Water-saving cultivation plus super rice hybrid genotype improves water productivity and yield

Labor shortage, low water availability, and poor land use practice cause serious threats to rice (Oryza sativa L.) production around the world. Semiarid cultivation is a classical strategy for achieving high water productivity (WP) with lower labor inputs. However, it remains largely unknown whether the application of "super" or drought-resistant hybrid rice could achieve higher economic benefits (WP and yield) under semiarid cultivation. This study attempted to combine three irrigation management systems (semiarid rice cultivation, traditional flood irrigation, and dryland cultivation) with two cultivars (Yangliangyou 6, YLY6, a super hybrid rice genotype; Hanyou 113, HY113, a drought-resistant rice genotype), and evaluate their effects on the water-saving ability and yield (the economic benefits). The two genotypes showed no significant differences in grain yield under the semiarid and flood irrigation, and both had a greater WP (13.8-51.8%) under semiarid cultivation than under flood irrigation. YLY6 produced more panicles (P < .05), more spikelets per panicle (P < .05), and higher grain yield (P < .01) than HY113. Semiarid cultivation plus YLY6 showed higher stomatal conductance and net photosynthetic rate (P < .05), resulting in higher biomass accumulation, grain yield, and WP compared with those under other treatments. YLY6 under semiarid cultivation had greater stem water content and leaf water potential, and thus showed improvement of leaf gas exchange characteristics. In conclusion, super hybrid rice has the potential to achieve greater WP and higher grain yield under semiarid irrigation, and this combination may be introduced for sustainable rice production.