Challenges and opportunities for aman rice cultivation in ghers used for brackish water shrimp production

Challenges and opportunities for aman rice cultivation in

ghers used for brackish water shrimp production M. Akhlasur Rahman

Polder-3 Satkhira

HIGHLY SALINE

Study areas for varietal trial and cropping systems

2

Rice-aquaculture: Salinity fluctuates from

high in dry season to low in rainy season

Challenges for rice in ghers

High salinity at transplanting

Submergence after transplanting

Water stagnation – prolonged periods water 30-50 cm deep

Fresh water scarcity during dry spells

Fresh water scarcity when rains end early

Water management problems (drainage, irrigation)

Salinity…!

Salt stress: tolerance at both seedling and reproductive stages is needed

Seedling: important in coastal areas for good crop establishment

Reproductive: if long dry spells during WS and in both coastal and inlands during DS season

Salinity is a problem in some locations in some or all seasons

Salinity tolerant varieties

Salt sensitive varieties

BRRI dhan28-Saltol BRRI dhan28

BRRI dhan47

September – drainage congestion in whole region

after heavy rain due to inadequate water conveyance

system (drainage)

October – water shortage - plenty of freshwater in

river but inadequate conveyance system (irrigation)

Trials at Sehara (Polder 3), Kaliganj,

Satkhira during T. Aman 2012

Recovery rate 10-90% after

desubmergence

Highest survival rate 90%

BRRI dhan52 (BR11-Sub1)

Varietal trial completely

submerged for 5 days immediate

after transplanting

Aman cultivation at ghers, 2013

Transplanting

Water stagnation

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan

Traditional/HYV Rice (2-4 t/ha)

Existing cropping pattern: HIGH SALINE area

Aquaculture

(250-300 kg/ha)

Use of tolerant variety with proper management

Submergence tolerance

2nd transplanting submerged for 1 week shortly after transplanting – BRRI dhan52 survived well (Sub1 gene)

BRRI dhan52

14

0

2

4

6

8

10

Wate

r sali

nit

y (

dS

/m)

Polder 3 - Sehara - Aman 2011

Good leaching/water mgt Poor leaching/water mgt

36 day-old seedlings

26 day-old seedlings

Farmer water (drainage) management has a huge influence on salinity for aman rice

Water salinity 4-7 dS/m

0

5

10

15

20

25

30

Wa

ter

dep

th (

cm

) Polder 3 - Sehara - Aman 2011

Poor leaching/water mgt

36 day-old seedlings

26 day-old seedlings

Varietal trial at farmers

gher at aman, Polder 3

Well managed crop in ghers

PVS Activities

Variety

Vote Preference

score

Rank

Yield (tha-1)

Male Female Total

BRRI dhan47 9 3 12 0.083 Positive: 2nd 3.4

BRRI dhan52 18 7 25 0.192 Positive: 1st 4.0

BRRI dhan28 BRRI dhan52

BRRI dhan47

Total voter: 20 male+ 10 female

Intervention needed

3 in 1 varieties (Saltol, Subtol, water stagnation tol)

Appropriate water and agronomic management system

Current status

Advanced lines of 2 in 1

Submergence tolerant variety

All plants completely damaged due to

submergence

Salinity

Combined tolerance

of salinity and

submergence

(SalTol + Sub1)

Rice under saline water

Water level

G.B. Gregorio

Future variety Multiple stress

tolerant

Variety with

Saltol+Sub1+Dty2.1

+AG1+Pup1+High

Zn+BB+RTV

Progress/Opportunities Salinity tolerance Aman

It is important to develop and use of both salinity and submergence

tolerant variety for this areas.

Submergence tolerance

Water stagnation tolerant

Improved water management and drainage system

Seedling stage

Later stage-reproductive

Key findings

• Site specific variety, agronomic practices like optimum sowing date and seedling age (> 35 days)

• Community water management including salinity and drainage are important to make rice-shrimp production system more cost-effective, productive and sustainable.

• Synchronization of agricultural & aquacultural activities needed to realize this potential

The optimum seeding date for polder 3 is July 31 may

be recommended for polder 3

BRRI dhan47, BRRI dhan52, BRRI dhan54 and BINA dhan8 are

potential varieties for boost up productivity in this fragile

environment.

BRRI dhan44 produced the highest yield, both male and female

farmers preferred BRRI dhan52 and BRRI dhan47 as the best bet

varieties.

Appropriate water management (drainage/irrig) system is also

one of the vital issues to obtain more rice and fish/shrimp yield

Water stagnation is also a problem immediately after

transplanting

Conclusions

Thank you