Session 3: Irrigation and Drainage
Unit 5: Plant Nutrition and Irrigation
Textual Question-Answers
Check Your Progress
Fill in the Blanks
1. The artificial supply of water to support plant growth andproduction in the absence of adequate supply of water through rainfall
is known as —————
Ans: irrigation
2. Surface irrigation is irrigation through ———————— of thesurface, bed or border method, ring and basin method and furrowmethod.
Ans: flooding
3. Basin method of irrigation is suitable for —————— crop.
Ans: orchard
4. An irrigation method that involves slow application of water tothe root zone is called ——————
Ans: drip irrigation
5. Water with pressure is forced through revolving nozzles is ——————— system of irrigation.
Ans: sprinkler
Multiple Choice Questions
1. Flood irrigation is followed in ——————
(a) highly spaced crops
(b) densely planted crops
(c) Both (a) and (b)
(d) None of the above
Ans: (b) densely planted crops
2. Waterlogging (bad drainage) is a problem that arises due to ——
(a) excessive or continuous use of water
(b) hard pan to lower strata
(c) slow-permeable soils
(d) All of the above
Ans: (d) All of the above
3. What about the sprinkler system of irrigation is true?(a) It saves water up to 30–35 per cent.
(b) It distributes water up to a depth of 10–15 mm.
(c) Both (a) and (b)
(d) None of the above
Ans: (c) Both (a) and (b)
4. Addition of sulphuric acid or sulphur pH of irrigation water ——————
(a) increases
(b) reduces
(c) neutralises
(d) None of the above
Ans: (b) reduces
Subjective Questions
1. Why is irrigation important for plant life?
Ans: Irrigation is important for plant life because it supplies adequatemoisture for germination, nutrient absorption, photosynthesis and propergrowth when rainfall is insufficient or irregular.
2. What are the different methods of irrigation? Describe sprinklerirrigation.
Ans: The different methods of irrigation are surface irrigation, sprinklerirrigation and drip irrigation. Sprinkler irrigation is a method in which wateris forced under pressure through pipes and sprayed into the air through nozzles, simulating rainfall and ensuring uniform distribution of water.
3. Give the merits and demerits of border irrigation system.
Ans: Merits of border irrigation include simple layout, low cost andsuitability for large fields. Demerits include wastage of water, unevendistribution and requirement of well-levelled land.
4. What is drip irrigation? How is it useful?
Ans: Drip irrigation is a method in which water is supplied slowly anddirectly to the root zone of plants through emitters. It is useful because it saveswater, reduces weed growth, improves fertiliser efficiency and increases cropyield.
Match the Columns
A
1. Flood irrigation
2. Border irrigation method
3. Basin irrigation
4. Furrow (ridges) method
5. Sprinkler irrigation
6. Drip or trickle irrigation
B
(a) Slow application of water to the root zone
(b) Size of the plot to be irrigated is very small
(c) Suitable to irrigate crops on steep slopes
(d) Followed in densely planted crops
(e) High water efficiency
(f) Water is forced through revolving nozzles
Ans:
1 – (d) Followed in densely planted crops
2 – (b) Size of the plot to be irrigated is very small
3 – (c) Suitable to irrigate crops on steep slopes
4 – (e) High water efficiency
5 – (f) Water is forced through revolving nozzles
6 – (a) Slow application of water to the root zone
