Packet 3

Question 1

Soil Wetness

Answer 1

The proportion of the total soil volume that is water-filled.

Question 2

Water Saturated Soil

Answer 2

When the volumetric water content of a soil equals the total porosity of the soil.

Question 3

Air-Filled Porosity

Answer 3

The proportion of the total soil volume that is air-filled.

Question 4

Solutes

Answer 4

Dissolved substances, such as cations, anions, organic compounds, and gases.

Question 5

Soil Solution

Answer 5

Where plant roots and soil microbes take-up nutrients

Question 6

Dissolved State of Solutes

Answer 6

When solutes are dissolved in the soil solution.

Question 7

Colloid-Associated State

Answer 7

Solutes are associated in some manner with the soil solids.

Question 8

Soil pH

Answer 8

The negative logarithm of the hydrogen ion concentration.

Question 9

Active Acidity

Answer 9

H and Al dissolved in solution.

Question 10

Reserved Acidity

Answer 10

Presence of sources (or sinks) of acidity contributed by the soil solids.

Question 11

Bound Acidity

Answer 11

Ions bound to soil colloids.

Question 12

Exchangeable Acidity

Answer 12

Ions more freely exchange states between the limit of colloid attraction and the soil solution.

Question 13

Acidic Cations

Answer 13

The cations, H+, Al3+, Fe3+, that contribute to H+ ion activity in soil either directly or through hydrolysis reactions

Question 14

Basic Cations

Answer 14

the cations, (Ca2+, Mg2+, K+, Na+) that when present in large quantities on the exchange sites are associated with alkaline pH values