IA Irrigation Scheduling & Evapotranspiration

Question 1

Which term describes the combined process of water evaporation from soil and transpiration from plants?

Accepted Answer

Evapotranspiration

Answer

Evapotranspiration (ET) is the combined water loss through evaporation from soil surfaces and transpiration from plant leaves.

Question 2

Reference evapotranspiration (ETo) is most commonly calculated using which method recognized by the FAO?

Accepted Answer

Penman-Monteith method

Answer

The FAO-56 Penman-Monteith equation is the globally recognized standard for calculating reference evapotranspiration.

Question 3

A crop coefficient (Kc) is used to adjust ETo for a specific crop. What does a Kc value of 1.2 indicate?

Accepted Answer

The crop uses 20% more water than the reference crop

Answer

A Kc of 1.2 means the actual crop evapotranspiration (ETc) is 20% greater than the reference ETo.

Question 4

Which irrigation scheduling method uses soil moisture sensors to determine when to irrigate?

Accepted Answer

Soil water depletion method

Answer

The soil water depletion method uses sensors such as tensiometers or capacitance probes to monitor soil moisture and trigger irrigation at a set threshold.

Question 5

What is the Management Allowable Depletion (MAD) typically set at for most turf and landscape irrigation?

Accepted Answer

25–40%

Answer

MAD for turf and landscape is typically set between 25–40% of plant available water to avoid plant stress.

IA - Irrigation Association Certification Practice Test

IA - Irrigation Association Certification Practice Test

IA Irrigation Scheduling & Evapotranspiration