Effect of elevated [CO₂] on yield, intra‐plant nutrient dynamics, and grain quality of rice cultivars in eastern India

Abstract

Abstract BACKGROUND Climate models predict an increase in global temperature in response to a doubling of atmospheric [CO 2 ]. This may affect future rice production and quality. In this study, the effect of elevated [CO 2 ] on yield, nutrient acquisition and utilization, and grain quality of rice genotypes was investigated in the subtropical climate of eastern India (Kharagpur). Three environments (open field, ambient, and elevated [CO 2 ]) were tested using four rice cultivars of eastern India. RESULTS Under elevated [CO 2 ] (25% higher), the yield of high‐yielding cultivars (HYCs) viz IR 36, Swarna, and Swarna sub1 was significantly reduced (by 11–13%), whereas the yield increased (by 6–9%) for Badshabhog, a low‐yielding aromatic cultivar. Elevated [CO 2 ] significantly enhanced K uptake (by 14–21%), but did not influence the uptake of total N and P. The nutrient harvest index and use efficiency values in HYCs were reduced under elevated [CO 2 ] indicating that nutrient translocation from source to sink (grain) was significantly reduced. An increase in alkali spreading value (10%) and reduction in grain protein (2–3%) and iron (5–6%) was also observed upon [CO 2 ] elevation. CONCLUSION The study highlights the importance of nutrient management (increasing N rate for HYCs) and selective breeding of tolerant cultivars in minimizing the adverse effects of elevated [CO 2 ] on rice yield and quality. © 2018 Society of Chemical Industry