Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

SOIL 140 > Chapter 4 > Flashcards

Chapter 4 Flashcards

1
Q

Adsorbed cations are also known as ____.

A

exchangeable cations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the charge of agriculturally important soils?

A

negative charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The process whereby cations adsorbed on the surface of soil colloids is exchanged for those in the soil solution or in any medium that comes in contact with the soil colloids.

A

Cation exchange

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

If nutrients are not absorbed by soil colloids, they are subject to what.

A

Loss through leaching

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Na-rich soils are in what state?

A

dispersed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The element that is responsible in dispersing soil.

A

Na

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Ca-rich soils make the soil to be?

A

flocculated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Element responsible in making flocculated soil

A

Ca

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Is dispersion a desirable characteristic of productive soil?

A

NOT desirable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The CEC of permanent charge clays.

A

low CEC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The buffering capacity of permanent charge clays?

A

low buffering capacity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Accompanying ions

A

complementary ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What will happen to the ion of interest if the complementary ion is strongly adsorbed?

A

easily released

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The quantitative measure of the ability of soil to adsorb and exchange cations with those in the surrounding solution and with plant roots.

A

cation exchange capacity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The sum of the negative charges of the soil.

A

cation exchange capacity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The sum total of the exchangeable cations that a soil can adsorb.

A

cation exchange capacity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

The easily exchangeable cations.

A

electrostatically retained cations

18
Q

The cations that are readily available for plant uptake.

A

electrostatically retained cations

19
Q

The dissociation of H from OH- groups

A

deprotonation

20
Q

What will happen to the charge if there is deprotonation?

A

additional negative charge

21
Q

What is the CEC of OM?

A

100-300 cmolc/kg soil

22
Q

Tells us the degree to which the exchange sites are occupied by basic cations.

A

percentage base saturation

23
Q

Give examples of basic cations.

A

K
Ca
Mg
Na

24
Q

Give examples of acidic cations.

A

Al
H

25
Q

The atomic weight of Ca.

A

40 g/mol

26
Q

The atomic weight of Na.

A

23g/mol

27
Q

The atomic weight of K?

A

39g/mol

28
Q

The atomic weight of Mg.

A

24g/mol

29
Q

What will happen to the cations if there is high percentage cation saturation?

A

easily and rapidly released

30
Q

Enumerate the practical applications of CEC.

A

plant nutrition
liming
amelioration of Na affected soil
environmental quality

31
Q

Enumerate the soil properties that determine CEC.

A

soil texture
organic matter content
nature of clay colloid
pH
percentage base saturation

32
Q

Enumerate the methods of determining CEC.

A

CEC determination at pH7 ammonium acetate:1N
calculation of effective CEC
CC determination using BaCl2

33
Q

Enumerate the soil processes that affect cation exchange.

A

weathering
nutrient retention
dispersion and flocculation
buffering pH change

34
Q

The characteristics of cation exchange reactions

A

ER are stoichiometric and take place in equivalent amounts
CE are instantaneous
ER are reversible

35
Q

Factors affecting the extent of cation exchange.

A
  1. Relative adsorbability of the cation on soil colloid or the relative replacing the power of the cation
  2. Concentration of the solution
  3. Nature of exchange materials
  4. Geometric fit of ions into the mineral structure
  5. Influence of complementary ions
36
Q

Between Kaolinite and Illite which has a rapid cation exchange?

A

Kaolinite

37
Q

Between kaolinite and illite which takes longer time?

A

illite

38
Q

High level of Ca is antagonistic to?

A

inhibit K

39
Q

High K would lead to

A

interfere Mg

40
Q

ESP stands for

A

Exchangeable Sodium Percentage

41
Q

Soils with high amounts of soluble sodium

A

Sodic soils

SOIL 140 (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions