Effect of Elevated CO₂ on Nutritional Quality of Legume Crops: A Meta-Analysis

Abstract

Rising atmospheric CO₂ levels affect crop nutritional quality. A meta-analysis of 45 peer-reviewed studies was conducted to quantify the impact of elevated CO₂ (>550 ppm) on protein, iron, and zinc content in legumes (soybean, lentil, cowpea, and chickpea). Random-effects models were used to estimate effect sizes.
Results showed a consistent decline in protein (−6.3%) and micronutrients (iron −9.2%, zinc −6.8%). The magnitude varied by species and cultivar. These findings raise concerns over nutrient security under climate change and stress the need for breeding nutrient-resilient legume varieties.