Energieeinsatz und Energieeffizienz von Winterweizen bei unterschiedlicher mineralischer Stickstoffdüngung im Marchfeld

The grain and straw yield, the energy input (fuel, fertilizer, pesticides, machinery) and energy efficiency parameters (energy output, net-energy output, energy intensity, energy use efficiency) as affected by the amount of mineral nitrogen fertilizer (0 kg, 60 kg, 120 kg und 180 kg N ha⁻¹) and mineral fertilizer strategies (different mineral N-fertilizer, splitting) were analyzed on two sites in the Marchfeld plain (Engelhartstetten und Groß-Enzersdorf) in two two-year experiments. The question should be answered which mineral nitrogen fertilizations (N form, N amount and N splitting) has the highest energy efficiency. With increasing N-fertilizer amount (60 kg, 120 kg und 180 kg N ha⁻¹), the share of fertilizer energy to total energy increased: 24%, 38% and 48%. Due to the law of decreasing yield increments, the energy efficiency for the nitrogen amount of 180 kg ha⁻¹ was statistically significant lower than for 60 kg ha⁻¹ and 120 kg ha⁻¹ in Engelhartstetten. Splitting the amount of N fertilizer into three doses increased fuel consumption by 4 % compared to a single application of the total amount of fertilizer. The energy efficiency parameters were hardly influenced by splitting. N-fertilization with calcium ammonium nitrate was more energy efficient than with urea (pure, stabilized, soil incorporated). The energy efficiency analyses can contribute to the assessment of environmental effects of management practices.