Soil as a gift of nature
Potters shape clay into pots, diyas and idols. A farmer lifts a handful of black soil and says, "This will give a good crop." The same soil that grows our food also gives iron, aluminium and clay.
A gift of nature (निसर्गाची देणगी) is wealth that nature gives us free, like soil, water and minerals. Soil texture (मातीचा पोत) tells how rough or soft the soil is. Water-holding capacity (जलधारण क्षमता) is the ability of soil to retain moisture.
In the figure : In the figure soil gives us minerals for iron, aluminium and pottery.
Rule 1: Minerals from soil — Red soil from red rocks in Karnataka, Odisha and Maharashtra is infertile for farming, but its red colour is due to iron minerals, from which iron and steel are made. Konkan, Kolhapur and Ratnagiri soil has bauxite, which gives aluminium. China clay is found in Bihar and Kerala, and multani mati in Rajasthan.
- Easy : Red colour of red soil: iron minerals.
- Medium : Bauxite → aluminium.
- Exam-type : Terracotta clay is used for decorative items and idols.
Rule 2: Soil texture and water-holding — Soil can be rough like sand or soft like flour; by the size of sand-like particles it is classed as very coarse, moderately coarse or fine. Water-holding capacity depends on decayed leaves, dung and sand-like particles in the soil.
- Easy : Sandy soil is rough.
- Medium : Fine soil feels soft like flour.
- Exam-type : Adding decayed leaves and dung helps soil to hold water.
Soil gives food, iron, aluminium and clay. Texture depends on particle size.
Thinking red soil is useless because it is infertile. It gives iron minerals.
Memory clue: Red = Iron; Bauxite = Aluminium (Al).
Spot the difference
| Soil or mineral | Gives us |
|---|---|
| Red soil (iron minerals) | Iron and steel |
| Bauxite | Aluminium |
| China clay, terracotta | Pottery, idols |
Practice questions
- 1What gives red soil its colour?
- 2Which mineral in Konkan soil gives aluminium?
- 3Where is multani mati found?
- 4What is terracotta used for?
- 5What is soil texture?
- 6What is water-holding capacity of soil?
- 7How can we increase the water-holding capacity of soil?
- 8Mohan says red soil is infertile so it is of no use. Correct him.
Show answers (try them yourself first)
- 1Minerals of iron.
- 2Bauxite
- 3Rajasthan
- 4Decorative items and idols.
- 5How rough or soft the soil is.
- 6Ability of the soil to retain moisture.
- 7By adding decayed leaves and dung.
- 8It contains iron minerals from which iron and steel are made.
Water as a resource
When a tap runs dry in summer we realise how precious water is. A rooftop on a rainy day sends gallons of water down the drain, while a nearby well may be going dry.
Surface water (भूपृष्ठीय पाणी) is water collected on the earth's surface; groundwater (भूजल) is water under the ground. Hard water does not form lather with soap; soft water does. Rainwater harvesting (जलसंधारण) is collecting rainwater for use or for seeping into the ground.
In the figure : In the figure water comes from the surface and from under the ground.
Rule 1: Why water matters — Water is needed by cells, for making food in plants, digestion, transport of nutrients, sweating and removal of waste. About 340 to 500 litres of water are needed to make one kilogram of paper; sugar and medicines also need much water. Only a small portion of ocean water is fit for drinking.
- Easy : 340 litres per kg of paper (lower value).
- Medium : For 10 kg of paper at 340 litres per kg: 10 × 340 = 3400 litres at least.
- Exam-type : At 500 litres per kg, 10 kg need 10 × 500 = 5000 litres, so the range for 10 kg is 3400 to 5000 litres.
Rule 2: Hard and soft water — Surface water: rivers, ponds, dams. Groundwater: seeps into the ground and reaches wells and bore wells. Soap forms little lather in hard water and a lot of lather in soft water.
- Easy : River water is surface water.
- Medium : Well water is groundwater.
- Exam-type : Test: shake soap in water: lots of lather → soft; little lather → hard.
In the figure : In the figure rainwater harvesting stores rain and raises the groundwater level.
Rule 3: Saving water — "Save water – Save life". Old stone tanks, the Bawadi of Rajasthan and the Vav of Gujarat store water for a long time. In rainwater harvesting rain from rooftops and open grounds is stored in tanks or allowed to seep into the ground, raising the groundwater level.
- Easy : Collect rain from the roof in a tank.
- Medium : Let rain seep into the ground to raise the groundwater level.
- Exam-type : Bawadi and Vav are old structures that store water for a long time.
Water as a resource
In the app you can move this figure with your finger.
Open in the appSurface water + groundwater = our supply. Rainwater harvesting raises the groundwater level.
Thinking all sea water can be drunk. Only a small portion is suitable.
Memory clue: Hard water = Hardly any lather.
Spot the difference
| Type | Meaning | Example |
|---|---|---|
| Surface water | On the earth's surface | River, pond, dam |
| Groundwater | Under the ground | Well, bore well |
| Hard / soft water | Little / lots of lather | Soap test |
Practice questions
- 1Name the two sources of water for us.
- 2What is groundwater?
- 3What is hard water?
- 4What is rainwater harvesting?
- 5Name two old water-storing structures.
- 6How many litres of water are needed for 10 kg of paper at 340 litres per kg?
- 7Name three uses of water in the body or plants.
- 8A school wants to raise the groundwater level near its well. Suggest what to do and explain.
Show answers (try them yourself first)
- 1Surface water and groundwater.
- 2Water that seeps into the ground and reaches wells and bore wells.
- 3Water in which soap does not form lather.
- 4Storing rainwater in tanks or letting it seep into the ground.
- 5Bawadi of Rajasthan and Vav of Gujarat.
- 610 × 340 = 3400 litres
- 7Making food in plants, digestion, removal of waste.
- 8Do rainwater harvesting: let rain from the roof and ground seep into the earth.
Marine wealth, solar and wind energy
A sailing boat moves on the wind with no petrol. A solar lamp glows by itself in the evening. The sea gives fish to the fisherman and salt to the cook. Sun, wind and sea give so much without asking for payment.
Solar energy (सौर ऊर्जा) is energy from the sun. Wind energy (पवन ऊर्जा) is energy from moving air, used in windmills to make electricity.
Rule 1: Marine wealth — From the sea we get fish, prawns, crabs, salt, minerals, shells and marine plants (algae, iodine). Valuable metals lie in the sediments of the ocean floor, and the coastal sands of Kerala, Tamilnadu, Andhra Pradesh and Odisha contain valuable minerals. Mineral oil and natural gas are found under the sea and underground.
- Easy : Salt, fish and shells come from the sea.
- Medium : Sediments of the ocean floor have valuable metals.
- Exam-type : Mineral oil and natural gas give fuel.
In the figure : In the figure solar panels turn sunlight into electricity.
Rule 2: Solar energy — People have long dried grains and clothes in the sun and made salt in salt pans. Solar panels make electricity; solar heaters and solar cookers are used. Solar energy is environment-friendly, free and inexhaustible.
- Easy : Drying clothes in the sun uses solar energy.
- Medium : A solar cooker cooks food with sunlight.
- Exam-type : Solar panels give electricity without smoke.
In the figure : In the figure windmills turn the energy of wind into electricity.
Rule 3: Wind energy — Windmills fitted in always-windy places generate electricity (wind energy projects). Chalkewadi in Satara district, Maharashtra, is one of the largest in Asia.
- Easy : A windmill turns when wind blows.
- Medium : Windy places are chosen for windmills.
- Exam-type : Chalkewadi (Satara) is a big wind energy project.
Sun, wind and sea give wealth that does not run out (sun, wind).
Thinking solar and wind energy cause smoke and pollution. They are clean.
Memory clue: Sun and Wind: clean, free, never end.
Spot the difference
| Source | Gives | Example |
|---|---|---|
| Sea | Fish, salt, minerals, oil | Prawns, shells |
| Sun | Heat and electricity | Solar panel, cooker |
| Wind | Electricity | Chalkewadi windmills |
Practice questions
- 1Name two things we get from the sea.
- 2What is solar energy?
- 3What do solar panels do?
- 4What is wind energy?
- 5Where is Chalkewadi wind energy project?
- 6Give two advantages of solar energy.
- 7Where are windmills fitted and why?
- 8Ravi says solar panels work equally well at midnight. Is he right?
Show answers (try them yourself first)
- 1Fish and salt.
- 2Energy from the sun.
- 3Turn sunlight into electricity.
- 4Energy of moving air used by windmills to make electricity.
- 5In Satara district, Maharashtra.
- 6Environment-friendly and inexhaustible (also free).
- 7In always-windy places, because they need wind to turn.
- 8No. They need sunlight to make electricity.
Forest wealth
Grandmother gives tulsi leaves for a cough and amla for a strong body. Paper, furniture and medicines all come from the forest. A forest is like a big free shop and also a big water tank for the land.
Forest wealth (वनसंपत्ती) is everything we get from forests. The Chipko Movement (चिपको आंदोलन) was begun in 1973 to protect trees. Ayurveda is a system of treatment with medicines from plants.
Rule 1: Wealth of forests — Forests give wood (furniture, paper, medicines), fruits, hirda, beheda, shikekai, gum and medicinal plants (holy basil, ashwagandha, aloe vera, amla). Large-scale cutting of forests has caused loss of animal habitats and reduced rainfall.
- Easy : Tulsi, ashwagandha, aloe vera and amla are medicinal plants.
- Medium : Wood from forests gives furniture and paper.
- Exam-type : Cutting forests harms animals and reduces rain, so more forests are being grown.
Rule 2: Chipko and Charak — In 1973 the Chipko Movement began: local women including Gaura Devi hugged trees to oppose deforestation; Sunderlal Bahuguna gave it direction. About 2500 years ago Sage Charak developed Ayurveda; his Charak Samhita describes medicinal plants, their use, cultivation and proportions.
- Easy : Chipko: hugging trees to save them.
- Medium : Chipko began in 1973 to save trees, while Charak's Ayurveda is about 2500 years old; one protects forests, the other uses their plants.
- Exam-type : Charak Samhita explains medicinal plants, use, cultivation and proportions.
Forests give wood, fruits, gum and medicines. Protect them (Chipko).
Thinking forests only give wood. They give medicines, gum, fruits and also bring rain.
Memory clue: Chipko = Cling to the tree.
Spot the difference
| Name | Who or what | Work |
|---|---|---|
| Chipko Movement | Gaura Devi, Sunderlal Bahuguna | Saved trees (1973) |
| Charak | Sage | Ayurveda, Charak Samhita |
| Medicinal plants | Tulsi, amla, aloe vera | Used in medicines |
Practice questions
- 1Name two things we get from forests.
- 2Name two medicinal plants.
- 3When did the Chipko Movement begin?
- 4Who gave direction to the Chipko Movement?
- 5Who developed Ayurveda about 2500 years ago?
- 6What does the Charak Samhita describe?
- 7What problems did large-scale cutting of forests cause?
- 8Your village wants to cut the forest for more fields. Which movement and reasons would you quote to stop it?
Show answers (try them yourself first)
- 1Wood and gum (also fruits, medicinal plants).
- 2Holy basil (tulsi) and amla.
- 3In 1973
- 4Sunderlal Bahuguna
- 5Sage Charak
- 6Medicinal plants, their use, cultivation and proportions.
- 7Loss of animal habitats and reduced rainfall.
- 8Chipko Movement; cutting forests destroys animal homes and reduces rain.
Fossil fuels and types of natural resources
The petrol in a scooter and the gas in a kitchen cylinder were made over millions of years from dead living things. We use in an hour what nature made in ages.
Fossil fuels (जीवाश्म इंधने) are coal, petroleum and natural gas, formed from remains of dead organisms over millions of years. Renewable resources are made again by nature; non-renewable resources are limited; sustainable resources never end.
In the figure : In the figure fossil fuels take millions of years to form.
Rule 1: Fossil fuels — Dead organisms buried under mud, sand and rocks turned into coal, petroleum and natural gas. Coal came from ancient plants; crude oil gives petrol, diesel, kerosene and tar; natural gas (methane and other gases) is used for cooking and electricity.
- Easy : Coal came from ancient plants.
- Medium : Crude oil gives petrol, diesel, kerosene and tar.
- Exam-type : Excess use mixes harmful substances in the air, and oil reserves will be exhausted.
In the figure : In the figure renewable resources are made again by nature; non-renewable ones are limited.
Rule 2: Types of resources — Renewable (water, soil) are produced again and again by nature. Non-renewable (petrol, coal, natural gas) are limited and take thousands of years to regenerate. Sustainable (sunlight, wind, sea waves) never end.
- Easy : Water and soil: renewable.
- Medium : Petrol and coal: non-renewable.
- Exam-type : Sunlight, wind and sea waves: sustainable.
Use fossil fuels carefully. Prefer sustainable sun and wind where possible.
Thinking petrol will never finish. It is non-renewable and limited.
Memory clue: Fossil = Finishes; Sun and wind = Stay.
Spot the difference
| Type | Meaning | Example |
|---|---|---|
| Renewable | Made again by nature | Water, soil |
| Non-renewable | Limited, takes thousands of years | Petrol, coal, natural gas |
| Sustainable | Never ending | Sunlight, wind, sea waves |
Practice questions
- 1What are fossil fuels?
- 2From what did coal form?
- 3Name two things obtained from crude oil.
- 4Name two renewable resources.
- 5Name two non-renewable resources.
- 6Name two sustainable resources.
- 7Why should fossil fuels be used carefully?
- 8Classify as renewable, non-renewable or sustainable: soil, petrol, sea waves, natural gas.
Show answers (try them yourself first)
- 1Coal, petroleum and natural gas formed from dead organisms.
- 2Ancient plants
- 3Petrol and diesel.
- 4Water and soil.
- 5Coal and petrol.
- 6Sunlight and wind.
- 7They are limited, take millions of years to form and pollute the air.
- 8Soil: renewable; petrol: non-renewable; sea waves: sustainable; natural gas: non-renewable.
Quick revision
- Soil, water, sea, sun, air, forests and fossil fuels are gifts of nature.
- Solar and wind energy are sustainable; fossil fuels are non-renewable and should be used carefully.
- Hard water does not form lather with soap; rainwater harvesting raises groundwater level.