Nitrogen use efficiency of milk production – A comparative study of the Republic of Ireland and the Netherlands

Policymakers are increasingly interested in the sustainability of milk production due to the intensive nature of the production system and the associated risk to the environment. This study uses national extensions of the EU Farm Accountancy Data Network to derive nationally representative farm gate level nitrogen use efficiency indicators for specialist dairy farms in the Republic of Ireland and the Netherlands between 2006 and 2014. The Republic of Ireland and the Netherlands are of particular interest as dairy production is an important sector in both countries and milk production has grown in these two Member States following the removal of the EU milk quota regime in 2015. Results indicate relatively similar N balances per hectare across both countries with the Netherlands returning significantly higher N use efficiency and lower N surplus per kg of milk solids produced. Results generally show improvements in nutrient use over the study period across both countries, due to efficiency gains, but highlight differences between a grazed grass system and a more concentrate feed high input orientated system and illustrate the need for the development of a life-cycle analysis approach to fully capture the full scale environmental efficiency of differing systems of milk production