Hybrid rice has a higher yield potential than inbred rice, but the difference in nitrogen (N) use efficiency between hybrid rice and inbred rice remains unclear. The objective of this study was to examine the effects of hybrid rice on yield and N use efficiency through meta-analysis techniques.
The peer-reviewed articles were collected, which included inbred rice as the control in comparison with a hybrid rice treatment. In total, the dataset included 56 studies involving 367 paired observations. Then, the meta-analysis was conducted to identify the response of grain yield and N use efficiency to hybrid rice as affected by hybrid type, N rate, the number of N application, soil total N content, the ratio of soil organic carbon to N, and soil texture.
Overall, the hybrid rice significantly increased rice yield (+11%) and biomass (+14%), but did not affect harvest index compared with inbred rice. Hybrid rice could improve rice yield relative to inbred rice under various N rates. However, the increase in rice yield under hybrid rice reduced with increasing N application rates. Moreover, the hybrid rice significantly increased N uptake, N physiological efficiency, and N recovery efficiency by 8.1%, 2.9%, and 3.6 units, respectively.
Hybrid rice could improve yield and N use efficiency relative to inbred rice, which provided an insight to evaluate the effect of hybrid rice on grain yield and N use efficiency in China.