In order to investigate the possibility of reducing GHG in winter wheat production, field trial was set up in a 3-year experiment (VS) with four different tillage systems (TS) and three N fertilization norms (FN). The tillage systems were CT-conventional tillage, DT-disk harrowing, LT-soil loosening, and NT-no tillage system. N fertilization norms were set to 120, 150 and 180 kg ha-1. Fuel consumption was measured with three-channel valve, and total value of consumption was calculated on total machinery passes according to technological map. Calculation of greenhouse gas (GHG) emissions from winter wheat production were done by BioGrace model (version 4d 2015). GHG emission per ton of yearly raw material was calculated from fertilizers (production and field emissions), seed, plant protection and diesel usage, so the result was expressed in kg CO2eq ha-1 per year. The main properties of research (TS, FN and VS) are showing statistical significance on total GHG emission from winter wheat production. The largest GHG emission had LT tillage system with 261.89 kg CO2eq ha-1 from fuel emission and 2919.22 kg CO2eq ha-1 in total. This tillage system also had highest yield of 7.78 t ha-1. The lowest yield was observed at NT system (6.92 t ha-1), also with the lowest GHG emission from fuel consumption and total production (fuel 118.30 and total 2685.94 kg CO2eq ha-1). Reduced tillage system such as DT can significantly reduce GHG emissions from diesel consumption without having an impact on wheat yield. This study suggests that DT, primarily, and NT can be recommended as convenient agricultural practices conducive to reconstruct an optimal balance between GHG emissions, yields, and N excesses.
Keywords: BioGrace model; Fuel consumption; Greenhouse gas emission (GHG); N fertilization norm; Tillage system; Winter wheat.