Unit 4

Question 0

What does a plant use water for?

Answer 0

Evaporation on leaf cools it
Required for photosynthesis
Needed for cell growth and expansion 
Keeps turgor
Has to have it to live!

Question 1

What is turgor?

Answer 1

Maintaining plant shape

Question 2

What do plants use the most water for?

Answer 2

Transpiration

Question 3

What are symptoms of water stress?

Answer 3

Purple color
Wilting
Foot printing

Question 4

What are the stages a plant goes through during drought stress?

Answer 4

First it decreases photosynthesis,
Then it goes through a temporary wilting point,
Finally it enters a permanent wilting point = death

Question 5

Transpiration usually keeps leafs below _______ degrees.

Answer 5

90 degrees

Question 6

Describe a water molecule’s physical make up and how it’s formed.

Answer 6

2 Hydrogens are held at an angle…away from the 1 Oxygen.

Question 7

Hydrogen Bonding means….

Answer 7

Water sticks together

Question 8

Water freezes below _______ degrees Celsius?

Answer 8

0 degrees Celsius

Question 10

Define adhesion:

Answer 10

The attraction of water Molecules to solid surfaces that also have an electrical charge.

Question 10

How does water dissolve salt?

Answer 10

Water pulls the + and - atoms apart and “dissolves” them

Question 11

Define cohesion:

Answer 11

The attraction of water molecules to eachother

Question 12

Adhesion +Cohesion = ?

Answer 12

Capillarity

Question 13

In regards to capillarity….the height of the rise is inversely proportional to what?

Answer 13

The radius of the tube

Question 14

Capillarity can happen in any direction. True or False?

Answer 14

True

Question 15

Define saturation:

Answer 15

Maximum amount of water that a soil can hold.

Question 16

How do we measure moisture potential?

Answer 16

How many Bars

Question 17

Is gravitational water available to plants?

Answer 17

No

Question 18

Define gravitational water:

Answer 18

Amount of water held by the soil between saturation and field capacity. It is unavailable to plants

Question 19

Define field capacity:

Answer 19

Max amount of water a soil can hold against the force of gravity.

Question 20

There is plant available water once you reach ____________.

Answer 20

Field capacity

Question 21

How long does it take to drain from saturation to field capacity?

Answer 21

24 - 48 hours

Question 22

Saturation = how many Bars?

Field Capacity = how many Bars?

Answer 22

Saturation = 0 bars

Field Capacity = -1/3 bars

Question 23

At Field Capacity…..Plant available water is about ?% - ?% of total soil volume?

Answer 23

25-40%

Question 24

when draining…How much longer does clay loam take to reach field capacity compared to a sandy soil?

Answer 24

2 - 3 days longer

Question 25

What are different ways that a soil dries?

Answer 25

Plant use
Evaporation
Water Moves out of root zone

Question 26

What is the moisture potential at wilting point?

Answer 26

-15 bars

Question 27

Is there still water in the soil when a plant reaches permanent wilting point?

Answer 27

Yes, but it’s being held so tightly in the micropores that the plant cannot use it.

Question 29

Field Capacity has a moisture potential between ____ and _____ bars. Which means it is between ________ and _________.

Answer 29

-1/3 and -15 Bars

Saturation and Permanent Wilting Point

Question 30

Why does water hold onto clay?

Answer 30

because clay is electrically negative

Question 31

as far as water holding is concerned …..Why is Loam a prefered soil?

Answer 31

It maximizes the Plant Available Water.

Question 32

what are the two ways water can be held in soils?

Answer 32

As a film on individual soil particles or in the micropores of the soil

Question 33

Water stored in micropores is called__________.

Answer 33

Capillary Storage

Question 34

What is a large determining factor in how much water a soil can hold?

Answer 34

Soil Texture because it influences pore spaces (aggregation) and types of particles (sand vs. silt vs. clay etc.) and amount of O.M.

Question 35

define Infiltration:

Answer 35

the entry of water into a soil

Question 36

define Percolation (permeability):

Answer 36

Movement of water through the root zone

Question 37

define Saturated Flow:

Answer 37

Downward movement of water in response to gravity

Question 38

define Unsaturated Flow:

Answer 38

Capillary movement of water (moving within the pores)

Question 39

define Water Vapor movement:

Answer 39

Water moving as a gas

Question 40

define Drainage:

Answer 40

Movement of water out of the root zone

Question 41

Define Polarity:

Answer 41

Molecule is electrically neitral but has a + and - side.

Question 42

define Cappilarity:

Answer 42

Adhesion + Cohesion….,,,,attraction of water to fine openings