Elevated CO2 cannot compensate for japonica grain yield losses under increasing air temperature because of the decrease in spikelet density

Abstract

Extensive evidence shows that elevated carbon dioxide (CO2) stimulates rice yield, but increasing global surface temperature decreases it. However, few studies have been conducted to evaluate whether elevated CO2 compensates for the rice yield losses induced by increased air temperature under field conditions. Here, we report the effects of four treatments, namely, ambient condition (ACAT), CO2 enrichment (590 ppm, ECAT), canopy air warming (1 °C above the ambient temperature, ACET), and combined CO2 enrichment and warming (ECET) on leaf photosynthesis, nitrogen (N) uptake, spikelet architecture and yield components over two rice growing seasons using a free-air CO2 enrichment facility. We f..