Packet 3 Flashcards
Soil Wetness
The proportion of the total soil volume that is water-filled.
Water Saturated Soil
When the volumetric water content of a soil equals the total porosity of the soil.
Air-Filled Porosity
The proportion of the total soil volume that is air-filled.
Solutes
Dissolved substances, such as cations, anions, organic compounds, and gases.
Soil Solution
Where plant roots and soil microbes take-up nutrients
Dissolved State of Solutes
When solutes are dissolved in the soil solution.
Colloid-Associated State
Solutes are associated in some manner with the soil solids.
Soil pH
The negative logarithm of the hydrogen ion concentration.
Active Acidity
H and Al dissolved in solution.
Reserved Acidity
Presence of sources (or sinks) of acidity contributed by the soil solids.
Bound Acidity
Ions bound to soil colloids.
Exchangeable Acidity
Ions more freely exchange states between the limit of colloid attraction and the soil solution.
Acidic Cations
The cations, H+, Al3+, Fe3+, that contribute to H+ ion activity in soil either directly or through hydrolysis reactions
Basic Cations
the cations, (Ca2+, Mg2+, K+, Na+) that when present in large quantities on the exchange sites are associated with alkaline pH values
