Ambient ozone pollution degrades rice grain nutritional quality and straw feed value under field conditions in Bangladesh

Ambient tropospheric ozone is a pervasive air pollutant and an emerging threat to crop quality, food security, and agroecosystem sustainability. While ozone-induced yield losses are well documented, its impacts on crop nutritional quality and livestock feed value under field conditions remain poorly quantified. We investigated the effects of chronic ambient ozone exposure on nutrient uptake, grain micronutrient composition, and straw feed quality in six genotypes grown under field conditions in Bangladesh, one of the world's most ozone-exposed rice-growing regions. Ethylenediurea was applied to provide a diagnostic contrast for ozone-related responses under ambient field conditions across three consecutive growing seasons. Ambient ozone was associated with reduced plant carbon and nitrogen uptake and lower crop nitrogen-use efficiency in ozone-sensitive genotypes. Grain nutrient…