Question 31 from UPSC CSE 2020 - ENVIRONME NT

Question

What are the advantages of fertigation in agriculture?
1. Controlling the alkalinity of irrigation water is possible.
2. Efficient application of Rock Phosphate and all other phosphatic fertilizers is possible.
3. Increased availability of nutrients to plants is possible.
4. Reduction in the leaching of chemical nutrients is possible.
Select the correct answer using the code given below:

IASCODEX · Accepted Answer

Correct Option: C. 1, 3, and 4 only

Strategy: - Fertigation enables direct fertilizer application through irrigation, enhancing nutrient efficiency and reducing leaching (supporting statements 3 and 4).
- It allows management of irrigation water quality, including alkalinity, by injecting acids (supporting statement 1).
- Rock phosphate, being a largely insoluble source, is not efficiently used via fertigation, making statement 2 incorrect.
- Therefore, the strategy supports statements 1, 3, and 4.

Key Info: Fertigation is the application of fertilizers, soil amendments, or other water-soluble products through an irrigation system.

**Advantages:**
- Improved nutrient use efficiency due to targeted delivery near root zones; nutrients remain more available for plant uptake, especially nitrogen and potassium.
- Allows control of pH and alkalinity in irrigation water by injecting acids (such as phosphoric or sulfuric acid), critical for optimizing nutrient uptake and minimizing emitter clogging.
- Reduces nutrient leaching losses as fertilizers are applied in small, frequent doses, matching plant demand and minimizing movement beyond root zones, particularly in sandy or light soils.
- Offers flexibility in timing and frequency of fertilization, enabling precise adjustments during the crop growth cycle.

**Limitations:**
- Not all fertilizers are compatible: only water-soluble fertilizers can be efficiently supplied via fertigation. Rock phosphate is mostly insoluble in water and unsuitable for fertigation; it is better used in acid soils or applied with organic amendments. Fully or largely soluble phosphatic fertilizers (e.g., monoammonium phosphate, diammonium phosphate, phosphoric acid) are commonly used instead.

Proper fertigation management increases yields, conserves water, reduces fertilizer wastage, and improves environmental outcomes by limiting chemical runoff into water bodies.

IASCODEX · Answer

Option A: 1, 2, and 3 only

IASCODEX · Answer

Option B: 1, 2, and 4 only

IASCODEX · Answer

Option D: 2, 3, and 4 only