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SRI (System of Rice Intensification) Photo: Jim Evans · CC BY-SA 4.0 · source ↗

SRI (System of Rice Intensification)

The System of Rice Intensification (SRI) is a rice agronomy package developed in Madagascar in the 1980s by Fr Henri de Laulanie and adapted to Indian conditions from 2000 onward by ICAR-NRRI Cuttack, WASSAN, PRADAN, ANGRAU and a network of state agriculture departments. It rests on four principles - young single seedlings, wide square spacing, intermittent moist (not flooded) soil, and mechanical weeding with organic matter - and is promoted as a low-input, water-saving alternative to conventional puddled transplanting.

Principle

Conventional puddled transplanting suppresses rice tillering, root development and panicle exsertion by clumping multiple older seedlings together under continuous flooding. SRI removes those penalties: single 8-12 day seedlings transplanted at 25 x 25 cm in moist (not flooded) soil produce 30-80 tillers per plant, large root systems and panicles with 200-400 filled grains - versus 8-15 tillers and 80-150 grains in conventional crops.

Procedure

A raised, well-prepared dry nursery is sown sparsely so seedlings emerge with intact root mass. Seedlings are transplanted at 8-12 days old with the lifted root and a piece of nursery soil placed shallow, one seedling per hill, on a 25 x 25 cm square grid using a marker. The field is kept moist but not flooded for the first 35-40 days, with a thin water film restored after panicle initiation. Cono-weeder is rotated between rows three to four times during the vegetative phase. Compost, FYM and green manure provide most nutrients, supplemented by mineral fertiliser as needed.

Where it applies

SRI suits assured-irrigation tracts with controlled water inlets - canal commands, lift irrigation, tank-irrigated paddy - and farmers with access to enough labour for square-grid planting and cono-weeding. It has been demonstrated and adopted in Tamil Nadu (TANSRI), Andhra Pradesh, Telangana, Tripura, Odisha, Chhattisgarh, Karnataka, Bihar, Jharkhand and Uttarakhand. Documented yield gains range from 15-30% with 30-50% irrigation-water savings and 15-25% seed-rate savings.

Limitations

Square-grid planting at 25 x 25 cm with single 8-day seedlings is labour-intensive on first adoption; manual transplanters and motorised markers ease the constraint. Continuous flooding is required for snail and weedy-rice suppression in some areas, conflicting with SRI's moist regime. Yield gains depend critically on prompt cono-weeding and good drainage during the moist phase - poorly drained low-lying plots default back to flooded SRI with smaller advantage.

See also Rice Alternate Wetting Drying Awd, Transplanting Paddy, Paddy Nursery Management, Paddy Water Management, Paddy Weed Management.

Sources

  1. System of Rice Intensification: A Methodology Brief. ICAR-National Rice Research Institute, Cuttack.
  2. SRI Package of Practices. WASSAN / SRI-India network.