integrated aqua-agricultural production systems in the brackish water zones of bangladesh
TRANSCRIPT
Jahangir Alam, S.B. Saha, M.L. Islam, T.P. Tuong and B. K. Barman
Integrated Aqua-Agricultural Production Systems in the Brackish Water Zones of Bangladesh
Bangladesh Coastal ZoneBangladesh Coastal Zone
Khul
na
Shrimp Farming Areas
Satk
hira
Bage
rhat
Gopa
lgon
j
Narai
l
Jessore
N
>80% of shrimp cultivation area in the southwest region, particularly in Satkhira, Khulna and Bagerhat districts
Background
Background
• The CP10 Project of CPWF in Phase 1 implemented on-field research, during the period of 2004-07 in farmers gher in the polder # 16/1 at Paikgacha, a southwest sub-district.
• On-farm survey - overview of the aquaculture systems in salinity influenced areas
• Series of experiments were conducted to improve shrimp (P. monodon) rice system to maximize farm output to increase production and income.
Evolution of shrimp farmingBefore 1980Before 1980 1980-19851980-1985 1985-19951985-1995 1995-20051995-2005
T. aman T. aman rice rice
Extensive traditional Extensive traditional shrimp farmingshrimp farming
Extensive/improved Extensive/improved extensive shrimpextensive shrimp
IntensificatioIntensificationnDiversificatioDiversificationn
Extensive traditional Extensive traditional shrimp farming / shrimp farming / T. T. amanaman rice rice
Extensive/improved Extensive/improved extensive shrimp / extensive shrimp / T. T. amanaman rice rice
Pushing/pulling Pushing/pulling and enabling and enabling factorsfactors
International market International market for shrimp;for shrimp;wild shrimp capture
Development of Development of hatcheries;hatcheries;Reduction of natural Reduction of natural stockstock
Disease Disease outbreaks;outbreaks;Access to Access to knowledge;knowledge;
Survey Findings
Survey Findings
• The usual farming pattern in the area - monoculture of shrimp (5%); or - alternating wet-season rice with dry-season shrimp
(95%)
J F M A M J J A S O N DSalinity > 4 pptExtensive shrimp
S S S-H S-H S-H S-H S-H H H H LP S
Shrimp/ T. Aman
S S S-H S-H H H H LP-T Rc Rc Rc Rh-LP-S
S = Stocking, LP= Land preparation, H = harvesting, Rc =Rice crop, Rh= Rice harvest; T= Transplanting.
Extensive shrimp farming followed byT. aman rice
Stocking density: 1- 2 PL.m-2
Yield Shrimp: Up to 250 kg.ha-1.y-1 Rice: 1 t.ha-1 of traditional variety – 3 t.ha-1 HYV (BR11);
average 2.8 t.ha-1
Net return: Tk. 6000 to Tk. 83 000.ha-1.y-1
• Enabling factor o Access to water and drainage facilities to flush the salt
water before the rice crop• Pushing factors
o Higher return for shrimp compared to riceo Rice: secure crop compared to shrimp
Survey Findings
Extensive shrimp farming followed by T. aman rice
• Constraintso Water Management Large ghers with low depth of water is a problem for shrimpWater logging is problem for rice o Higher shrimp mortality o High loan rates from middlemen o Low level of knowledge for shrimp
grow-out managemento Lower adoption of HYVs of rice
Survey findings
Objectives of on-farm experiments
Rice, prawn and fish (GIFT)•Determining appropriate combination, stocking rate, and culture management for integration of fish (GIFT) and prawn (M. rosenbergii) with rice production
•Identifying the suitable HYVs of rice for fresh and saline water interface area
Shrimp•Assess different stocking pattern and management options for increased production of shrimp (P. monodon)
Land preparation prior to shrimp stocking
Fertilization Fish harvesting
StockingStockingprawn PLprawn PL1010 (0.007g)(0.007g)
Rice plantation
Stocking Prawn PL & GIFT (1.5g)
Shrimp grow-out plots
Preparation & conducting on-farm experiments
Results (Shrimp)
• Single stocking (T1) resulted in higher average production values, though not significant.
• Average production of shrimp is 2-5 times higher than that of existing system
• Single stocking resulted in higher net return
Fig. Variations in average water depth
43 45 4749 5046
65 65
53
10
20
30
40
50
60
70
T-1 T-2 T-3
TreatmentW
ater
dep
th (c
m) R1
R2
R3
Replication-wise shrimp production
345
230 208185 177228
583528 503
0100200300400500600700
T-1 T-2 T-3
Treatment
Prod
uctio
n (k
g/ha
) R1
R2
R3
• Replication in each treatment with higher water depth yielded higher shrimp biomass.
Results (Shrimp)
Seas
onal
rain
fall
Periodical flashing
o Monsoon tidal flashing helps to keep up the soil fertility reducing salinity 2-3 ppt.
o HYVs viz. BR 23, BRRIdhan 40 & 41 resulted in a higher yield rate
of 4-5 t.ha-1
Results (Rice-aquaculture)
2.94d
4.11bc
5.09a
4.07
bc
4.82ab2.
90d
3.74cd
3.16a 3.09a2.89a
0
1
2
3
4
5
6
Ric
e yi
eld
(t/h
a)
2004 2005
Year
Hork
oz BR
-23L
BR-2
3
BRRI
dhan
-40
BRRI
dhan
-41
HR-1
HR-1
4
BR-2
3
BRRI
dhan
-40
BRRI
dhan
-41
• Water logging in relatively higher depth dry season shrimp gher resulted in lower yield
Results (Rice-aquaculture)
F M A M J J A S O N D J
GIFT & Prawn stockingGIFT & Prawn stocking
Rice growing seasonShrimp growing season
Rice plantationRice plantation
Results (Rice-aquaculture)
2004-05
• We obtained av. production of GIFT - 270 kg/ha and that of prawn - 70 kg/ha
• Net return from prawn was very low (only 3%)
• Identified causes were -- higher cost at stocking
- lower body weight at harvest
Results (Rice-aquaculture)
F M A M J J A S O N D J
Prawn Prawn stockingstocking(0.5/m(0.5/m22))
Rice growing seasonShrimp growing season
Rice plantationRice plantation& &
GIFT stockingGIFT stocking(0.5/m(0.5/m22))
4 replications for each T
Results (Rice-aquaculture)
2006-07
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Wet season Dry season
Gher preparation
• Water depth 60-80 cm• Single stocking: @ 3-5.m-
²
• Yield: 350-550 kg.ha-1
• NR: Tk. 75,000-100,000.ha-1
(1:1.9)
Golda GIFT
5,000-10,000.ha-1 at 1:1 ratio
Yield• Rice: 4-5 t.ha-1.• Fish: 200-250 kg.ha-1
• Prawn: 70-90 kg. ha-1
Seedling
Bagda Rice
Improved rice (aman)-shrimp system Improved rice (aman)-shrimp system modelmodel
HYVs: BR 23/40/41
