Besides the rapid population growth over the past few decades, water scarcity and soil degradation have intensified the challenges faced by the Iranian agriculture sector to ensure food security over the long term. Despite its paramount importance, the extent to which the land and water resources of Iran can meet the nation’s future food demand is not well understood. Herein, we systematically evaluated the capacity of Iran’s land for sustainable agriculture based on the soil properties, topography, and climate conditions relevant to crop production. Our objectives were to: i) quantify and map the suitability of Iran’s land resources for cropping ii) examine if further increase in production can be achieved through agriculture expansion or the redistribution of cropping areas.
Iran's land suitability for agriculture was classified as: very good 0.6, good 3.6, medium 12.8, poor 18.5, very poor 10.2, and unsuitable 97.4 million ha. Among the considered soil and terrain attributes, low soil organic carbon, steep slope, and high soil sodium content were identified as the most frequent factors limiting the suitability of lands for cropping. Our analysis also revealed that 30%, 5%, and 17% of the current agricultural lands (cultivated and uncultivated) are located in poor, very poor, and unsuitable areas, respectively. Cultivation in very poor or unsuitable lands can be partially avoided as there exist unused lands with at least a medium level of suitability for substitution that can improve the overall sustainability of the agriculture sector in Iran.