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

Abstract

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 CO2-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.