Soil Texture Flashcards Preview

Rhs Level 2 Horticulture > Soil Texture > Flashcards

Flashcards in Soil Texture Deck (7)
Loading flashcards...
1

What are the classes of particle in soil texture? Give sizes.

Sand 2.0mm - 0.06mm

Silt 0.06mm - 0.002mm

Clay 0.002mm and smaller

2

Explain the different types of weathering that create soil.

Chemical - rainwater and carbon dioxide create carbonic acid

Physical - wind and water erosion. Freeze and thaw breaks up rock.

Biological - plant roots penetrate rock cavities and expand. Plants create CO2 through respiration which combines with rainwater to form carbonic acid.

3

Describe the different layers that form soil.

O horizon - surface soil

A horizon - topsoil

B horizon - subsoil

C horizon - partially broken down parent rock

Parent rock

4

How do you identify a clay soil, and what are its characteristics?

Clay soil will roll into a sausage in the hands and bend in a circle.

It is heavy to work, sticky in winter and hard in summer.

It has a high cation exchange capacity.

It is prone to compaction and structural damage if worked when wet. It is slow to drain and warm up in spring, and poorly aerated.

5

How do you identify a sandy soil, and what are its characteristics?

Sandy soils will feel gritty, and sandy loam may roll into a sausage but won't bend.

Inert, free draining, well aerated, quick to warm and cool, easily leached of nutrients.

Easy to work.

6

How do you identify a silty soil and what are its characteristics?

Usually occur in alluvial valleys.

Behave like sandy soil but have a small CEC.

prone to surface capping.

7

Give the proportions of ingredients in a perfect loam.

50% sand, 30% silt, 20% clay