Table 2 Seasonal variation of soil nitrogen pools (mg kg⁻¹) in a 2-year giant reed (Arundo donax L.) plantations under different weed control managements, i.e., sweet clover intercropping, herbicide, and hoeing.

Season (sampling time)

 Spring

9.03 ± 0.02 a

2.62 ± 0.03 a

3.54 ± 0.08 a

15.2 ± 0.06 a

 Autumn

8.84 ± 0.01 b

2.37 ± 0.01 b

3.43 ± 0.06 b

14.7 ± 0.05 b

Weed control method

 Intercropping

17.03 ± 0.06 a

4.19 ± 0.02 a

4.57 ± 0.02 a

25.8 ± 0.02 a

 Herbicide

5.93 ± 0.02 b

1.64 ± 0.01 b

3.30 ± 0.04 b

10.9 ± 0.03 b

 Hoeing

3.86 ± 0.04 c

1.66 ± 0.00 b

2.60 ± 0.03 c

8.1 ± 0.03 b

Interaction

 Spring

  Intercropping

17.23 ± 0.07 a

4.34 ± 0.03 a

4.67 ± 0.05 a

26.2 ± 0.04 a

  Herbicide

5.98 ± 0.08 c

1.71 ± 0.05 c

3.35 ± 0.06 c

11.0 ± 0.06 c

  Hoeing

3.89 ± 0.09 d

1.81 ± 0.05 c

2.62 ± 0.09 d

8.3 ± 0.06 e

 Autumn

  Intercropping

16.83 ± 0.06 b

4.04 ± 0.01 b

4.47 ± 0.07 b

25.3 ± 0.13 b

  Herbicide

5.88 ± 0.11 c

1.57 ± 0.03 d

3.25 ± 0.05 c

10.7 ± 0.03 d

  Hoeing

3.82 ± 0.07 d

1.51 ± 0.03 d

2.57 ± 0.05 d

7.9 ± 0.01 f.

Two-way ANOVA

 Season

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 Weed control

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 Interaction

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