Edunes Online Education
Class 8 Science Crops and Its Management
CBSE Notes, Activities & Explanations
Science | Class 8 | CBSE & SEBA Board
Edunes Online Education
BOARD: CBSE | CLASS: 8 | Science | Chapter 1
π Crops and its management
πΎ Class 8 Science – Crop Production and Management (Chapter 1)
π‘ Think First:
Food does not come directly from shops. It comes from planned scientific practices carried out on crops.
Food does not come directly from shops. It comes from planned scientific practices carried out on crops.
π± What is a Crop?
When the same kind of plants are grown on a large scale in fields to obtain food, it is called a crop.
How to think:
Same plant + large area + food purpose = Crop
Same plant + large area + food purpose = Crop
| Crop Type | Examples |
|---|---|
| Cereals | Wheat, Paddy, Maize, Millet |
| Pulses | Gram, Peas, Beans |
| Oil Seeds | Mustard, Groundnut |
| Vegetables | Tomato, Cabbage, Spinach |
| Fruits | Banana, Grapes, Guava, Mango |
π§ Remember:
Crops are classified by what we eat from them.
π¦️ Types of Crops
Crops are mainly classified based on the season of growing.
Kharif Crops:
Sown in rainy season (June–September)
Examples: Paddy, Maize, Millet, Soyabean, Groundnut, Cotton
Sown in rainy season (June–September)
Examples: Paddy, Maize, Millet, Soyabean, Groundnut, Cotton
Rabi Crops:
Grown in winter season (October–March)
Examples: Wheat, Gram, Peas, Mustard, Linseed
Grown in winter season (October–March)
Examples: Wheat, Gram, Peas, Mustard, Linseed
Think Season → Think Crop
Rain = Kharif π§️
Winter = Rabi ❄️
Rain = Kharif π§️
Winter = Rabi ❄️
π§ Kharif drinks rain, Rabi loves cold.
π Agriculture
The practice of growing crops in fields to obtain food is called agriculture.
Think Broadly:
Agriculture = Crop growing + planning + care
Agriculture = Crop growing + planning + care
π ️ Basic Practices of Crop Production
The different steps followed by farmers to grow crops are called agricultural practices.
- Preparation of soil
- Sowing
- Adding manure and fertilisers
- Irrigation
- Removal of weeds
- Harvesting
- Storage of food grains
Think Step-by-Step:
No step skipped → Good yield
No step skipped → Good yield
π§ Healthy crop = Right step at right time
π Crop Rotation
Growing different crops in the same field in a planned order to improve soil fertility is called crop rotation.
Think Soil Health:
Same crop again and again → soil weak Different crops → soil strong
Same crop again and again → soil weak Different crops → soil strong
π± Preparation of Soil
Soil preparation is the foundation of a healthy crop.
- Ploughing
- Levelling
- Manuring
π§ Good soil = Good crop
① Ploughing
The process of loosening and turning the soil is called ploughing or tilling.
Why plough?
✔ Roots grow easily
✔ Air enters soil
✔ Microbes become active
✔ Roots grow easily
✔ Air enters soil
✔ Microbes become active
② Levelling
Levelling is done using a leveller to prevent soil erosion and uneven watering.
Think Balance:
Flat land → equal water → healthy plants
Flat land → equal water → healthy plants
③ Manuring
Adding manure to the soil to increase its fertility is called manuring.
Think Nutrition:
Soil also needs food — manure feeds the soil.
Soil also needs food — manure feeds the soil.
π§ No nutrition → No production
π§ Agricultural Implements
Plough:
A traditional agricultural tool made of wood used for ploughing the soil. A wooden plough: The wooden plough consists of a long log of wood which is called plough shaft. There is a handle at one end of the ploughshaft. Below the handle is a strong triangular iron strip called ploughshare. The other end of ploughshaft can be attached to a wooden beam which is fixed at right angles to the ploughshaft.
A traditional agricultural tool made of wood used for ploughing the soil. A wooden plough: The wooden plough consists of a long log of wood which is called plough shaft. There is a handle at one end of the ploughshaft. Below the handle is a strong triangular iron strip called ploughshare. The other end of ploughshaft can be attached to a wooden beam which is fixed at right angles to the ploughshaft.
Think Tool Purpose:
Tool helps farmer do hard work efficiently.
Tool helps farmer do hard work efficiently.
π§ Final Thought:
Agriculture is a science of care — care for soil, water, seeds, and time.
Agriculture is a science of care — care for soil, water, seeds, and time.
π§ (ii) Hoe
π‘ Think Tool + Purpose:
Every agricultural tool is designed to solve a specific field problem.
Every agricultural tool is designed to solve a specific field problem.
A hoe is an agricultural implement used for:
- Removing weeds
- Loosening the soil
- Turning the soil
Structure → Function:
Long handle → easy movement
Broad iron blade → cuts weeds
Bent shape → loosens soil effectively
Long handle → easy movement
Broad iron blade → cuts weeds
Bent shape → loosens soil effectively
It consists of:
- A long rod made of wood or iron
- A handle at one end
- A strong, broad, bent iron plate fixed below the handle (blade)
- A beam at the other end which is tied to the neck of bullocks
π§ Hoe = Weed killer + Soil loosener
π (iii) Cultivator
π‘ Think Upgrade:
Traditional tools → Slow work Machines → Fast & efficient
Traditional tools → Slow work Machines → Fast & efficient
A cultivator is a tractor-driven agricultural implement used for:
- Loosening the soil
- Turning the soil
- Ploughing large fields quickly
Why cultivator?
✔ Covers large area at once
✔ Saves time and labour
✔ Improves soil aeration
✔ Covers large area at once
✔ Saves time and labour
✔ Improves soil aeration
A cultivator has many ploughshares which dig into the soil simultaneously and turn it.
π§ Cultivator = Speed + Scale in farming
π± 2. Sowing
π‘ Think Foundation:
A healthy crop begins with correct sowing.
A healthy crop begins with correct sowing.
Sowing is the process of scattering or placing seeds into the soil to grow crop plants.
Why is sowing important?
Wrong depth or spacing → weak plants Correct sowing → strong crop
Wrong depth or spacing → weak plants Correct sowing → strong crop
π§ Sow right today → Harvest more tomorrow
πΎ (i) Selection of Seeds
π‘ Think Quality:
The quality of seeds decides the quantity of harvest.
The quality of seeds decides the quantity of harvest.
Good quality seeds are:
- Clean
- Healthy
- Free from disease
- High-yielding
π§ Bad seed → Bad crop (no matter how good the soil)
π± (ii) Methods of Sowing Seeds
There are two main methods of sowing seeds.
(a) Sowing by Hand:
Seeds are scattered manually by farmers.
Seeds are scattered manually by farmers.
Limitations:
❌ Uneven distribution
❌ Some seeds too deep or too shallow
❌ Uneven distribution
❌ Some seeds too deep or too shallow
(b) Sowing with Seed Drill:
A machine that sows seeds at proper depth and equal distance.
A machine that sows seeds at proper depth and equal distance.
Advantages:
✔ Uniform spacing
✔ Correct depth
✔ Better crop growth
✔ Uniform spacing
✔ Correct depth
✔ Better crop growth
π§ Seed drill = Smart sowing
π Final Thinking Tip:
Tools prepare the soil, but sowing decides the future crop.
Tools prepare the soil, but sowing decides the future crop.
(iii) PRECAUTIONS FOR SOWING SEEDS — How should a farmer THINK before sowing?
Sowing is not just dropping seeds. A farmer must think about depth, distance, and moisture to ensure successful germination.
-
Right Depth: Seeds should be sown at the correct depth suitable for germination.
π Too deep → seed cannot come out π Too shallow → seed dries or is eaten by birds
-
Right Spacing: Seeds should be sown at proper intervals.
π Less space → competition for water & nutrients π Proper space → healthy plant growth
-
Avoid Dry Soil: Seeds should not be sown in dry soil.
π No water → no germination
-
Avoid Waterlogged Soil: Seeds should not be sown in highly wet soil.
π Excess water → lack of oxygen → seed rots
π§ MEMORY HOOK:
Good sowing = Depth + Distance + Moisture (DDM)
Good sowing = Depth + Distance + Moisture (DDM)
(iv) ADVANTAGES OF SOWING WITH A SEED DRILL — Why is technology better?
A seed drill helps a farmer apply all sowing precautions automatically and accurately.
-
Seeds are sown at correct depth and correct intervals.
π This ensures uniform germination and equal growth
-
Seeds are sown in regular rows.
π Easy irrigation, weeding, and harvesting
-
Seeds get covered with soil.
π Birds cannot see or eat the seeds → prevents loss
-
Tractor-driven seed drill saves time and labour.
π More area covered in less time
π§ MEMORY HOOK:
Seed Drill = Correct • Covered • Continuous
Seed Drill = Correct • Covered • Continuous
(v) TRANSPLANTATION — Why don’t farmers sow seeds directly in the field?
Transplantation means shifting young seedlings from a nursery to the main field.
π± Example Crops: Paddy (Rice), Tomato, Chilli
Advantages of Transplantation — THINK in terms of SELECTION and GROWTH
-
Selection of Healthy Seedlings:
π Weak or damaged seedlings are rejected π Only strong plants are cultivated
-
Better Root Penetration:
π Roots grow deeper → plant becomes strong
-
Better Shoot Development:
π Strong shoots → more leaves → more food production
π§ MEMORY HOOK:
Transplantation = Select → Shift → Strengthen
Transplantation = Select → Shift → Strengthen