Showing posts with label SOIL. Show all posts
Showing posts with label SOIL. Show all posts

Thursday, 16 January 2014

HOW TO LOOK AFTER SOIL


Soil is essential for people.
This is because plants need soil to grow.
We need plants for food and for wood.
Plant roots help fix soil and prevent wind and water sweeping it away.
Plant leaves and branches protect soil from heavy rains.
For this reason, we must protect the plants that grow in soil.

SOIL IS MADE UP OF LAYERS


Soil is made up of three layers, each containing different materials:
  • Topsoil: This top layer contains sand, clay, water, air and humus.
  • Subsoil: This middle layer contains stones, sand, clay and some water.
  • Bedrock: This bottom layer is made up of rocks, and contains very little water.
A: TOPSOIL; B: SUBSOIL; C: BEDROCK.
Photo from Wikipedia

HOW IS SOIL FORMED?


Soil is a mixture of many things.
It forms very slowly over a long period of time.
First, wind, rain and ice wear down rocks into smaller pieces.
Then, the action of animals and plant roots breaks the rocks into even smaller pieces.
Little by little, the pieces of rock mix with the remains of plants or animals.
These remains of living things turn into a dark mixture called humus.
The little pieces of rock mix with the humus to form soil.
There are different types of soils because they are formed from different mixtures of rocks and organic matter.


WHAT IS SOIL?


In many places, rocks are covered by a layer of earth, called soil.
Soil consists of stones, water, air, minerals and the remains of animals and plants.


Thursday, 9 January 2014

REMEMBER

ROCKS AND MINERALS

Rocks and minerals have many uses.
For example, pencils are made up of a mineral called graphite.
Roof tiles are made of a rock called clay.

Pencil (photo by Saurabh R. Patil (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons) 
Graphite (photo by Rob Lavinsky, iRocks.com – CC-BY-SA-3.0 [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons)

Roof tiles (photo by Procsilas Moscas (Flickr) [CC-BY-2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons)
Clay mineral (photo from Wikipedia)


SOIL

Soil is the top layer of the Earth's surface.
This is where plants grow.
Some animals, such as rabbits and worms, make their homes in soil.

Soil (photo from Wikipedia)