Fertilizers are broadly categorized into different types based on their origin, composition, and mode of application. Here’s an overview of the major types of fertilizers available in the market:

1. Nitrogen-Based Fertilizers

  • Ammonium Nitrate: High nitrogen content, promotes rapid plant growth and greening.
  • Urea: Most common nitrogen fertilizer, with 46% nitrogen content.
  • Ammonium Sulfate: Contains both nitrogen and sulfur, used for crops requiring additional sulfur.
  • Calcium Nitrate: Supplies calcium and nitrogen, improves soil pH and plant strength.

2. Phosphorus-Based Fertilizers

  • Single Super Phosphate (SSP): Contains phosphorus, sulfur, and calcium.
  • Triple Super Phosphate (TSP): Higher concentration of phosphorus compared to SSP.
  • Monoammonium Phosphate (MAP): Contains both nitrogen and phosphorus, widely used in crops needing balanced nutrients.
  • Diammonium Phosphate (DAP): Popular phosphorus fertilizer with added nitrogen.

3. Potassium-Based Fertilizers

  • Potassium Chloride (Muriate of Potash – MOP): Most common potassium source, used widely in farming.
  • Potassium Sulfate (Sulfate of Potash – SOP): Contains potassium and sulfur, ideal for chloride-sensitive crops.
  • Potassium Nitrate: Supplies potassium and nitrogen, suitable for fertigation.

4. Compound (NPK) Fertilizers

  • Combines nitrogen (N), phosphorus (P), and potassium (K) in various proportions (e.g., 10-10-10, 20-20-20).
  • Suitable for balanced nutrient supply, tailored to crop-specific needs.

5. Micronutrient Fertilizers

  • Zinc Sulfate: Provides zinc for better crop growth and grain development.
  • Boron Fertilizers: Borax or boric acid supplements crops with boron.
  • Iron Fertilizers: Chelated iron compounds or ferrous sulfate for iron-deficient soils.
  • Other Micronutrients: Manganese, copper, and molybdenum fertilizers to address specific deficiencies.

6. Organic Fertilizers

  • Animal Manure: Cow dung, poultry litter, and pig manure enrich soil with organic matter and nutrients.
  • Compost: Decomposed organic waste that improves soil structure and fertility.
  • Bone Meal: Rich in phosphorus and calcium, often used in organic farming.
  • Green Manures: Cover crops (e.g., clover, alfalfa) that are tilled into the soil to improve fertility.

7. Biofertilizers

  • Rhizobium: Enhances nitrogen fixation in legumes.
  • Azotobacter and Azospirillum: Non-symbiotic nitrogen-fixing bacteria for non-leguminous crops.
  • Phosphate-Solubilizing Bacteria (PSB): Help in phosphorus availability to plants.
  • Mycorrhizal Fungi: Improves nutrient and water absorption through root associations.

8. Slow-Release and Controlled-Release Fertilizers

  • Coated Fertilizers: Urea or other nutrients coated with polymers for gradual nutrient release.
  • Sulfur-Coated Urea: Slow nitrogen release over time.
  • Suitable for reducing nutrient loss and improving efficiency.

9. Liquid Fertilizers

  • Anhydrous Ammonia: Highly concentrated nitrogen source, applied directly to soil.
  • Ammonium Polyphosphate: Liquid fertilizer supplying nitrogen and phosphorus.
  • Micronutrient Solutions: Liquid formulations of zinc, iron, manganese, etc.
  • Used in foliar application or fertigation systems.

10. Specialty Fertilizers

  • Water-Soluble Fertilizers: Ideal for hydroponics and fertigation, dissolves completely in water.
  • Foliar Fertilizers: Sprayed directly on leaves for quick nutrient absorption.
  • Customized Fertilizers: Tailored blends for specific soil and crop requirements.

11. Secondary Nutrient Fertilizers

  • Gypsum (Calcium Sulfate): Provides calcium and sulfur, improves soil structure.
  • Magnesium Sulfate (Epsom Salt): Supplies magnesium and sulfur for photosynthesis and growth.
  • Lime (Calcium Carbonate): Neutralizes soil acidity, adds calcium.

Each type of fertilizer has its specific advantages and is chosen based on crop requirements, soil conditions, and farming practices.