Aarhus University admits error in figures for new farm rules

Aarhus University has admitted errors in calculations underpinning Denmark’s new nitrogen rules for agriculture, calling into question figures that could make the rules too strict for some farmers. DR reported that the university apologised for the mistake.

DR climate analyst Filip Knaack Kirkegaard called the episode “enormously remarkable” and a “huge blunder” by both the authorities and Aarhus University. He said the error did not mean that all of the agricultural sector’s claims about the rules were correct.

The university had initially rejected concerns raised by agricultural think tank Seges Innovation, which said some farmers’ nitrogen discharge limits for next year were too low. After checking the figures again, the university found it had underestimated nitrogen leaching in places where large amounts of livestock manure are used. As a result, some farmers faced stricter limits than the level set by politicians.

The new rules, agreed as part of the Green Tripartite, take effect on 1 January 2027. They replace a system based mainly on how much fertiliser was used with limits on how much nitrogen farmers may discharge.

Seges Innovation said it was positive that the university had acknowledged the error. Its director, Lisbeth Henricksen, said the calculations now needed to be corrected so farmers could make decisions using the most accurate professional basis. The organisation had earlier warned that the errors would make it significantly harder for farmers and advisers to plan field work for 2027.

Farmer and milk producer Peter Mortensen, who farms near Horsens, said he still did not know which crops he would be allowed to grow next year or how much fertiliser he could use. He said farmers needed reliable figures and more time, and that it was not realistic to start under the new rules on 1 January if the figures were incorrect.

Jørgen E. Olesen, a professor and head of the Aarhus University department responsible for the calculations, said a series of changes and revisions made between May and August had distracted the team from the error. He said the university was not aware of further problems in the data it had supplied after correcting the figures.