Soil Formation and Its Components

These flashcards cover key concepts related to soil formation, its components, and processes of weathering.

Soil Formation

The process in which rocks and organic matter break down and combine to create soil over time.

Pedalogy

The branch of science dealing with soils.

Mineral Matter

Approx. 45% of soil, defines soil texture and comes from rock disintegration.

Organic Matter

Approx. 5% of soil that provides nutrients, improves soil structure, and acts as a food source for microorganisms.

Soil Water

Approx. 25% of soil responsible for dissolving nutrients and making them available to roots.

Soil Air

Approx. 25% of soil that fills pores not occupied by water and affects aeration.

Weathering

The gradual breakdown of rocks caused by agents such as rain, frost, and temperature changes.

Chemical Weathering

The weakening and disintegration of rock by chemical reactions.

Mechanical Weathering

The process that breaks rock into smaller pieces while retaining the original mineral composition.

Biological Weathering

Weathering caused by the actions of plants and animals.

Soil Profile

The arrangement of layers (horizons) in soil, studied to classify and interpret soil.

O Horizon

The organic-rich layer from decomposed plant matter.

A Horizon

The surface or topsoil, rich in organic matter and darker in color.

B Horizon

Subsoil, a zone of accumulation where clay, salts, and iron build up.

C Horizon

Parent material with little alteration, minimal soil-forming processes.

R Horizon

Bedrock beneath the soil layers.