Crop Production & Management Class 8 Science Notes - Ch. 1

Chapter 1: Crop Production and Management

Introduction to Crops

When plants of the same kind are cultivated at one place on a large scale, it is referred to as a crop. For instance, a field dedicated to growing wheat constitutes a crop of wheat. Crops are a primary source of food, providing us with essential cereals, vegetables, and fruits.

Crop Classification

In India, crops are broadly classified into two main categories based on the season of cultivation:

1. Kharif Crops

• Season: Rainy (Monsoon)
• Sowing Period: June / July
• Harvesting Period: September / October
• Key Requirement: Abundant water.
• Examples: Paddy (rice), Maize, Soyabean, Cotton.

2. Rabi Crops

• Season: Winter
• Sowing Period: October / November
• Harvesting Period: March / April
• Key Requirement: Cooler climate.
• Examples: Wheat, Gram, Pea, Mustard.

Basic Agricultural Practices

The cultivation of crops involves several sequential activities undertaken by farmers over a period of time. These are known as agricultural practices.

1. Preparation of Soil

The initial and most crucial step is to prepare the soil by turning and loosening it. This process is called ploughing or tilling.

Key Benefits:

• Allows plant roots to penetrate deep into the soil and respire easily.
• Promotes the growth of earthworms and beneficial microbes.
• Brings nutrient-rich soil to the surface for plant use.

Common Tools:

Plough, Hoe, and modern Cultivators (tractor-driven).

2. Sowing

Sowing is the process of planting seeds in the soil. The quality of seeds is a critical factor for crop yield.

Process Overview:

• Selection of high-quality, healthy seeds.
• Planting them at an appropriate depth and maintaining proper distance.
• Modern Tool: A Seed Drill is highly efficient, ensuring uniform sowing at the correct depth and covering seeds with soil.

3. Adding Manure and Fertilisers

These substances are added to the soil to replenish essential plant nutrients and ensure healthy growth, as continuous cropping can deplete the soil.

Feature	Manure	Fertiliser
Type	Natural (organic) substance	Man-made chemical salt
Source	Decomposed cattle dung & plant waste	Produced in factories
Humus	Provides abundant humus to the soil	Does not provide any humus
Nutrients	Relatively less rich in plant nutrients	Very rich in specific nutrients (N, P, K)
Example	Vermicompost, Cow dung	Urea, NPK (Nitrogen, Phosphorus, Potassium)

Advanced Technique: Crop Rotation
This is the practice of growing different crops in succession on the same piece of land. For example, planting a legume crop (like peas) after a wheat crop helps replenish the soil's nitrogen naturally, thanks to root nodule bacteria.

4. Irrigation

The supply of water to crops at appropriate intervals is called irrigation. The method and frequency vary based on the crop, soil type, and season.

Modern Methods (Water-Efficient):

• Sprinkler System: Water is sprinkled over plants, mimicking rainfall. Ideal for uneven land and sandy soils.
• Drip System: Water is delivered drop by drop directly to the base of the plants. It's the most efficient method, preventing any water wastage.

5. Protection from Weeds

Weeds are unwanted plants that grow alongside the main crop, competing for essential resources like water, nutrients, and sunlight.

Removal Methods:

• Weeding: The manual removal of weeds using tools like a khurpi.
• Weedicides: Chemical sprays (e.g., 2,4-D) that kill weeds without damaging the crop.

6. Harvesting

The cutting of a crop after it has matured is called harvesting. This is followed by threshing, the process of separating grain from the chaff.

Equipment Used:

• Manually with a Sickle.
• Mechanically with a Harvester.
• A "Combine" machine performs both harvesting and threshing.

7. Storage

Proper storage of harvested grains is vital to protect them from moisture, pests (insects, rats), and microorganisms.

Storage Procedure:

• Grains are first thoroughly dried in the sun to reduce moisture content.
• Stored in jute bags or metallic bins for domestic use.
• Large-scale storage is done in specialized structures called silos and granaries.

Food from Animals: Animal Husbandry

Similar to crop farming, animals are also reared on a large scale to obtain food products. This practice is known as Animal Husbandry.

It involves the management and care of farm animals by providing them with proper food, shelter, and healthcare to get milk, meat, eggs, and other products.

• Dairy: Rearing cows and buffaloes for milk.
• Poultry: Raising hens and ducks for eggs and meat.
• Pisciculture: Breeding and rearing fish.

Frequently Asked Questions (FAQ)

What are the 7 basic agricultural practices?

The 7 key steps are: 1. Soil Preparation, 2. Sowing, 3. Adding Manure and Fertilisers, 4. Irrigation, 5. Protecting from Weeds, 6. Harvesting, and 7. Storage.

What is the main difference between Kharif and Rabi crops?

The main difference lies in the season they are grown. Kharif crops are grown in the rainy season (e.g., rice), while Rabi crops are grown in the winter season (e.g., wheat).

Why is manure considered better than fertiliser?

Manure is considered better because it is organic, improves soil texture, enhances water-holding capacity, and adds humus to the soil, making it more fertile over the long term without causing pollution.