From niche to scale: enabling factors for saline agriculture in the North Sea and Mediterranean regions

BACKGROUND
Salinisation is one of the most pressing environmental challenges affecting agricultural land and food production worldwide. Although the challenge is substantial, saline agriculture represents a promising approach that integrates soil, water and crop management practices tailored to salt-affected lands, enabling both adaptation to and mitigation of saline conditions. Despite this, saline agriculture remains largely a niche innovation, applied under heterogeneous local conditions. This underscores the need to better understand the factors and barriers shaping the upscaling of saline agriculture.

RESULTS
We identify key factors enabling the upscaling of saline agriculture focusing on four salt-tolerant crops, quinoa, potato, tomato and New Zealand spinach, selected for their relevance to food security and sustainability in the North Sea and Mediterranean regions. Using a scaling framework, we design a survey integrating quantitative and qualitative survey data from experts across the four crop contexts. We find that, for potato, personal motivations and natural resource interaction are key enabling factors. In the case of New Zealand spinach, stakeholder communication plays a central role. Upscaling quinoa depends strongly on agricultural markets and access to knowledge, whereas tomato upscaling is primarily driven by farmer education. Household incomes and cultural factors consistently received lower importance across all crops. Recurring barriers for scaling include knowledge gaps, limited access to resources, and policy shortcomings.

CONCLUSION
Despite differences among crops and countries, access to knowledge, stakeholder collaboration and active support services emerge as the most important factors enabling scaling of saline agriculture, whereas key barriers include economic constraints and a lack of policy support.