Potentials of Integrated Nutrient

Management systems in Rice Cultivation in Sri Lanka

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

(01) Integrated

nutrient management is..

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.

(02) Why we must practice

it in our rice fields

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.

- 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….!!

(03) nutrient requirement

for rice plant

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..

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 110P2O5 34K2O 156MgO 23CaO 20S 5Fe 2Mn 2Zn 0.2Cu 0.15B 0.15Si 0.25Cl 25

(04) how to practice INM

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.

( I ) Artificially synthesized fertilizers

Triple Super Phosphate (TSP)

Urea

Mureate Of Potash (MOP)

Zinc Sulphate (ZnSO4)

“…Paddy consumes the largest proportion of imported chemical

fertilizers,

It accounts for approximately 50% of the overall use of chemicals

fertilizers in Sri Lanka….”

Do you know..??

( 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

(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)

(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.

Sesbania rostrata (diya siyambala)

Cassia occidentalis (panithora)

Crotalaria juncea(sunhemp)

Gliricidea maculata (makulatha)

Tithonia diversifolia (wild Sunflower)

Thespesia populnea(Sooriya)

(05) what are the

limitations in INM

- 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

- 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

(06) how to overcome

those

- 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.

- 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

(07) what are the potentials

in Sri Lanka

- 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

Thank You..