1. Potentials of
Integrated Nutrient Management
systems in
Rice Cultivation in Sri Lanka

2. Content
1) Integrated nutrient management (INM) is..
2) Why we must practice it in rice fields
3) nutrient requirement for rice plant
4) how to practice INM
5) what are the limitations in INM
6) how to overcome those
7) what are the potentials in Sri Lanka

3. (01)
Integrated
nutrient management is..

4. IPNS is a holistic approach
to plant nutrition by obtaining
the nutrients available from
different sources such as
inorganic and organic sources
to maintain and sustain soil fertility.
This will enhance crop productivity in a
framework of an ecologically
accommodated, socially acceptable
and economically viable situation.

5. (02)
Why we must practice it
in our rice fields

6. There are many Advantages …
- Enhances the availability of applied nutrients
as well as native soil nutrients.
- Synchronizes the nutrient demand of the crop,
with nutrient supply from native and applied
sources.
- Provides balanced nutrition to crops and
minimizes the antagonistic effects resulting from
hidden deficiencies and nutrient imbalance.
- Improves and sustains the physical, chemical
and biological functioning of soil.

7. - Minimizes the deterioration of soil, water and
ecosystem by promoting carbon sequestration,
reducing nutrient losses to ground and surface
water bodies and to atmosphere
- Increase fertilizer use efficiency
chemical fertilizer yield from only chemical fertilizer
+ > or
organic manure yield yield from only organic manure
- Generally rice growing soils in SL are low in
organic matter and poor in available P amount so
application of organic manure is definitely increase
the yield….!!

8. (03)
nutrient requirement
for rice plant

9. There are 17 essential elements for a rice plant to
grow and develop properly.
These elements can be grouped into
macro-elements : C, H, O, N, P, S, K, Mg, Ca
and
micro-elements : Fe, Mn, Cu, Zn, Mo, B, Cl
Modern high-yielding rice varieties producing
around 5 t/ha of grain, in general, can remove
from the soil about..

10. Removals of Si and K2O are
particularly large if the
panicles and straw are taken
away from the field at
harvest.
However, if only the grains
are removed and the straw is
returned and incorporated
back into the soil, the
removal of Si and K2O is
greatly reduced, although
significant amounts of N and
P2O5 are still removed.
Nutrient Weight (kg per 5ha)
N 110
P2O5 34
K2O 156
MgO 23
CaO 20
S 5
Fe 2
Mn 2
Zn 0.2
Cu 0.15
B 0.15
Si 0.25
Cl 25

11. (04)
how to practice INM

12. Use combinations of
- synthetic fertilizers (Urea, TSP, MOP),
- mineral (ERP, Dolomite)
- organic fertilizers (farmyard manure,
green manure, crop residues etc.)
obtained on farm and off farm for
recycling of nutrients.
Using proper application methods
such as Broadcasting, Placement,
Foliar application and Fertigation.

13. ( I ) Artificially synthesized fertilizers
Triple Super Phosphate
(TSP)
Urea

14. Mureate Of Potash
(MOP)
Zinc Sulphate
(ZnSO4)

15. “…Paddy consumes the largest
proportion of imported chemical
fertilizers,
It accounts for approximately 50%
of the overall use of chemicals
fertilizers in Sri Lanka….”

16. ( II ) Organic manure
There are various sources of organic
manure to be used for INM. Some of
these are mentioned below
- Compost
- Farm Yard Manure (FYM)
- Poultry Manure
- Piggery manure
- Urban and rural solid and liquid waste
- Wastes from agro based industries
- Crop wastes
- Vermicompost

18. (III) Crop residues
- Rice straw
- Rice husk
- Bean straw
- Sugarcane trash
- Cowpea stems
- Wood ashes
-1/3 of N required by Rice plant
could be provide by Rice straw
- Rice straw can provide almost
all K Requirement (30-40 g/ha)

19. (IV) Green Manure
- Provide N, organic matter and improve soil
fertility. Grown before and after rice crop.
- Can be broadcast in to standing rice crop
shortly before harvesting.
- Also can be broadcast into rice stubble without
cultivation.
- Can grown in bunds of rice fields or in fallow
lands during the off season and their leaves are
incorporated.

20. Sesbania rostrata
(diya siyambala)
Cassia occidentalis
(panithora)

21. Crotalaria juncea
(sunhemp)
Gliricidea maculata
(makulatha)

22. Tithonia diversifolia
(wild Sunflower)
Thespesia populnea
(Sooriya)

23. (05)
what are the
limitations in INM

24. - Financial credit is available only for
mineral fertilizer.
- No organized credit system to promote
organic fertilizer
- Farmers who have domesticated
animals, do not have facilities to collect,
store and market their animal waste.
- Low awareness about using biofertilizers
- Non-availability of water

25. - Chemical fertilizers are easily
available and easy to use
- Organic manure is not available in
own holdings most of time
- Storage and retail marketing of
organic manure is limited, is not easily
accessible to most farmers
- Scarcity of labour

26. (06)
how to overcome
those

27. - Initiatives have to be directed to utilize
all available organic materials such as
rice straw, animal manure and paddy
husk, and incentives have to be given
for the popularization of same
- Large scale on farm and off farm
production of organic manure should be
encouraged in Island wide
- Planting of Gliricidia, or Ipil Ipil on the
major bunds and hedge rows to supply
green manure.

28. - Use of charred rice husk.
- Cultivation of sandwich crops.
- Encourage farmers who practicing
IPNM methods by providing subsidies
and monetary prizes.
- Make new rules and regulations to
boost organic manure usage.
- Introducing new green manure
crops and latest composting methods

29. (07)
what are the potentials
in Sri Lanka

30. - Inherit tropical climate which helps to
practice INM (microbial, environmental
etc)
- Not producing artificially synthesized
fertilizers locally (so organic manure
usage is a must)
- naturally grown evergreen vegetation in
any rice growing agroecological zone
- large phosphate mineral deposition in
Eppawala and dolomite deposition in
Matale area

31. Thank You..