N (kg/ha)

Vegetable fields

Wheat fields

Maize fields

Chemical fertilizer N

1117.5

156

158

Manure N

1060

0

0

Straw N

0

24.43 (all straw returning)

57.8 (all straw returning)

Root N

0 (cleaning root residue)

6.04

9.41

Irrigation N [20]

125

12.5

12.5

N deposition [21]

28

14

14

Seed N

0 (transplantation)

8

10

Biological N fixation [22]

15

15

15

Total

2345.5

235.97

276.71

C:N ratio of the input

4.18

9.94

10.36