Nearly four in ten dairy farmers did not report their nitrogen fertiliser use in the 2024/25 financial year, despite a legal requirement to do so.
Associate Environment Minister Andrew Hoggard disclosed the 61% compliance rate in written parliamentary answers. The figure marks a drop from 70% in the previous two years and 47% when the rule was introduced in 2021 under the previous Labour government.
Te Uru Kahika, which represents the country's 16 regional councils, said compliance declined as central government raised the possibility of removing reporting requirements. Christina Robb, the organisation's freshwater director, said "less effort by councils and the primary industries went into following up non-reporting". She added that councils "generally viewed the reporting requirements to be complex, particularly as synthetic nitrogen use is only one factor in nitrogen losses from farms".
The nitrogen cap sets a 190kg per hectare limit on synthetic fertiliser use by livestock farmers and requires dairy farmers to file reports. Among dairy farms that did report, barely 1% exceeded the limit, while about 2% of all reporting farms exceeded the cap, with some apparent exceedances turning out to be errors.
Hoggard questioned whether the collected data serves any purpose, telling a select committee: "To be brutally honest, I would be amazed if anything's actually done with these reports, you know? It takes a hell of a lot of time and effort to go through and fill out all this information, and quite frankly, I think it just goes and sits in a storage room somewhere."
The minister said price had been a bigger driver of nitrogen reductions than the cap, noting that "with the price of fertiliser, farmers certainly don't have any incentive to waste it". He added: "I understand that per-hectare nitrogen use is coming down across the industry and especially in key dairy regions, as farmers focus on being more efficient."
The Ministry for the Environment consulted in 2025 on three options for changing the rule, including removing both the 190kg per hectare limit and the reporting requirement. However, Dairy NZ and the Fertiliser Association submitted they wanted the nitrogen regime kept until proposed farm plans can replace it. Fertiliser Association chief executive Vera Power said her organisation wanted system simplification but felt complete repeal would undermine existing work, given that fertiliser companies had made investments in digital apps to support reporting.
The Environment Select Committee is expected to report later this month on bills replacing the Resource Management Act. The committee was granted a four-week extension due to the legislation's complexity and tens of thousands of submissions.