Chapter Notes - Crop Production and Management Class 8 Notes | EduRev

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Class 8 : Chapter Notes - Crop Production and Management Class 8 Notes | EduRev

The document Chapter Notes - Crop Production and Management Class 8 Notes | EduRev is a part of the Class 8 Course Science Class 8.
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AGRICULTURAL PRACTICES

(i) When the same kinds of plants are grown at one place on a large scale, it is called a 'crop'. Different types of crops like cereals, vegetables and fruits etc, can be classified on the basis of the season in which they grow.
(ii) India is a vast country. Here climatic conditions like temperature, humidity and rainfall vary from one region to another. There is a rich variety of crops grown in different parts of the India. Despite this diversity, two broad cropping patterns can be identified.

1. Kharif crops: Plants that are planted during the rainy season are called kharif crops. The rainy season in India is generally from June to September. Paddy, maize, soyabean, groundnut, cotton, etc., are the examples of kharif crops.
Examples of Kharif Crops:
Chapter Notes - Crop Production and Management Class 8 Notes | EduRev
2. Rabi Crops: Crops which are grown in the winter season are called rabi crops. Their time period is generally from October to March. Wheat, gram, pea, mustard and linseed are the examples of rabi crops.
Examples of Rabi Crops:

Chapter Notes - Crop Production and Management Class 8 Notes | EduRev

Basic Practices of Crop Production:
The several activities undertaken by the farmers for the cultivation of crops over a period of time are referred to as agricultural practices. These activities are:
1. Preparation of soil
2. Sowing
3. Adding manure and fertilizers
4. Irrigation
5. Protection from weeds
6. Harvest and storage

1. Preparation of soil:
One of the most important tasks in agriculture is to turn the soil and loosen it. The top layer of soil supports plant growth and is rich in nutrients.The loose soil allows the roots to penetrate and breathe easily even when they go deep into the soil. The loosened soil helps in the growth of earthworms and microbes present in the soil.
The process of loosening and turning of the soil is called tilling or ploughing. This is done by using a plough which is made of wood or iron.
If the soil is very dry, it may need watering before ploughing. The ploughed field may have big pieces of soil called crumbs. It is necessary to break these crumbs with a plank. The field is levelled by leveller for sowing as well as for irrigation purposes.
Chapter Notes - Crop Production and Management Class 8 Notes | EduRev

Preparation of Soil

2. Sowing:
Sowing is the most important part of crop production. Before sowing, good quality seeds are selected. These are clean and healthy seeds of a good variety. Farmers prefer to use seeds which give a high yield.
Before sowing, one of the important tasks is to know about the tools used for sowing seeds.
(i) Traditional Tool: It is the tool shaped liked funnel used traditionally for sowing seeds. The seeds are filled into the funnel, passed down through two or three pipes having sharp ends. These ends pierce into the soil and place seeds there.
Chapter Notes - Crop Production and Management Class 8 Notes | EduRev

Traditional tool

(ii) Seed Drill: Now a days the seed drill is used for sowing with the help of tractors. With help of this tool sows the seeds uniformly at proper distances and depths. It ensures that seeds get covered by the soil after sowing and prevents damage caused by birds. It saves time and labour.
Chapter Notes - Crop Production and Management Class 8 Notes | EduRev

Seed Drill

Point to Remember
How to separate damaged seeds from healthy seeds?
Put the seeds in water. Damaged seeds are hollow and lighter and thus, float on water. Good and healthy seeds sink in water and settle down.

Precautions to be taken while sowing:
While sowing seeds, it is essential to make sure that:
(i) Seeds are healthy and of high quality.
(ii) They are planted at correct distance from each other so that they can get proper light, water and nutrients from soil.
(iii) They must be sown deep enough to protect them from animals and birds (which might eat them) and wind (which might blow them away) but not so deep that they may not get enough air to germinate.

3. Adding Manure and Fertilizers:
When crop after crop is grown in the same field, the soil becomes poor in certain nutrients. Manure and fertilizers are added to the soil to replenish it with nutrients to ensure healthy growth of plants. Fertilizers are chemicals used to add minerals like potassium, phosphorus and nitrates to the soil.

Different types of manure that farmers can use:
Manure can be of various types, such as:
1. Natural Organic Manure:
This includes raw manure, compost, and green manure:
(i) Raw manure is a mixture of cattle and domestic waste.
(ii) Compost is well-rotted plant and animal residue.
(iii) Green Manure are crops grown in the field as the pure crop or as an intercrop between the main crops and then, buried in the field to enrich the soil.

2. Biofertilizers: These are the nitrogen-fixing organisms that are widely used in organic farming and make agriculture sustainable. These include Rhizobium, Azotobacter, blue-green algae.

3. Vermi-Compost: It is a type of compost which is made using earthworms.
Three methods of replenishing the soil with nutrients:
The three methods of replenishing the soil are:
(i) Adding organic manure to the soil
(ii) Adding chemical fertilizers to the soil
(iii) Leaving the field uncultivated (or fallow) between two crops and Crop rotation, in which different crops are grown alternately to allow the soil to replenish with different nutrients.

Pros and Cons of using Fertilizers:
Pros: They are chemicals, rich in particular nutrients and help farmers get better yield of crops like wheat, paddy and maize.
Cons: They make soil less fertile and also cause water pollution.

Why is Manure better than Fertilizers?
Organic Manure is better than Fertilizers because:
(i) It adds humus to the soil and increases its water holding capacity,
(ii) Improves soil texture,
(iii) Makes soil porous which makes exchange of gases easier, and
(iv) Increases the number of friendly microbes.

Difference between Manure and Fertilizers:

S.no.

Manure

Fertiliser

1.

Easily made using animal and plant waste

Made in factories in well defined way

2.

No harmful effect as fully natural

Side effects as it is a chemicals

3.

Provides mainly organic matter

Provides mainly nutrients

4.

Good for long term soil fertility

Not good for long term soil fertility. If uses in excessive amount

5.

Not effective  as fertilisers

Very effective in obtaining fast result.

6.

It is very cheap

It is very costly


4. Irrigation:
(i) Water is important for proper growth and development of plants.
(ii) Water is essential because germination of seeds does not take place under dry conditions. Nutrients dissolved in water get transported to each part of the plant.
(iii) Water also protects the crop from both frost and hot air currents. The supply of water to crops at different intervals is called irrigation.
(iv) It’s not a good idea to depend on rain for water as it is not fully reliable. A proper irrigation system will ensure timely and adequate water to crops. This will lead to more yield.
Sources of Irrigation: Wells, Tube wells, Ponds, Lakes, Rivers, Dams and Canals are the sources of Irrigation.
Chapter Notes - Crop Production and Management Class 8 Notes | EduRev

Tubewells


1. Traditional Methods of Irrigation:
The water available in wells, lakes and canals is lifted up by different methods in different regions, for taking it to the fields. Here various traditional methods are:
Chapter Notes - Crop Production and Management Class 8 Notes | EduRev
Chapter Notes - Crop Production and Management Class 8 Notes | EduRev

2.Modern Methods of Irrigation:
(i) Sprinkler System:
In this system, perpendicular pipes, having rotating nozzles on top, are joined to the main pipeline at regular intervals. When water is allowed to flow through the main pipe under pressure with the help of a pump, it sprinkles from the rotating nozzles. It gets sprinkled on the crop as if it is raining.
Chapter Notes - Crop Production and Management Class 8 Notes | EduRev

(ii) Drip system:
In this system, the water falls drop by drop just at the position of the roots. So it is called drip system.
Chapter Notes - Crop Production and Management Class 8 Notes | EduRev

 
5. Protection from Weeds:
(i) Weeds are the undesirable plants which may grow naturally along with the crop in the field.
(ii) The removal of weeds is called weeding. Weeding is necessary because they affect the growth of the crop by competing with the crop plants for water, nutrients, space and light.
Weed Control:
Farmers use many ways to remove weeds and control their growth. Tilling before sowing of crops helps in uprooting and killing of weeds, which may then dry up and get mixed with the soil. The best time for the removal of weeds is before they produce flowers and seeds. The manual removal includes physical removal of weeds by uprooting or cutting them close to the ground, from time to time with the help of a khurpi. Weeds are also controlled by spraying certain chemicals called weedicides, in the fields to kill the weeds. They do not damage the crops.

6. Harvest and Storage:
Chapter Notes - Crop Production and Management Class 8 Notes | EduRevFig: Grain harvesting and storageCutting the crop after it has ripened and gathering the grains is known as harvesting. We can use the word crop ripened rather than using the word crop mature. A sickle has a sharp serrated-edged metal blade attached to a wooden handle.

A sickle is used for cutting the crop. A harvester is a machine that helps to cut the ripened crop from the fields.
Threshing is the process of separating the grains from the straw and chaff. A thresher is used for threshing.
Chapter Notes - Crop Production and Management Class 8 Notes | EduRev

Fig: Threshing


A combine is a combination of a thresher and a harvester. 

Winnowing is a process in which we allow natural wind to blow through the grains, so the lighter substances fly away, whereas the heavier grains fall to the ground. The fan in a winnowing machine blows away the chaff.
Chapter Notes - Crop Production and Management Class 8 Notes | EduRev

Fig: Winnowing


Storage:
How are grains protected from pests, bacteria and fungi?

(i) Grains (seeds) are dried in the sun to reduce their moisture.

(ii) At small scale, grains are stored in jute bags or metallic bins.

(iii) At large scale, they are kept in silos and granaries.

(iv) Dried neem leaves are used at home to protect food grains.

(v) In big godowns, chemical treatments are done to protect the large quantities of grain.

Precautions to be taken during storage of food grains are:
(i) Grains should be dried properly or they might rot easily.
(ii) They should be stored in completely dry gunny bags.
(iii) The bags should be kept in a place which is completely moisture-free.
(iv) Storage areas should be well-ventilated.
(v) In larger godowns, care should be taken that chemicals used to repel or kill insects and rats do not contaminate food grains.

Granaries:
Granaries are the place where the freshly obtained food grains are stored.
Chapter Notes - Crop Production and Management Class 8 Notes | EduRev

Fig: Grains stored in granaries


Animal Husbandry:
Animal husbandry is the management and care of farm animals for milk, egg or meat. Animal husbandry has been practiced for thousands of years since the first domestication of animals. Humans are dependent on animals in innumerable ways. The animals are domesticated by humans for many purposes.
Chapter Notes - Crop Production and Management Class 8 Notes | EduRev

Fig: Animal Husbandary

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