Any decision on changes to the current cap on synthetic nitrogen fertilizer should wait until the review scheduled in 2023, a majority on Parliament’s Environment Select Committee says.
The Committee was considering a petition from Steve Abel on behalf of Greenpeace, which called for staged reductions in use on synthetic nitrogen fertilizer leading to a full ban on its sale, production and importation by 2024.
Greenpeace likened the usage of chemical fertilisers to an “addiction”, and argued the climate crisis cannot be solved without addressing it. They said that synthetic nitrogen fertiliser has driven an increase in greenhouse gas emissions, and water pollution arising from intensive farming and the higher stocking rates that synthetic fertilisers enable.
The Ministry for the Environment and Ministry for Primary Industries did not support the move to a ban. MfE said that while nitrogen fertiliser contributes to environmental issues, it did not support a phase-out for three over-arching reasons:
- the uncertainty of environmental benefits
- potentially disruptive impacts for potentially modest environmental benefits
- the need to allow recent policy measures a chance to be implemented.
Livestock farming uses nearly 90 percent of the nation’s synthetic nitrogen fertiliser. Nitrogen to promote growth can also be added to soils by planting clover or other leguminous crops, and rotating pasture and other crops around them, and
spreading nitrogen-rich plant and animal waste in the forms of manure, compost, and effluent.
The two ministries told the committee that synthetic nitrogen fertilisers are generally the option preferred by farmers, as they tend to be viewed as comparatively economic, cost-effective, and reliable, and cheaper than buying supplementary feed.
Data collected by the Fertiliser Association shows that about 452,000 tonnes of synthetic nitrogen fertiliser was purchased in New Zealand in 2019. About 60 percent was manufactured in New Zealand at Kapuni in Taranaki, and the rest was imported, mostly from China.
Similarly, Agriculture Production Surveys and Censuses (APS) data shows year-on-year increases in synthetic nitrogen use over the last decade. In 2009, 218,000 tonnes was used, compared with 343,000 tonnes in 2020—a 57 percent increase in a decade.
However, the increase in synthetic nitrogen fertiliser usage in New Zealand started from a low base—in 1990, New Zealand farmers were late adopters of synthetic fertilisers. The ministries said New Zealand farmers are currently “on par” with other OECD countries in terms of nitrogen usage.
Federated Farmers told the committee that the cost of synthetic nitrogen fertiliser is increasingly high, and this encourages careful use. In 2020, there was an 8 percent decline in use compared to 2019.
The submission from Feds questioned the value in distinguishing between synthetic and organic sources of nitrogen when considering the environmental effects of excessive nitrogen or nitrogen loss. Farm management practices would be a better focus as the solution. More and more farms were using precision farming techniques, where technology and mapping data help guide the application of fertiliser.
The targeting of nitrogen application cannot be done with the same precision using the main alternative methods such as clover. There are limitations to organic alternatives; for example, clover could be attacked by pests.
Over time, technology will continue to improve and precision farming will become more commonplace, Feds said.
In 2021, the Government introduced several regulatory changes under the Essential Freshwater package, aimed at improving the state of New Zealand’s waterways and wetlands. The regulations include a cap on the permitted amount of synthetic nitrogen fertiliser that can be applied on farms over 20 hectares in size. The cap requires that, from 1 July 2021, synthetic nitrogen fertiliser applied to grazed land is limited to 190 kilograms of nitrogen per hectare per year (190 kgN/ha/yr).
Dairy farms – the main users of synthetic nitrogen fertiliser – average about 150 kilograms per hectare per year (150 kgN/ha/yr). They are required to report certain information about their usage of synthetic nitrogen fertiliser to regional councils. The first year of reporting ends on 30 June 2022. If a farm is likely to exceed the permitted amount under the cap, then it must either reduce its usage of synthetic nitrogen fertiliser or apply for a resource consent from the regional council.
The Fertiliser Association said the ban proposed by Greenpeace would be “economically catastrophic”, with a $20 billion drop in gross output, and would not achieve environmental aspirations.
Nitrogen fertiliser is directly responsible for about 5 percent of agricultural greenhouse gas emissions (mainly in the form of nitrous oxide emissions) and under 10 percent of nitrate leaching, but the association acknowledged there is room for improvement. Resources and training for farmers and farm advisors were continually improving, it said.
Research trials demonstrated that whole-farm nitrate leaching is not significantly different between clover-based pastures and pasture receiving synthetic nitrogen of up to 200 kilograms per hectare per year (200 kgN/ha/yr). (This assessment does not include nitrate leaching from the urine of the increased stock numbers which synthetic fertiliser enables.)
The association considered the current nitrogen cap “very precautionary”, and raised concerns about its effectiveness. If there were a compensatory increase in supplementary feed, the total amount of nitrogen in the system may not alter, so there might be no change in nitrate leaching.
While the majority on the Select Committee said the scheduled 2023 review of the cap on nitrogen fertiliser could address the issues raised by Greenpeace, Green Party MPs on the Committee disagreed.
Its section of the Committee’s report to the House said MPI and MfE should, in preparation for the 2023 review, be directed to look into potential measures such as:
- a four month “close down” period in autumn and winter when the application of synthetic nitrogen fertiliser is prohibited to reduce leaching risk to waterways after rain
- shifting the current 190 kg/ha/year cap on synthetic nitrogen fertiliser use to a sinking cap directed at phase out
- requiring regional councils to identify Nitrate Vulnerability Zones in regional plans with stricter controls on land uses which cause nitrate leaching, such as the application of synthetic and other nitrogenous fertilisers and high animal stocking rates
- economic instruments such as a levy on the amount of nitrogen in synthetic fertiliser collected at the point of sale with the revenue generated being used to promote sustainable land and water management.