1 Soil Formation and Soil-Forming Factors Free Online FlashCards

What is soil formation?

Soil formation, or pedogenesis, is the development of soil as rock and sediment are weathered and altered by water, air, and living organisms.

What happens during physical weathering?

Physical weathering breaks rock into smaller pieces without changing its mineral composition, such as when water freezes in cracks.

How do soil-forming processes create horizons?

Soil-forming processes add, transform, move, or remove material. These changes help create soil layers called horizons.

What is parent material, and what does it influence?

Parent material is the mineral or organic material from which soil develops. Its composition and particle sizes influence soil texture, drainage, and available nutrients.

Why can the same parent material form different soils?

The same parent material can develop into different soils under different climates or vegetation, showing that soil-forming factors interact.

What distinguishes chemical weathering?

Chemical weathering changes minerals through reactions with water, oxygen, or acids; it can dissolve minerals or form new ones such as clay minerals.

How do organisms cause biological weathering?

Biological weathering occurs through organism activity: roots can widen cracks, and microbes or lichens can release compounds that alter minerals.

How do warm, moist conditions affect soil formation?

Warm, moist conditions generally promote chemical weathering and biological activity, while cold or dry conditions often slow them.

What is leaching?

Leaching is the movement of dissolved substances through soil by water.

How do decomposers contribute to soil?

Decomposers break down plant residues, releasing nutrients and forming soil organic matter.

How do roots and burrowing animals affect soil structure?

Roots help bind soil particles and open pathways, while earthworms and burrowing animals mix soil and create pores.

Why are soils often thin on steep slopes?

Steep slopes commonly lose soil through runoff and erosion, so the soil may remain relatively thin.