METHODS OF CROP ESTABLISMENT OF RICE

INTRODUCTION Establishment stage is an important practice in rice cultivation It is done at the end of the land preparation Establishment methods of rice are changed with; Resource availability (inputs, labor, capital- financial and mechanical) Environmental conditions (rainfall, moisture availability) Age of the variety to be sown Technological advancement of the society

TYPES OF ESTABLISHMENT METHODS Direct seeding Transplanting Strip crushing Nawa kekulama System of Rice Intensification(SRI method) Parachute method

DIRECT SEEDING Direct Seeding Wet Seeding Row Seeding Random Seeding (Broadcasting) Dry Seeding (Kekulama)

DIRECT SEEDING (contd.) Sowing of seeds directly onto the soil Categorize into two groups; according to the seed condition/seed nature to be sown Dry seeding Wet seeding Both dry and wet seeding methods can subdivided as; Row seeding Random seeding(broadcasting) Row and random seeding can be done by either Manually or Mechanically

WET SEEDING Use pre-germinated/sprouted seeds Field is puddled, leveled and free from standing water when seeding Basal fertilizer mixtures are added at the time of puddling Intermittent irrigation is done after germination/emerging of coloeptile

DRY SEEDING Use ungerminated dry seeds Field is either ploughed or harrowed according to the environmental conditions Field is dry(no water) or moist soil Sowing with anticipating of rains(onset of the rainy season) After sowing/seeding harrowing is done again to cover-up the seeds With the rain, seeds are germinated Called as Kekulam or Manawari method Seed rate is high than other methods (150-300 kg/ha)

RANDOM AND ROW SEEDING ROW SEEDING Both dry seeding and wet seeding can be divided into those two groups ROW SEEDING Pre-germinated or ungerminated seeds are sown/established according to the parallel rows in the field Manual or mechanical seeding Machine seeding using seeders is popular When use of seeders it is difficult to use pre- germinated seeds

RANDOM AND ROW SEEDING (contd.) RANDOM SEEDING Pre-germinated or ungerminated seeds are sown random manner in the field Normally called as broadcasting of seeds Can be done by manually or using broadcasting machines Difficult to use broadcasting machines when apply wet seeds(pre-germinated seeds) Seed rate is about 100-200 kg/ha

DIRECT SEEDING Advantages Disadvantages Well establishment of plants (undamaged vigorous root system) No transplanting shock to the plant Suitable method for short duration varieties Disadvantages High weed growth if not controlled properly Mechanical weed control is difficult Seed wastage is high due to bird, rodent attack and flood, drought

TRANSPLANTING Field planting of young rice seedlings (12-14days old) taken from nurseries Plant 2-4 healthy seedlings per hill Spacing can change with the age of the variety Generally recommended for; For 4-4 1/2 months varieties (for 3-3 1/2 months varieties should transplant in young stage) When land preparation is not up to the standard and water management is poor

TRANSPLANTING (contd.) Recommended spacing by Department of Agriculture is; In transplanted rice, major yield determining factor is the age of seedlings Variety Spacing (cm) Plant density (hills per m2) 4 – 4 ½ months 20x20 25 3 – 3 ½ months 20x15 30-35

TRANSPLANTING (contd.) Transplanting is done by manually or mechanically Also it can be done by random or row manner For machine transplanting special type of nurseries are needed Seed rate ranges from 100 – 150 kg/ha

STRIP CRUSHING First, broadcast pre-germinated or ungerminated seeds After emerging of seedlings, crush excessive seedlings remaining rows Use Japanese Rotary Weeder to crush the plants Advantages Easy to control weeds Have more space to tillering (inter row spacing is high) Disadvantages More seed wastage Labor and time consuming method

NAWA KEKULAMA METHOD More similar to the kekulama method Sow ungerminated (dry) seeds onto the moist soil/dry soil Water saving method Use organic matter to build up soil structure Use straw mulch after sowing Mulch Reduce weed growth Reduce moisture loss Seed rate is lower than Kekulama method

NAWA KEKULAMA METHOD (contd.) Advantages Paddy straw mulch has a weedicide effect Suppress the weed growth at critical growth stage of rice plant Can reduce water wastage Reduce birds, rodents attack Reduce agro-chemical use Disadvantages Uncertainty of rainfall Yield may be lower than lowland methods

SYSTEM OF RICE INTENSIFICATION (SRI METHOD) A transplanting method Use inter-row and intra-row spacing much higher than normal transplanting methods Spacing differ with the variety as 25x25 cm, 30x30 cm, 40x40 cm, 50x50 cm Aim is to capturing full potential of tillering and full root growth potential No flooding, only intermittent watering of fields Roots are ‘L’ shape after transplanting Seed rate is about 10 kg/ha

SYSTEM OF RICE INTENSIFICATION (SRI METHOD) Advantages Water requirement is low Low seed requirement Less chemical use for weed control High tillering ability Disadvantages High labor requirement Cost of production is high Time consuming method Suitable for long duration varieties )at least 3 – 3 ½ months variety)

PARACHUTE METHOD A transplanting method Rice seeds are plant on a nursery tray filled with suitable medium After grown them up to 2-3 leaf stage thy are randomly spread out onto the puddled field with the root ball

DIRECT SEEDING vs TRANSPLANTING -Relatively cheaper than transplanting -Relatively costly -Require less labor -labor requirement is high -Average yield is high -Average yield is lower excepting long aged varieties -Plants are usually healthier and have stronger, deeper root system -Plants have not vigorous deep root system -Final plant cover is random and looks natural -Final plant cover is regular -Large amount of seed is required -Seed requirement is less -Plant density is higher -Plant density is optimum -Weed control is difficult -Easy of weed control

Distribution of the methods of establishment of rice in Sri Lanka 99/2000 Maha 2000 Yala Broadcasting 79% 85.5% Row seeding 0.3% 0.1% Transplanting in rows 3.3% 1.4% Transplanting random 15.7% 12.6% Source: Department of Agriculture

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