Finals Unit 2

Question 1

What is the process of determining when to irrigate and how much water to apply based on measurements or estimates of soil moisture or water used by plants.

Answer 1

Irrigation Scheduling

Question 2

a measure of the adsorptive forces by which soil retains water. It is the negative pressure (suction) relative to the prevailing atmospheric gauge pressure of zero.

Answer 2

Tension

Question 3

The unit commonly used in irrigation scheduling to express soil-water tension.

Answer 3

Bar

Question 4

A condition where the soil pores are filled with water.

Answer 4

Saturation

Question 5

At saturation, how much is soil-water tension?

Answer 5

Zero

Question 6

The soil-water content after the force of gravity has drained or removed all the water.

Answer 6

Field Capacity

Question 7

It is considered as the upper limit of plant-available water.

Answer 7

Field Capacity

Question 8

Water in the soil that is free to drain or move by the force of gravity.

Answer 8

Gravitational water

Question 9

It is the volume of water in the soil between saturation and field capacity

Answer 9

Gravitational Water

Question 10

This water is not usually used by plants.

Answer 10

Gravitational water

Question 11

Water retained in soil pores after gravitational water has drained or that is held loosely around soil particles by surface tension.

Answer 11

Capillary water

Question 12

Most of the water available to plants

Answer 12

Capillary Water

Question 13

The soil-water content at which the healthy plants can no longer extract water fast enough to recover from wilting.

Answer 13

Permanent Wilting Point

Question 14

The lower limit of plant-available water.

Answer 14

Permanent Wilting Point

Question 15

Soil-water tension of 15 bars.

Answer 15

Permanent Wilting Point

Question 16

The amount of water held in soil available to plants. The difference between FC and PWP.

Answer 16

Plant Available Water

Question 17

Water in thin, tightly held films around soil particles not available to plants.

Answer 17

Unavailable water

Question 18

The amount of plant-available water removed from the soil by plants and evaporation from the soil surface.

Answer 18

Depletion Volume

Question 19

The amount of plant-available water can be removed from the soil without seriously affecting plant growth and development.

Answer 19

Allowable Depletion Volume

Question 20

This method determines soil moisture by taking a sample from the desired soil depth, weighing it to be oven-dried. The dried sample is then re-weighed to determine amount of water lost.

Answer 20

Gravimetric Method

Question 21

A sealed, airtight, water-filled tube with a pourous tip on one end and a vacuum gauge.

Answer 21

Tensiometer

Question 22

This tool isnuesd to measure soil water suction, usually expressed as tension.

Answer 22

Tensiometer

Question 23

This measurement tool consist of two electrodes enclosed in a block of pourous material.

Answer 23

Electrical Resistance Block

Question 24

The electrical block is often made of:

Answer 24

Gypsum

Question 25

It is a device used for measuring the rate of water uptake of a leafy shoot.

Answer 25

Photometer

Question 26

What is the other term for photometer?

Answer 26

Transpirometer

Question 27

A symptom shown when plants lose their turgidity usually at midday.

Answer 27

Temporary Wilting

Question 28

Soils taken from root zone depth

Answer 28

Feel the Soil