community water management: the key to unlocking the production potential of the polder ecosystems...
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By Manoranjan Mondal, Elizabeth Humphreys, TP Tuong Revitalizing the Ganges Coastal Zone Conference 21-23 October 2014, Dhaka, Bangladesh http://waterandfood.org/ganges-conference/TRANSCRIPT
Community water management: The key to unlocking the produc7on poten7al of the polder ecosystems in Bangladesh
Manoranjan Mondal Elizabeth Humphreys
T P Tuong
SCL
M J J A S O N D J F M A M J
T. Aman (140-‐160 d)
Rabi (130-‐140 d)
Deep flooding at the beginning of rainy season constrains the establishment of aman rice and adop6on of modern HYV rice
Prolonged water logging at the end of rainy season delay establishment and risky harvest of rabi crop
Beginning of cyclone period
Crop & water management-‐causes of low produc6vity
0
10
20
30
40
End-‐Jan
Mid-‐Feb
End-‐Feb
Mid-‐M
ar
End-‐Mar
Mid-‐Apr
End-‐Ap
r
Mid-‐M
ay
End-‐May
Soil moisture (%
)
PWP
FC
Sesame seeds were broadcast during 14-‐28 February 2013
Damaged sesame field in pilot watershed on 25 May 2013
Major Ac6vi6es
Selec7on of the water management unit
6
Sluice gate
River
Sluicegate
Road
Rural road
Canal(khal)
Drainage canal
Outlet
6 ha pilot water management unit on polder 30
7
• Obtain the agreement to create a hydrologically separate watershed & operate the sluice gate systema6cally
Construction of drainage outlet and drainage canals
• Constructed internal drains/bunds to separate high and low land.
• Constructed drains along the perimeter of the watershed.
• Constructed drainage outlet .
• Obtained the agreement of the farmers to grow – HYV rice – High value and tradi7onal rabi crops
in the watershed area • Provided seed & training
in recommended management for rice and rabi crops
• Provided year-‐round coaching
What we have done to improve produc7vity of coastal BD?
9
Major Achievements
Rice submerged twice in 2012
• Farmers operated the sluice gate systema6cally to quickly drain out excess water during the rainy season
• BUT couldn’t drain on 6me for rabi establishment because of late maturing tradi6onal varie6es
Drainage during aman season
13
Tradi7onal varie7es mature late (photoperiod sensi7ve)
HYV – ready for harvest
Tradi7onal (local)
0 20 40 60 80
100 120 140 160 180 200 220 240
Rainfall & W
ater dep
th (m
m) Target drainage 6me – but irriga6on!
because local variety late maturing
Transplan6ng
Surface water gone but weather cold, foggy, soil too wet for 6llage
Late drainage at the end of wet season soil too wet for early rabi crop establishment
Sunflower established on 1st January 2013, harvested before cyclone (yield = 1.5 t/ha)
Maize established on 24 February 2013 was in late grain filling at 6me of rains & farmer harvested 5 t/ha (~ 1/2 fer6liser
rate!)
Rainfall at Kismat Fultola, Ba7aghata, Khulna Rabi season 2012-‐13
0
10
20
30
40
50
60
70
1-‐Dec 1-‐Jan 1-‐Feb 1-‐Mar 1-‐Apr 1-‐May 1-‐Jun
Rainfall (m
m)
Damaged Sesame field in pilot watershed
Damaged mungbean field in pilot watershed
Damaged sunflower field in pilot watershed on 31 May 2013
HYV Rice (Recommended mngt)
Traditional + HYV Rice (Farmers’ mngt)
Stocked FISH in 6 ha –both areas
(Tilapia, Mola)
Aman 2013: Selected 1 ha sub-‐pilot
21
Aman Rice in 2013: ~ 5-‐6 t/ha from HYV
Early establishment of rabi crops in 2013-‐14 at Kismat Fultola, Khulna
Wheat in pilot watershed at Kismat Fultola, Ba6aghata, Khulna, Rabi season 2012-‐13
Good growth of early established sunflower in rabi season 2013-‐14
Yield of Maize and Sunflower at Kismat Fultola, Ba6aghata, Khulna, Rabi season 2013-‐14
0
1
2
3
4
5
6
Maize Sunflower
Yield (t/ha)
Rainfall at Kismat Fultola, Ba7aghata, Khulna, Rabi season 2013-‐14
0
20
40
60
80
100
120
140
1-‐Dec 1-‐Jan 1-‐Feb 1-‐Mar 1-‐Apr 1-‐May 1-‐Jun
Rainfall (m
m)
Poor growth of late established sesame due to lack of soil moisture and rainfall in rabi season 2013-‐14
Challenges
• Soil drying • Tillage equipments • Soil cracking • Fer6lizer applica6on – N topdressing • Water quality
None address produc7on issues with WUA??
Major Challenges
Soil drying is a major problem: Perched WT is high, low EV, slow internal drainage
0 5
10 15 20 25 30 35
Soil moisture (%
)
PWP
Field Capacity
• Land was ready for plowing in mid-‐February 2013 • But
– Small tractor owners increased price (x2) of 6llage when they knew the farmers wanted to prepare the land early & quickly.
– Farmers had to wait for more than a week for big tractor to come down from further north (Jessore) where agriculture is intensified for land prepara6on.
Tillage for rabi crop cul7va7on
No 7ll seems good, but soil cracked -‐ damaged roots and ineffec7ve N topdressing
0
5
10
15
20
25 Water Salinity
(dS/m)
Saline irriga7on water Canal water EC at Kismalultola, Khulna
Concluding Remarks
• An individual cannot successfully modify their cropping system schedule and adopt improved agricultural technologies in coastal polders due to the prevailing hydrology.
• Requires community coordina6on at a range of scales – within small hydrological units, within a sub-‐polder, and at the sub-‐polder scale. – Many considered the catchment is hydraulically separated
– In reality it is not in polders
Concluding Remarks
• Further engagement with polder communi6es is needed to determine – how to empower them with the ability to adopt improved cropping systems selected by them from the suite of available op6ons
– how to address social and environmental challenges for higher produc6vity and farm income .
THANK YOU
SCL