Question

Water use efficiency in decreasing order
(A). Pitcher Irrigation
(B). Drip Irrigation
(C). Sprinkler Irrigation
(D). Surface Irrigation
Choose the correct answer from the options given below:

• A. (A), (B), (C), (D).
• B. (D), (C), (A), (B).
• C. (B), (A), (D), (C).
• D. (C), (B), (D), (A).

Hint:

To remember water use efficiency orders, think of direct placement: the more localized and subsurface the water delivery, the higher the efficiency.
Buried porous pitchers provide the absolute minimum water loss to the atmosphere.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Water use efficiency (WUE) refers to the ratio of water utilized by crops to the total water applied through irrigation.
Different irrigation techniques exhibit varying levels of efficiency based on conveyance losses, deep percolation, and surface evaporation.

Step 2: Detailed Explanation:
Let us analyze the water application efficiency of the listed systems:
- Pitcher Irrigation (A): This is an ancient, highly efficient localized irrigation system where unglazed clay pots are buried in the soil and filled with water.
Water slowly seeps out through the porous walls directly into the root zone because of the soil moisture tension gradient.
Since the system is completely subsurface, there is virtually zero surface evaporation or deep percolation, achieving a water use efficiency of up to \( 85\% - 98\% \).
- Drip Irrigation (B): Water is applied directly near the root zone drop-by-drop through emitters.
This micro-irrigation system has an efficiency of \( 90\% - 95\% \), slightly below perfectly managed pitcher setups under hyper-arid conditions because of occasional superficial losses from dripper lines.
- Sprinkler Irrigation (C): Water is sprayed over the crop canopy, mimicking rainfall, with an efficiency of \( 70\% - 80\% \).
It is subject to drift and evaporation losses from the air and foliage.
- Surface Irrigation (D): This includes flooding, furrow, or basin methods.
It is highly inefficient (\( 30\% - 50\% \)) due to heavy runoff, deep percolation, and evaporation.
Therefore, the decreasing order of water use efficiency is Pitcher \( > \) Drip \( > \) Sprinkler \( > \) Surface.

Step 3: Final Answer:
The decreasing order of water use efficiency is (A), (B), (C), (D).