Browsing by Subject "sadon määrä"

Maize (Zea mays L.) is cultivated in large scale for various purposes worldwide and maize is also commonly used as roughage for cattle. Due to climate warming and lengthening of the growing season, the cultivation of forage maize has been predicted to increase also in Finland. Maize provides a significantly higher dry matter yield in one harvest in comparison with other annual crops or silage grass. The aim of this master's thesis was to investigate the effect of the nitrogen (N) fertilization rate on the quantity and quality of the forage maize yield. The field trial was conducted in Helsinki during the growing seasons of 2019 and 2020. There were three rates of N fertilization in the experiment (100, 150 and 200 kg N/ha). Increasing the amount of N fertilization increased the crude protein (CP) content of forage maize, but the amount of N fertilization had no effect on the other analyzed quality factors or the yield rate. Nitrogen fertilization and year neither had an interaction on the quantity or quality of the forage maize yield. The fresh yield rate was higher in 2020 than in 2019. The starch and CP contents of the 2019 harvest were higher, and the ash and indigestible neutral detergent fiber (iNDF) contents were lower than in the 2020 harvest. On the other hand, there was no difference in the neutral detergent fiber (NDF) content between the years 2019 and 2020. The higher starch and CP contents and lower ash and iNDF contents of the 2019 forage maize yield compared to the 2020 yield is explained by the higher ear percentage of the 2019 yield (58% vs. 51%). In 2019, the proportion of ears of the dry matter yield was higher. The N fertilization rates for maize permitted by the Nitrates Directive (at most 110–150 N kg/ha) and Yara's recommendation of 140 N kg/ha are sufficient to produce a high forage maize yield under the prevailing growing conditions in Finland. The increase in the rate of N fertilization from the current recommendations cannot be justified by increasing the CP content of forage maize either, because it is not economically viable with N fertilization. The results indicate that it is possible to produce forage maize yield that is good in quality and especially in quantity in southern Finland. Maize silage can be used to replace grass silage in cattle feeding without reducing production, and with improved utilization of nitrogen for production.