Climate change increases toxic cadmium loads more than nutritional metals in spinach
In addition to food quantity, food quality is paramount for meeting the demands of a growing global population. Food quality encompasses both nutritional and contaminant contents, yet their transfer within soil-crop systems remains poorly understood under impending climate change. This greenhouse study is the first to demonstrate that future climatic conditions increase the transfer of metals from oxic soils to crops, showcased for four soil-spinach variety combinations (Spinacia oleracea). Future conditions raised harmful metal cadmium levels in edible spinach tissues by 26-54 %. In contrast, changes in micronutrient (Zn, Mn, Mg) contents were inconsistent and dependent on the specific soil-spinach combination. Climate-induced shifts in soil carbon composition and bacterial communities were linked to greater soil Cd phytoavailability, enhancing Cd transfer from soil to roots. These findings suggest that while spinach's nutritional values may remain stable, future conditions could lead to higher metal contaminants levels in edible tissues.