Greenhouse gas emissions

Gases produced by human activity are affecting the global climate. Agriculture plays a role in this. But with the rising global human population, how can farmers increase food production to meet demands while simultaneously cutting back on greenhouse gas emissions?

Efficient and responsible use of fertiliser and related products can help ensure food security and economic wellbeing while contributing to reducing New Zealand's overall greenhouse gas emissions.

New Zealand's emissions profile

As part of ratifying the Paris agreement on climate change, New Zealand has set a target of reducing our emissions by 50% below gross 2005 levels by 2030.

New Zealand's emissions profile is unique amongst OECD countries. In 2022, 82% of New Zealand's electricity was produced from renewable sources, while just 9% of New Zealand's greenhouse gas emissions were from fossil fuels used for manufacturing processes. In contrast, primary industry generates almost half of New Zealand's total greenhouse gas emissions. It also generates more than half of New Zealand's export income.

There is no silver bullet for reducing agricultural emissions, which presents some real challenges for meeting New Zealand's emissions reduction target while maintaining a strong, vibrant economy.

Where does fertiliser fit in?

The contribution of fertiliser to greenhouse gases comes mainly from nitrogen. Applying nitrogen fertiliser to land results in nitrous oxide emissions, because of the natural biological soil processes.

In New Zealand in 2021, 6% of agricultural emissions were from nitrogen fertilisers.

Greenhouse gas emissions from the manufacture of urea fertiliser in New Zealand is accounted for under existing Emissions Trading Scheme commitments.

Solutions

We need new technologies that increase productivity while using less fertiliser, to reduce greenhouse gas emissions from fertiliser. Precision agriculture technologies have an important role to play. There are also products that help reduce nitrous oxide emissions from soil. These products affect the transformation pathways for nitrogen in the soil by reducing the release of ammonia gas or by reducing the conversion of ammonia to nitrate.

Urease inhibitors are increasingly used in New Zealand to reduce the volatilisation of nitrogen. In 2023, 60% of urea fertiliser sold was coated in urease inhibitors. These had a minor overall impact on greenhouse gas emissions. However, they have an important role to play in enabling farmers to use less nitrogen fertiliser, typically less than 10%. Nitrification inhibitors have wider applications than just fertiliser emissions. They have the potential to significantly reduce nitrous oxide emissions from livestock urine patches. These are not currently used in New Zealand but could be an important part of future analysis

Research

The fertiliser industry invests in research aimed at efficient and responsible use of nutrients, including reducing greenhouse gas emissions. Learn more here.