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

Conceptual Design of a Comprehensive Farm Nitrogen Management System

“…(a) Systematization of digital models and components relevant for an FNMS due to the following aspects: Results from several years of application and testing of FNMS components, for example, in pilot farms [31,42].…”

Reducing Carbon Footprint of Agriculture—Can Organic Farming Help to Mitigate Climate Change?

“…Taking a holistic view and identifying the critical places in the N cycle of the farm, leads to an improvement in the efficiency of the N use and the reduction of N losses in agricultural production [60]. In the literature, it is noted that organic farming leads to closing the nutrient cycle on the farm and minimizing nutrient losses [57,61].…”

Combination of Inorganic Nitrogen and Organic Soil Amendment Improves Nitrogen Use Efficiency While Reducing Nitrogen Runoff

“…The recovery of fertiliser N as determined from the NUE of major agricultural systems in Australia ranges from 28% in sugarcane to 45-62% for irrigated cotton and 78% for dairy [30], compared with an estimated global NUE of 33% [32]. Clearly, the inclusion of organic materials as an N source can be highly beneficial for increasing NUE in pasture and cropping systems, and represents a key strategy to better manage N in the environment with the intensification of agriculture [31,32,50,51]. Importantly, the inclusion of organic materials capable of supplying plant nutrients may represent one step in the development of cropping systems on marginal soils such as sands.…”