Aarhus University corrects error in nitrogen regulation calculations

Aarhus University has found errors in calculations used to set when land should be left fallow under Denmark’s new nitrogen rules, DR reports.

The university said the calculations were prepared to determine the timing of fallowing. It is reviewing the scale of the error and will correct it.

The error affects places where large amounts of livestock manure are used, according to the university. It said it had found the same problem identified last week by the Seges Innovation think tank, which said errors in emission limits could mean some farmers were allowed to emit too little next year.

Seges Innovation identified the problem in calculations of nitrogen leaching from spring barley grown with a catch crop. Aarhus University reviewed the figures at the request of the Danish Agency for Green Land Transition and Aquatic Environment.

Jørgen Eriksen, a professor and section head at the university’s Department of Agroecology, apologised to the agency and affected stakeholders, saying the university alone was responsible for ensuring the figures were correct.

The new nitrogen regulation was agreed as part of the green tripartite agreement. Previously, rules primarily focused on the amount of fertiliser used. The new system instead sets a limit on how much nitrogen can be released.