Home › MCQs › Agronomy › Question #2059
Back to Questions
Agronomy QUESTION #2059
Question 1
Evapotranspiration (ET) differs from evaporation (E) in that:
  • ET occurs only from open water surfaces while E includes transpiration
  • ET is the combined water loss from soil evaporation and plant transpiration from a cropped surface, while E refers only to physical vaporization from soil or water surfaces without plant involvement✔️
  • ET can be measured directly with a rain gauge while E requires a lysimeter
  • ET decreases with increasing leaf area index while E increases
Correct Answer Explanation
Evapotranspiration combines two processes: evaporation (physical — from soil, water surfaces) and transpiration (biological — water movement through plant tissues and vapor loss from stomata). As crop canopy develops, the E component decreases (shading reduces soil evaporation) while T increases, but total ET is governed by available energy and atmospheric demand.