Comparison of Agronomic Performance between Japonica/Indica Hybrid and Japonica Cultivars of Rice Based on Different Nitrogen Rates

Abstract

Previous studies have revealed that the japonica/indica hybrid rice has a higher yield potential, biomass production, and nitrogen (N) accumulation than japonica rice in China, however, at a single N application rate. It remains unclear whether it also occurs at a higher or lower N application rate under the same field condition. To investigate the effects of nitrogen application rates on grain yield, N uptake, dry matter accumulation, and agronomic N use efficiency, field experiments were conducted in Jinhua City, Zhejiang Province during three consecutive growth seasons in 2016, 2017, and 2018. Two japonica/indica hybrid varieties (Yongyou 12 and Yongyou 538) and two japonica varieties (Xiushui 134 and Jia 58) were exposed to five N application rates (0, 150, 225, 300, and 375 kg ha−1). The results showed that grain yields of all the varieties increased with increasing nitrogen application rates, except for Jia 58 whose optimum nitrogen level was 225 kg ha−1, because no significant difference was observed between N225 and N300. Across the four rice varieties, N uptake increased significantly with increased N-fertilizer rates at all the growth stages (p < 0.05). Across the three planting years, the average grain yield of japonica/indica hybrid rice was higher than that of japonica rice by 75.6% at N0, 57.2% at N150, 41.1% at N225, 38.3% at N300, and 45.8% at N375. We also found that as compared with japonica rice, the japonica/indica hybrid rice had more grain yield, higher dry matter, and higher N uptake at all growth stages, regardless of the N application rate.

Evaluation of Growth, Yield, and Water Productivity of Paddy Rice with Water-Saving Irrigation and Optimization of Nitrogen Fertilization

“…This results is not in agreement with [78], who found a significant increase in yield at 120 kg N ha −1 , and there was a decrease in yield due to an increase in nitrogen at 180 kg N ha −1 . Similar results have also been observed in previous studies [79][80][81], revealing that an excessive N application rate has no contribution to the achievement of high grain yield in rice.…”

Evaluation of Water Productivity and Agronomic Performance of Paddy Rice Through Water Saving Irrigation and Nitrogen Fertilization

“…Yield increased with increase in nitrogen level but any further increase in fertilizer amount to 150 kg N ha -1 showed no significant effects on yield, thus the yield followed this order 120>60>90>150>0>ABC .This is in agreement with Sah et al, 2019 who found significant increase yield at 120 kg N ha -1 , and there was decrease in yield due to increase in nitrogen at 180 kg N ha -1 . Similar results have also been observed in previous studies Sun et al, 2020: Hou et al, 2019Zhu et al, 2017 revealing that an excessive N application rate has no contribution to the achievement of high grain yield.…”

Optimum Nitrogen Application Acclimatizes Root Morpho-Physiological Traits and Yield Potential in Rice under Subtropical Conditions

“…In our study, the GY reached a peak at the N 140 level irrespective of all varieties; at the N 210 level, it was decreased. Many of the earlier investigations also revealed that the higher GY values of rice are not influenced by an excessive N application rate [72][73][74]. The risk of lodging was shown to increase due to the overuse of N fertilizers, which might significantly reduce the GY [75].…”