Rice (Oryza sativa L.) growth and nitrogen distribution under elevated CO2 concentration and air temperature

Abstract A field experiment was conducted to investigate the effects of elevated atmospheric CO 2 concentration and temperature, singly and in combination, on grain yield and the distribution of nitrogen (N) in different rice organs. The rice ‘Wuyunjing 23’ was planted under four treatments: ambient CO 2 and temperature (ACT), elevated CO 2 (200 μmol mol −1 higher than ambient CO 2 ) (EC), elevated temperature (1 °C above the ambient temperature) (ET), and the combination of elevated CO 2 and temperature (ECT) under T‐FACE (temperature and CO 2 free air controlled enrichment) system. CO 2 ‐induced increment and temperature‐induced reduction in grain yield was 6.0 and 25.2% in 2013, and that was 9.8 and 10.8% in 2014, respectively. Dry matter (DM) production in different organs increased under EC at vegetative stage but decreased under ET at reproductive stage. The negative effects of temperature on grain yield and DM was weakened when combined with CO 2 enrichment. And the trends of decrease for yield and DM under ET and ECT in 2013 were more obvious than those in 2014 due to the annual temperature differences. Furthermore, ET led to greater distribution of N in root and stem but not for panicle than that under ACT. These mainly demonstrated that the rice production would be suffered varying degree of loss under global warming in future although the CO 2 enrichment could alleviate the effects of high temperature on rice growth.