Table 2 Maize ear number, grains per ear, 1000-grain weight, grain yield and profit in 2017 and 2018.

From: Optimizing planting density and nitrogen application to enhance profit and nitrogen use of summer maize in Huanghuaihai region of China

N rate

Planting density

Ear number (1000 ears ha−1)

Grain number per ear

Grain weight (moisture 14%, g)

Grain yield (moisture 14%, t ha−1)

Profit ($ ha−1)

2017

2018

2017

2018

2017

2018

2017

2018

2017

2018

N1

D1

59.9e

54.5e

546bc

516a

327.4b

322.0a

9.87d

9.08d

2488e

2274c

D2

73.5cd

66.3c

507d

509b

314.6c

314.7b

11.20b

10.40b

2823cd

2607b

D3

78.7abc

77.7a

479e

490d

307.5c

294.2d

11.23b

10.96a

2809d

2734a

N2

D1

58.9e

56.3de

550b

516a

338.5a

324.3a

10.30c

9.40cd

2564e

2321c

D2

76.1bcd

65.6c

510d

517a

323.8b

323.0a

11.99a

10.91a

2997a

2705a

D3

80.2ab

79.5a

495de

487d

313.8c

305.2c

11.78a

11.15a

2916ab

2748a

N3

D1

56.5e

56.8d

573a

518a

337.1a

327.2a

10.35c

9.56c

2537e

2326c

D2

71.7d

68.4b

530c

509b

327.3b

323.8a

11.93a

11.17a

2939ab

2735a

D3

82.1a

79.1a

487e

498c

308.6c

305.3c

11.87a

11.23a

2901bc

2729a

Significance

N rate (N)

ns

ns

ns

ns

*

*

**

*

*

ns

Density (D)

***

***

***

***

***

***

***

***

***

***

  1. ns no significant difference.
  2. Means within a column followed by the different letters are significantly different at P < 0.05. N is N rate, and D is planting density. The three N rates are 120 (N1), 180 (N2), and 240 (N3) kg ha−1. The three planting density levels are 60,000 (D1), 75,000 (D2), and 90,000 plants ha−1 (D3).
  3. *Significance at the P < 0.05 level.
  4. **Significance at the P < 0.01 level.
  5. ***Significance at the P < 0.001 level.
Back to article page