Revised proceedings - The System of Rice Intensification - Cornell ...

THE CRITICAL FACTORS OF SRI
– Rice is water loving plant but we treated an aquatic
plant.
– Rice seedlings lose much of their growth potential if
they are transplanted more than 15 days after they
emerge in their nursery.
– During transplanting, trauma to seedlings and
especially to their roots should be minimized.
– Wide spacing of plants will lead to greater root
growth and accompanying tillering.
– Soil aeration and organic matter create beneficial
conditions for plant root growth
THE CRITICAL FACTORS OF SRI
4. To Transplant the seedlings far apart,
• One seedling per hill
• Relatively few plants per m 2
• In some soils, 2 plants per hill may give more
tillers per m 2
• More plants in a hill will create inhibitions on root
growth due to competition
5. To transplant in a square pattern to facilitate weeding.
• The most common SRI spacing is 25 x 25 cm,
• With good soil conditions, the hills can be up to 50
x 50 cm apart.
• With a square pattern, weeding can be done in
perpendicular rows.
THE CRITICAL FACTORS OF SRI
7. To control weeds, early and frequent
weeding.
• This is best done with a simple
mechanical hand weeder often called a
'rotating hoe,' starting about 20 days after
transplanting.
• At least once more and if possible 2 or 3
times more, until canopy closure makes
weeding difficult and no longer necessary.
8. To add nutrients to the soil, preferably in
organic form such as compost or mulch.
Objectives of the research work
The study has been undertaken with following
objectives:
• To find out the effect of crop establishment time and
seedling age on crop performance of Boro rice under
SRI.
• To find out the water management and soil stirring
effect on the performance of Boro rice under SRI
• To find out the effect of spacing and seedling raising
method on crop performance of Boro rice under SRI
• To find out the integrated use of manure and fertilizer
on crop performance in Boro season under SRI
• To find out the critical factors for higher performance
of Boro crop under SRI
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THE CRITICAL FACTORS OF SRI
To give effect to these factors, SRI is communicated in
terms of a set of practices or techniques which should be
understood as starting points for experimentation and for
fitting SRI to local conditions.
1. To start transplanting by young seedlings
• Preferably 8-12 days old and not more than 15 days
• When the plant still has just two small leaves and
the seed sac is still attached to the root
2. To transplant seedlings quickly and carefully
Allowing only 15-30 minutes between uprooting from
the nursery and planting in the field
3. Seedlings should be put 1-2 cm deep into soil that is muddy
but not flooded.
They should be laid into the soil with care, with roots
lying horizontally so that their root tips are not pointing
upward
THE CRITICAL FACTORS OF SRI
6. Keep the soil well drained
– No need to keep water continuously flooded during
the vegetative growth period.
– Panicle initiation stage, keep only a thin layer of water
on the field until 10-15 days before harvest,
A. Apply small amounts of water daily
– Just as much as needed to keep the soil moist and
saturated, but no standing water.
– During tillering stage, the field should be left to
dry out for several short periods (2-6 days), to the
point of surface hairy cracking,
B. Alternate Flooding and drying the field
– For alternating periods of 3-6 days each
throughout the period of vegetative growth.
An understanding of the critical factors
of SRI underlying the higher productivity
is yet to be developed.
It is needed to establish agro
ecologically suited critical factors of SRI
for sustainable productivity.
It is also needed to validate and
promote SRI technology for uptake to
Bangladeshi farmers.
Methodology to be followed
• The proposed research has been carried out at the
BRRI research farm at Gazipur.
• Total Six experiments will be conducted to fulfill the
above objectives.
• Experiments No. 1, 2, 3, 4 and 5 have been already
experimented.
• Based on the 1st year performance of experiments No.
1, 2, 3 and 4, Experiment No 5 has been designed for
2nd year.
• In 3rd year, experiment No. 6 has been under taken.