Browsing by Subject "nurmi"

Eloperäisestä materiaalista pyrolyysillä valmistetun biohiilen on esitetty tuovan helpotusta moniin ajankohtaisiin maataloutta koskettaviin ongelmiin. Biohiilen maanparannuskäytöllä saattaa olla mahdollista esimerkiksi parantaa maan viljavuutta, lisätä viljelykasvien satoja ja hillitä ilmastonmuutosta. Tämän tutkimuksen tavoitteena oli tutkia kuusihakkeesta valmistetun biohiilen vaikutuksia nurmiin neljäntenä vuonna biohiilen maaperään levittämisen jälkeen. Biohiilen vaikutukset Suomen tärkeimmän viljelykasvin tuotantoon on aihe, jota ei ole tiettävästi koskaan aikaisemmin tutkittu kenttäkokeessa boreaalisissa olosuhteissa. Etelä-Suomeen perustetussa kenttäkokeessa havainnoitiin eri biohiilitasojen (0–30 t/ha) vaikutuksia maaperän kosteuspitoisuuteen, puna-apila-timoteinurmen lehtialaindeksiin, lehtivihreäpitoisuuteen, sadon määrään ja kasvustossa vallitseviin kasvilajisuhteisiin. Biohiilen ja erilaisten lannoitusmenetelmien yhdysvaikutusten selvittämiseksi kokeessa oli mukana epäorgaanisella ja orgaanisella lannoitteella käsiteltyjä sekä täysin lannoittamattomia koejäseniä. Biohiili ei vaikuttanut tilastollisesti merkitsevästi maaperän kosteuspitoisuuteen tai yhteenkään kokeessa havainnoiduista nurmikasvuston ominaisuuksista. Myöskään merkittävää yhdysvaikutusta biohiilen ja erilaisten lannoitusmenetelmien välillä ei tässä tutkimuksessa havaittu. Tulosten taustalla ovat todennäköisesti sekä kokeessa käytetyn biohiilen että koekentän maaperän ominaisuudet. Havupuupohjainen biohiili sisälsi melko niukasti ravinteita ja esimerkiksi hiilipitoisuuden ja happamuuden osalta maaperän viljavuusominaisuudet olivat kohtuullisen hyvät jo ennen biohiilen levitystä. Osa biohiilestä on myös saattanut poistua pintamaasta ajan kuluessa, mikä voi osaltaan laimentaa sen vaikutuksia. Tulokset osoittavat toisaalta sen, ettei biohiilen levittämisellä pH:ltaan neutraaliin ja runsaasti orgaanista ainesta sisältävään boreaaliseen maaperään ole todennäköisesti haitallisia seurauksia neljän ensimmäisen levityksestä kuluneen vuoden aikana. Biohiili voisi siten tarjota turvallisen keinon sitoa hiiltä pitkäaikaisesti maaperään Suomen olosuhteissa. Kasvukunnoltaan heikommassa maaperässä ja muita valmistusmateriaaleja hyödyntämällä myös biohiilen myönteiset vaikutukset maan viljavuuteen ja kasvien kasvuun saattaisivat tulla selkeämmin esille. Pitkäaikaisten vaikutusten ja sopivien käyttökohteiden kartoittamiseksi tutkimuksia aiheen parissa on siten tärkeää jatkaa edelleen.

This thesis was undertaken to determine effects of genotype, vernalization and harvesting on the root growth of grass plants. Greenhouse experiments were carried out at Viikki experimental farm of University of Helsinki. The thesis was a part of a larger research of grasses. Grass species were two timothy (Phleum pratense L.) parental lines, northern (021/1) and southern (B112) genotype (Boreal Plant Breeding Ltd). The trial material was propagated using the plant material conserve of Viikki. A half of the trial material got a vernalization treatment (10 weeks) after pre-breeding (2 weeks, DL 12 h) and the other half of plants got only pre-breeding (3 weeks, DL 12h) before establishment of two separate trials in rhitsotubes and rhitsotrones. High, growth stage, dry matter of shoots and roots, depth of the root system and shoot to root ratios were measured from rhitsotubes seven times during the study. The growth samples from rhitzotrones were collected twice. The harvesting was done in the middle of the study from both separate trials. Genotype had an influence on all measured growth features in both separate trials. Treatments of southern genotypes were mainly higher, development was faster and dry matter of shoots was greater at harvest time compared to the same treatments of the northern genotype. There were no differences on growth features between genotypes in the end. The dry matter of roots was also greater at the harvest time with treatments of the southern genotype. In the end of the trial there were no differences between genotypes or treatments, but the genotype influenced on root growth in repeated measurements between weeks 6-8. The root system of the southern genotype spread out in deeper soil layers with both treatments and survived better after harvesting compared to treatments of the northern genotype. The vernalization had influence on growth features and the root system with most of the occasions of measurements with both the genotypes. The vernalization reduced biomass of roots in the both separate trials. This was partly due to low weight of shoots especially in the beginning of the study. In the other hand the vernalization improved on development before the harvesting and the carbohydrates allocated on shoots instead of roots. This was visible especially in the rhitsotubes. Differences between vernalized and non-vernalized treatments were levelled towards the end of the study. The vernalization increased growth of roots to deeper soil layers comparing to the non-vernalized treatment with the northern genotype. In weekly monitoring the growth of roots of both the vernalized genotypes were strong before ending the study. This might cite better overwintering but in the other hand shoot to root ratios were almost the same in all treatments. This study showed out that a plant tries to keep the growth of shoots and roots in balance but also that the biomass allocates in shoots in the beginning of the growing season and more in roots after harvesting. According to this study adding the southern genetic heritage to the timothy refinement programs brings higher yield level and moreover more abundant and deeper root system.

Leys productivity decreases over time in Finland. After three years the yield is usually low. Most of the finnish leys are renovated less than five years old. Leys suffer from winter, foraging and grazing and they become thinner. Grass height and density correlate relatively well to the yield. Leys which are thinned out can be fixed with overseeding. The object of this study was to find out how grass overseeding affects to the growth and assess how profitable it is with grass roller. One year field experiment was made. It’s goal was to test the features of the Kivi-Pekka grass roller. Effects to the growth were also studied but the significance was considered low because of the one year test. Overseeding field experiment was made in 3, 5 and 8 years old leys. Yield was cut two times. The profitability of the grass roller was estimated with calculations. Yields can be maintained with overseeding and new plants can be added to the growth. Overseeding succeed better with clover than grasses referring to the literature. The density of old growth and moisture are main features which affect to succes in overseeding. Seeds need warmth, space for growing, moisture and good soil contact to germinate properly. There were only minor differences between the overseeding techniques and results. Surface seeding without harrowing or rolling wasn’t very effective. There were no significant differences between the yields of different treatments in field experiment. Newly sown seeds probably lost in growth competition. Yield value, renovating costs and seed cost had major effect to the profitability of overseeding. According to the calculations grass rollers profitability increased when overseeded area increased and the age of leys become longer.

In Finland 90% of all farmers and 95% of cultivated land are committed to the environmental support program of agriculture. One of the goals of this program is to reduce phosphorus (P) runoff from fields to the water system by limiting the amount of P used in cultivation process. Experiments on P rates allowed in environmental support program and practices of P fertilization were conducted at two sites on ley during 2003-2011. The research aimed to define the effects of annual fertilization, incorporated fertilization and the use of liquid manures on ley yield and P status of the soil. Earlier studies have shown that more water soluble P runs off from leys than from cereal fields and that reserved P hasn’t been sufficient for the whole ley rotation. The experiment consisted of seven different fertilization treatments in which phosphorus treatments were done as incorporate fertilization or annual fertilization. Low or high-release mineral fertilizer was used for incorporate fertilization and either mineral fertilizer or at first mineral fertilizer and liquid manures in next rotation for annual fertilization on the surface. P given as liquid manure was used by three members of the experiment group. The experiment included cultivating ley for seven years and cereal forage for two years. The control group used no P fertilization. P given in fertilization treatments had no effect on ley yields compared with control treatment. Negative P balance in all treatments caused the P rate in ploughed layer of the soil to decrease, however the P levels of surface layer fluctuated greatly regardless of the way P treatments were done. The study indicated that using liquid manures for fertilizing ley cultivations does not pose any greater threat to the environment than mineral fertilizers. However, balanced fertilization, sufficient nitrogen and reducing nitrogen loss of liquid manures are required in order to achieve high yields. The results also indicate that it should be made possible to raise the amount of P fertilization of highly productive leys closer to the zero level of the nutrient balance so that productivity of the soil measured by acid ammonium acetate (PAC) would be preserved. Depending on the other qualities of the soil, this can be done when PAC has reached the value nearby 10 mg l-1. More information on controlling P of the surface soil by means of cultivation management is needed.