Table 4 Current practices on N and P control from agricultural runoff

1

Source control

Conservation

Reduced

Cropland

64

7.7

–

[45]

2

No-tillage

Paddy soil

25.9

8.5

7.8

[46]

3

SPG cover

Cabbage field

29.4

34.7

7.8

[49]

4

Amendment

Tropical soil

16.8

41.8

39.1

[50]

5

Rotation tillage

Rotation tillage

Canadian prairies

-

60

38

[54]

6

Fertilization management

Orchard

–

36.2

31.4

[62]

7

Band placement

Nursery land

–

61.2

68.1

[60]

8

Hole placement

Nursery land

–

65.1

67.9

[61]

9

Controlled-release N

Wheat-maize

–

30.5

–

[64]

10

Controlled-release

rotation Corn land

–

27.8

34

[65]

11

Controlled-release

Paddy soil

[66]

12

Water saving irrigation

Alternate wetting and drying

Paddy soil

30.2 ~ 36.7

-

–

[73]

13

14

15

Process control

Ecological ditch

Ecological ditch

Paddy soil

–

72

64

[85]

16

Microbial treatment

A²/O with Eco-ditch

Suburban

–

82

81

[95]

17

End treatment

Surface-flow wetland

Agricultural runoff

–

60

–

[98]

18

Surface-flow wetland

Agricultural runoff

–

–

41

[100]

19

Subsurface-flow wetland

Urban

–

62

52

[106]

20

21

Buffer strips

Integrated buffer zone

Agricultural runoff

–

39

50

[112]

22

Vegetated buffer strips

Maize field

–

52

–

[113]