Soil Properties

What is soil?

Weathered and decomposed rock that may or may not include organic matter.

What is the pedosphere?

The soil layer on Earth, located between the lithosphere (below) and the atmosphere and hydrosphere (above).

What are the three main types of soil particles?

Sand, silt, and clay.

How does particle size affect soil texture?

Particle size influences drainage, water retention, air dispersal, and nutrient capacity.

Which type of soil has the largest particle size?

Sand (1–0.1 mm).

Which type of soil has the smallest particle size?

Clay (< 0.001 mm).

What is the texture of soil?

The physical makeup of soil based on the amounts of sand, silt, and clay.

What are the properties of sand in soil?

Excellent drainage and air dispersal, but poor water retention and nutrient capacity.

What are the properties of clay in soil?

Excellent water retention and nutrient capacity, but poor drainage and air dispersal.

What are the properties of silt in soil?

Moderate in drainage, water retention, air dispersal, and nutrient capacity—"OK" at everything.

What type of rock does granite weather into?

Granite weathers into quartz sand.

What is basalt, and how does it differ from granite?

Basalt is a rock formed when magma cools quickly, creating tiny, uniform crystals. Granite cools slowly, forming large crystals.

How do mica and feldspar weather?

Mica and feldspar decompose into flat, flaky particles that form clay.

What type of soil component comes from mica and feldspar?

Clay.

What happens when clay undergoes metamorphosis into rock?

Clay forms shale, and with more heat and pressure, it becomes slate.

How is limestone formed?

Limestone is formed by the precipitation of calcium carbonate, either chemically or biologically.

What happens when limestone weathers?

Limestone dissolves in water and does not form soil.

What is humus?

Organic matter that binds soil particles, enhances soil structure, and provides nutrients for microorganisms.

What is the ideal soil texture?

Loam, which is a balanced mix of sand, silt, and clay that drains well and holds water and nutrients.

Why is organic matter important in soil?

Organic matter improves drainage, water retention, nutrient capacity, and supports microorganisms.

How does air dispersal in soil affect plants?

Air dispersal allows plant roots to access oxygen, essential for their growth.