Which of the following is/are the advantage/advantages of practising drip irrigation?

1. Reduction in weed
2. Reduction in soil salinity
3. Reduction in soil erosion

Select the correct answer using the code given below:

The correct answer is Option 3: 1 and 3 only — meaning that Reduction in weed and Reduction in soil erosion are genuine advantages of practising drip irrigation, while Reduction in soil salinity is not an advantage.

Let us analyse each statement carefully to understand the reasoning behind this answer.

Understanding Drip Irrigation First:
Drip irrigation (also called trickle irrigation) is a method of delivering water slowly and directly to the root zone of plants through a network of pipes, tubes, and emitters. The water drips at low pressure, drop by drop, precisely at the base of each plant. This targeted delivery is the key to understanding its advantages and limitations.

Statement 1 — Reduction in Weed: ✅ CORRECT
Weeds, like all plants, need water to germinate and grow. In conventional irrigation methods (like flood or furrow irrigation), water is spread across the entire field surface, moistening large areas including the spaces between crop rows. This creates ideal conditions for weed seeds to germinate throughout the field.

In drip irrigation, water is delivered only to a very small, targeted area right at the root zone of the crop plant. The inter-row spaces and the soil surface away from the emitters remain relatively dry. Since these areas receive no water, weed germination and growth are significantly suppressed. Fewer weeds mean less competition for nutrients and less labour for weeding. Therefore, Statement 1 is a genuine advantage of drip irrigation.

Statement 2 — Reduction in Soil Salinity: ❌ INCORRECT
This is the tricky statement and the reason why options containing "2" are wrong. In fact, drip irrigation can increase or concentrate soil salinity rather than reduce it, and here is the scientific reasoning:

All irrigation water contains dissolved salts to some degree. In conventional irrigation, water wets a large soil volume, and when excess water drains or leaches below the root zone, it carries salts away with it — this is called leaching.

In drip irrigation, water is applied in very small, frequent amounts only near the emitter. As this water is absorbed by plant roots or evaporates, the salts dissolved in it are left behind in the soil. Over time, salts tend to accumulate and concentrate in the soil around the drip zone, especially at the boundary between the wet and dry zones. This is known as salt build-up or salt accumulation. Therefore, drip irrigation does not reduce soil salinity — it can even aggravate it if proper flushing/leaching practices are not followed. Statement 2 is NOT a correct advantage.

Statement 3 — Reduction in Soil Erosion: ✅ CORRECT
Soil erosion is primarily caused by the physical force of water hitting bare soil (splash erosion) and by water flowing rapidly across the soil surface (runoff erosion). Both of these are common problems in traditional irrigation methods where large volumes of water are applied quickly.

Drip irrigation delivers water at a very slow, controlled rate (often just a few litres per hour per emitter). This rate is typically at or below the soil's natural infiltration capacity, meaning the water soaks directly into the soil without creating surface runoff. There is no fast-moving sheet of water to dislodge and carry away soil particles. The gentle, drop-by-drop delivery causes virtually no disturbance to the soil structure. As a result, soil erosion is greatly reduced. Statement 3 is a genuine advantage.

Conclusion:
Bringing it all together:

Statement 1 (Weed Reduction) → True ✅ — Water is targeted only at plant roots, so inter-row areas stay dry, inhibiting weed growth.
Statement 2 (Salinity Reduction) → False ❌ — Drip irrigation can cause salt accumulation in the soil; it does not reduce salinity.
Statement 3 (Soil Erosion Reduction) → True ✅ — Slow, gentle water delivery prevents runoff and soil particle displacement.

Therefore, only Statements 1 and 3 are correct advantages of drip irrigation, making Option 3 ("1 and 3 only") the right answer.