Browsing by Author "Mäkilä, Riikka"

The aim of this thesis was to study differences between the yields and stability of grass mixtures and pure stands. In addition, the quality of forage was examined. Timothy cultivars which had different growth rhythms were selected for field experiments. The aim was also to examine how species proportions differ in mixtures between years and harvests and what causes observed variation. Moreover, the effect of the effective temperature sum on the quantity and quality of yield was evaluated. A three year field study was carried out in Jokioisinen and Sotkamo. Plots had either pure timothy stands (Phleum pratense L. cultivars Tuure, Rhonia ja Bor 0301) or mixtures that contained 75% timothy and 25% meadow fescue (Festuca pratensis Huds. cultivars Ilmari ja Klaara). Dry yield (kg ka/ha), D-value, iNDF, NDF, protein and lignin content were determined from each harvest. In addition, botanical composition was analysed in Sotkamo. Grass mixtures had higher dry yields and they were more stable than pure stands. The difference in yileds was more significant in Sotkamo than in Jokioinen. Timothy-meadow fescue growths' NDF and iNDF were closer to desired values than pure stands', but with other quality features weren't discovered advantages. In Sotkamo timothy cultivar's and type's (southern or north) dry yield, D-value, NDF, protein content and botanical composition reacted differently with the effective temperature sum. In Jokioinen the yield and quality of varieties reacted similarly with the effectice temperature sum. All timothy cultivars benefited occasionally from adding a meadow fescue to the mixture but not consistently. Year and harvest affected to the species proportions in the mixtures. Also the effective temperature sum had a correlation with yield and quality. According to the results cultivating grass mixtures instead of pure stands is a good way to achieve bigger dry yields that have high quality.