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Soil erosion
When soil is farmed
too much, its nutrients
get used up. The topsoil
blows or washes away.
Not many plants can
survive in these areas
without the rich topsoil.
Ploughing breaks up soil
to stop it getting hard
and solid. This helps
crops grow more easily.
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Soil
A pedologist.
Clay soils
have very
small particles. Water
collects between them.
Loamy soils
have a
mixture of small and
large particles.
Sandy soils
contain
particles about 2 mm
(0.08 in) across.
Sizing up soil
Different types of
soil have different
sized particles.
Important earthworms
Earthworms help to make fertile soil.
Their burrows let air into the soil, and
create pathways for water to move around
more easily. Earthworms also help the remains
of plants and animals to decompose. This
releases important nutrients into the soil.
Earthworm waste is good for soil too!
Half fill a jar
with soil and top it up
with water. Put on the lid
and shake. Leave for a
day. The soil should
separate into layers.
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