2. Triple rice in a year:
Is it feasible for low salinity areas of the
coastal zone of Bangladesh?
N. K. Saha, M. K. Mondal, E. Humphreys, M. H. Rashid,
P. C. Paul, S. P. Ritu
3. Rationale
● Fresh water all the year round in much of Barisal
● Current cropping patterns:
○ Fallow/Aus-T.Aman-Fallow/Keshari
○ 0-3 2-3.5 0-1 t/ha
● Possible technology to fit 3 rice crops in a year
● 50% cultivable land medium high (SRDI 2010)
● HYV rice
● River water for Boro, river water & rainfall for Aus
drainage to Aman crop.
4. Hypotheses of the study
M J J A S O N D J F M A M
T. Aman (130-140 d) Boro (140-145 d)
Aus (100-105 d)
● 3 high yielding rice crops per year IS possible in
coastal zone where
○ fresh water available throughout the year
○ ability to drain excess water
5. Objectives
To evaluate combination of planting dates and aman varieties
for triple rice system
● Feasibility
● System yield
● Irrigation water requirement for boro
6. Basic site information
● PSTU farm, Patuakhali
● Clay loam
● Lowland
Drain & Water source ~100 m
7. Experimental design
Treatments:
➢ E1-3: aus sowing dates/establishment method
➢ V1-4: aman varieties
➢ D1-5:boro sowing dates
8. Aus establishment treatments (E)
● E1= Sown 10 April, transplanted 1 May
● E2= Sown on 25 April, transplanted 15 May
● E3= Sown Direct (wet) seeded 1 May
Variety: OM1490 (100 days)
9. Aman variety treatments (V)
RULE:
Transplanting date 10 d after harvest of each aus treatment
E1 and E2:
● V1 BRRI dhan49 (duration 135 d)
● V2 BRRI dhan52 (duration 145 d, submergent tolerant)
E3:
● V3 BRRI dhan33 (duration 118 d)
● V4 BRRI dhan53 (duration 125 d)
10. Boro sowing date treatments (D)
RULES:
● First transplanting date NOT less than 10 d after aman
harvest, & NOT before 15 November
● Second transplanting date 15 d after first
● D1= 15 November
● D2= 20 November
● D3= 30 November
● D4= 05 December
● D5= 15 December
11. Treatment Combinations
Aus Aman Boro CS
E1 =1 May V1= BRRI dhan49 D1= 15 November 1
D2 = 30 November 2
V2 =BRRI dhan52 D1= 15 November 3
D2 = 30 November 4
E2=15 May V1 =BRRI dhan49 D1= 30 November 5
D2= 15 December 6
V2 =BRRI dhan52 D1=30 November 7
D2=15 December 8
E3=1 May V1 =BRRI dhan33 D1= 20 November 9
D2= 05 December 10
V2= BRRI dhan53 D1=20 November 11
D2= o5 December 12
12. Crop management information
● Crop establishment:
Transplanting (all crops): 21 day-old seedlings
20 cm x 20 cm
Direct seeded aus (Dsaus): 20 cm row spacing
13. ● Fertilizers:
Season N
(kg/ha)
P2O5
(kg/ha)
K2O
(kg/ha)
CaSO4
(kg/ha)
ZnSO4
(kg/ha)
Aus 100 60 40 60 10
Aman 100 60 40 60 10
Boro 120 60 40 60 10
DS.aus 10-15 DAE, 30-35 DAE, 45-50 DAE(5-7DBPI) and 60-65 DAE
T.Aus
T.Aman Final land preparation, 25 DAT, 5-7 DBPI and at heading
Boro
BRRI, 2012
14. Irrigation:
● T.Aus and DSaus – irrigated as needed from canal
● Boro– Fully irrigated from canal (pumping)
Drainage:
Excess water during aus & aman– at low tide
15. Weed, pest and disease management
• Good control of pests and diseases (BRRI, 2012 recs)
(except brown spot in aman 2013 and boro 2012-13 first 2
sowings)
• plastic barrier to keep rats out
• netting to keep birds out
Bird nets
Plastic barrier
30. Duration of the cropping pattern in the field during
2012-13 and 2013-14
31. Conclusion & Recommendation
● It is feasible to fit 3 rice crop in a year
● 13.4 to 17.2 t/ha/yr about 3 x farmers’ harvest
● Average 10-12 day turn around period
● Need for model simulation to evaluate performance
over range of weather conditions
● Will pests & diseases become a problem in triple rice
systems – need for ecologically friendly management
systems