Table 1.
The experimental conditions, N fertilizer levels, and measured stages.
| Exp. No. | Season and site | Cultivar | Soil characteristics | Treatments | Stages |
|---|---|---|---|---|---|
| Exp. 1 | 2012–2013 Zhengzhou city | Yumai 49–198 Zhengmai9694 | Type: fluvo-aquic soil, Organic-M: 17.47 kg−1, Soil pH (CaCl2): 7.9, Total N: 0.84 g kg−1, NO3-N: 8.1 mg kg−1, Available N:78.4 mg kg−1, Available P: 18.83 mg kg−1, Available K: 252.56 mg kg−1 | N rate (kg ha−1): N0(0), N1(120), N2(240), N3(360), and 50% prior to seeding and 50% at jointing | Jointing Booting Heading Anthesis |
| Exp. 2 | 2013–2014 Zhengzhou city | Yumai 49–198 Zhengmai 9694 | Type: fluvo-aquic soil, Organic-M: 16.8 g kg−1, Soil pH (CaCl2): 7.8, Total N: 0.89 g kg−1, NO3-N: 9.3 mg kg−1,Available N:113.0 mg kg−1, Available P: 19.20 mg kg−1, Available K: 252.30 mg kg−1 | N rate (kg ha−1): N0(0), N1(120), N2(240), N3(360), and 50% prior to seeding and 50% at jointing | Jointing Booting Heading Anthesis |
| Exp. 3 | 2013–2014 Shangshui city | Zhoumai 27 | Type: lime concretion black soil, Organic-M: 20.8 g kg−1, Soil pH (CaCl2): 7.1, Total N: 1.36 g kg−1, NO3-N:14.1 mg kg−1, Available N: 93.2 mg kg−1, Available P: 4.92 mg kg−1, Available K: 176.1 mg kg−1 | N rate (kg ha−1): N0(0), N1(180), N2 (240), N3(300), and 50% prior to seeding and 50% at jointing | Jointing Booting Anthesis |
| Exp. 4 | 2014–2015 Zhengzhou city | Yumai 49–198 Zhengmai9694 | Type: fluvo-aquic soil, Organic-M: 9.7 g kg−1, Soil pH (CaCl2): 8.01, Total N: 0.71 g kg−1 NO3-N: 7.2 mg kg−1, Available N: 64.6 mg kg−1, Available P: 28.8 mg kg−1, Available K: 101.7 mg kg−1 | N rate (kg ha−1): N0(0), N1(120), N2 (240), N3(360), N4(450), and 50% prior to seeding and 50% at jointing | Jointing Booting Heading Anthesis |
| Exp. 5 | 2014–2015 Shangshui city | Yumai 49–198 | Type: lime concretion black soil, Organic-M: 21.7 g kg−1, Soil pH (CaCl2): 8.06, Total N: 1.13 g kg−1, NO3-N: 10.6 mg kg−1, Available N: 85.7 mg kg−1, Available P: 13.1 mg kg−1, Available K: 111.3 mg kg−1 | N rate (kg ha−1): N0(0), N1 (120), N2 (240), N3(360), and 50% prior to seeding and 50% at jointing | Jointing Booting Anthesis |
| Exp. 6 | 2011–2012 Zhengzhou city | Yumai 49–198 Zhengmai9694 | Type: fluvo-aquic soil, Organic-M: 10.6 g kg−1, Soil pH (CaCl2): 7.9, Total N: 0.91 g kg−1, NO3-N: 8.4 mg kg−1, Available N: 82.0 mg kg−1, Available P: 25.6 mg kg−1, Available K: 124.5mg kg−1 | N rate (kg ha−1): N0(0), N1(120), N2 (240), N3(360), and 50% prior to seeding and 50% at jointing | Booting Heading Anthesis Initial-fillingMid-filling |