FARM MANAGEMENT PRACTICE IMPACT ON N2O EMISSION

Agricultural activities account for about a third of greenhouse gas (GHG) emissions. Most of the GHG in the atmosphere are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). The aim of this study is to measure N2O isotopes in two differently managed agricultural soils. One soil is with organic farming and the other with conventional. Samples were collected in 32 experimental plots as well as a control plot. The samples are thus weighed in 3 l buckets, each 1.8 kg in total. Two samples were made from each plot so that they could have a different moisture regime. Moistening is designed for wet aerobic and wet anaerobic soil conditions. Information on changes in soil weight after soil wetting was also collected. Measurements for N2O isotopes were performed using a Picarro G5131-i instrument under laboratory conditions. The obtained data were collected and analysed. It was concluded that not all differences and interrelationships of the N2O isotope data obtained can be directly attributed to soil management. Differences between the effects of the microorganism population and the physical properties of the soil cannot be ruled out. The maximum value of ?15NSP value is 18.58 and the minimum value is -53.41. On the other hand, the maximum value of ?15Nbulk values is 26.76, and the minimum value is -56.97. In the conclusions, we get that both nitrification and denitrification dominate among cultures.