rice ecosystems h ados training 7 june 2011
TRANSCRIPT
8/6/2019 Rice Ecosystems H ADOs Training 7 June 2011
http://slidepdf.com/reader/full/rice-ecosystems-h-ados-training-7-june-2011 1/23
CSISA 1
CEREAL SYSTEMS INITIATIVE FOR SOUTH ASIA (CSISA)
7 June 2011, IRRI Office, Dhaka
8/6/2019 Rice Ecosystems H ADOs Training 7 June 2011
http://slidepdf.com/reader/full/rice-ecosystems-h-ados-training-7-june-2011 2/23
CSISA 2
Systems of Rice Culture/Rice Ecosystems
An ecosystem is a biological environment consisting of all the
organisms living in a particular area, as well as all the
nonliving, physical components of the environment with which
the organisms interact, such as air, soil, water and sunlight.
Components:
Systems of growing rice: to suit specific environments and
socio-economic conditions of the farmers
Soil/land
Crop management practices
8/6/2019 Rice Ecosystems H ADOs Training 7 June 2011
http://slidepdf.com/reader/full/rice-ecosystems-h-ados-training-7-june-2011 3/23
CSISA 3
Classification of Rice Culture/Ecosystem
According to source of water supply: Rainfed (Aus, Aman)
Irrigated (Boro)
Based on land and water management practices:
Lowland (wetland preparation of fields): T. Aus, T. Aman
Upland (dryland preparation of fields): B. Aus
According to water regime:
Upland, with no standing water, no bunds
lowland, with 5-50 cm of standing water with bund
Deepwater, with > 51 cm to 5-6 m standing water
8/6/2019 Rice Ecosystems H ADOs Training 7 June 2011
http://slidepdf.com/reader/full/rice-ecosystems-h-ados-training-7-june-2011 4/23
CSISA 4
8/6/2019 Rice Ecosystems H ADOs Training 7 June 2011
http://slidepdf.com/reader/full/rice-ecosystems-h-ados-training-7-june-2011 5/23
CSISA 5
In Bangladesh the rice-growing environment has been
classified into three major ecosystems based on
physiography and land types.
These ecosystems are-
a) irrigated,
b) rainfed, and
c) floating or deepwater.
The rainfed ecosystem has been further classified as-
rainfed lowland and
rainfed upland
Rice Ecosystems in Bangladesh
8/6/2019 Rice Ecosystems H ADOs Training 7 June 2011
http://slidepdf.com/reader/full/rice-ecosystems-h-ados-training-7-june-2011 6/23
CSISA 6
Rainfed Ecosystems
Rainfed rice: The bulk of the rice is produced in the wet
season:
dependence of rainfall
rainfall is the most limiting production constraint for rainfed
rice culture
Rainfed Upland rice (during March to July)
Rainfed lowland pre-monsoon: T. Aus (during April to
August) and
Rainfed lowland monsoon: T. Aman (during July to
December)
8/6/2019 Rice Ecosystems H ADOs Training 7 June 2011
http://slidepdf.com/reader/full/rice-ecosystems-h-ados-training-7-june-2011 7/23
CSISA 7
Rainfed Upland rice (DS Aus):
Broadcast in to dry soil
Drilled in to dry soil
Dibbled in to dry soil (to escape drought & salinity)
Constraints:
The yield potential of this crop is the lowest due mostly to the
unfavorable weather.
The second important constraint is the lack of high yielding varieties.
Unpredictable distribution of rainfall hinders timeliness of some
management practices, particularly fertilizer management.
Thirdly, the climatic conditions are very much conducive for rapid
growth of weeds and pest and disease infestation.
Rainfed upland rice
8/6/2019 Rice Ecosystems H ADOs Training 7 June 2011
http://slidepdf.com/reader/full/rice-ecosystems-h-ados-training-7-june-2011 8/23
CSISA 8
In Bangladesh, rainfed lowland rice by direct seeding on to
non puddled soil at the beginning of the rainy season
is known as aus (meaning early)
The rice is direct seeded in March-April and harvested in
July-August
Early maturing varieties are more essential than
transplanted rice
varieties should have good drought tolerance
Rainfed upland rice: contd----
8/6/2019 Rice Ecosystems H ADOs Training 7 June 2011
http://slidepdf.com/reader/full/rice-ecosystems-h-ados-training-7-june-2011 9/23
CSISA 9
Rainfed lowland pre-monsoon rice (Aus: meaning early)
Rainfed lowland monsoon rice (T. Aman: meaning safety or
stability): (including medium deep stagnant water; 50-100 cm)
Enough water has to accumulate in the field to soften the soil before
plowing can be done Dikes/bunds are essential for rainfed culture because the undependable
water supply must be captured and controlled
Land is either prepared wet or dry but water is always held on the field
The establishment methods are:
- transplanting in puddled soil.
- WSR on puddled soil and
- direct seeded in to dry soil
Rainfed lowland rice
8/6/2019 Rice Ecosystems H ADOs Training 7 June 2011
http://slidepdf.com/reader/full/rice-ecosystems-h-ados-training-7-june-2011 10/23
CSISA 10Rainfed upland rice: dry DSR
Irrigated lowland rice: TPR
Rainfed lowland rice: TPR
Rainfed lowland rice: WSR
8/6/2019 Rice Ecosystems H ADOs Training 7 June 2011
http://slidepdf.com/reader/full/rice-ecosystems-h-ados-training-7-june-2011 11/23
CSISA 11
T. Aus, the wet season first crop, is grown when sufficient rainfall occurs
during April to August.
This is the period experiencing higher temperatures with minimum diurnal
fluctuation, moderate humidity during the reproductive stage, but
with occasional scanty rainfall during the early vegetative growth
period.
Such a climate is very much conductive to higher vegetative growth of the
crop with the lowest partitioning coefficient and
development of pests and diseases.
Rice varieties grown are all insensitive to photoperiod and mature within
110 to 130 days.
Therefore, climatic limitation is the most important constraint for this rice.
Rainfed lowland pre-monsoon rice: T. Aus
8/6/2019 Rice Ecosystems H ADOs Training 7 June 2011
http://slidepdf.com/reader/full/rice-ecosystems-h-ados-training-7-june-2011 12/23
CSISA 12
� The wet season second crop grown in the rainfed lowland ecosystem is
known as T. Aman, cultivated during full monsoon period.
� The crop experiences high rainfall and temperature during the vegetative
stage and low temperature often associated with drought during
the reproductive stage.
� Since the Aman crop experiences two extreme climates at two ends,planting time is very important for this rice but often farmers cannot
follow the appropriate planting schedule due to various socio-
economic factors and delayed on set of rainfall. This late planting
causes yield decline.
� To save the crop from low temperature stress at the reproductive stage
and also to establish a rabi crop timely after the harvest of Aman,
shorter duration varieties with less or no sensitivity to photoperiod
have been evolved recently for cultivation in shallow flooded areas.
Rainfed lowland monsoon rice: T. Aman
8/6/2019 Rice Ecosystems H ADOs Training 7 June 2011
http://slidepdf.com/reader/full/rice-ecosystems-h-ados-training-7-june-2011 13/23
CSISA 13
Coastal rice belongs to tidal wet land rice
This ecosystem includes both saline and non-saline ecologies.
In non-saline: single T. Aman, Boro-T. Aman, T. Aus-T. Aman CPs
In saline: single T. Aman, Boro/sesame/mungbean- T. Aman, Boro-
Shrimp/Prawn-Fish, T. Aman+ Fish CPs
Local varieties with taller seedling is used.
In the medium flooded area, harvesting of Aman rice in standing
water at the harvesting time, photo period sensitive var, better.
In saline ecologies, the only MV is practiced BR23 which can tolerate
stagnant water, some salinity, taller plant height, non-lodging, less sterility
There is little scope for further expansion of MVs unless varieties with
relatively higher growth rate in the nursery bed, sturdy culm and
profuse root system are evolved.
Special Ecosystem: Tidal saline and non saline wetlands
8/6/2019 Rice Ecosystems H ADOs Training 7 June 2011
http://slidepdf.com/reader/full/rice-ecosystems-h-ados-training-7-june-2011 14/23
Fig. Top soil salinity of Kismat Fultala, Batiaghata, Soil series: Dumuria (MHL)
0
5
10
15
20
25
30
35
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
S a l i n i t y
(
2006 2007 2008 2009
Fig. Water salinity of Pasur river, Mongla port , Mongla, Bagerhat
0
5
10
15
20
25
J F M A M J J A S O N D
Month
S a l i n i t y
( d S
2006 2007 2008 2009
14CSISA
8/6/2019 Rice Ecosystems H ADOs Training 7 June 2011
http://slidepdf.com/reader/full/rice-ecosystems-h-ados-training-7-june-2011 15/23
CSISA 15
8/6/2019 Rice Ecosystems H ADOs Training 7 June 2011
http://slidepdf.com/reader/full/rice-ecosystems-h-ados-training-7-june-2011 16/23
CSISA 16
Major crop management in Rainfed lowland rice
Transplanted rice:
In general, modern semi-dwarf varieties are grown in shallow rainfed
lowland (30 cm) rice growing area
Taller varieties with or without photoperiod sensitivity in medium deep LL
The maturity is controlled by short days (< 12 hrs) and cool climate (<27 0c) particularly during the reproductive and ripening phases of crop
growth
Aman crop is often subjected to flash flood and reduction in stand due to
seedling submergence needs submergence tolerant variety
Seedbeds starting with the onset of the monsoonal rains
Seeds are soaked for 24 hrs and then incubated for 48 hrs
In wet seedbed with 80-100 g/m2 of seedbed
8/6/2019 Rice Ecosystems H ADOs Training 7 June 2011
http://slidepdf.com/reader/full/rice-ecosystems-h-ados-training-7-june-2011 17/23
8/6/2019 Rice Ecosystems H ADOs Training 7 June 2011
http://slidepdf.com/reader/full/rice-ecosystems-h-ados-training-7-june-2011 18/23
CSISA 18
Wet-seeded lowland rice
Pre-germinated seeds are broadcasted or drilled on to puddled fields
without much standing water
Stand establishment is often poor because of poor land preparation,
weed competition and poor water control
Early maturing variety (about 100- day duration) are preferred
Where rainfall distribution is good and farmers can puddle the fieldsquickly and thoroughly
Dr y seeded lowland rice
Establishment of dry seeded rice in lowland fields must be in accord with
the local rainfall pattern
To obtain high yields with direct seeded rice optimum time of planting
based rainfall pattern, good weed management, optimum fertilizer
management (N, K) are necessary
8/6/2019 Rice Ecosystems H ADOs Training 7 June 2011
http://slidepdf.com/reader/full/rice-ecosystems-h-ados-training-7-june-2011 19/23
CSISA 19
Transplanted rice
Drilled/broadcast onto puddled soil (WSR by drum seeder)
Irrigated rice is grown after the harvest of T. Aman rice or after
harvesting a non-rice crop like potato, mustard or quick growing
vegetables.
Low temperature during the early vegetative stage of the crop prolongs
growth duration and thus most of the existing modern varieties
mature within 165 days.
This requires use of a high level of inputs like irrigation, fertilizer and plant protection measures.
Of all the constraints of Boro rice cultivation, the most pressing
one is the availability of irrigation water followed by farmers
incapability of using the required amount of fertilizer in a balanced
Irrigated lowland rice: Boro
8/6/2019 Rice Ecosystems H ADOs Training 7 June 2011
http://slidepdf.com/reader/full/rice-ecosystems-h-ados-training-7-june-2011 20/23
CSISA 20
Farmers of some regions delay planting in order to shorten growth
duration vis-à-vis the production cost, particularly of irrigation. This
delayed planting, however, reduces yield significantly.
Recently BRRI released relatively shorter duration Boro varieties. But
some farmers without being fully aware of the appropriatetechnologies for such varieties often stick to their traditional
practices of early transplanting, subjecting the crop to cold injury
during the flowering stage and thus realize poor harvests.
With ideal conditions, it is possible to obtain similar high grain yield with
rice transplanted or direct seeded in puddled soil.
Irrigated lowland rice: Boro-contd---
8/6/2019 Rice Ecosystems H ADOs Training 7 June 2011
http://slidepdf.com/reader/full/rice-ecosystems-h-ados-training-7-june-2011 21/23
CSISA 21
To obtain high yields with direct seeded rice optimum time of planting,
precise water management, good weed management, optimum fertilizer
management (N, K) are necessary
Aus area-9%, Aman -48 % and Boro-43 % of total rice
area (10.58 m ha): BBS, 2009
Irrigated lowland rice: Boro-contd---
8/6/2019 Rice Ecosystems H ADOs Training 7 June 2011
http://slidepdf.com/reader/full/rice-ecosystems-h-ados-training-7-june-2011 22/23
CSISA 22
Broadcast onto dry soil
Transplanted
This is a very long duration crop sown in March/April and harvested in
November/December.
This rice requires a special habitat of prolonged flooding.
The varieties are strongly sensitive to photoperiod and low tillering,
producing a very high amount of biomass but with the least HI.
The most important constraints of this rice are lack of varieties with high
yield potential, unpredictable flooding, and low response to
fertilizers.
The maximum water depths vary between 51-100 cm for ,ore than half of
the growth duration and sometimes there is completely
submergence of the plant. The depth of water, duration of flooding, the rate of increase in water level,
temperature, turbidity, and time of occurrence, vary for different
areas, so that the term deepwater may have different meanings in
different countries.
Deep water/floating rice
8/6/2019 Rice Ecosystems H ADOs Training 7 June 2011
http://slidepdf.com/reader/full/rice-ecosystems-h-ados-training-7-june-2011 23/23
CSISA 23