Grain yield and nitrogen use efficiency of various modern rice cultivars grown at different nitrogen levels |
| |
| Authors: | Xiaokun Li Zhengwei Xu Chen Guo Tao Ren Rihuan Cong |
| |
| Institution: | 1. College of Resources and Environment, Huazhong Agricultural University, Wuhan, China;2. Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, Wuhan, China |
| |
| Abstract: | Field trials were conducted to study the responses of grain yield and nitrogen (N) use efficiency at five input rates (N0, N82.5, N165, N247.5, and N330 kg ha?1) in a set of nine of the most representative rice cultivars. Grain yields of rice across the nine cultivars were increased significantly by N level. All the cultivars contained a significant linear plus plateau or quadratic relationship between N levels and grain yields.The minimum yields (means of 2 years) at N0, N82.5, N165, N247.5, and N330 level all occurred in No. 2 cultivar. Compared with the grain yield of No. 2 at different N levels, those of the maximum cultivars increased by 37.1 (No. 8), 39.1 (No. 7), 48.4 (No.3), 43.3 (No. 4), and 43.9% (No. 3), respectively. In 2011, the highest average apparent nitrogen recovery efficiency (ANRE) in grain of the 4 N levels occurred in No. 3 cultivar (45.9%), followed by No. 4, No. 6, and No. 1, and the highest average agronomic efficiency (AE) in grain of the 4 N levels occurred in No. 9 cultivar 29.0 kg (kg N)?1], followed by No. 3, No. 1, and No. 4. For the second-season planting, the highest average ANRE occurred in No. 4 cultivar (28.4%), followed by No. 3, No. 5, and No. 6, and the highest average AE occurred in No. 5 cultivar 18.1 kg (kg N)?1], followed by No. 4, No. 3, and No. 7. Overall, No. 3 and No. 4 cultivars were the ideal ones that not only increased the grain yield but also improved the N use efficiency. |
| |
| Keywords: | agronomic efficiency apparent nitrogen recovery efficiency grain yield rice cultivar |
|
|
