Exploring the role of high-value crops to reduce agricultural greenhouse gas emissions in New Zealand

This study explores the potential benefits of transitioning from livestock farming to high-value alternative crops as a strategy for mitigating agricultural greenhouse gas (GHG) emissions in New Zealand. The government has set ambitious targets for reducing methane (CH₄) emissions. However, since animal product exports play a crucial role in New Zealand's economy, any shift in land use will have significant impacts on both the regional and national economy.

We developed a GIS framework that integrated (i) growing requirements, (ii) GHG emissions and (iii) profitability for crops. Analysis of export market opportunities identified twelve high-value "alternative crops". Availability of suitable land for crop expansion was not a limiting factor.

Working with the Ministry for Primary Industries, we explored how land use change scenarios contributed to Government 2050 biogenic CH₄ emission reduction targets. Doubling the area of alternative crops (a 195,000-ha increase) by reallocating land from livestock farming resulted in reducing biogenic CH₄ emissions by 1.2 to 5.4% (0.35 to 1.57 Mt CO_2-e) compared to 2017 baseline values, contributing to between 2.6 and 22.5% of the 2050 CH₄ reduction targets, simultaneously increasing profitability by $NZ1.25 to 1.32 billion annually.

While this approach demonstrates potential benefits of land use change, a deeper understanding of the complexity of land use decision-making is required to enable successful transitions. Addressing barriers to change requires collaborative efforts from land users, researchers and policy makers.