CIT Soil Science and Plant Water Requirements 2

Question 1

The effective root depth of cool-season turfgrass used for irrigation scheduling is typically:

Accepted Answer

4 to 6 inches

Answer

1 to 2 inches

Answer

12 to 18 inches

Answer

24 to 36 inches

Question 2

If the reference ET is 0.25 inches/day and the crop coefficient (Kc) is 0.8, the crop water requirement is:

Accepted Answer

0.20 inches/day

Answer

0.25 inches/day

Answer

0.31 inches/day

Answer

0.80 inches/day

Question 3

A Management Allowable Depletion (MAD) of 50% means irrigation should be triggered when:

Accepted Answer

50% of plant available water has been consumed

Answer

50% of total soil volume has dried out

Answer

Soil moisture drops below 50% of saturation level

Answer

Plants show 50% visible drought stress symptoms

Question 4

Which soil moisture sensor type measures moisture by analyzing electromagnetic wave propagation through the soil?

Accepted Answer

TDR/FDR sensor

Answer

Tensiometer

Answer

Granular matrix sensor

Answer

Neutron probe

Question 5

On the USDA soil texture triangle, a soil with 40% sand, 40% silt, and 20% clay is classified as:

Accepted Answer

Loam

Answer

Sandy clay loam

Answer

Silt loam

Answer

Clay loam

Question 6

In a managed turfgrass landscape, which factor most directly determines required irrigation frequency?

Accepted Answer

The rate of ET relative to soil water storage capacity in the root zone

Answer

The age and manufacturer of the irrigation system

Answer

The type of sprinkler heads installed

Answer

The color and variety of grass species

Question 7

Pushing a screwdriver or soil probe into the ground is a simple field method to quickly estimate:

Accepted Answer

Soil compaction and moisture level

Answer

Soil pH and nutrient level

Answer

Nitrogen and phosphorus content

Answer

Organic matter percentage