Soil Physical Properties - AGN 1240 Lecture Notes

These flashcards cover key vocabulary and concepts regarding soil physical properties from the AGN 1240 lecture notes.

Soil Texture

The composition of soil based on the percentage of sand, silt, and clay, indicating its feel.

Texture Triangle

A graphical representation used to determine soil texture based on the proportions of sand, silt, and clay.

Primary Minerals

Unchanged minerals from the origin of cooling lava with a crystal structure.

Secondary Minerals

Minerals that have undergone further breakdown from primary minerals, including silicate clays.

Carbonate Minerals

Minerals formed from calcite and dolomite originating from limestone bedrock, contributing to alkaline pH.

Chemical Activity

The capacity of clay particles to affect soil chemical properties due to their large surface area.

Soil Separation Sizes

Classification based on particle diameter: Sand (2.0-0.05 mm), Silt (0.05-0.002 mm), Clay (<0.002 mm).

Adhesion

The attraction between soil particles and water molecules.

Cohesion

The attraction between water molecules.

Organic Matter

Composed of plant and animal residues that contribute to soil fertility and health.

Clay Properties

Characterized by stickiness, swelling, and slow water movement due to a large surface area.

Silt Properties

Holds more water than sand, feels like talc when dry, and is slippery when wet.

Sand Properties

Chemically inactive, with large pore spaces and good drainage but poor nutrient retention.

Lab Analysis

Method to determine soil texture by measuring the settling time of soil in water.

Hand Texturing

Field method to estimate soil texture using tactile assessment.

Productivity vs Texture

Relationship indicating how soil texture affects fertility, moisture retention, and erosion potential.