Effects of different irrigation treatments on yield formation and nitrogen uptake in water-saving and drought-resistance rice

To elucidate the characteristics of yield formation and nitrogen uptake of water-saving and drought-resistance rice (WDR) under different irrigation conditions, five irrigation treatments were set up: 100% (0.63 L/kg), 80% (0.51 L/kg), 60% (0.38 L/kg), 40% (0.26 L/kg) and 20% (0.14 L/kg). Single factor analysis of variance was employed to investigate the impacts of different irrigation treatments on the yield components, the root wounding sap rate and the dry weight at maturity, and nitrogen accumulation of four test varieties, including HY73, WDR129, HY518 and YJ4038. The results demonstrated a reduction in yield, yield components, root wounding sap rate, and dry weight of the four test varieties with the reduction of irrigation. The decreases in the traditional rice varieties HY518 and YJ4038 were more severe than those of the WDR varieties HY73 and WDR129; the impacts of low irrigation treatments on the WDR varieties HY73 and WDR129 were slight, and the amount of nitrogen accumulated significantly higher than that of the traditional rice varieties HY518 and YJ4038. The research showed that the WDR varieties HY73 and WDR129 exhibited enhanced nitrogen accumulation and yield under low irrigation conditions, as a consequence of maintaining a higher rate of root wounding sap.