Roi Gy 1653498419 Soil Powerpoint Ver 2
Roi Gy 1653498419 Soil Powerpoint Ver 2
Roi Gy 1653498419 Soil Powerpoint Ver 2
The most common minerals found in soil are phosphorus, potassium and
nitrogen, and these minerals help plants grow.
How is soil formed?
Soil takes a long, long time to form. It can take around 1,000 years, just to make
a couple of centimetres of soil!
Lots of different factors influence how soil is made, one such factor is climate.
Climate
A country’s climate, or usual weather patterns affects the kinds of plants and
animals that will live there. The amount of rain and the temperature affects the
type of plants that grow there. In warm and moist climates soil can be produced
quickly, as dead leaves break down quicky. Colder climates slow this down.
Rain causes minerals to be washed deep into the layers of the soil.
Parent Materials
Soils around the world are different, depending on what gets dropped on them
from the air and water. Parent materials are materials which over time affect the
soil. In areas with lots of volcanoes, volcanic ash can drop onto soil. Rocks in an
area can affect the soil, as rain over time can wear away the rock and wash
minerals into the soil.
Living Organisms
In autumn leaves fall from trees. In fact, twigs, fruit, pieces of bark and other
such things are always falling on the ground from the plants that grow nearby.
These living things are broken down by bacteria, fungi and earthworms. This
gives off nitrogen and sulphur that plants use.
The Landscape
The shape of the land affects the soil as steep hills mean that water can run off it
and make it dry and hard for plants to grow there.
Time
It takes a long time to make soil. It takes even longer for soil to form on
mountains as the wind and the slope slow the process down.
Layers of soil
• Organic - This top layer is the layer with twigs, leaves etc that fall
onto the ground.
• Subsoil - This layer is made of iron, clay and other remains from
once-living plants and animals
• Parent material - This is called the parent material as the other
layers formed from this. It is very rocky.
Although we might not realise it, soil is very important! Lots of people think of
it as mud, that we might want to wipe off our shoes, but it has an extremely
important job in supporting life on earth.
Plants grow in soil
Plants grow in soil. They use the soil to get nutrients and water to help them
grow. They also use the soil layers to keep them steady in
the ground.
Food
Soil allows plants and trees to grow. Trees and plants are used as food sources
for humans and animals.
If we think of all the food items we eat every day, many of them are grown on
trees and plants. Wheat, fruit, vegetables, rice and even pasta are all produced
from plants.
Flooding
Soil helps to prevent flooding. This is because during heavy rainfall, soil helps
to soak up excess water. This helps control the amount of water on the ground
and prevents roads and other areas from being flooded.
Did you know?
You can help by composting. You can make a compost heap for fruit and vegetable scraps.
These will eventually break down and return nutrients to the soil.
Buy organic food. It is best to buy fruit and vegetables that have not used chemical
pesticides, herbicides or fertlizers on the soil.
Help out with gardening by pulling up weeds! This reduces the need for pesticides.