PowerPoint by Joong-Dae Choi, Woon-Ji Park, Ki-Wook Park and Kyong-Jae Lim Presented at the Paddy and Water Environment Engineering Society PAWEES International Conference, Taipei, October 27, 2011

1. Paddy and Water Environment Engineering Society PAWEES
International Conference, Taipei, October 27, 2011
Feasibility of SRI Application in Korea
for Reduction of Irrigation Requirements
and Non-Point Source (NPS) Pollution
Joong-Dae Choi, Woon-Ji Park
Ki-Wook Park and Kyong-Jae Lim
Dept. of Regional Infrastructures Engineering,
Kangwon National University (KNU)

2. Contents
Contents
Background and Objective
Material and Methods
Results and Discussion
Conclusions

4. What is SRI ?
SRI is an innovative paddy
cultivation method to achieve Irrigation water
30-50% decrease
increased rice yields with less
inputs of water, agro-chemicals,
and labor in developing countries
Effects of
Production cost
SRI
0-20% decrease
Paddy yield
50-100% increase
Chemical use
30-50 % decrease

5. Necessities and Justification
• SRI is currently practiced in over 40
countries in the world
• PWE issued a special issue on SRI in
March, 2011 as Vol. 9 (1) with 17 papers.
• Several papers on SRI were published in
Korea in 2009, 2010 and 2011 under the
guidance of Prof. Jin-Yong Choi of
Kyeongsang National University.
- Key words of the papers were: no-till
cropping, residue and cover crop effect,
planting density, and nutrient uptake.

6. Necessities and Justification
• Most SRI practices and research are
focused on rice yield, water saving, and
reduction in management and labor cost.
• However, effects of SRI on water saving
and its environmental impacts in Korea
have not been yet studied.
• It is very important to save irrigation
water and reduce NPS pollution in Korea
because Korea expects water shortage in
the near future and is pressed to improve
its water quality.

7. Necessities and Justification
• Rice is produced in about 60% of the
farm land in South Korea
• Agricultural water use is about 48% of
the total water consumption in South
Korea
• About 89% of agricultural water is
consumed in rice farming
• Water shortage is expected in Korea in
the near future

8. Necessities and Justification
• Water-saving crop cultivation is strongly
required in agricultural areas, especially
in rice farming
• Water quality improvement has always
been an important pending issue
• Pollution discharge from paddy fields is
required to be cut down as much as
possible because of their wide area.

9. Source of Agricultural Water
0
5 2
Reservoir
12
Pumping
Stream Weir
19
62 Groundwater
Others

10. Water Use in Agriculture
Livestock
288
Upland (2%)
1,317 Reducing paddy water
(9%)
use can give savings:
10% = 1.317 bill m3
20% = 2.634 bill m3
Paddy
13.170 B m3
30% = 3.951 bill m3
(89%)

11. Objectives
• To experimentally investigate the
feasibility of SRI rice farming in Korea
• To quantify the reduction of irrigation
water possible with SRI, and
• To analyze effect of SRI on reduction of
NPS pollution from paddy fields

13. Location of the experimental fields
8
7
6
5 2 1
4
3
Site (N) 37° 55′ 57″,
(E) 127° 46′ 59″
Area 1,873 m2

14. Layout of conventional (CT) and SRI plots

15. Seed preparation and sowing
Seed disinfection by chemical solution SRI sowing 21-4-2010
for 24 hours
① 200 port tray ② Soil 1 ③ Soil 2
Conventional sowing 21-4-10
④ 200 port ⑤ Sowing 1 ⑥ Sowing 2
① Preparation ② Watering ③ Sowing
④ Soil cover ⑤ Smoothing ⑥ Plastic cover ⑦ Soil cover ⑧ Watering ⑨ Watering 2

16. Plots and watering pipe preparation
① Levee -1 ② Pipe layout ③ Flow meter
④ Water tank and pump ⑤ Electrical line ⑥ Watering
⑦ Fertilizer ⑧ Puddling ⑨ After puddling

17. 9/45
Drain channel preparation
① Drain -1 ② Drain -2 ③ Drain -3
④ Drain -4 ⑤ Drain -5 ⑥ Drain -6

18. Plots and equipment
① Flume calibration ② Flume setting ③ Cashockton wheel sampler
④ Flumes and samplers ⑤ Water level meter ⑥ Automatic weather system

19. Infiltration and evapotranspiration
ET
200 mm 300 mm
300 mm
150 mm
Infiltration Consumption
Infiltration Consumption

20. Transplanting (May 21, 2010)
No. of seedling per hill
SRI = 1
Non-SRI = 3~5
Transplanting spacing
① SRI transplanting-1 ② SRI transplanting -2
CT : 30x15 cm
SRI : 30x30 cm
SRI : 40x40 cm
SRI : 50x50 cm
④ Conventional transplanting
③ SRI transplanting -3
by transplanting machine

21. Irrigation management
Standard management for conventional culture
Water
Stage Description
depth (cm)
Transplanting Shallow irrigation 2~3
Root development Deep irrigation 5~7
Tillering Shallow irrigation 2~3
End of tillering No irrigation for 5~10 days – 30~40 0
days before heading
Panicle initiation/ AWD from 30 days before heading to 2~4
booting heading (3 days ponding, 2 days dry)
Heading/flowering Medium irrigation 3~4
Ripening AWD (3 days ponding, 2 days dry) 2~3
Draining Complete draining – 30-40 days after 0
heading

22. Water management of SRI plots
AWD irrigation from transplanting until the end of tillering -- plots
irrigated to 1 cm depth, and then let to dry for 3~4 days
Soil condition : 0~2 cm cracks were allowed to develop on the soil
surface of the SRI plots
During panicle initiation stage, water depth of 1 cm maintained
After this, frequent rain ponded in the plots and then was drained
manually. Minimal irrigation was provided.

23. SRI variables evaluated
Amount of irrigation measured by flow meter
Runoff measured by flume
Rainfall by automatic rain gauge
Soil water content before spring farming work
Composite water sample collection by cashocton wheel sampler
Sample analysis to assess BOD, COD, T-N, T-P, SS concentration
No. of tillers and plant height
Soil analysis
Rice yield

25. Soil analysis
Particle composition (%)
Group Texture
Sand Silt Clay
RDA (2008) 34.8 45.4 20.2
Loam
National average (20∼50% ) (30∼60%) (12∼25%)
This study 49.4 35.8 14.8 Loam
OM Exchangeable cations (cmol/kg)
Group pH
(g/kg) Ca Mg K
Optimum range 6.0-6.5 25-30 5.0-6.0 1.5-2.0 0.25-0.30
This study 6.1±0.2 25 4.6±0.2 1.7±0.3 0.28±0.1

26. Irrigation water quality
This study
National
Index Standard
average 2010 (n=6) 2011 (n=8)
pH 6.0∼8.5 7.8 7.2 ± 0.1 7.5 ± 0.3
BOD (mg/L) ≤8 - 1.6 ± 1.1 2.3 ± 0.5
COD (mg/L) ≤8 4.5 4.9 ± 0.8 5.3 ± 1.2
SS (mg/L) ≤ 100 - 16.1 ± 3.3 12.9 ± 7.3
DO (mg/L) ≥2 9.4 8.4 ± 0.2 8.6 ± 0.4
T-N (mg/L) - 2.269 2.067 ± 0.1 1.946 ± 0.4
T-P (mg/L) - 0.055 0.084 ± 0.01 0.067 ± 0.01

27. Development of seedlings
SRI CT
20
18 CT
°üÆà
SRI
16
ÆÄ
Á¾ 14
Plant height
ÈÄ Transplant not later
12
¹¦
than 20
10
days after sowing
Å©
±â 8
º¯
È­ 6
(cm) 4
2
0
5 10 15 20 25 30 35
CT SRI day

28. No. of tillers and height of plants
50
100
CT Plot 1
No. of Tiller
Plant height 91 90
40
74 80
70
30 58 61
60
52
No. of Tiller Plant height
44 50
(Ea) (cm)
20 21 23 22
33 40
29
27 19
17 30
30x15 cm 10
18
11
15
20
spacing 0
4
5
8 10
0
2010.6.2 6.8 6.11 6.15 6.20 6.25 6.30 7.8 7.16 8.4
Date
50
CT Plot 2
No. of Tiller 100
Plant height 92 90
40
73 80
70
30 56 60
60
51 Plant height
No. of Tiller
43 25 50
(Ea) 22 25 (cm)
20 40
28 32
26 19
17 30
18 15
10 20
12
8 10
6
4
0 0
2010.6.2 6.8 6.11 6.15 6.20 6.25 6.30 7.8 7.16 8.4
Date

29. No. of tillers and height of plants
50
100
SRI Plot 5
No. of Tiller 97
Plant height 90
40 78 80
73
62 70
30
54 60
No. of Tiller 47 Plant height
26 26 50
(Ea) 41 (cm)
20 21
34 40
29 20
18 30
22 17
15
30 ×30 cm 10
10
13 20
spacing 0
5
10
0
2010.6.2 6.8 6.11 6.15 6.20 6.25 6.30 7.8 7.16 8.4
Date
50
100
SRI Plot 6
No. of Tiller
Plant height 90 90
40
75 80
70
70
30 60
53 60
No. of Tiller Plant height
45 50
(Ea) 25 25 (cm)
20 39
33 20 40
29
17 19 30
21 16
15
10 13 20
10
10
5
0 0
2010.6.2 6.8 6.11 6.15 6.20 6.25 6.30 7.8 7.16 8.4
Date

30. No. of tillers and height of plants
50
SRI Plot 3 No. of Tiller 100
98
Plant height 90
40 78
74 80
70
62
30
55 60
No. of Tiller 46 27 28 Plant height
50
(Ea) (cm)
39 22
20 34 40
28 18 20
18
40 ×40 cm 10
21
11
16 30
20
spacing 5
8
10
0 0
2010.6.2 6.8 6.11 6.15 6.20 6.25 6.30 7.8 7.16 8.4
Date
50
SRI Plot 4 No. of Tiller
Plant height
99 100
90
40 78
80
71
63 70
30 33 33
54 60
No. of Tiller 46 Plant height
50
(Ea) 41 22 (cm)
20 34 40
29 21
18 19
21 30
16
10 12 20
10
10
4
0 0
2010.6.2 6.8 6.11 6.15 6.20 6.25 6.30 7.8 7.16 8.4
Date

31. No. of tillers and height of plants
50
SRI Plot 1
103 100
No. of Tiller
Plant height 90
40 78
75 80
35 35 70
61
30 56 60
No. of Tiller 47 Plant height
50
(Ea) 41 22 (cm)
20 35 40
29 20
19
22 17 30
50 ×50 cm 10
11
16
20
spacing 0
4
7 10
0
2010.6.2 6.8 6.11 6.15 6.20 6.25 6.30 7.8 7.16 8.4
Date
50
SRI Plot 2 No. of Tiller 100
98
Plant height 90
40 79
75 80
63 70
34 34
30
55 60
No. of Tiller 47 Plant height
42 50
(Ea) 23 (cm)
20 35 40
30 20 22
19
23 17 30
10 13 20
8
10
4
0 0
2010.6.2 6.8 6.11 6.15 6.20 6.25 6.30 7.8 7.16 8.4
Date

32. No. of tillers and height of plants
Date 6. 2 6. 8 6. 11 6. 15 6. 20 6.25 6.30 7.8 7.16 8.4
SRI
50×50 cm 4 8 12 16 18 19 21 22 34 35
# of SRI
40×40 cm 4 9 12 16 18 19 20 22 30 30
tillers
SRI
30×30 cm 5 10 13 15 17 18 20 21 26 26
(each)
CT
30X15 cm 4 5 8 11 15 17 19 22 24 23
SRI
50×50 cm 22 30 35 42 47 55 62 75 79 101
Plant SRI
40×40 cm 21 28 34 40 46 54 62 73 78 99
height
SRI
30×30 cm 21 29 34 40 46 54 61 72 76 94
(cm)
CT
30X15 cm 18 27 29 32 44 52 57 60 74 92

33. Comparison of lodging resistance (2010. 8. 15)
CT plots SRI plots

34. Irrigation water use efficiency (IWUE)
600 2.0
Water Use Irrigation
547.3
500 IWUE 1.8
1.84
Conventional plots 400 1.6
Irrigation (mm)
IWUE (kg/m3)
547.3 mm 300 1.4
243.2
SRI plots 200 1.2
0.98
243.2 mm 100 1.0
0 0.8
CT SRI
Reduction of irrigation water: 55.6% IWUE = Rice yield (kg)/Irrigation(m3)

35. Comparisons of rice yield (2010)
Yield Yield
Average No. of
ratio per
Treatment yield hills
to CT hill
(kg/10a) per plot
(%) (g)
SRI (50×50 cm) 408.4 76 232 93.6
SRI (40×40 cm) 441.3 82 385 65.3
SRI (30×30 cm) 490.3 92 644 43.4
CT (30×15 cm) 535.3 100 1,430 24.3

36. A means to increase yield
7cm
40cm
40
cm
Original SRI Modified SRI:
oblong with triangl
e
• Japonica rice variety does not
produce as many tillers as
Indica rice variety does.
• Therefore, transplanting 2 to 3
seedlings per hill may help to
increase SRI rice yield when
Japonica variety is planted.

37. Comparisons of rice yield (2011)
Average yield Yield ratio to CT
(kg/10a) (%)
Treatment
Polished Head r Polished Head
rice ice rice rice
CT (30×15 cm) 540.5 430.5 100 100
SRI CT
SRI
1 611 532 113 124
(30×30 cm)
SRI
2 612 532.5 113 124
(30×30 cm)
No. of
SRI
seed- l 3 647 573.5 120 133
(30×30 cm)
ings
SRI
per 1 590 517.5 109 120
(40×40 cm)
hill
SRI
2 591 505 109 117
(40×40 cm)
SRI
3 627 542 116 130
(40×40 cm)

38. Comparisons of runoff water quality
Treat-
SS CODCr CODMn BOD TN TP
ment
CT 159 30.1 10.7 3.0 4.4 0.56
(mg/L) ±146a ±14.7a ±5.4a ±0.9a ±1.9a ±0.2a
SRI 89.4 26.1 7.5 2.0 4.2 0.4
(mg/L) ±90.1b ±13.2a ±3.7b ±1.5b ±2.0a ±0.2b
Water quality differences among SRI plots were not
significant, thus respective concentrations were pooled and
averaged.

39. Comparisons of NPS pollution loads
Treatment SS CODCr CODMn BOD T-N T-P
CT
1,444 242.5 71.7 23.2 43.8 3.76
(kg/ha)
SRI
874 199.5 47.0 12.96 36.9 2.92
(kg/ha)
Reduc-
39.5 17.7 34.4 44.1 15.8 22.3
tion (%)

40. Comparison of methane gas emission
1000
840.1
800
kg CH4 / ha
600 72 %
400
237.6
200
0
CT SRI
Emission (kg/ha) CO2 ton/ha
Treatment
CH4 N2O equivalent
CT 840.1 0 17.6
SRI 237.6 0.074 5.0

42. Conclusion
s
• Rice plants in SRI plots were healthier and stronger
than those in CT plots.
• Number of tillers per hill was greater in SRI plots
than in CT plots.
• Rice yield from SRI plots was only 76~92% of that
from CT plots because of late transplanting and
mistakes in irrigation supply. Yield could probably
have been higher with better use of SRI methods.
• Irrigation water requirement of SRI and CT plots
was 243.2 and 547.3 mm, respectively, resulting in
55.6% reduction of irrigation water with SRI practice
.

43. 41/45
Conclusions - continued
• Measured pollution loads from SRI plots were: SS
874 kg/ha, CODCr 199.5 kg/ha, CODMn 47 kg/ha, BOD
13 kg/ha, TN 36.9 kg/ha, and TP 2.92 kg/ha. These
loads were 15.8-44.1% less than those from CT
plots.
• It is concluded that SRI could be successfully
adopted in Korea and could help reduce irrigation
requirements and NPS pollution discharge.
• It is also suggested that further studies to increase
rice sector productivity with SRI should be
continued. Direct-seeding and no-till practices are
also recommended for study with SRI methods to
reduce production costs.

44. Thank you !
For more information, please contact:
jdchoi@kangwon.ac.kr

45. 현재 시험포 사진 (2011년)
시험포 (4번) 7월 5일

46. 현재 시험포 사진 (2011년)
SRI 시험포 (8번) 7월 5일

47. 포트이앙기 견학 (2011.5.28, 여주 능서면 마래리)
• Mechanical transplanting of rice seedlings grown in pot
trays is practiced in many parts of Korea and Japan.
Mechanical transplanting may not be a problem for SRI
practice.
• Weeding may be a problem for organic farmers. But
common farmers may use herbicides to control weeds.