Generation of Emission Factors for Irish Conventional and Conservation Tillage Systems

Agriculture is one of Ireland’s main greenhouse gas emitters, but it is a vital industry for employment, and in this instance, the tillage industry. This spring barley trial was carried out in the 2023/2034 growing season in UCD Lyons Research Farm and was carried out for one year. Greenhouse gas emissions, N2O, CH4 and CO2, were collected for one entire year from spring barley grown under two different cultivation systems, conservation no-till and conventional tillage. Gas fluxes were collected using the static chamber method. Soil properties were determined, such as bulk density, porosity, particle size analysis, as well as properties which varied over time such as soil moisture, water-filled pore space (WFPS) and total oxidised nitrogen (TON) and ammonium (NH4+) concentrations. In addition, grain quality and harvest parameters were measured, such as yields, grain components, nitrogen levels, dry matter, thousand grain weight (TGW) and screenings. Our findings suggest that cultivation practice had no significant difference on greenhouse gas emissions. However, when an emissions factor was established for N2O, both cultivation practices resulted in a negative emission factor, with conventional tillage practices generating lowest emissions. Conservation tillage systems generated significantly lower yields, and nitrogen and protein levels in grain. Nitrogen fertiliser applications also resulted in visible peaks in emissions in the days post-application.