusto, ammattitaito ja rutiini tuotantoon. Tutkimukseen osallistuneet viljelijät katsoivat lisäksi, että oma maatila soveltui erittäin hyvin siemententuotantoon. Suurimpana uhkana siementuotannolle kyselyyn vastanneet viljelijät pitivät hukkakauraa omilla tai naapureidensa pelloilla.

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Colorectal cancer is among the major cancers and one of the leading causes of cancer-related deaths in Western societies. Its occurrence is strongly affected by environmental factors such as diet. Thus, for preventative strategies it is vitally important to understand the mechanisms that stimulate adenoma growth and development towards accelerated malignancy or, in contrast, attenuate them to remain in quiescence for periods as long as decades. The main objective of this study was to investigate whether diet is able to modulate β-catenin signalling related to the promotion or prevention of intestinal tumourigenesis in an animal model of colon cancer, the Min/+ mouse. A series of dietary experiments with Min/+ mice were performed where fructo-oligosaccharide inulin was used for tumour promotion and four berries, bilberry (Vaccinium myrtillus), lingonberry (Vaccinium vitis-idaea), cloudberry (Rubus chamaemorus) and white currant (Ribes x pallidum), were used for tumour prevention. The adenomas (Apc-/-) and surrounding normal-appearing mucosa (Apc+/-) were investigated separately due to their mutational and functional differences. Tumour promotive and preventive diets had opposite effects on β-catenin signalling in the adenomas that was related to the different adenoma growth effects of dietary inulin and berries. The levels of nuclear β-catenin and cyclin D1 combined with size of the adenomas in the treatment groups suggests that diets induced differences in the cancerous process. Adenomas progressing to malignant carcinomas are most likely found in the sub-groups having the highest levels of β-catenin. On the other hand, adenomas staying quiescent for a long period of time are most probably found in the cloudberry or white currant diet groups. The levels of membranous E-cadherin and β-catenin increased as the adenomas in the inulin diet group grew, which could be a result of the overall increase in the protein levels of the cell. Therefore, the increasing levels of membranous β-catenin in Min/+ mice adenomas would be undesirable, due to the simultaneous increase in oncogenic nuclear β-catenin. We propose that the decreased amount of membranous β-catenin in benign adenomas of berry groups also means a decrease in the nuclear pool of β-catenin. Tumour promotion, but not the tumour prevention, influenced β-catenin signalling already in the normal appearing mucosa. Inulin-induced tumour promotion was related to β-catenin signalling in Min/+ mice, and in WT mice changes were also visible. The preventative effects of berries in the initiation phase were not mediated by β-catenin signalling. Our results suggest that, in addition to the number, size, and growth rate of adenomatous polyps, the signalling pattern of the adenomas should be considered when evaluating preventative dietary strategies.

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Microbes have a decisive role in the barley-malt-beer chain. A major goal of this thesis was to study the relationships between microbial communities and germinating grains during malting. Furthermore, the study provided a basis for tailoring of malt properties with natural, malt-derived microbes. The malting ecosystem is a dynamic process, exhibiting continous change. The first hours of steeping and kilning were the most important steps in the process with regard to microbiological quality. The microbial communities consisting of various types of bacteria, yeasts and filamentous fungi formed complex biofilms in barley tissues and were well-protected. Inhibition of one microbial population within the complex ecosystem led to an increase of non-suppressed populations, which must be taken into account because a shift in microbial community dynamics may be undesirable. Both bacterial and fungal communities should be monitored simultaneously. Using different molecular approaches we showed that the diversity of microbes in the malting ecosystem was greater than expected. Even some new microbial groups were found in the malting ecosystem. Suppression of Gram-negative bacteria during steeping was advanategous for grain germination and malt brewhouse performance. Fungal communities including both filamentous fungi and yeasts significantly contributed to the production of microbial beta-glucanases and xylanases, and were also involved in proteolysis. Well-characterized lactic acid bacteria (Lactobacillus plantarum VTT E-78076 and Pediococcus pentosaceus VTT E-90390) proved to be an effective way of balancing the microbial communities in malting. Furthermore, they had positive effects on malt characteristics and notably improved wort separation. Previously the significance of yeasts in the malting ecosystem has been largely underestimated. This study showed that yeast community was an important part of the industrial malting ecosystem. Yeasts produced extracellular hydrolytic enzymes with a potentially positive contribution to malt processability. Furthermore, several yeasts showed strong antagonistic activity against field and storage moulds. Addition of a selected yeast culture (Pichia anomala VTT C-04565) into steeping restricted Fusarium growth and hydrophobin production and thus prevented beer gushing. Addition of P. anomala C565 into steeping water tended to retard wort filtration, but the filtration was improved when the yeast culture was combined with L. plantarum E76. The combination of different microbial cultures offers a possibility to use ther different properties, thus making the system more robust. Improved understanding of complex microbial communities and their role in malting enables a more controlled process management and the production of high quality malt with tailored properties

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Volatilization of ammonia (NH3) from animal manure is a major pathway for nitrogen (N) losses that cause eutrophication, acidification, and other environmental hazards. In this study, the effect of alternative techniques of manure treatment (aeration, separation, addition of peat) and application (broadcast spreading, band spreading, injection, incorporation by harrowing) on ammonia emissions in the field and on nitrogen uptake by ley or cereals was studied. The effect of a mixture of slurry and peat on soil properties was also investigated. The aim of this study was to find ways to improve the utilization of manure nitrogen and reduce its release to the environment. Injection into the soil or incorporation by harrowing clearly reduced ammonia volatilization from slurry more than did the surface application onto a smaller area by band spreading or reduction of the dry matter of slurry by aeration or separation. Surface application showed low ammonia volatilization, when pig slurry was applied to tilled bare clay soil or to spring wheat stands in early growth stages. Apparently, the properties of both slurry and soil enabled the rapid infiltration and absorption of slurry and its ammoniacal nitrogen by the soil. On ley, however, surface-applied cattle slurry lost about half of its ammoniacal nitrogen. The volatilization of ammonia from surface-applied peat manure was slow, but proceeded over a long period of time. After rain or irrigation, the peat manure layer on the soil surface retarded evaporation. Incorporation was less important for the fertilizer effect of peat manure than for pig slurry, but both manures were more effective when incorporated. Peat manure applications increase soil organic matter content and aggregate stability. Stubble mulch tillage hastens the effect in surface soil compared with ploughing. The apparent recovery of ammoniacal manure nitrogen in crop yield was higher with injection and incorporation than with surface applications. This was the case for leys as well as for spring cereals, even though ammonia losses from manures applied to cereals were relatively low with surface applications as well. The ammoniacal nitrogen of surface-applied slurry was obviously adsorbed by the very surface soil and remained mostly unavailable to plant roots in the dry soil. Supplementing manures with inorganic fertilizer nitrogen, which adds plant-available nitrogen to the soil at the start of growth, increased the overall recovery of applied nitrogen in crop yields.

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In agricultural systems which rely on organic sources of nitrogen (N), of which the primary source is biological N fixation (BNF), it is extremely important to use N as efficiently as possible with minimal losses to the environment. The amount of N through BNF should be maximised and the availability of the residual N after legumes should be synchronised to the subsequent plant needs in the crop rotation. Six field experiments in three locations in Finland were conducted in 1994-2006 to determine the productivity and amount of BNF in red clover-grass leys of different ages. The residual effects of the leys for subsequent cereals as well as the N leaching risk were studied by field measurements and by simulation using the CoupModel. N use efficiency (NUE) and N balances were also calculated. The yields of red clover-grass leys were highest in the two-year-old leys (6 700 kg ha-1) under study, but the differences between 2- and 3-year old leys were not high in most cases. BNF (90 kg ha-1 in harvested biomass) correlated strongly with red clover dry matter yield, as the proportion of red clover N derived from the atmosphere (> 85%) was high in our conditions of organically farmed field with low soil mineral N. A red clover content of over 40% in dry matter is targeted to avoid negative N-balances and to gain N for the subsequent crop. Surprisingly, the leys had no significant effect on the yields and N uptake of the two subsequent cereals (winter rye or spring wheat, followed by spring oats). On the other hand, yield and C:N of leys, as well as BNF-N and total-N incorporated into the soil influenced on subsequent cereal yields. NUE of cereals from incorporated ley crop residues was rather high, varying from 30% to 80% (mean 48%). The mineral N content of soil in the profile of 0-90 cm was low, mainly 15-30 kg ha-1. Simulation of N dynamics by CoupModel functioned satisfactorily and is considered a useful tool to estimate N flows in cropping systems relying on organic N sources. Understanding the long-term influence of cultivation history and soil properties on N dynamics remains to be a challenge to further research.

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The first synthesis of long chain 5-n-alkylresorcinols (C15-C25) in whole grains and whole grain products by a novel modification of Wittig reaction is described. 5-n-Alkylresorcinols are phenolic lipids that have various effects on biological systems, such as antioxidant activity and interaction with biological membranes. These compounds are considered as biomarkers of whole grain intake, which is connected with reduced risk of cardiovascular diseases and certain cancers. Novel hapten derivatives of 5-n-alkylresorcinols, potential compounds for immunoanalytical techniques, are prepared by the same procedure utilizing microwave catalysed aqueous Wittig reaction as the key step. The synthesised analogues are required by various analytical, metabolism and bioactivity investigations. Four alternative strategies for producing deuterium polylabelled 5-n-alkylresorcinols are explored. Ring-labelled D3-alkylresorcinols were synthesized by acidic H/D exchange. Side chain -labelled D4-derivative was prepared by a total synthesis approach utilizing D2 deuterogenation of a D2-alkene derivative, and deuterogenation of alkynes was investigated in another total synthesis approach. An -D3-labelled alkylresorcinol is isotopically pure and completely stable under all relevant conditions encountered during analytical work. The labelling of another phenolic component of whole grains was explored. The preparation of D3-ferulic acid and related compounds by way of selective methylation of the precursors is described. The deuterated compounds are useful as standards in the quantification of these natural products in various substances, such as food and human fluids. The pure 5-n-alkylresorcinol analogues prepared were used in in vitro experiments on alkylresorcinol antioxidant activity and antigenotoxicity. The in vitro experiments show that alkylresorcinols act as antioxidants, especially when incorporated into biological systems, but possess lower activity in chemical tests (FRAP and DPPH assay). Whole grain alkylresorcinols are shown for the first time to have a protective effect against copper induced oxidation of LDL, and H2O2 or genotoxic faecal water induced damage on HT29 cells.

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The biodiversity of farmland ecosystems has decreased remarkably during the latter half of the 20th century, and this development is due to intensive farming with its various environmental effects. In the countries of the EU the Common Agricultural Policy (CAP) is the main determinant affecting farmland biodiversity, since the agricultural policy defines guidelines of agricultural practices. In addition to policies promoting intensive farming, CAP also includes national agri-environment schemes (AES), in which a part of subsidies paid to farmers is directed to acts that are presumed to promote environmental protection and biodiversity. In order to shape AES into relevant and powerful tools for biodiversity protection, detailed studies on the effects of agriculture on species and species assemblages are needed. In my thesis I investigated the importance of habitat heterogeneity and effects of different habitat and landscape characteristics on farmland bird abundance and diversity in typical cereal cultivation-dominated southern Finnish agricultural environments. The extensive data used were collected by territory mapping. My two main study species were the drastically declined ortolan bunting (Emberiza hortulana) and the phenomenally increased tree sparrow (Passer montanus); in addition I studied assemblages of 20 species breeding in open arable and edge/bush habitats. In light of my results I discuss whether the Finnish AES take into account the habitat needs of farmland birds, and I provide suggestions for improvement of the future AES. My results show that heterogeneity of both uncultivated and cultivated habitats increases abundance and species richness among farmland birds, but in this respect the amount and diversity of uncultivated habitats are essential. Ditches in particular are a keystone structure for farmland birds in boreal landscapes. Ditches lined by trees or bushes increased ortolan bunting abundance. Loss of that kind of ditches (and clearance of forest and bush patches), reduced breeding ortolan buntings, mainly by decreasing availability of song-posts that are important for the breeding groups of the species. Heterogeneity of uncultivated habitats, most importantly open ditches and the habitat patch richness, increased densities and species richnesses of species assemblages of open arable and edge/bush habitats. Human impact (winter-feeding, nest-boxes) affected favourably the tree sparrow s rapid range expansion in southern Finland, but any habitat types had no significant effects. At the moment the Finnish agri-environmental policy does not conserve farmland ditches as a habitat type. Instead, sub-surface drainage is financially promoted. This is a fatal mistake as far as farmland biodiversity is concerned. In addition to the maintenance of ditches, at least the following aspects should be included more than is done previously in the measures of the future AES: 1) promotion of diverse crop rotation (especially by promoting animal husbandry), 2) maintenance of tree and bush vegetation in islets and along ditches, 3) promotion of organic farming.

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Viljakylvösiemensektorin toimintaympäristön muutoksiin on hyvä valmistautua ennalta ja pohtia toimintatapoja, joiden turvin toimia muuttuvassa toimintaympäristössä. Suomen kylvösiemenmarkkinat ovat pienentyneet voimakkaasti 1980-luvun lopulta lähtien. 2000-luvulla sertifioidun siemenen käyttöaste on ollut keskimäärin vain 30 % ja viljojen kohdalla käyttöaste on ollut tätäkin alhaisempi. Tulevaisuudessa yhteisen maatalouspolitiikan uudistukset, kiristyvä kilpailu, ilmastonmuutos, teknologian kehitys, kulutustottumusten muutokset sekä lähivuosina uudistava EU:n siemenlainsäädäntö tulevat muokkaamaan alan toimintaympäristöä. Jotta tulevaisuuden haasteisiin voidaan vastata, kartoitettiin tutkimuksessa asiantuntijoiden näkemyksiä siitä, mitkä ovat tuotantoketjun ongelmakohdat sekä alan toiminnan edistämismahdollisuudet. Työn teoreettisena viitekehyksenä oli toimialan taloustiede. Teorian rakennetta käytettiin siemenalan ongelmakohtien jäsentämiseen ja toimenpide-ehdotusten kartoittamiseen. Asiantuntijat näkivät sertifioidun siemenen heikkoon kysyntään vaikuttavan korvaavien tuotteiden, eli tilan oman kylvösiemen ja sertifioimattomana markkinoidun kylvösiemenen ns. harmaan siemenen, yleisyys. Tilan oman siemenen kohdalla suurin epäkohta on sen arvottamisessa. Harmaan siemenen käytön suosioon vaikuttavat sen edullisuuden lisäksi myös kaupan asiakaslähtöisyys. Sertifioidun siemenen kysyntää heikentävät myös puutteelliset markkinointitavat, kausivaihtelu sekä siemenmyyjien tietämättömyys viljelijöiden ostokäyttäytymisestä. Tarjonnan epäkohdiksi nousivat siemenestä saatava hinta, tuotantotekijäsidonnaisuus sekä hukkakauran leviäminen. Siemenestä saatu hinta ei aina riitä kattamaan paljon tuotantotekijöitä vaativan siementuotannon kustannuksia. Myös hukkakauran leviäminen vaikeuttaa ja rajoittaa tuotannon lisäämistä. Lisäksi siemenketjun kannalta ongelmia aiheuttivat teknologian ja tuotantoprosessien myönteinen mutta hidas kehitys. Markkinan rakenteen ongelmakohtina olivat markkinoiden oligopolisuisuus sekä tuotteiden tehoton erilaistaminen asiakkaiden tarpeiden mukaisesti. Alan yritysrakenteen todettiin olevan pienyritysvaltainen ja osin tehoton, vaikka rakennekehitystä onkin viime vuosina tapahtunut. Alalle tulon esteet liittyvät siemenviljelijöiden ja -pakkaajien kohdalla läheisesti tuotantotekijäsidonnaisuuteen sekä hukkakauran leviämiseen ja hukkakauralainsäädäntöön. Vastaavasti Suomen syrjäinen sijainti ja ilmasto- olosuhteet ovat pitäneet ulkomaisen kilpailun vähäisenä. Toimialan kustannusten todettiin jakaantuneen epätasaisesti siemenketjun toimijoiden välillä. Kustannusrakenteen todettiin olevan nykyisellään kestämätön ja tilanteen todettiin korjaantuvan ainoastaan tuntuvalla volyymin kasvulla. Lisäksi toimijoiden välinen vertikaalinen integraatio nähtiin vähäiseksi, vaikka sillä olisi merkittävä vaikutus tuotannon kannattavuuteen. Asiantuntijat näkivät maatalouspolitiikan sekä markkinoiden ja talouden muutosten etenevän eri suuntiin. Suurimpina epäkohtina nousivat siementuotannon tuen loppuminen sekä lainsäädännön asettamat rajoitukset. Lisäksi isona ongelmana pidettiin ulkoisen tiedottamisen tehottomuutta. Tutkimuksen perusteella viljakylvösiemensektorin toimintaedellytykset liittyvät pääasiallisesti markkinointiosaamisen ja informoinnin kehittämiseen sekä verkostoitumisen lisäämiseen. Tärkeänä osana toimintaedellytysten turvaamisessa on myös vaikuttaminen tulevaan EU:n siemenlainsäädäntöön siten, että kansalliset poikkeukset olisivat mahdollisia myös tulevaisuudessa.