MCQ on Agronomic Practices for Using Problem Water
1. What are the main cations commonly found in irrigation water?
Answer: B
Explanation: The primary cations in irrigation water are calcium (Ca), magnesium (Mg), sodium (Na), and potassium (K).
Explanation: The primary cations in irrigation water are calcium (Ca), magnesium (Mg), sodium (Na), and potassium (K).
2. High salinity in irrigation water primarily affects plants by:
Answer: C
Explanation: Excessive salinity increases the soil solution’s concentration, making it difficult for plants to absorb water.
Explanation: Excessive salinity increases the soil solution’s concentration, making it difficult for plants to absorb water.
3. Which factor is NOT a determinant of irrigation water quality?
Answer: C
Explanation: While soil texture, permeability, and drainage are significant, weather conditions are not a direct determinant of irrigation water quality.
Explanation: While soil texture, permeability, and drainage are significant, weather conditions are not a direct determinant of irrigation water quality.
4. What is the acceptable pH range for water classified as “excellent” quality?
Answer: B
Explanation: Water classified as “excellent” quality has a pH range of 6.5–7.5.
Explanation: Water classified as “excellent” quality has a pH range of 6.5–7.5.
5. Sodium Adsorption Ratio (SAR) measures:
Answer: B
Explanation: SAR measures the proportion of sodium ions compared to calcium and magnesium in irrigation water.
Explanation: SAR measures the proportion of sodium ions compared to calcium and magnesium in irrigation water.
6. Excessive nitrogen in irrigation water can cause:
Answer: B
Explanation: High nitrogen levels promote vegetative growth, which may lead to lodging and delayed maturity.
Explanation: High nitrogen levels promote vegetative growth, which may lead to lodging and delayed maturity.
7. What is the classification of irrigation water with EC greater than 6.0 m.mhos/cm?
Answer: D
Explanation: Water with EC >6.0 m.mhos/cm is classified as unsuitable for irrigation.
Explanation: Water with EC >6.0 m.mhos/cm is classified as unsuitable for irrigation.
8. Which crop is highly tolerant to saline water irrigation?
Answer: B
Explanation: Cotton is one of the most salt-tolerant crops.
Explanation: Cotton is one of the most salt-tolerant crops.
9. What is a recommended management practice for using saline water?
Answer: A
Explanation: Frequent and light irrigation minimizes salt accumulation in the root zone.
Explanation: Frequent and light irrigation minimizes salt accumulation in the root zone.
10. Which element is considered toxic to plants at high concentrations in irrigation water?
Answer: A
Explanation: Boron can be toxic to plants if present beyond permissible limits.
Explanation: Boron can be toxic to plants if present beyond permissible limits.
11. What does BOD stand for in wastewater management?
Answer: B
Explanation: BOD stands for Biochemical Oxygen Demand, which indicates organic pollution in water.
Explanation: BOD stands for Biochemical Oxygen Demand, which indicates organic pollution in water.
12. Which of the following is NOT a treatment method for wastewater before irrigation?
Answer: D
Explanation: Adding excessive fertilizers is not a wastewater treatment method.
Explanation: Adding excessive fertilizers is not a wastewater treatment method.
13. The parameter that primarily affects the infiltration rate of water into soil is:
Answer: B
Explanation: Specific salts in irrigation water can reduce infiltration rates.
Explanation: Specific salts in irrigation water can reduce infiltration rates.
14. What does EC measure in irrigation water?
Answer: B
Explanation: EC measures the electrical conductivity of water, indicating its salinity.
Explanation: EC measures the electrical conductivity of water, indicating its salinity.
15. Which irrigation water classification is most suitable for crops?
Answer: B
Explanation: Excellent quality water has the least salinity and is most suitable for crops.
Explanation: Excellent quality water has the least salinity and is most suitable for crops.
16. Excessive bicarbonates in irrigation water cause:
Answer: B
Explanation: High bicarbonate levels cause white deposits when using sprinkler irrigation.
Explanation: High bicarbonate levels cause white deposits when using sprinkler irrigation.
17. What is the best way to improve soil permeability when using poor-quality water?
Answer: C
Explanation: Adding gypsum improves soil permeability and structure.
Explanation: Adding gypsum improves soil permeability and structure.
18. Which climatic factor helps in leaching salts from the root zone?
Answer: A
Explanation: Rainfall naturally leaches salts from the plant root zone.
Explanation: Rainfall naturally leaches salts from the plant root zone.
19. What crop stage is most sensitive to salinity?
Answer: A
Explanation: Germination and seedling stages are highly sensitive to salinity.
Explanation: Germination and seedling stages are highly sensitive to salinity.
20. Alternate irrigation with wastewater and good quality water is recommended to:
Answer: B
Explanation: Alternating irrigation sources helps minimize salt buildup in the soil.
Explanation: Alternating irrigation sources helps minimize salt buildup in the soil.