Organic Nutrient Sources and Their Fortification 

In organic farming, various organic materials are used as nutrient sources for crops. These materials provide essential macronutrients like nitrogen (N), phosphorus (P), potassium (K), as well as secondary and micronutrients. Fortification of these sources involves supplementing them with additional nutrients to enhance their efficiency. Below is a detailed discussion of common organic nutrient sources along with their nutrient content in percentages and the fortification strategies employed for organic farming.

1. Compost

• Description: Compost is decomposed organic material, primarily consisting of plant residues, animal manure, and food waste.
• Nutrient Content:
  • Nitrogen (N): 1-2%
  • Phosphorus (P): 0.5-1%
  • Potassium (K): 1-2%
  • Calcium (Ca): 1-2%
  • Magnesium (Mg): 0.5-1%
• Fortification: Compost can be fortified with additional nutrients to address specific soil deficiencies:
  • Rock phosphate for phosphorus supplementation.
  • Blood meal or neem cake for nitrogen enrichment.
  • Bone meal for additional calcium and phosphorus.

2. Farmyard Manure (FYM)

• Description: Composed of dung, urine, bedding materials (straw, sawdust), and other organic matter from livestock.
• Nutrient Content:
  • Nitrogen (N): 0.5-1.5%
  • Phosphorus (P): 0.1-0.5%
  • Potassium (K): 0.5-1%
  • Calcium (Ca): 1-2%
  • Magnesium (Mg): 0.2-0.5%
• Fortification:
  • Zinc sulfate for zinc.
  • Dolomite for magnesium and calcium.
  • Fish meal for nitrogen enrichment.

3. Green Manure

• Description: Plants, usually legumes, grown to be tilled into the soil to enhance soil organic matter and provide nutrients.
• Nutrient Content (depending on species):
  • Nitrogen (N): 2-5% (legumes fix atmospheric nitrogen)
  • Phosphorus (P): 0.1-0.3%
  • Potassium (K): 0.5-1.5%
  • Calcium (Ca): 0.5-1%
  • Magnesium (Mg): 0.2-0.5%
• Fortification:
  • Green manure can be supplemented with biofertilizers like Rhizobium (to enhance nitrogen fixation) and enriched with rock phosphate for phosphorus.

4. Vermicompost

• Description: Compost produced by the activity of earthworms feeding on organic material.
• Nutrient Content:
  • Nitrogen (N): 1-2%
  • Phosphorus (P): 0.5-1%
  • Potassium (K): 1-1.5%
  • Calcium (Ca): 2-4%
  • Magnesium (Mg): 0.5-1%
• Fortification:
  • Humic acids for soil structure improvement and nutrient retention.
  • Rock phosphate for phosphorus fortification.
  • Micronutrient mixtures (like zinc, copper) for trace element deficiencies.

5. Bone Meal

• Description: A powder made from ground animal bones, commonly used to supply phosphorus and calcium.
• Nutrient Content:
  • Phosphorus (P): 12-15%
  • Calcium (Ca): 20-30%
  • Nitrogen (N): 0.5-1%
• Fortification:
  • Bone meal can be mixed with neem cake for nitrogen or dolomite for calcium and magnesium.

6. Animal Manures

• Description: Manure from animals such as cows, goats, chickens, etc., rich in organic matter and essential nutrients.
• Nutrient Content (varies by animal species):
  • Cow dung:
    • Nitrogen (N): 0.5-1.5%
    • Phosphorus (P): 0.1-0.3%
    • Potassium (K): 0.5-1%
  • Chicken manure:
    • Nitrogen (N): 1.5-3%
    • Phosphorus (P): 1-2%
    • Potassium (K): 1-1.5%
• Fortification:
  • Zinc sulfate for zinc.
  • Gypsum for calcium supplementation in calcareous soils.
  • Fish meal for nitrogen.

7. Fish Emulsion

• Description: A liquid fertilizer made from processed fish parts, providing essential nutrients in a readily available form.
• Nutrient Content:
  • Nitrogen (N): 4-5%
  • Phosphorus (P): 1-2%
  • Potassium (K): 1-2%
  • Calcium (Ca): 1-2%
• Fortification:
  • Fish emulsion can be fortified with kelp for trace minerals (iodine, iron, magnesium) or boron for plant health.

8. Seaweed and Kelp Extracts

• Description: Extracts from seaweed and kelp, rich in trace minerals, growth hormones, and organic matter.
• Nutrient Content:
  • Nitrogen (N): 0.5-2%
  • Phosphorus (P): 0.5-1%
  • Potassium (K): 5-10%
  • Calcium (Ca): 1-2%
  • Magnesium (Mg): 1-2%
• Fortification:
  • Can be mixed with bone meal for enhanced phosphorus and calcium content.
  • Micronutrient mixtures to supply iron, manganese, copper, and boron.

9. Biofertilizers

• Description: Biological agents that help in nutrient cycling, especially nitrogen fixation and phosphorus solubilization.
• Types:
  • Rhizobium (for nitrogen fixation in legumes).
  • Azotobacter (for nitrogen fixation in non-legumes).
  • Mycorrhizal fungi (for enhancing phosphorus absorption).
  • Phosphate-solubilizing bacteria (PSB) (to improve phosphorus availability).
• Fortification:
  • Biofertilizers can be fortified with trace elements like zinc and boron to ensure proper functioning of microbes.

10. Green Leaf Manure

• Description: Fresh or dried leaves of fast-growing plants, especially leguminous species, which are incorporated into the soil to enrich its nutrient content.
• Nutrient Content:
  • Nitrogen (N): 2-5%
  • Phosphorus (P): 0.1-0.2%
  • Potassium (K): 0.5-1.5%
  • Calcium (Ca): 0.5-1%
• Fortification:
  • Can be enriched with biofertilizers like Rhizobium for increased nitrogen fixation.
  • Fish meal for additional nitrogen or rock phosphate for phosphorus.

Summarizing the nutrient content of various organic nutrient sources:

Note:

• The nutrient values are approximate ranges and can vary depending on the source, preparation, and environmental factors.
• The “Other Nutrients” column highlights additional nutrients or biological activities like Rhizobium and Mycorrhiza that enhance nutrient uptake, especially nitrogen fixation, and phosphorus solubilization.