1. Which of the following is the most efficient method of irrigation in terms of water use efficiency?
a) Surface irrigation
b) Drip irrigation
c) Sprinkler irrigation
d) Furrow irrigation
Answer: b) Drip irrigation
Explanation: Drip irrigation delivers water directly to the root zone of plants, minimizing water loss due to evaporation and runoff, thus providing the highest water use efficiency.
2. What is the main purpose of subsurface drainage in agricultural fields?
a) To increase the soil’s water retention capacity
b) To prevent waterlogging and improve root growth
c) To improve water distribution across the field
d) To irrigate crops during dry spells
Answer: b) To prevent waterlogging and improve root growth
Explanation: Subsurface drainage helps to remove excess water from the root zone, preventing waterlogging, improving aeration, and enhancing root growth.
3. The term “field capacity” refers to:
a) The amount of water the soil can hold after it has been saturated and drained
b) The maximum water retention capacity of a soil
c) The rate at which water is applied to the soil
d) The amount of water available to plants from the soil
Answer: a) The amount of water the soil can hold after it has been saturated and drained
Explanation: Field capacity is the amount of water that remains in the soil after it has been saturated and excess water has drained away, representing the optimal moisture content for plant growth.
4. Which of the following types of irrigation is most suitable for crops in hilly or uneven terrain?
a) Flood irrigation
b) Drip irrigation
c) Furrow irrigation
d) Border irrigation
Answer: b) Drip irrigation
Explanation: Drip irrigation is ideal for uneven or hilly terrain as it provides localized watering, reducing water wastage and ensuring precise irrigation, even on slopes.
5. The concept of “irrigation efficiency” is defined as the ratio of:
a) Water actually applied to the field versus total water supplied
b) Water lost to evaporation versus total water applied
c) The amount of water stored in the soil versus total water applied
d) Water lost to surface runoff versus total water supplied
Answer: a) Water actually applied to the field versus total water supplied
Explanation: Irrigation efficiency refers to the proportion of the total water supplied to a field that is effectively used by the crops, excluding losses through evaporation, runoff, or deep percolation.
6. Which of the following is a primary factor that affects the design of a drainage system in agricultural fields?
a) Soil texture
b) Crop type
c) Climatic conditions
d) Field slope and permeability
Answer: d) Field slope and permeability
Explanation: The design of a drainage system is influenced by the slope of the land and the permeability of the soil, as these factors determine how quickly water can be drained from the field.
7. What is the effect of waterlogging on crops?
a) It improves crop yields due to enhanced moisture availability
b) It inhibits root respiration and nutrient uptake, leading to reduced yields
c) It encourages the growth of beneficial microorganisms
d) It has no significant effect on crop growth
Answer: b) It inhibits root respiration and nutrient uptake, leading to reduced yields
Explanation: Waterlogging occurs when excessive water prevents proper oxygen flow to plant roots, disrupting respiration and nutrient uptake, which negatively affects crop growth and yields.
8. Which of the following is a major limitation of surface irrigation systems?
a) High initial cost
b) Poor uniformity in water distribution
c) High water use efficiency
d) It is only suitable for small-scale farming
Answer: b) Poor uniformity in water distribution
Explanation: Surface irrigation, such as furrow or flood irrigation, can result in uneven water distribution, leading to over-irrigation in some areas and under-irrigation in others, thus reducing water use efficiency.
9. In sprinkler irrigation, the pressure of water applied to the system primarily influences:
a) The amount of water available for crops
b) The uniformity of water distribution
c) The evaporation rate of water
d) The rate of percolation in the soil
Answer: b) The uniformity of water distribution
Explanation: The pressure in a sprinkler system affects how uniformly the water is distributed across the field. Low pressure can result in inadequate coverage, while too high a pressure can lead to misting and inefficient watering.
10. What is the key challenge when implementing drip irrigation in large-scale agriculture?
a) High water use efficiency
b) The need for constant monitoring of water salinity
c) The difficulty in distributing water evenly to large areas
d) High initial setup cost and maintenance
Answer: d) High initial setup cost and maintenance
Explanation: Drip irrigation systems, while highly efficient, can be costly to set up and maintain, especially in large-scale operations, due to the need for extensive piping, filters, and emitters.
11. Which of the following factors is most critical for determining the irrigation schedule?
a) Soil texture and water holding capacity
b) Water quality and chemical composition
c) Crop water requirements and growth stage
d) Topography and drainage rate
Answer: c) Crop water requirements and growth stage
Explanation: The irrigation schedule should be based on the crop’s specific water needs, which vary depending on the stage of growth, weather conditions, and soil moisture levels.
12. What is the primary benefit of sub-surface irrigation compared to surface irrigation?
a) Lower initial cost
b) Higher water application rate
c) Reduced evaporation losses and better water distribution
d) Simpler system maintenance
Answer: c) Reduced evaporation losses and better water distribution
Explanation: Sub-surface irrigation delivers water directly to the root zone, minimizing evaporation losses, improving water use efficiency, and reducing surface runoff.
13. Which of the following is a common method to manage water quality in irrigation systems?
a) Liming of soil
b) Use of drip irrigation
c) Proper filtration and treatment of water before use
d) Flooding fields during winter months
Answer: c) Proper filtration and treatment of water before use
Explanation: Managing water quality involves filtering and treating water before it is applied to crops to reduce the risk of disease, salinity, and clogging of irrigation equipment.
14. What is the term used to describe the total amount of water required to meet the needs of crops throughout their growing season?
a) Evapotranspiration (ET)
b) Irrigation efficiency
c) Field capacity
d) Consumptive use
Answer: a) Evapotranspiration (ET)
Explanation: Evapotranspiration (ET) is the total water loss from both soil evaporation and plant transpiration, which collectively defines the water requirement of crops throughout their growing season.
15. Which of the following drainage systems is best suited for high-value crops that require precise soil moisture control?
a) Open ditches
b) Subsurface drainage systems
c) Surface drains
d) Gravity-fed drainage systems
Answer: b) Subsurface drainage systems
Explanation: Subsurface drainage systems provide precise control over soil moisture levels, making them ideal for high-value crops that require specific conditions for optimal growth.