Objective  Effects of N applications on the yield and quality of currently popular varieties of long grain indica rice cultivated in Hubei were studied.

  Method   In Jianghan Plain of Hubei province, the high-quality, high-tolerance, long-grain indica rice, Huanghuazan, was compared on yield and quality under the N application rates of 120 kg·hm⁻² (N1), 150 kg·hm⁻² (N2), 180 kg·hm⁻² (N3), and 240 kg·hm⁻² (N4) with Lixiang 85, Nongxiang 32, Yuzhenxiang, and Taiyouexiangsimiao.

  Result  The grain yields of the varieties of rice increased with increasing N application to peak at an average of 8.3 t·hm⁻² under N2 representing a 3.8% over N1, 7.8% over N3, or 18.6% over N4. The aboveground dry matters of the rice accumulated from heading to maturity stage was enhanced by the increased N. The weights of leaves, stems, and ears reached the highest levels under N4, N3, and N2, respectively. N2 also produced the optimal proportions of stems, leaves, and ears of 29.8%, 17.7%, and 52.5%, respectively, at maturity. The increased N promoted the yield on polished grains which reached the significantly highest level among all treatments at 52.6% under N2. The treatments induced little change in the visual appearance of the grains. However, a significant alternation occurred to the straight-chain starch as the RVA of the polished rice grain exhibited a great degradation, low reduction, and highly desirable taste under N2.

  Conclusion  At the N application rate of 150 kg·hm⁻² (N2), a yield of 6.5–9.5 t·hm⁻² on the rice could be expected. Of the 4 varieties, Taiyouexiangsimiao displayed a high yield and properties appropriate for processing and was considered most suitable for industrial applications, while Lixiang 85, with its appealing eating quality, best fitting for home consumption.