Impacts of CO₂ elevation on the physiology and seed quality of soybean

Understanding the responses of crops to elevated atmospheric carbon dioxide concentrations (E[CO₂]) is very important in terms of global food supplies. The present study investigates the effects of CO₂ enrichment (to 800 μmol mol^-1) on the physiology of soybean plants and the nutritional value of their seeds under growth chamber conditions. The photosynthesis of soybean was significantly promoted by E[CO₂] at all growth stages, but leaf area and specific leaf weight were not affected. The levels of mineral elements in the leaves decreased under E[CO₂]. The soil properties after soybean cultivation under E[CO₂] were not affected, except for a decrease in available potassium. Moreover, the levels of soluble sugars in the seeds were not affected by E[CO₂], but the levels of natural antioxidants decreased. In addition, the level of oleic acid decreased under E[CO₂]. However, levels of fatty acid peroxidation and saturation were maintained. In conclusion, E[CO₂] appears to have positive effects on the growth of cultivated soybean plants, but its influence on the nutritional values of soybean seeds is complex.