Policies for agricultural nitrogen management—trends, challenges and prospects for improved efficiency in Denmark

Abstract

With more than 60% of the land farmed, with vulnerable freshwater and marine environments, and with one of the most intensive, export-oriented livestock sectors in the world, the nitrogen (N) pollution pressure from Danish agriculture is severe. Consequently, a series of policy action plans have been implemented since the mid 1980s with significant effects on the surplus, efficiency and environmental loadings of N. This paper reviews the policies and actions taken and their ability to mitigate effects of reactive N (N r ) while maintaining agricultural production. In summary, the average N-surplus has been reduced from approximately 170 kg N ha −1 yr −1 to below 100 kg N ha −1 yr −1 during the past 30 yrs, while the overall N-efficiency for the agricultural sector (crop + livestock farming) has increased from around 20-30% to 40-45%, the N-leaching from the field root zone has been halved, and N losses to the aquatic and atmospheric environment have been significantly reduced. This has been achieved through a combination of approaches and measures (ranging from command and control legislation, over market-based regulation and governmental expenditure to information and voluntary action), with specific measures addressing the whole N cascade, in order to improve the quality of ground-and surface waters, and to reduce the deposition to terrestrial natural ecosystems. However, there is still a major challenge in complying with the EU Water Framework and Habitats Directives, calling for Environmental Research Letters Environ.

Nitrogen fertiliser replacement values for organic amendments appear to increase with N application rates

“…NFRV coefficients play a key role in fertiliser recommendation systems and tools (e.g. MANNER-NPK, Nicholson et al 2013) and values of 0.45, 0.75 and 0.60-0.80 kg/kg for pig slurry (Dalgaard et al 2014;RVO 2014;UK 2015).…”

Advances in NANI and NAPI accounting for the Baltic drainage basin: spatial and temporal trends and relationships to watershed TN and TP fluxes

“…NANI and NAPI declined in the watersheds of both the Kattegat and Danish straits, as did corresponding fluxes of TN and TP. Danish policy to reduce N surpluses on farms and the associated reductions in N loads to aquatic environments in these regions is well documented (Dalgaard et al 2014). Some increase in NANI and NAPI occurred in the Gulf of Riga, driven by increases in fertilizer in the region (from 728 to 1181 kg km watershed area year -1 for P), but with little change evident in watershed fluxes.…”

Nitrogen footprints: Regional realities and options to reduce nitrogen loss to the environment

“…In Denmark a series of N policy action plans have been implemented since the mid-1980s with significant effects on the N surplus, the NUE, and the environmental loadings of N (Dalgaard et al 2014). Dalgaard et al (2014) describe how significant impacts have been achieved through a combination of N policies and N measures (ranging from command and control legislation, over market-based regulation and governmental expenditure to information and voluntary actions), with specific measures addressing the whole N cascade.…”

“…Dalgaard et al (2014) describe how significant impacts have been achieved through a combination of N policies and N measures (ranging from command and control legislation, over market-based regulation and governmental expenditure to information and voluntary actions), with specific measures addressing the whole N cascade. However, to comply with the ecological conditions required in the EU Water Framework Directive further N reductions are required.…”