CIT Soil Science and Plant Water Requirements 1

Question 1

Which soil type has the highest water-holding capacity?

Accepted Answer

Clay soil

Answer

Clay soil has the smallest particle size and greatest surface area, allowing it to retain more water than coarser-textured soils.

Question 2

Field capacity is defined as the soil moisture level that remains after:

Accepted Answer

Excess water has drained away by gravity

Answer

Field capacity is the water content remaining in soil 24–48 hours after saturation, once gravitational drainage has stopped.

Question 3

The permanent wilting point is the soil moisture level at which:

Accepted Answer

Plants can no longer extract water and wilt permanently

Answer

At the permanent wilting point, remaining soil water is held too tightly by soil particles for plant roots to extract it, causing irreversible wilting.

Question 4

Which of the following best describes evapotranspiration (ET)?

Accepted Answer

The combined loss of water through soil evaporation and plant transpiration

Answer

ET represents total landscape water demand by combining direct evaporation from soil and transpiration through plant leaves.

Question 5

Plant Available Water (PAW) is correctly calculated as:

Accepted Answer

Field capacity minus permanent wilting point

Answer

PAW is the range of soil moisture between field capacity and permanent wilting point that plant roots can actually extract and use.

CIT - Certified Irrigation Technician Practice Test

CIT - Certified Irrigation Technician Practice Test

CIT Soil Science and Plant Water Requirements 1