Abstract:
In this paper, the yield of 16 rice varieties and their nitrogen (N) use efficiency were studied so as to provide a basis for reasonable application of N fertilizer. The effects of N fertilizer application on rice yield and its components of 16 rice varieties, N uptake and N use efficiency were analyzed based on a field experiment in the Jianghan plain, Hubei Province. N fertilizer treatment (NPK) significantly increased the grain rice yield by 9.7% ~ 64.8% compared with no N fertilizer treatment (PK). N contribution percentage (NCR) was 8.9% ~ 39.1%, N agronomic efficiency (NAE) was 4.5 ~ 19.8 kg kg
−1, partial factor productivity of applied N fertilizer (PEP
N) was 35.3 ~ 56.6 kg kg
−1, N recovery efficiency (NRE) was 23.2% ~ 59.9%, and N physiological efficiency (NPE) was 11.8 ~ 52.3 kg kg
−1. The 16 rice varieties were roughly divided into three types. Huanghuazhan, Quanyou 822, Quanyousimiao and huiliangyou 898 were the efficient and sensitive to N fertilizer type, with the main characteristics of high NCR, NAE and NRE. Shenliangyou 3206, Shenliangyou 828 and Taiyoumengdao (Liangyou S6) were the low efficient and insensitive to N fertilizer type, with the characteristics of low NCR, NAE, NRE and NPE. The other 9 varieties were the intermediate type, and their response to N fertilizer was between the above 2 types. For the high efficiency and sensitive rice type, the application amount of N fertilizer in this study be suggested, and the applied amount of N fertilizer should be optimized to increase rice yield. For the low efficiency and insensitive rice type, N fertilization rate should be appropriately reduced in order to obtain high N use efficiency and minimize the negative impact of excessive N fertilizer application. The intermediate rice type had a high yield potential, and its optimal N fertilizer amount should be recommended by field experiments, so as to achieve both high yield of rice and high N use efficiency at the same time.