The document discusses the System of Rice Intensification (SRI), an agro-ecological methodology for increasing rice productivity with fewer inputs. SRI involves cultivating rice with organic manure, transplanting young seedlings singly in a square pattern with wider spacing, and keeping soil moist but not flooded through intermittent irrigation and frequent weeding. SRI results in higher yields from less seed, water, and labor through stimulating stronger root and plant growth. It debunks myths that rice requires flooded fields and instead promotes soil aeration to the benefit of rice plants and soil health.

1. Achieving more with less
System of rice intensification

2. What is SRI?
 An agro-ecological methodology for increasing the
productivity of irrigated rice by changing the
management of plants, soil, water and nutrients.
 More output from less input
 The System of Rice Intensification involves
cultivating rice with as much organic manure as
possible, starting with young seedlings planted
singly at wider spacing in a square pattern; and
with intermittent irrigation that keeps the soil moist
but not inundated, and frequent weeding that
actively aerates the soil.

3. The main concepts, ideas and
principles of SRI
Stimulating plant growth by:
 Transplanting young seedlings to preserve
growth potential
 Avoid disturbance to the roots - transplant
quickly and shallow, not inverting root tips
 Provide plants wider spacing - one plant per hill
and in square pattern

4. Enhance the growth and health of roots and of
soil Biota by:
 Keeping soil moist but not flooded - soil should be
mostly aerobic, not continuously saturated
 Aerating the soil frequently by weeding frequently
 Enhancing the soil organic matter content by the
addition of organic manure

5. History of SRI
 Put into practice in the early 1980s by French Jesuit
priest and agronomist Henri de Laulanié
 After many years of observation in field trials with
small-scale farmers in Madagascar, he came up with
the System of Rice Intensification (SRI); a system that
requires less
 Today it is one of the most rapidly growing rice
cultivation practices.

7. Breaking the rice myths
 We have been led to believe that rice is an aquatic
plant and grows best in standing water.
 But rice is not an aquatic plant; it can survive in water
but does not thrive under reduced oxygen (hypoxic)
levels.
 Rice plants spend lot of its energy to develop air
pockets (aerenchyma tissue) in its roots under
continuous inundation. Nearly 70% of rice root tips get
degenerated by flowering period.

8. SRI : debunking the myths
 The SRI rice fields are not flooded but kept moist
during the vegetative phase.
 Later about 1 inch of water is maintained.
 SRI requires only about half as much water as
normally applied in irrigated rice.
 Without the traditional flooded rice condition, rice
yield is increased from 20-100%

9. Comparison between conventional
and SRI method
Particulars Conventional method SRI
Spacing 15*10cm 25*25cm
No. of plants per sq. m 66 16
No. of seedlings per hill 3 1
No. of plants per acre 792000 64000
Seed requirement per acre 20kg 2kg
However SRI is initially labor intensive as it needs 50% more man-days
for transplanting and weeding.

10. SRI allows plant to grow healthy by:
 Large root volume
 Profuse and strong tillers - Maximum tillering (30
tillers/plant can be easily achieved; 50 tillers per plant are
quite attainable). Under excellent management even 100
fertile tillers per plant or even more can be achieved due to
early transplanting and absence of die back of roots.
 Non lodging
 Big panicles
 More and well filled grain panicles and higher grain weight
 Resists insects because it allows rice to absorb soil nutrients
naturally

11. Method:

12. Land preparation
 Land preparation is not different from regular irrigated
rice cultivation.
 Leveling should be done carefully so that water can be
applied very evenly.

13. Seedling preparation
 Seed rate 2 kg/acre
 Select healthy seeds
 Apply a layer of fine manure
 Spread seed sparsely
 Cover with another layer of manure
 Mulch with paddy straw
 Water carefully

14. Transplanting
 8-12 days old seedlings are transplanted
 Care should be taken during pulling out and
transplanting of seedlings
 Seedlings are transplanted shallow and therefore
establish quickly.
 Spacing is 25*25cm
 So, seedlings do not compete for nutrients, space and
sun, and develop stronger roots and more tillers.

15. Water application
 Instead of continuously flooding fields, plants only
receive the ideal amount of water and the soil is
temporarily kept dry. This favors soil microbial
development and reduces methane emissions.
 The purpose of irrigation is just to wet the soil, just
enough to saturate the soil with moisture
 Subsequent irrigation is only when soil develops fine
cracks.
 Regular wetting and drying of soil results in increased
microbial activity in the soil and easy availability of
nutrients to the plants.

16. Weed management
 Absence of standing water leads to more weed growth
in SRI.
 Incorporate the weeds in the soil by moving the
weeder between the rows
 Weeds close to the hills/tillers have to be removed by
hand
 Since weed has to be controlled manually using a
mechanical hand tool, the soil is well aerated, thereby
improving plant growth.

17. Organic fertilization
 Organic manure and compost is used for fertilization
 Compost / FYM applied instead of or in addition to
chemical fertilizer

18. Advantages
 Increase in yield/ha – 52% (21 to 105%)
 Increased net income/ha – 128% (59 – 412% )
 Reduction in cost of production – 24% (7 – 56%)
 Reduction in water requirement – 44% (24 – 60%)
 Shorter time to maturity (1-3 weeks less)
 Protection against biotic stresses pests/diseases
(Sheath blight, leaf folder, brown plant hopper) – 70%
reduction in incidence
 Tolerant to abiotic stresses - drought, storm damage,
extreme temperatures
 Higher milling outturn (by ~ 15%) – less chaffy

19. Disadvantages
 Higher labour costs in the initial years
 Difficulties in acquiring the necessary skills
 Not suitable when no irrigation source available

20. SRI in Nepal
 In Nepal, SRI was pioneered by Rajendra Uprety when
he was District Agriculture Extension Officer in
Morang. He read about it in an agriculture journal and
decided to give it a try.
 Today there are SRI tests and demonstrations being
carried out in 35 districts across the country.