Browsing by Author "Mäki-Asiala, Hanna"

It is necessary actively seek effective ways to reduce agricultural emissions so that the proportion of agricultural greenhouse gas emissions in total national emissions does not increase. The aim of this study was to evaluate with carbon footprint calculators different options for reducing greenhouse gas emissions of dairy production and the carbon footprint of energy-corrected milk. The scenarios included the changes in the dietary concentrate proportion, the proportion of grass in cultivation, the digestibility of roughage and the level of milk production. In addition, the effect of temperature on methane emissions from manure was examined. Data of a dairy farm located in Central Ostrobothnia from year 2020 were utilized in the study. The assessment was carried out by using the carbon footprint calculator developed by the European Commission and the Valio Carbo® environmental calculator. According to the results of both calculators, the effect of the changes in the concentrate proportion in the diet on the carbon footprint of milk was very small. Reducing the proportion of concentrate in the diet reduced total emissions. Reducing the proportion of rapeseed meal in feeding reduced total emissions more than reducing the proportion of barley. Increasing the proportion of grass in cultivation reduced the carbon footprint of milk and the total amount of greenhouse gas emissions with both calculators. According to the European Commission carbon calculator, increasing grass yield and also increasing the proportion of grain in cultivation reduced the carbon footprint of milk and the total amount of greenhouse gas emissions. With Valio Carbo® environmental calculator, increasing the proportion of grain in cultivation increased the carbon footprint of milk and the total emissions. According to European Commission calculator, the total emissions and the carbon footprint of milk decreased when the digestibility of roughage decreased. The increase of milk production level also clearly reduced the carbon footprint of milk with both calculators. However, the change in the milk production level had only a small effect on the amount of emissions produced. Reducing the conversion factor describing the effect of temperature on methane formation from slurry reduced the carbon footprint of milk. The decrease in the conversion factor reduced the emissions from the manure system by 51.3 percentage and reduced the milk carbon footprint from 1.21 to 1.15 kg CO2e/kg ECM. In conclusion, there are many feasible opportunities to reduce the carbon footprint. The most effective ways to reduce total emissions at farm level are to increase the proportion of grass in cultivation and to increase the yield of grass. Raising the milk production level effectively reduces the carbon footprint, but in the future the calculations must take into account that the dry matter intake is higher as the milk yield increases. The main differences between the calculators are currently in the coefficients they use. When comparing the results given by the calculators, it is important to note that the calculation principles cannot fully take into account the possible opposite effects of different factors. The results should be looked critically with a caution that the results given by different calculators are not directly comparable.