4 Match the words to the correct definition.
1. Subsoil
2. Ground
3. Profile
4. Leaching
5. Top soil
6. Weathered
☐ a. Layer of soil immediately below the surface.
☐ b. A vertical section of soil showing the sequence of the various layers.
☐ c. The upper portion of a soil, dark coloured and rich in organic material.
☐ d. Eroded or altered by the action of water, wind, frost, heat, etc.
☐ e. Process of removal of soluble constituents.
☐ f. The solid surface of the earth.
5 Find the questions to these statements.
1. .................................................................................................................................
A section of soil is made up of different colours, chemical compositions and size of material.
2. ................................................................................................................................
We can evaluate the fertility of soil by examining its profile: the soil is infertile if it contains a lightcoloured layer in the subsurface soil from which nutrients have been removed; it is fertile when it has a deep surface layer containing a high quantity of organic matter
3. ................................................................................................................................
Soil formation is affected by a range of geological, chemical and biological processes that occur over long periods of time.
4. .................................................................................................................................
A soil profile is usually made up of six layers.
5. ................................................................................................................................
There are four basic types of soil: sand, silt, clay and loam.
6. .................................................................................................................................
It is dark and very fertile, and consists of minerals and a large amount of organic matter.
7. .................................................................................................................................
It is composed of mineral materials leached from the upper layers, but is not very rich in humus.
8. .................................................................................................................................
This layer is mostly unaffected by atmospheric agents and is at the base of a soil profile.
6 Complete the table.
GLOSSARY
clay: argilla
eluviated: eluviale
floodplain: pianura alluvionale
layer: strato del terreno
to leach away: percolare
leached: lisciviato
loam: terreno a medio impasto
parent rock: roccia madre
silt: limo
unweathered: inalterato dal clima
to weather: deteriorarsi con l’azione dell’acqua, vento o gelo
wetland: palude