Have you ever picked up a stone from the ground or the riverbank? Stones and rocks are all around us. The mountains, the riverbeds, and even the ground beneath our feet are made of rocks.
When rocks break into tiny pieces over thousands of years, they mix with dead leaves and other materials to form soil. Soil is what plants grow in. Without soil, there would be no food for us!
Let us learn about rocks and soil and why they are so important.
Rocks are hard, solid materials found in the earth. They come in many shapes, sizes, and colours. Some rocks are very hard like granite, and some are softer like chalk.
Rocks are found everywhere — on mountains, under the sea, in rivers, and deep inside the earth.
| Type | How It Forms | Examples |
|---|---|---|
| Igneous Rock | Forms when hot melted rock (lava) from a volcano cools down and becomes hard | Granite, Basalt |
| Sedimentary Rock | Forms when layers of sand, mud, and tiny pieces settle and press together over many years | Sandstone, Limestone, Coal |
| Metamorphic Rock | Forms when igneous or sedimentary rocks are changed by great heat and pressure deep inside the earth | Marble, Slate |
The Taj Mahal in Agra is made of white marble, which is a metamorphic rock. Many temples in South India are built from granite, which is an igneous rock.
Soil is the top layer of the earth. It is made of tiny pieces of rock, dead plants and animals, water, and air. It takes hundreds of years for rocks to break down and form soil.
Soil has different layers called horizons:
| Layer | What It Contains |
|---|---|
| Topsoil (top layer) | Dark, rich in nutrients, where plants grow. Contains humus (dead plant and animal matter). |
| Subsoil (middle layer) | Lighter in colour, less nutrients, contains minerals and clay. |
| Bedrock (bottom layer) | Solid rock. Roots of large trees can reach here. |
| Type | Features | Best For |
|---|---|---|
| Sandy Soil | Loose, gritty, drains water quickly, does not hold water well | Grows some vegetables like carrots and groundnuts |
| Clay Soil | Heavy, sticky when wet, holds water for a long time | Good for making pots and bricks; grows rice and wheat |
| Loamy Soil | Mix of sand, clay, and silt; holds water and nutrients well | Best for growing most crops and plants |
| Silty Soil | Smooth and fine, found near rivers, very fertile | Good for growing vegetables and fruits |
Soil is one of our most important natural resources. Here is why:
| Word | Meaning |
|---|---|
| Rock | A hard, solid material found in the earth, made of minerals |
| Lava | Hot melted rock that comes out of a volcano |
| Igneous rock | Rock formed when lava cools and becomes hard |
| Sedimentary rock | Rock formed from layers of sand and mud pressed together |
| Metamorphic rock | Rock changed by heat and pressure inside the earth |
| Soil | The top layer of the earth made of rock pieces, humus, water, and air |
| Humus | Dead and decayed plant and animal matter that makes soil fertile |
| Loamy soil | The best type of soil for farming; a mix of sand, clay, and silt |
| Erosion | The wearing away of soil by wind, water, or other forces |
What you need: Three small cups, soil from your garden, sand from a playground, and clay (or mud from a pond).
What to do: Put a little water in each cup. Stir and observe. Answer the questions below.
| Soil Type | Does it absorb water quickly? | Does it feel sticky? | Does it clump together? |
|---|---|---|---|
| Garden soil | |||
| Sand | |||
| Clay / Mud |
Which soil do you think is best for growing plants? Why?
Want to use this as a worksheet? Switch to the A4 printable view.
Have you ever picked up a stone from the ground or the riverbank? Stones and rocks are all around us. The mountains, the riverbeds, and even the ground beneath our feet are made of rocks.
When rocks break into tiny pieces over thousands of years, they mix with dead leaves and other materials to form soil. Soil is what plants grow in. Without soil, there would be no food for us!
Rocks are hard, solid materials found in the earth. They come in many shapes, sizes, and colours. Some rocks are very hard like granite, and some are softer like chalk.
Think about it: The walls of old forts and temples in India are made of rocks like sandstone and granite. Can you name a famous monument made of stone?
| Type | How It Forms | Examples |
|---|---|---|
| Igneous Rock | Forms when hot melted rock (lava) from a volcano cools down and becomes hard | Granite, Basalt |
| Sedimentary Rock | Forms when layers of sand, mud, and tiny pieces settle and press together over many years | Sandstone, Limestone, Coal |
| Metamorphic Rock | Forms when igneous or sedimentary rocks are changed by great heat and pressure deep inside the earth | Marble, Slate |
The Taj Mahal in Agra is made of white marble (metamorphic rock). Many temples in South India are built from granite (igneous rock).
Soil is the top layer of the earth. It is made of tiny pieces of rock, dead plants and animals, water, and air. Soil has three layers:
| Layer | What It Contains |
|---|---|
| Topsoil | Dark, rich in nutrients and humus. This is where plants grow. |
| Subsoil | Lighter in colour, less nutrients, contains minerals and clay. |
| Bedrock | Solid rock at the bottom. |
| Type | Features | Best For |
|---|---|---|
| Sandy Soil | Loose, gritty, drains water quickly | Carrots, groundnuts |
| Clay Soil | Heavy, sticky when wet, holds water long | Rice, wheat; making pots |
| Loamy Soil | Mix of sand, clay, silt; holds water and nutrients well | Best for most crops |
| Silty Soil | Smooth and fine, found near rivers, very fertile | Vegetables and fruits |
| Word | Meaning |
|---|---|
| Lava | Hot melted rock that comes out of a volcano |
| Humus | Dead and decayed plant and animal matter that makes soil fertile |
| Loamy soil | The best type of soil for farming; a mix of sand, clay, and silt |
| Erosion | The wearing away of soil by wind or water |
| Topsoil | The top layer of soil, richest in nutrients |
A. Fill in the Blanks
B. Multiple Choice Questions
C. Short Answer Questions
Collect a little garden soil, sand, and clay. Put each in a cup with some water. Stir and observe. Fill in the table below.
| Soil Type | Absorbs water quickly? | Feels sticky? | Clumps together? |
|---|---|---|---|
| Garden soil | |||
| Sand | |||
| Clay / Mud |
Which soil is best for growing plants? Why?