Impacts of climate change on land suitability of key crops in New Zealand.

Climate change threatens global agriculture, food security and nutrition. Understanding its regional impacts is necessary to help agricultural sectors adapt and increase their resilience in these changing climate conditions. In New Zealand (NZ), studies on the impacts of climate change on agriculture have been conducted on a limited number of crops, using different methods and without assessing uncertainties. This study aims to bridge these gaps by applying a consistent method of Land Suitability Analysis (LSA) to four key crops for NZ agriculture – apple, cherry, maize and wheat – and assessing suitability robustness. The results show that historical suitability patterns are consistent with current production areas. An increase in suitability is projected for all the crops in almost all of the South Island of NZ, whereas in the North Island, some of the crops are less suitable, highlighting both constraints and opportunities for future NZ agriculture. The robustness of results varies depending on the climate scenario and period considered. In addition, an increase in net irrigation requirements is also projected for the crops, requiring critical management of future water supplies. The limits of the study include the climate data resolution and the omission of the water availability seasonality and other biotic factors, such as diseases. The framework and methodology developed and applied in this study to New Zealand can readily be adapted for use in other regions.