Nitrogen-use efficiency of organic and conventional arable and dairy farming systems in Germany

Abstract Optimising nitrogen (N) management improves soil fertility and reduces negative environmental impacts. Mineral N fertilizers are of key importance in intensive conventional farming (CF). In contrast, organic (OF) is highly dependent on closed nutrient cycles, biological fixation crop rotations. However, both systems need to minimise balances maximise nitrogen-use efficiency (NUE). NUE production was evaluated three regions Germany by analysing input, output balance 30 pairs one OF CF farm each from the network pilot farms for period 2009–2011; indicators were calculated using system REPRO. had higher input all pairs. 90% comparisons, than OF, 7% it same 3% lower. 60% 37% lower only 3%. The 91% (arable farms: 83%; mixed/dairy 95%) 79% 77%; dairy 80%). OF. yearly average four times (59 kg ha ?1 a ) (15 ). results show huge individual variability within CF. Organic lowest highest NUE. A further expansion area can help reduce high increase production.