Chemical Fertilizer Application

Any one of the following fertilizer sets can be applied per acre as per the requirement of the rice variety and season:

Fertilizer Schedule for Different Types of Aman Rice (kg per acre)

Top Dressing (Nitrogen)

• 1st Top Dressing (15 days after transplanting):
  Urea – 22.25 kg (Deshi), 26.50 kg (Early), 35.50 kg (Late shallow), 31.50 kg (Medium), 22.25 kg (Deep)
• 2nd Top Dressing (at panicle initiation):
  Urea – 11.00 kg (Deshi), 13.25 kg (Early), 17.50 kg (Late shallow), 15.00 kg (Medium), 11.00 kg (Deep)

Note: In sandy soils, potash fertilizer should be applied in splits. Along with NPK, sulphur and zinc application is necessary. Apply 4–8 kg sulphur and 10 kg zinc sulphate per acre. If Single Super Phosphate is used as the source of phosphorus, separate sulphur application is not required.

Fertilizer Application for Boro Rice

Apply 8–10 cartloads of well-decomposed cow dung or compost manure per acre during the first ploughing. Use chemical fertilizers according to soil test recommendations. Otherwise, follow the schedule given below.

At the time of final puddling (before last ploughing), apply 1/4th of the total nitrogen and the full dose of phosphate and 3/4th of the total potash. Mix them thoroughly with the soil. The remaining 3/4th nitrogen and 1/4th potash should be applied as top dressing in splits. Nitrogen application can be adjusted using the Leaf Colour Chart (LCC).

Recommended Fertilizer Dose for Boro Rice (kg per acre)

Apply 8 kg sulphur per acre. If half of the total phosphate is applied in the form of Single Super Phosphate, separate sulphur application is not needed.

In zinc-deficient areas, apply 10 kg zinc sulphate per acre as basal dose or with the first top dressing. For foliar application, spray 0.5 g chelated zinc per litre of water at 1 month and 1.5 months after transplanting.

Fertilizer Sets for High-Yielding Boro Rice (kg per acre)

Fertilizer Sets for Hybrid Boro Rice (kg per acre)

Direct Seeding (Aus and Aman)

For direct seeding of Aus or Aman rice, use a drum seeder or seed drill, or sow in lines 20 cm (8 inches) apart behind the plough. This method reduces seed requirement and makes weeding easier. In rain-fed areas, sow seeds 5–6 cm deep and level the field with a harrow. Boro rice is not sown directly.

Transplanting (Aus, Aman and Boro)

• For transplanted Aus: Use 20 cm × 10 cm (8″ × 4″) spacing.
• For Aman rice:
• Early varieties: 20 cm × 10 cm
• Medium varieties: 20 cm × 15 cm
• Late varieties: 20 cm × 20 cm

Generally, 3–4 seedlings per hill are sufficient. In deep water, older seedlings, or saline soils, use 7–8 seedlings per hill. Keep some extra seedlings in one corner of the field for gap filling within 7 days of transplanting.

Timing:

• Aus transplanting should be completed by Ashar (June–July).
• Aman transplanting should be completed between Ashar and Shravan (July to mid-August). Ideal seedling age: 3 weeks for early, 4 weeks for medium, and 5 weeks for late varieties (when 4–5 leaves have emerged). Do not plant deeper than 5 cm (2 inches).
• Boro transplanting should be completed by mid-Magh (end of January). Use 5–6 leaf stage seedlings (about 5 weeks old) at 20 cm × 15 cm spacing with 4–5 seedlings per hill. In saline areas, use 6–7 seedlings per hill. In brown plant hopper prone areas, leave every 15–20 lines blank as a trap.

Irrigation (Aus, Aman and Boro)

Broadcast Aus rice is mostly rain-fed. Provide irrigation every 7–10 days if rainfall is insufficient.

For transplanted rice, maintain a thin film of water (about 5 cm or 2 inches) from transplanting until 10–15 days before harvest. Avoid continuous deep flooding.

In Boro rice, water shortage at the panicle initiation stage severely reduces yield. Shortage during tillering can be compensated later, but water stress at the booting stage causes heavy loss.

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