1. On-site evaluation and practice of AWD
- A case from the Mekong Delta -
Takayoshi YAMGUCHI (NARO)

2. On-site practice and evaluation
While the basic efficacies of AWD are gradually clarified through field experiments; on-site practice and evaluation are still unclear.
Knowing on-site practice and evaluation would help to understand why farmers accepted (or didn’t accept) AWD.

3. An Giang province
, where AWD has been successfully diffused

4. Our papers regarding AWD in An Giang
T. YAMAGUCHI, L. M. TUAN, K. MINAMIKAWA, S. YOKOYAMA.
2016
Alternate Wetting and Drying (AWD) Irrigation Technology
Uptake in Rice Paddies of the Mekong Delta, Vietnam
Asian and African Area Studies, 15(2), pp
T. YAMAGUCHI, M. T. LUU, K. MINAMIKAWA, and S. YOKOYAMA.
2017.
Compatibility of Alternate Wetting and Drying
Irrigation with Local Agriculture in An Giang
Province, Mekong Delta, Vietnam
Tropical Agriculture and Development, 31(3). (in printing)

5. AWD history in An Giang 2005～ ・ Exhibition fields and seminars 2009～
・ The agricultural campaign called
“1 must do, 5 reduction”
・must use certified seeds
・reduce sawing seeds -> Drum seeder
・reduce fertilizer > Leaf color index
・reduce agrochemical -> IPM
・reduce irrigation water -> AWD
・reduce post-harvest losses -> Combine
instructed

6. AWD adoption ratio in An Giang
by area
48%
(2014)
53%
(2015)
37%
(2012)
AWD was
incorporated
in the policy
Project
started
17%
(2010)

7. Farmer’s benefits from AWD by the extension agents
This is not surprising
Damage of rice lodging has been much severe even today,
Lodge rice is diffiicult to harvest by combine harvester , farmers must raise up lodged rice in advance.

8. Rice farming before/after AWD adoption
(Interviewees were 25 households which adopted AWD.)
Rice farming before/after AWD adoption
→Invisible
→Visible
Effect would be a big advantage for AWD diffusion in AG.

9. Why AWD has been smoothly accepted in An Giang ?
AWD was officially incorporated into the local agricultural policy.
In addition to water saving (invisible), AWD decrease culm lodging (visible).

10. Distribution of AWD in An Giang

11. Restriction factors in farmer’s AWD adoption by the extension agents
Four factors are related to water issues
/17

12. Restriction factors in farmer’s AWD adoption by the extension agents
Elevation of paddy plots
The high-lying paddies are prone to be dried up due to higher percolation rate, moreover, they are difficult to irrigate when channel water level decrease; the low-lying paddies are difficult to be drained.
Density and quality of water canals
It is difficult to implement precise water control in the paddies which are not directly connected with well maintained channels.
Amount of precipitation
Channel water level tends to decline in the year with less precipitation, causing problem in smooth irrigation.
Pump ownership status
In the communes which have less pump owners, pump borrowing household are difficult to decide own watering schedules by themselves.

13. ← → AWD Paddy elevation adoption ratio Spearman’s correlation
coefficient
←　　 →
Mid-lying paddies (1-2m) shows positive correlation.
Low-lying paddies (<1m) shows negative correlation.
High-lying paddies (3m<) shows negative correlation.

14. Stepwise multiple regression analysis (using GIS)
Provincial capital
Channel density
Paddy elevation (middle)
Full-dike ratio

15. Summary Contradiction ?
In the case of the Mekong Delta, farmers realized the AWD benefits of decreasing rice lodging (visible) in addition to the water-saving effect.
However, AWD required good irrigation conditions.
Water scarce area [FAO, 2008]
・Shortage of total water amount
・Unreliable water source
Contradiction ?
Raise question

16. Restriction factors of nakaboshi in 1966
A clue from Nakaboshi
Nakaboshi is the traditional Japanese technique of intermittent irrigation in the paddy fields. (
Restriction factors of nakaboshi in 1966
Paddies with irrigation water shortage
31 %
Paddies with poor drainage
22 %
Farmers felt it was unnecessary
13 %
Defect in irrigation practices
10 %
Water-leaking paddies
7 %
Labor shortage
6 %
(SSDEABMAF, 1967)

17. A clue from Nakaboshi Nakaboshi has been diffused through …
(SSDEABMAF, 1967)
1. Development of irrigation infrastructure
2. Reformation into well-drained paddy field
3. Optimization of fertilizer management
4. Diffusion of herbicide
5. Specific information of Nakaboshi for each area and cultivar
We should consider the
proper technology package of AWD for each area.