Proper fertilization is crucial for maximizing cereal crop yields while maintaining soil health. This guide covers scientifically proven fertilizer practices for wheat, rice, maize, and millets, including NPK ratios, organic alternatives, and precision techniques.
1. Understanding Macronutrient Requirements
Cereal crops need three primary nutrients in balanced proportions:
| Nutrient | Role | Deficiency Signs | Best Sources |
|---|---|---|---|
| Nitrogen (N) | Promotes leaf & stem growth. | Yellowing leaves, stunted growth. | Urea, DAP, compost. |
| Phosphorus (P) | Supports root & grain development. | Purple leaves, poor tillering. | DAP, SSP, bone meal. |
| Potassium (K) | Improves drought & disease resistance. | Brown leaf edges, weak stems. | MOP, SOP, wood ash. |
General NPK Recommendations for Cereals
| Crop | N (kg/ha) | P (kg/ha) | K (kg/ha) |
|---|---|---|---|
| Wheat | 120-150 | 60-75 | 40-60 |
| Rice | 100-120 | 50-60 | 40-50 |
| Maize | 150-180 | 70-80 | 60-80 |
| Millets | 50-80 | 30-40 | 20-30 |
2. Fertilizer Application Techniques
A. Basal Dose (At Sowing/Transplanting)
- Apply 50% N, 100% P, 50% K before planting.
- Mix with soil or place 5-7 cm deep near roots.
- Best fertilizers:
- DAP (18:46:0) – Good P source.
- SSP (0:16:0) – Cheaper but slower-acting.
B. Top Dressing (During Growth Stages)
- 1st Dose (Tillering – 20-25 DAS): 25% N.
- 2nd Dose (Panicle Initiation – 45-50 DAS): 25% N + 50% K.
- Best for N supplementation:
- Urea (46% N) – Most common.
- Ammonium Sulfate (21% N + 24% S) – Good for sulfur-deficient soils.
C. Foliar Spray (For Quick Nutrient Fixes)
- Use 2% urea (for N deficiency) or 0.5% ZnSO₄ (for zinc deficiency).
- Spray early morning or late evening to avoid leaf burn.
3. Organic & Natural Fertilizer Options
For organic farming or reducing chemical dependency:
| Fertilizer | Nutrient Content | How to Use |
|---|---|---|
| Vermicompost | 1-2% N, 1% P, 1% K | 5-10 tonnes/ha (basal application). |
| Farmyard Manure (FYM) | 0.5% N, 0.2% P, 0.5% K | 10-15 tonnes/ha (before sowing). |
| Jeevamrit (Liquid Biofertilizer) | NPK + microbes | 500 L/acre (soil drenching). |
| Neem Cake | 4-5% N, 1% P, 1.5% K | 250-500 kg/ha (controls nematodes). |
4. Precision Fertilization Methods
A. Soil Testing (Essential for Efficiency)
- Test soil every 2-3 years (₹200-500/test at KVKs).
- Adjust NPK based on soil health reports.
B. Leaf Color Chart (LCC) for Nitrogen Management
- Measures leaf greenness to optimize urea application.
- How it works:
- If LCC reading < 3 (pale leaves), apply extra N.
- If > 4 (dark leaves), skip N to avoid lodging.
C. Drip Fertigation (For Maize & Hybrid Rice)
- Saves 30% fertilizer by direct root-zone delivery.
- Best for urea, SOP (soluble potassium).
5. Crop-Specific Fertilizer Tips
Wheat
- Avoid excess N (causes lodging).
- Zinc & sulfur often needed in Indo-Gangetic soils.
Rice
- Use ammonium sulfate in waterlogged fields (reduces N loss).
- Silicon (rice hull ash) strengthens stems.
Maize
- High N demand – Split into 3 doses.
- Zinc & boron critical for grain filling.
Millets
- Low fertilizer needs – Excess N reduces drought tolerance.
- Biofertilizers (Azospirillum) boost growth.
6. Common Mistakes to Avoid
Overusing urea → Wastes money, pollutes water.
Ignoring micronutrients (Zn, B, S) → Limits yield.
Uneven application → Patchy crop growth.
7. Government Subsidies on Fertilizers
- Urea: Subsidized at ₹242/bag (fixed by GoI).
- DAP & NPK: Under Nutrient-Based Subsidy (NBS) scheme.
- Organic Farming: PKVY offers ₹50,000/acre aid.
FAQs
Q: How much urea per acre for wheat?
A: 100-120 kg/acre (split into 2-3 doses).
Q: Can I replace DAP with organic P sources?
A: Yes! Use rock phosphate (20-30% P) + compost.
Q: Which fertilizer increases grain size?
A: Potassium (SOP) + boron at flowering stage.
