📘 Handbook on Fertilizers: Farming Guide
🧩 1. Introduction to Fertilizers
Fertilizers are substances that provide essential nutrients to plants to promote growth, improve yield, and restore soil fertility. Modern farming relies on fertilizers to maintain productivity as soils gradually lose nutrients due to continuous cultivation.
🕰️ 2. Evolution of Fertilizers (Historical Development)
A. Prehistoric & Ancient Agriculture
- Early farmers used animal manure, kitchen waste, ash, bones, and compost.
- Ancient civilizations (Egypt, China, India) documented the use of manure and green crops to maintain soil fertility.
B. Middle Ages
- Introduction of crop rotations, especially legumes, which naturally fix nitrogen.
- Animal manure became more widely used across Europe.
C. 19th Century: Scientific Breakthrough
- 1840: Justus von Liebig discovered that plants require specific nutrients — the basis of modern fertilizer science.
- Development of superphosphate (first chemical fertilizer), made by treating phosphate rock with sulfuric acid.
D. 20th Century: Industrial Fertilizers
- 1910s: Haber–Bosch process enabled industrial synthesis of ammonia, revolutionizing nitrogen fertilizers.
- Mass production of NPK fertilizers, chemical blends targeting specific plant needs.
E. 21st Century: Smart Fertilizers
Modern fertilizers focus on efficiency, sustainability, and environmental protection:
- Nano fertilizers
- Controlled-release fertilizers
- Biofertilizers
- Microbial inoculants
- Fertigation-grade soluble fertilizers
🧪 3. Essential Plant Nutrients
Plants need 17 essential nutrients, grouped as:
Primary Macronutrients (Required in large amounts)
- Nitrogen (N) – leaf growth
- Phosphorus (P) – root & flower development
- Potassium (K) – disease resistance & quality
Secondary Macronutrients
- Calcium (Ca)
- Magnesium (Mg)
- Sulfur (S)
Micronutrients
- Zinc (Zn), Iron (Fe), Copper (Cu), Boron (B), Manganese (Mn), Molybdenum (Mo), Chlorine (Cl)
🧭 4. Types of Fertilizers (Detailed Classification)
A. Based on Origin
1. Organic Fertilizers
Derived from natural sources.
| Fertilizer | Source | Benefits |
|---|---|---|
| Farmyard manure (FYM) | Animal waste | Improves soil structure |
| Compost | Plant/food waste | Adds organic matter |
| Vermicompost | Earthworms | Nutrient-rich |
| Bone meal | Animal bones | Slow-release Phosphorus |
| Oil cakes | Mustard, neem | Nitrogen & pest control |
2. Inorganic / Chemical Fertilizers
Manufactured industrially for specific nutrient supply.
| Fertilizer | Nutrient Provided |
|---|---|
| Urea | Nitrogen |
| DAP (Diammonium Phosphate) | N & P |
| MOP (Muriate of Potash) | Potassium |
| MAP | Soluble Phosphorus |
| 19:19:19 | Balanced NPK |
| SSP (Single Super Phosphate) | P + S |
3. Biofertilizers
Living microorganisms improving nutrient uptake.
| Type | Role |
|---|---|
| Rhizobium | Fixes nitrogen in legumes |
| Azotobacter | N fixation for non-legumes |
| PSB (Phosphate Solubilizing Bacteria) | Makes P available |
| Trichoderma | Improves disease resistance |
4. Special Fertilizers
| Fertilizer | Description |
|---|---|
| Nano fertilizers | High efficiency, low dose |
| Chelated micronutrients | Highly absorbable metals |
| Slow-release fertilizers | Controlled nutrient release |
| Water-soluble fertilizers (WSF) | Best for drip & fertigation |
📊 5. Fertilizer Chart / Layout (Easy-to-Use Tables)
A. Nutrient Content of Major Fertilizers
| Fertilizer | N% | P% | K% | Notes |
|---|---|---|---|---|
| Urea | 46 | – | – | Quick N source |
| DAP | 18 | 46 | – | Best for basal |
| MAP | 12 | 61 | – | Soluble |
| SSP | – | 16 | – | Contains sulfur |
| MOP | – | – | 60 | Avoid in chloride-sensitive crops |
| SOP | – | – | 50 | Chloride-free K |
| 19:19:19 | 19 | 19 | 19 | Balanced WSF |
| 13:0:45 | 13 | – | 45 | Flowering stage |
| 00:52:34 | – | 52 | 34 | Bud stage |
B. Crop-Wise Fertilizer Requirement Chart (Per Hectare)
1. Cereals
| Crop | N (kg) | P₂O₅ (kg) | K₂O (kg) |
|---|---|---|---|
| Rice | 80–120 | 40–60 | 40–50 |
| Wheat | 100–150 | 50 | 40 |
2. Pulses
| Crop | N | P₂O₅ | K₂O |
|---|---|---|---|
| Chickpea | 20 | 40 | 20 |
| Pigeon pea | 25 | 50 | 25 |
3. Oilseeds
| Crop | N | P₂O₅ | K₂O |
|---|---|---|---|
| Groundnut | 20 | 40 | 40 |
| Mustard | 60 | 40 | 20 |
4. Vegetables (General)
| Stage | Fertilizer | Dose |
|---|---|---|
| Basal | FYM | 10–20 tons |
| Growth | Urea | 40–60 kg |
| Flowering | 13:0:45 or 19:19:19 | 10–15 kg |
| Fruiting | MOP/SOP | 20–30 kg |
5. Fruit Trees (Annual Requirement per Mature Tree)
| Fruit | Fertilizer/Year | Application Schedule |
|---|---|---|
| Mango | 1 kg NPK + 20 kg manure | 2–3 splits |
| Banana | 200g NPK/month | Monthly fertigation |
| Citrus | 600g NPK | 3 splits |
🧴 6. How to Use Fertilizers (Application Methods)
A. Basal Application
Applied during land preparation to strengthen roots.
- DAP
- SSP
- FYM
B. Top Dressing
Applied after plant establishment.
- Urea
- Ammonium sulfate
C. Foliar Spray
For immediate nutrient correction.
- Micronutrients
- WSF like 19:19:19
D. Fertigation
Through drip irrigation.
- Only water-soluble fertilizers
- Used weekly or biweekly
E. Side Dressing
Placed beside plant rows.
- Vegetables, maize, sugarcane
F. Broadcasting
Manual spreading; suitable for rice & wheat.
🔔 7. Safety & Best Practices
- Always follow soil testing to avoid overuse.
- Do not mix calcium with sulfates or phosphates in one tank.
- Apply nitrogen in splits to avoid losses.
- Use organic matter to improve fertilizer efficiency.
- Ensure adequate moisture when applying fertilizers.
🧾 8. Conclusion
Fertilizers have evolved from simple organic materials used by ancient civilizations to modern, scientifically formulated nutrient solutions designed for precision agriculture. Proper fertilizer knowledge is essential for sustainable farming — from understanding nutrient roles and soil conditions to selecting the right type and application method.
When used correctly, fertilizers:
- Increase yields
- Improve crop quality
- Restore depleted soils
- Promote long-term sustainability
But misuse can lead to:
- Soil degradation
- Reduced fertility
- Environmental harm
Therefore, the key to successful farming lies in balanced, responsible, and informed fertilizer management, integrating both organic and inorganic sources, supported by soil testing and modern application techniques like fertigation.
Healthy soils and correct fertilization practices ensure healthier crops, better harvests, and sustainable agriculture for future generations.
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