WBBSE Notes For Class 8 School Science Chapter 8 Human Food And Food Production

Chapter 8 Human Food and Food Production



Food is any nutritious substance that people or animals eat or drink or that plants absorb in order to maintain life and growth.

Food materials consist essentially of protein, carbohydrates, and fat used in the body of an organism to sustain growth, repair, and vital processes and to furnish energy. Food manufacturing and processing is one of the world’s largest industries.

Terminologies Associated with Food and Food Production

Agriculture is the process of producing food, feeding products, fiber, and other desired products by the cultivation of certain plants and the raising of domesticated animals (livestock).

The practice of agriculture is also known as ‘farming’. More people in the world are involved in agriculture as their primary economic activity.

Food processing is the transformation of raw ingredients, by physical or chemical means into food, or of food into other forms. Food processing combines raw food ingredients to produce marketable food products that can be easily prepared and served by the consumer.

Food processing typically involves activities such as mincing and macerating, liquefaction, emulsification, cooking (such as boiling, broiling, frying, or grilling),

Pickling and preservation, canning or jarring (primary processing such as dicing or slicing, freezing or drying when leading to secondary products are also included).

Agronomy is the science and technology of producing and using plants for food, fuel, fiber, and land reclamation.

Agronomy encompasses work in the areas of plant genetics, plant physiology, meteorology, and soil science. Agronomy is the application of a combination of Most food and has its origin in plants.

Read And Learn More WBBSE NotesFor Class 8 School Science

Some food is obtained directly from plants, but even animals that are used as food sources are raised by feeding them food derived from plants.

Cereal grain is a staple food that provides more food energy worldwide than any other type of crop. Maize, wheat, and rice – in all of their varieties – account for 87% of all grain production worldwide. Most of the grain that is produced worldwide is fed to livestock.

sciences like biology, chemistry, economics, ecology, earth science, and genetics. Horticulture is the branch of agriculture that deals with the art, science, technology, and business of plant cultivation.

It includes the cultivation of fruits, vegetables, nuts, seeds, herbs, sprouts, mushrooms, algae, flowers, seaweeds, and non-food crops such as grass and ornamental trees and plants.

It also includes plant conservation, landscape restoration, landscape and garden design, construction, and maintenance.
A crop is any cultivated plant, fungus, or alga that is harvested for food, clothing, livestock fodder, biofuel, medicine, or other uses.

In contrast, animals that are raised by humans are called livestock, except those that are kept as pets. Crop production is a complex business, requiring many skills (such as biology, agronomy, mechanics, and marketing) and covering a variety of operations throughout the year.

Based on the growing season, the crops grown in India can be classified as Kharif crops and Rabi crops.

Soil management Soil is the basis of farming It delivers water and nutrients to crops, physically supports plants, helps control pests, determines where rainfall goes after it hits the earth, and protects the quality of drinking water, air, and wildlife habitat.

Animal husbandry is the management and care of farm animals by humans for profit, in which genetic qualities and behavior, considered to be advantageous to humans, are further developed.

The term can refer to the practice of selectively breeding and raising livestock to promote desirable traits in animals for utility, sport, pleasure, or research.


A crop is the annual or seasonal yield of any plant that is grown in significant quantities to be harvested as food, fodder, fuel, or for any other economic purpose. In other words, a crop is the product of a plant grown and harvested on a large scale for subsistence.

Diversity of Crop

Traditional agriculture involved planting a wide diversity of different plants. This had considerable advantages. Among other things, it was a method of insurance.

The farmer who grows a single crop runs the risk that conditions in a particular year might not be appropriate for it. The weather may not be right or his crop might be subject to pest infestations.

This means that the more different crops the farmer grows, the lower must be the risk, since at least some of his crops are likely to tolerate the weather conditions, and the pest outbreak is extremely unlikely to affect each of his crops

Classification of Crop Plants

Importance of classifying the Crop Plants

  1. To get acquainted with crops.
  2. To understand the requirement of soil and water for different crops.
  3. To know the adaptability of crops.
  4. To know the growing habit of crops.
  5. To understand the climatic requirements of different crops.
  6. To know the economic production of the crop plant and its use.
  7. To know the growing season of the crop.
  8. Overall to know the actual condition required for the cultivation of plants.

1. Classification Based on the growing season

Kharif/Rainy/Monsoon crops: The crops grown in monsoon months from June to Oct-Nov. Require warm, wet weather at major periods of crop growth, also required short day length for flowering, e.g. cotton, rice, jowar, banjara, etc.

Rabi/winter/cold seasons crops: Require winter season to grow well from Oct to March month. Crops grow well in cold and dry weather. Require longer day length for flowering, e.g. wheat, gram, sunflower, etc.

Summer crops: Crops grown in summer months from March to June. Require warm day weather for major growth periods and longer day length for flowering, e.g. groundnuts, watermelon, pumpkins, gourds, etc.

2. Agronomic classification

Grain crops: May be cereals as millets cereals are cultivated grasses grown for their edible starchy grains. The larger grain used as a staple food is cereals, e.g. rice, jowar, wheat, maize, and millets are the small-grained cereals that are of importance as food.

Puise/legume crops: Seeds of leguminous crops plant used as food. On splitting they produce dal which is rich in protein, e.g. green gram, black gram, soybean, pea, cowpea, etc.

Oil seeds crops: Crop seeds are rich in fatty acids, and are used to extract vegetable oil to meet various requirements, e.g. groundnut, mustard, sunflower, linseed, etc.

Forage Crop: It refers to vegetative matter fresh and preserved and utilized as food for animals, e.g. sorghum, elephant grass, etc.

Fiber crops: Grown for fiber yield. Fiber may be obtained from the seed. e.g. cotton, jute, etc.

Roots crops: Roots are the economic production of root crops. e.g. sweet potato, sugar beet, carrot, turnip, etc.

Tuber crop: Crop whose edible portion is not a root but a short thickened underground stem. e.g. potato.

Sugar crops: The two important crops are, sugarcane and sugar beet cultivated for the production of sugar.

Starch crops: Grown for the production of starch, e.g. tapioca, potato, sweet potato, etc.

Drug crop: Used for preparation for medicines, e.g. tobacco, mint, pyrethrum, etc.

Spices and condiments/spices crops: Crop plants as their products are used to flavor taste and sometimes color the fresh preserved food. e.g. ginger, garlic, chili, cumin onion, coriander, cardamom, pepper, turmeric, etc.

Vegetable crops: May be leafy as fruity vegetables, e.g. palak, brinjal, tomato, etc.

Medicinal and aromatic crops: Medicinal plants include cinchona, isabgol, opium poppy, senna, belladonna, rauwolfia, and aromatic plants such as lemon grass, citronella grass, palmarosa, Japanese mint, peppermint, rose, jasmine, henna, etc.

  1. Plantation crops: Tea, coffee, and coconut are important.
  2. Fruit crops: Such as apples, bananas, pears, etc.

3. Classification based on the life of crops/duration of crops

  1. Seasonal crops: A crop completes its life cycle in one season-Karin, Rabi, summer, e.g. rice, jowar, wheat, etc.
  2. Two seasonal crops: Crops complete their life in two seasons, e.g. cotton, turmeric, ginger, etc.
  3. Annual crops: Crops require one full year to complete their life cycle, e.g. sugarcane.
  4. Biennial crops: These grow in one year and flower, fructify and perish the next year. e.g. banana, papaya etc.
  5. Perennial crops: Crops live for several years, e.g. mango, guava, etc.

4. Classification based on cultural method/water

  1. Rain-fed: Crops grow only on rainwater, e.g.
  2. Irrigated crops: Crops grow with the help of Jowar, banjara, mung, etc. of irrigation water, e.g. chili, sugarcane, banana, papaya, etc.

5. Classification based on the economic importance

  1. Cash crop: Grown for earning money, e.g. sugarcane, cotton, etc.
  2. Food crops: Grown for raising food grain for the population and fodder for cattle, e.g.jowar, wheat, rice, etc.

Crop Production and Management

We know that the energy from food is utilized by organisms for carrying out their various bodily functions, such as digestion, respiration, and excretion.

We get our food from plants, animals, or both. Since we all need food, how can we provide food to a large number of people in our country? In order to provide food for a large population— regular production, proper management, and distribution of food are necessary.

Till 10,000 B.C. people were nomadic. They were wandering in groups from place to place in search of food and shelter. They ate raw fruits and vegetables and started hunting for animals for food.

Later, they could cultivate the land and produce rice, wheat, and other food crops. Thus, was born ‘Agriculture’. When plants of the same kind are grown and cultivated in one place on a large scale, they are collectively called a crop.

For example, a crop of wheat means that all the plants grown in a field are of wheat. We already know that crops are of different types like cereals, vegetables, and fruits.

These can be classified on the basis of the season in which they grow. India is a vast country. The climatic conditions like temperature, humidity, and rainfall vary from one region to another.

Accordingly, there is a rich variety of crops grown in different parts of the country. Despite this diversity, two broad cropping patterns can be identified. These are:

Kharif Crops: The crops which are sown in the rainy season are called Kharif crops. The rainy season in India is generally from June to September. Paddy, maize, soybean, groundnut, cotton, etc., are Kharif crops.

Rabi Crops: The crops grown in the winter season are called rabi crops. Their time period is generally from October to March. Examples of rabi crops are wheat, gram, pea, mustard, and linseed.

Besides these, pulses and vegetables are grown during summer in many places. Basic Practices of Crop Production Cultivation of crops involves several activities undertaken by farmers over a period of time.


Kharif Rabi
Season of sowing Rainy season Winter season
Cultivation period June to September October to March
Examples of such crops Paddy, maize and soybeans, pulses, and vegetables are grown during summer Wheat, gram, pea, and mustard


You may find that these activities are similar to those carried out by a gardener or even by you when you grow ornamental plants in your house. These activities or tasks are referred to as agricultural practices. These activities are listed below-

  1. Preparation of soil
  2. Sowing
  3. Adding manure and fertilizers
  4. Irrigation
  5. Protection from weeds, pests, etc
  6. Harvesting
  7. Storage.


Preparation of soil

The preparation of the soil is the first step before growing a crop. This involves turning the soil and loosening it so that roots can penetrate deep into the soil and also allows the roots to breathe easily.

Loosening of soil helps in the growth of earthworms and microbes which further loosens the soil and also adds humus to it. Need for the soil to be loosened – Soil is rich in minerals, water, air & some living organisms.

The dead plants and animals when decomposed, release nutrients back into the soil making it nutrient-rich. Loosening of soil brings the nutrient, rich soil to the top for the plants to use for their growth.

The process of loosening and turning the soil is called Tilling or Ploughing. Tilling / Ploughing is done by using Ploughs made of wood & iron.

Big pieces of soil or crumbs left in the plowed field are broken with the help of a plank. Leveling of soil is done with the help of a leveler which is important for the purpose of Sowing and Irrigation.

Tilling also ensures proper mixing of manure with soil. A home is also sometimes used for removing weeds and for plowing.


WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production Preparation of soil


Agricultural Implements: Before sowing the seeds, it is necessary to break the soil to the size of grains to get a better yield. This is done with the help of various tools. The main tools used for this purpose are the plow, hoe, and cultivator.

Plough: This is being used since ancient times for tilling the soil, adding fertilizers to the crop, removing the weeds, scraping of soil, etc. This implement is made of wood and is drawn by a pair of bulls or other animals (horses, camels, etc.).

It contains a strong triangular iron strip called plowshare. The main part of the plow is a long log of wood which is called a plow shaft.

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production Plough


Removing the weeds, scraping off the soil, etc. This implement is made of wood and is drawn by a pair of bulls or other animals (horses, camels, etc.).

It contains a strong triangular iron strip called plowshare. The main part of the plow is a long log of wood which is called a plow shaft.

There is a handle at one end of the shaft. The other end is attached to a beam that is placed on the bulls’ necks. One pair of bulls and a man can easily operate the plow.

The indigenous wooden plow is increasingly being replaced by iron plows nowadays.

Hoe: It is a simple tool that is used for removing weeds and for loosening the soil. It has a long rod of wood or iron. A strong, broad, and bent plate of iron is fixed to one of its ends and works like a blade. It is pulled by animals.

Cultivator: Nowadays plowing is done by tractor-driven cultivators. The use of cultivators saves labor and time. For plowing small agricultural land or flower garden nowadays power tiller is used.


Sowing is the most important part of crop production as it decides the final yield. Good quality seeds that are clear and healthy are selected by the farmers to get a high yield.

Good seeds can be separated from damaged ones by putting them into water. Damaged seeds are hollow and float on the water while good quality, healthy seeds settle at the bottom.


WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production taditional tool seed drill


There are two types of sowing tools.

1. Traditional Tool is a funnel-shaped tool that is filled with seeds, while sowing, seeds are passed down through pipes having sharp ends. The ends are sharp as they pierce into the soil and put the seeds there.

2. Seed Drill is the modern-day tool for sowing seeds & is used with the help of tractors. This tool has an edge over the traditional tool as it sows the seeds uniformly at proper distances & depths.

It also covers the seeds with soil after sowing which prevents damage caused by birds. Seed Drill saves time and labor. An appropriate distance between the seeds is important to avoid overcrowding of plants.

This allows plants to get sufficient sunlight, a few plants have to be removed to prevent nutrients and water from the soil. Sometimes overcrowding.

Adding manure and fertilizers

The substances which are added to the soil in the form of nutrients for the healthy growth of plants are called manure and fertilizers.

Soil supplies mineral nutrients to the crop. These nutrients are essential for the growth of plants. Continuous growing of crops makes the soil poorer in certain nutrients.

Therefore, farmers have to add manure to the fields to replenish the soil with nutrients. This process is called manuring. Improper or insufficient manuring results in weak plants.

Manure is an organic substance obtained from the decomposition of plant or animal wastes. Farmers dump plant and animal waste in pits in open places and allow it to decompose. The decomposition is caused by some microorganisms. The decomposed matter is used as organic manure.

Fertilizers are chemical substances that are rich in a particular nutrient. How are these different from manure? Fertilizers are produced in factories.

Some examples of fertilizers are- urea, ammonium sulfate, superphosphate, potash, and NPK (Nitrogen, Phosphorus, and Potassium). The use of fertilizers has helped farmers to get a better yield of crops such as wheat, paddy, and maize.

But excessive use of fertilizers has made the soil less fertile. Fertilizers have also become a source of water pollution. Therefore, in order to maintain the fertility of the soil,

we have to substitute fertilizers with organic manure or leave the field uncultivated (fallow) in between two crops.


WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production Adding manure and fertilisers


The use of manure improves soil texture as well as its water-retaining capacity. It replenishes the soil with all the nutrients.

Another method of replenishing the soil with nutrients is through crop rotation. This can be done by growing different crops alternately.

Farmers sometimes grow legumes as fodder in one season and wheat in the next season. This helps in the replenishment of the soil with nitrogen.

In the previous chapter, you learned about Rhizobium bacteria. These are present in the nodules of the roots of leguminous plants. They fix atmospheric nitrogen.

Differences between Fertiliser and Manure


Fertiliser Manure
(1) A fertilizer is an inorganic salt. (1) Manure is a natural substance obtained by the decomposition of cattle dung, human waste, and plant residues.
(2) A fertilizer is prepared in factories. (2) Manure can be prepared in the fields.
(3) A fertilizer does not provide any humus to the soil. (3) Manure provides a lot of humus to the soil.
(4) Fertilisers are very rich in plant nutrients like nitrogen, phosphorus, and potassium. (4) Manure is relatively less rich in plant nutrients.


Advantages of Manure: Organic manure is considered better than fertilizers. This is because It enhances the water-holding capacity of the soil. It makes the soil porous which exchange of gases becomes easy.


All living beings need water to live. Water is important for the proper growth and development of flowers, fruits, and seeds of plants. Water is absorbed by the plant roots.

Along with water, minerals, and fertilizers are also absorbed. Plants contain nearly 90% water. Water is essential because the germination of seeds does not take place under dry conditions.

Nutrients dissolved in the water get transported to each part of the plant. Water also protects the crop from both frost and hot air currents. To maintain the moisture of the soil for healthy crop growth, fields have to be watered regularly.

The supply of water to crops at different intervals is called irrigation. The time and frequency of irrigation vary from crop to crop, soil to soil, and season to season.

In summer, the frequency of watering is higher due to the increased rate of evaporation of water from the soil and the leaves.

Sources of irrigation: The sources of irrigation are— wells, tube wells, ponds, lakes, rivers, dams, and canals.

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.


WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production Taditional methods o0f irrigation

Protection from Weeds

In a field, many other undesirable plants may be Cattle or human labor is used in these methods. So these methods are cheaper but less efficient. The various traditional ways are:

  1. Moat (pulley system)
  2. Chain pump
  3. Dhekli, and
  4. Rahat (Lever system)

Pumps are commonly used for lifting water. Diesel, biogas, electricity, and solar energy are used to run these pumps.
Modern Methods of Irrigation Modern methods of irrigation help us to use water economically. The main methods used are as follows:

Sprinkler System: This system is more useful on uneven land where sufficient water is not available. The 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 escapes from the rotating nozzles. It gets sprinkled on the crop as if it is raining. The sprinkler is very useful for sandy soil.


WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production drip system


Drip system: In this system, the water falls drop by drop just at the position of the roots. So it is called a drip system. It is the best technique for watering fruit plants, gardens, and trees.

The system provides water to plants drop by drop. Water is not wasted at all. It is a boon in regions where the availability of water is poor and grows naturally along with the crop. These undesirable plants are called weeds.

The removal of weeds is called weeding. Weeding is necessary since weeds compete with crop plants for water, nutrients, space, and light.

Thus, they affect the growth of the crop. Some weeds interfere even in harvesting and may be poisonous for animals and human beings.

Farmers adopt many ways to remove weeds and control their growth. Tilling before sowing crops helps in uprooting and killing weeds, which may then dry up and get mixed with the soil.

Protection from weeds 

The best time for the removal of weeds is before they produce flowers and seeds. Manual removal includes the physical removal of weeds by uprooting or cutting them close to the ground, from time to time.

This is done with the help of a kauri. A seed drill is also used to uproot weeds repel, or control certain forms of plants Weeds are also controlled by using certain chemicals, called weedicides, like 2,4-D, Dalapon, Pichloram, etc.

These are sprayed in the fields to kill the weeds. They do not damage crops. The weedicides are diluted with water to the extent required and sprayed in the fields with a sprayer animal life that is considered to be pests.

Pesticides include herbicides for destroying weeds and other unwanted vegetation, insecticides for controlling a wide variety of insects,

Fungicides are used to prevent the growth of molds and mildew, disinfectants for preventing the spread of bacteria, and rodenticide compounds are used to control mice and rats.

Protection from pests

A pest is a plant or animal detrimental to humans or human concerns (such as agriculture or ‘ livestock production). Pest control refers to the regulation or management of a species defined as a pest, usually

Because it is perceived to be detrimental to a person’s health, ecology, or economy. Pest control is at least as old as agriculture, as there has always been a need to keep crops free from pests,

Types of pest control: Several methods of pest control are adapted-Biological pest control is the control of one through the control and management of natural predators and parasites.

Mechanical pest control is the use of hands-on techniques as well as simple equipment, devices, and natural ingredients that provide a protective barrier between plants and insects.


WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production weedicides


Physical pest control is a method of getting rid of insects and small rodents by removing, attacking, and setting up barriers that will prevent further destruction of one’s plants, or forcing insect infestations to become visual.

Every pest control chemical has a different mode of action. The mode of action is the way that the insecticide kills or repels the target pest. Most chemicals used in pest control are poisonous to humans.

A pesticide is any substance used to kill, Pesticide application refers to the practical way in which pesticides are delivered to their biological targets (e.g.pest organism, crop, or another plant).

One of the more common forms of pesticide application, especially in conventional agriculture, is the use of mechanical sprayers. Hydraulic sprayers consist of a tank, a pump, a lance (for single nozzles) or boom, and a nozzle (or multiple nozzles)


Harvesting a crop is an important task. The cutting of a crop after it is mature is called harvesting. In harvesting, crops are pulled out or cut close to the ground.

It usually takes 3 to 4 months for a cereal crop to mature. Harvesting in our country is either done manually by sickle or by a machine called a harvester.

In the harvested crop, the grain seeds need to be separated from the chaff. This process is called threshing. This is carried out with the help of a machine called ‘combine’ which is in fact a combined harvester and thresher.

After harvesting, sometimes stubs are left in the field, which is burnt by farmers. It causes air pollution. It may also catch fire and damage the crops lying in the fields. Farmers with small holdings of land do the separation of grain and chaff by winnowing.

Harvest Festivals: After three or four months of hard work there comes the day of the harvest. The sight of golden fields of standing crops, laden with grain, fills the hearts of farmers with joy and a sense of well-being.

The efforts of the past season have borne fruit and it is time to relax and enjoy a little. The period of harvest is, thus, of great joy and happiness in all parts of India.

Men and women celebrate it with great enthusiasm. Special festivals associated with the harvest season are Pongal, Baisakhi, Holi, Diwali, Nabanya, and Bihu.


WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production sickle


Storage of crops is an important task. If the crop grains are to be kept for a longer time, they should be safe from moisture, insects, rats, and microorganisms.

The fresh crop has more moisture. If freshly harvested grains (seeds) are stored without drying, they may get spoilt or attacked by organisms, losing their germination capacity.

Hence, before storing them, the grains are properly dried in the sun to reduce their moisture in them. This prevents attack by insect pests, bacteria, and fungi. Farmers store grains in jute bags or metallic bins.

However, large-scale storage of grains is done in silos and granaries to protect them from pests like rats and insects. Dried neem leaves are used for storing food grains at home.

For storing large quantities of grains in big godowns, specific chemical treatments are required to protect them from pests and microorganisms.

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production storage.2

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production winnowing Storage

Food Production Processes

Examples of a few food production processes are given below-


Rice is our principal food. Nearly half of the people of the world live on rice. We get it from paddy. The farmer first tills land very well.

Then they sow the seeds. In a few days, the seeds come up. About two months after, ears of paddy come out. After three months more, the paddy ripens.

Then we husk paddy and get rice. Rice is found all over the world. It grows best in India, Bangladesh, Pakistan, Burma, China, Japan, Thailand, etc.

Rice is a kind of food grain. It is obtained from a plant called paddy. It is a one-time breeding plant. It grows from two to three feet high. It feeds millions of people in the world.

Rice grows well in hot and moist climates. Sufficient rainfall is required for the proper growth of rice. Bangladesh, India, Pakistan, China, Japan, and Thailand are the main rice-producing countries in Asia.

Kinds of rice: There are four kinds of rice in our country. They are: push, aman, boro, and IRRI. Aush is sown in the month of baishakh and reaped in caravan or Bhadra.

Aman is sown in asar or sravan and reaped in agrarian or push. Boro is sown in winter and reaped in spring. IRRI is cultivated all year round.

Method of cultivation: Farmers plow and harrow their lands again and again and prepare them well for sowing seeds. Weeding is required for the proper growth of the plants.

Paddy becomes ripe in four to five months. Then they are cut, tied into bundles, carried home, and thrashed. Next, they are boiled, dried, and husked. This is how rice is obtained.

Utility: Rice is our staple food. We get many kinds of food from rice. We make chira, muri, khai, cake, polar, biriani, etc. from rice. Straw and husk are used as fuel. They are also used as fodder for cattle.

Process of cultivation

Rice cultivation is a complex activity that requires a series of processes to achieve the finished product. In general, paddy cultivation is quite distinctive and observes the following steps:

1. Preparation of Field

Paddy farmers get their fields ready before the rainy season. The weeds are cleared and the field is plowed by buffaloes or tractors to a depth of few Manures and fertilizers are added to the soil.

The whole surface is then covered with water of about 2.5 cm depth. The field then becomes ready for receiving seedlings from the nursery.

2. Transplantation

Generally, paddy seedlings are first prepared in the nursery and then transplanting is done in the field after about 40 days. Although in some areas of India and Sri Lanka seeds have been sown directly in the field and the seedlings sprout when the rain comes,

The yield of paddy from transplanting is greater than the direct sowing. The transplanted paddy also grows faster because of regular spacing and matures within a shorter period.

3. Field Maintenance and Irrigation

Paddy fields also require regular maintenance, such as occasional weeding and thinning out the more crowded patches, level of water is to be maintained according to the growth, and the fields are drained dry before the crop is harvested. Water standing 3 to 5 cm is essential at the base of the plant for proper growth.


WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production feild maintaince and irragation

4. Harvesting

The traditional harvesting system is either through a curved knife or a sharp-edged knife. It is very labor-intensive. Harvesting is done in the dry season when the weather is sunny. Mechanical combines which cut and thresh are used in Japan.

5. Threshing, Winnowing, and Milling

After the paddy stalks have been gathered and dried for a brief spell, their threshing is usually done. By beating the sheaves against the bars, the grains are separated from the stalks.

Now threshing machines have also been developed. Winnowing is a process of removing unwanted particles from paddy grains. The grains fall to the mat while lighter chaff blows out. Sometimes hand winnowing machines are also used.

Milling means the removal of the yellowish husks from paddy so that white or polished rice is obtained. In a rice mill, the paddy is made to pass between varying sets of hullers or rollers till it is milled or polished.


Mango (Mangifera indica) belonging to Family Anacardiaceae is the most important commercially grown fruit crop in the country. Mango is the leading fruit crop of India and is considered to be the king of fruits.

Besides the delicious taste, excellent flavor, and attractive fragrance, it is rich in vitamins A and C. The tree is hardy in nature and requires comparatively low maintenance costs.

Mango occupies 22% of the total under fruits comprising 1.2 million hectares, with a total production of 11 million tones. b

Uttar Pradesh and Andhra Pradesh are having the largest area under mango each with around 25% of the total area followed by Bihar, Karnataka, Kerala, and Tamil Nadu.

Mango fruit is utilized at all stages of its development both in its immature and mature state. Raw fruits are used for making chutney, pickles, and juices.

The ripe fruits besides being used for dessert are also utilized for preparing several products like squashes, syrups, nectars, jams, and jellies.

India is the largest mango-producing country, accounting for about 60% of world production, the export of fresh fruit is Limited to Alphonso and Dashehari varieties.

India’s share in the world mango market is about 15 percent. Mango accounts for 40 percent of the total fruit exports from the country. There is good scope for increasing the area and productivity of mango in the country.



Climate: Mango can be grown under both tropical and sub-tropical climates from sea level to 1400 m altitude, provided there is no high humidity, rain, or frost during the flowering period.

Places with good rainfall and dry summer are ideal for mango cultivation. It is better to avoid areas with winds and cyclones which may cause flower and fruit shedding and breaking of branches.

Soil: Mango comes up on a wide range of soils from alluvial to laterite provided they are deep (minimum 6′) and well drained. It prefers slightly acidic soils.

Varieties: Though there are nearly 1000 varieties of mango in India, only the following varieties are grown in different states: Alphonso,

the simplest way is by pouring the paddy down from a height on a windy day to a large square mat on open Bangalore, Banganpalli, Bombai, Bombay Green, Dashehari, Fazli, Fernandin, Himsagar, Kesar, KishenBhog, Langra, Mankhurd, Mulgoa, Neelam, Samarbehist, Chausa, Suvarnarekha, Vanaraj and Zardalu.

Recently some mango hybrids have been released for cultivation by different institutes/ universities. These are – mallika, amrapali, mangeera, ratna, arkaanmol, etc.

Propagation: Farmers should always get vegetatively propagated, true-to-type plants from recognized nurseries. Inarching, veneer grafting, side grafting, and epicotyl grafting are the popular methods of propagation in mango.

Planting: Land should be prepared by deep plowing followed by harrowing and leveling with a gentle slope for good drainage.
Planting is usually done in the month of July- August in rainfed areas and during February- March in irrigated areas. In case of heavy rainfall zones, planting is taken up at the end of the rainy season.

One-year-old healthy, straight-growing grafts from reliable sources can be planted at the center of pits along with the ball of the earth intact during the rainy season in such a way that the roots are not expanded and the graft union is above the ground level. Plants should be irrigated immediately after planting.

Fertiliser Application: Fertilizers may be applied in two split doses, one half immediately after the harvesting of fruits in June/July and the other half in October, in both young and old orchards followed by irrigation if there are no rains. Foliar application of 3% urea in sandy soils is recommended before flowering.


Tea is the dried leaf of a bush. It contains theine and when added to boiling water along with sugar and milk, it gives a very cheap and stimulating drink.

Thus it is the most important beverage crop in India. Tea bush is supposed to be indigenous to China but it was reported by Major Robert Bruce in 1823 that indigenous tea bushes grew wild on the hill slopes of upper Assam. In the year 1840, tea seeds were.

Irrigation: Young plants are watered frequently for proper establishment. In the case of grown-up trees, irrigation at 10 to 15 days intervals from fruit set to maturity is beneficial for improving yield.

Harvesting and yield: The yield of mango varies greatly, depending upon the variety and agro-climatic conditions prevailing in a region. Grafted mango trees start bearing from the fifth year onward. However, seedling trees may take 8-10 years.

Economic Importance: Raw fruits of local varieties of mango trees are used for preparing various traditional products like raw slices in brine, amchur, pickle, murabba, chutney, pane (sharbat), etc.

Presently, the raw fruit of local varieties of mango is used for preparing pickles and raw slices in brine on the commercial scale while fruits of the Alphonso variety are used for squash in the coastal western zone.

The wood is used as timber, and dried twigs are used for religious purposes. The mango kernel also contains about 8-10% good-quality fat which can be used for saponification. Its starch is used in the confectionery industry.

Weed control and Plant protection: The mango orchard should be completely free from weeds. In order to control weeds, shallow hoeing at quarterly intervals should be done. Black plastic mulch should be used to restrict the germination of weed seeds and suppression of weed growth.

Mango crop suffers seriously from pests: hopper, mealy bug, fruit fly, shoot and stem borer, and stone weevil. The Hoppers are most divesting during the flowering period as they suck the sap from tender shoots, leaves, and panicles.

Proper pesticides are recommended for the protection of trees imported from China and commercial tea plantations were set up in the Brahmaputra valley.

There are four main types of tea: green tea, black tea, oolong tea, and white tea. There are even more varieties, including flavored, scented, and “herbal infusions,” but for the sake of simplicity, we’ll focus on the big four right now.

What many people don’t know is that these four types of tea come from one plant, not four different species of plant.

All tea begins with the plant known as Camellia sinensis, it’s the way the tea leaves are processed that gives us the different teas and their specific taste, color, and scent.

Conditions of Growth

Tea bush is a tropical and sub-tropical plant and thrives well in a hot and humid climate. There is a very close relationship between climate, yield, and quality of tea. The ideal temperature for its growth is 208-30°C and temperatures above 35°C and below 10°C are harmful to the bush.

It requires 150-300 cm of annual rainfall which should be well distributed throughout the year. While the prolonged dry spell is harmful to tea, high humidity, and heavy demand morning fog favor the rapid development of young leaves.

Alternate waves of warm and cool winds are very helpful for tea leaves. Tea is a shade-loving plant and develops more vigorously when planted along with shady trees.

In order to increase the yield, the proper dose of nitrogenous fertilizers such; as ammonium sulfate should be given to the soil.
Although tea requires heavy rainfall for its growth, stagnant water is injurious to its roots.

It is, therefore, grown on hill slopes where water drains away easily and water-logging does not take place. However, it grows equally well in the valley if the drainage is good. Most of the tea plantations in India are found at elevations varying from 600 to 1,800 meters above sea level.

Tea is a labor-intensive crop and requires an abundant supply of cheap and skilled labor, especially at the time of plucking the tea leaves.

This is a tedious process that requires skilled manipulation of fingers for plucking two leaves and a bud at a time. For this purpose, women laborers are employed in large numbers.


Tea cultivation in India is highly concentrated in a few selected pockets. The following three areas of tea cultivation are identified according to their importance as tea producers and their location.

North-Eastern India: It is more or less a triangular area mainly in Assam and West Bengal. Assam is the largest producer of tea accounting for over 51 percent of the production and over 53 percent of the area under tea cultivation in India.

West Bengal is the second largest producer contributing over 22 percent of India’s tea from about one-fourth of the country’s total area under tea cultivation.

The entire tea of West Bengal is produced in three northern districts of Darjeeling, Jalpaiguri, and Coochbehar.
South India: In South India tea is produced in Nilgiri, Cardamom, Palni, and Anaimalai hills in Tamil Nadu, Kerala, and Karnataka states.

Northwest India: Some of the tea is produced in the Dehra Dun, Almora, and Garhwal districts of Uttaranchal and in Kangra Valley and Mandi district of Himachal Pradesh. Green tea is produced in the Kangra valley of Himachal Pradesh.


Planting: Planting is a crucial operation as it basically determines the development and productive level of tea throughout its economic life.

Wrong planting of good planting materials is doubly unproductive as an investment is lost both on account of producing the plants and in the failure to put them up for productivity. Therefore, care, planning, and refinement of techniques are essential for long-term benefits.

Pruning: It basically helps in maintaining the plant as a low bush in a phase of continuous vegetative growth. Pruning both stimulates and controls growth.

It removes dead, diseased, and overage wood, and thus helps rejuvenate bushes that have crossed the period of maximum productivity.

Fertilizer: The nutrients that are removed from the plant as yield and from the soil by the plant for its growth, should be replenished.

ideally, nutrient requirements should be related to local soil conditions in addition to yield and they must be monitored continuously to ensure an optimum balance of nutrients.

Weed control: Weeds affect tea by competing with it for moisture, nutrients, and sunlight. The ultimate effect is a considerable reduction in yield.

Thus, the timing of weed emergence relative to the growth stages of tea is an important parameter in weed management. Apart from directly causing crop losses, weeds in tea areas also act as secondary hosts for some important pests of tea.

Pest Management: The simultaneous presence of different species of mites and insects, each with their characteristic mode of feeding, diverse habitat, and seasonal cycles, call for optimal management of the pests which should be both ecologically and economically sound.

Crop duration and harvest: Plucking commences when the tea bush is 3 years old. The plucking of the extreme tip of the growing branch consists of an unopened bud together with two leaves popularly known as “Two leaves and a bud”, while fine plucking is anything less than this.

In South India, plucking continues throughout the year at weekly intervals during March-May and at intervals of 10 -14 days during the other months.

Processing of tea

Once workers gather enough quantities of tea leaves, their stash is quickly carried over to a tea factory located right on the plantation.

The factory is placed close to the source of the leaves because once the tea is plucked, oxidation immediately begins. The oxidation process is important in understanding tea — it must be closely monitored during production and is essential in determining the type and quality of the tea.

Oxidation is what happens when you cut up a piece of fruit and leave it out for too long — the color of the fruit changes, usually turning brown or black. Depending on the type of tea you want, oxidation can be a necessary part of processing tea leaves.

Tea tasting is the process in which a trained taster determines the quality of a particular tea. Due to climatic conditions, topography, manufacturing process, and different clones of the Camellia sinensis plant (tea), the final product may have vastly different flavors and appearances.

These differences can be tasted by a trained taster in order to ascertain the quality prior to the sale of possibly blended tea.

Animal Husbandry

Food is obtained from animals for which animals are reared & are provided with proper food & shelter. This is called Animal Husbandry. Examples of food obtained from animals are- eggs, milk, meat, etc.

  1. Honeybee and apiculture
  2. Apiculture is the management and study of honeybees.

Although apiculture refers to the honeybee, the vital role all bees play in the pollination of crops and flowering plants has caused apiculture to also include the management and study of non-Apis bees such as bumblebees and leafcutter bees.

Bees collect pollen and nectar. Pollen is the protein source needed for bee brood development while nectar is the carbohydrate source providing energy.

(Ni) Nectar is a sugar solution produced by flowers containing about 80% water and 20% sugar.

Foraging bees store the nectar in the ‘honey sac’ where the enzyme invertase will change complex sugars into simple sugars called monosaccharides.

Upon return to the hive, the foraging bee will disgorge the partially converted nectar solution and offer it to other bees. Housekeeping bees will complete the enzymatic conversion, further removing water until the honey solution contains between 14 – 20% water.

Honey is too dry for any microbes to live in. Honey is non-perishable and can be kept indefinitely in a cool, dry place.

The flavor, aroma, and color of honey are determined by the floral source The honeybee colony is comprised of one queen, thousands of worker bees and a few hundred male bees called drones. Colony size varies according to the season and condition of the colony.

Activities in the honeybee colony

A colony of honeybees comprises a cluster of several to 60,000 workers (sexually immature females), a queen (a sexually developed female), and, depending on the colony population and season of the year, a few to several hundred drones (sexually developed males). A colony normally has only one queen, whose sole function is egg-laying.

The bees cluster loosely over several wax combs, the cells of which are used to store honey (carbohydrate food) and pollen (protein food) and to rear young bees to replace old adults.

A beehive is an enclosed structure in which honey bees live and raise their young. Although worker bees only live for approximately six weeks, they spend their lives performing tasks that benefit the survival of their colony.

When a worker bee turns 10 days old, it develops a wax-producing gland inside its abdomen. Workers gather nectar from different flowering plants and carry nectar within their honey sacs, where it mixes with a specialized enzyme.

After returning to the hive, the worker bee vomits the nectar in the honey chamber and moves its wings very rapidly. By the flowing air, the liquid from the nectar evaporates and the stuff becomes honey.

The glands of worker bees convert the sugar contents of honey into wax, which oozes through the bee’s small pores to produce tiny flakes of wax on their abdomens.

Workers chew these pieces of wax until they become soft and moldable, and then add the chewed wax to the honeycomb construction.


WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production honey bee colony


Bee Development

All three types of adult honey bees pass through three developmental stages before emerging as adults: egg, larva, and pupa. The three stages are collectively labeled brood.

While the developmental stages are similar, they do differ in duration. Unfertilized eggs become drones, while fertilized eggs become either workers or queens.

Nutrition plays an important part in the caste development of female bees; larvae destined to become workers receive less royal jelly and more of a mixture of honey and pollen compared to the copious amounts of royal jelly that the queen larva receives.

Types of honeybees

  1. Four important species of honeybees are as follows.
  2. The rock bee, Apis dorsata.
  3. The Indian hive bee, Apis cerana indica. The Indian species in not Apis indica; it is Apis cerana indice.
  4. The little bee, Apisflorea.
  5. The European or Italian bee, Apis mellifera.
  6. Castes of Honeybee

Honeybee is a social insect. The nest of the honeybee is known as a beehive. A hive in summer consists of 32 to 50 thousand individuals, depending on the locality.

The members of honeybees are of three castes namely the queen bee, the worker bee, and the drone bee. All three types depend on each other for their existence. There is normally one queen, 10,000 to 30,000 workers, and a few hundred drones in a colony.

Queen Bee: There is only one queen in a honeybee colony. Queens are fertile females formed from fertilized eggs. It is slightly larger than a worker bee, with a longer abdomen.

It does not have pollen baskets on her legs. Eggs destined to become queens are laid in a larger cell, and the larvae are fed only royal jelly.

The royal jelly is a salivary secretion of the worker bees. The adult queen’s sole duty is to lay eggs, up to 2,000
a day.

it is fed by the workers and never leaves the hive except to mate. Queen bees also have stings and use them in battles with each other for dominance of the colony.

The life span of a queen bee is 3-4 years. When the colony is crowded with adult bees, the queen leaves with a set of workers to establish new colonies and promote propagation. This natural phenomenon is called swarming.

Drone Bee: Drones are haploid fertile males because they develop parthenogenetically from unfertilized eggs. They are larger than workers and smaller than queens.

They are quite noisy and unable to gather food. They are stingless and their sole biological function is to mate with the queen. The number of drones in a colony varies from 200-300 but during unfavorable seasons they are driven out.

Worker Bee: The vast majority of adult honey bees in any colony are female worker bees. The worker bees are sterile females. They have no individual existence throughout their life. They labor for the betterment of the colony.

The functions of the worker bees are: tending and feeding young bees (larvae), making honey, making royal jelly and beebread to feed larvae, producing wax, cooling the hive by fanning wings, gathering and storing pollen, nectar, and water, guarding the hive, building, cleaning and repairing the comb, and feeding and taking care of the queen and drones.

Life cycle: The virgin queen bee mates once in her life. During the breeding season of winter, a unique flight takes place by one queen followed by several drones.

This flight is called the “nuptial flight”. After mating, she returns to the hive and lays eggs. Honeybees pass through four distinct life stages namely the egg, larva, pupa, and adult through metamorphosis.

The queen bee lays an egg in the comb. The egg generally hatches into a larva which is a legless grub that resembles a tiny white sausage.

The larva is fed with a mixture of pollen and nectar called beebread. However, the queen-forming larvae are fed on royal jelly for full larval life and they are taken for further development into a special chamber called the queen’s chamber.

The cell is capped with wax by worker bees. Inside the cell larva spins a delicate silken cocoon around itself and the larva transforms into a pupa. The pupa doesn’t eat.

Ultimately the adult comes out of the cocoon. The queen, worker, and drone bees take 16,21, and 24 days respectively for their complete development.

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production Mordern beehive structure


How Do Honeybees Make Hives?

Worker honeybees make hives to store honey and feed themselves throughout winter when they cannot go outdoors to forage for food.

Honey bee hives are made of six-sided tubes, which are the shapes for optimal honey production because they require less wax and can hold more honey.

Similar to the habits of domesticated honeybees, they construct hives by chewing wax until it becomes soft, then bonding large quantities of wax into the cells of a honeycomb.

Structure of a bee comb. The combs of bees are formed mainly by the secretion from the wax glands present in the abdomen of the worker bee The cells of the comb are of various types.

The storage cells’ contains honey and pollen. They are. built in the margin and at the top of the comb. The brood cells contain the young stages of the honeybees and they are built in the center and the lower part of the comb.

Young ones of honey bees are collectively called broods. Brood chamber is divided into three types they are, Worker-chamber, Drone-chamber, Queen -chamber There is no special chamber for adults except the queen. They move on the surface of the comb.

Modern beehive structure: The modern beehive is a movable-frame hive. It is a wooden frame box made of single or double walls. A modern hive consists of a bottom board, brood chamber, supper chamber, inner cover, and top cover.

They are placed one above the other and fixed on a stand. The bottom board acts as the entrance for the bees. The brood chamber is a wooden box inside which numerous frames called “comb foundations” are fixed.

Comb foundations consist of sheets of pure bee wax. These wax sheets are embossed with the pattern of hexagons of a size equal to the base of natural brood cells.

The worker bees secrete wax to extend the walls of these cells. The comb foundation helps in controlling the rise of the cells and reduces the number of drone cells.

These frames of the comb are movable and can be lifted, hence the name for the hive “movable frame hive”. The chamber above the brood chamber is the super chamber inside which honey is secreted and stored.

This equipment has narrow spaces of 4 mm which allows only the workers to enter the super chamber. The top cover can be lifted to inspect the state of the colony or honey formation.

In India, apart from the modern hive, another three types of beehive namely Langstroth, Newton, and Jeolikote are in practice.
tablespoon of sugar will give you about 15 calories.

Furthermore, the carbohydrates in honey can be easily converted into glucose by even the most sensitive stomachs, since it is very easy for the body to digest this pure, natural substance.

Source of Vitamins and Minerals: Honey contains a variety of vitamins and minerals. The type of vitamins and minerals and their quantity depends on the type of flowers used for apiculture. Commonly, honey contains Vitamin C, Calcium, and Iron.

Antibacterial and Antifungal Properties: Honey has antibacterial and antifungal properties, so it is often used as a natural antiseptic in traditional medicines.

Antioxidants: Honey contains nutraceuticals, which are very effective for the removal of free radicals from the body. As a result, our body’s immunity is improved against many conditions, even potentially fatal ones like cancer or heart disease.

Beehive products

Honey: Honey has been treasured as one of nature’s most perfect food. Other than honey, the products such as bee wax, bee venom, propolis, royal jelly, and pollen are obtained as beehive products.

Health Benefits of Honey: The health benefits of honey include the following treatments, taken from both traditional and modern medical experts. aquatic (freshwater and marine) organisms like fish, prawns, crabs, pearls, etc.

Pisciculture- This is the method of fish farming in which fishes are raised in an artificial way for breeding and transportation.
Aquaculture- Aquaculture though simply means fish farming, in a broader sense, it is farming of aquatic organisms like fish, prawns, etc., and plants for breeding and rearing.

Fish Culture or Pisciculture

Fish is one of the most delicious and widely eaten aquatic animals and it is enriched with omega-3- fatty acid, a necessary constituent of a balanced diet.

As fish is a beloved food item all over the world, so its cultivation and harvesting are done on a larger scale in different parts of the globe.

Some branches of cultivation and harvesting fish are known as Fisheries, Pisciculture, Aquaculture, and Mariculture. Let us see the difference between these different ways of producing fish a larger scale.


Fisheries- It deals with all the aspects of harvesting or raising economically important

Weight Loss: Though honey has more calories than sugar, when honey is consumed with warm water, it helps in digesting the fat stored in your body. Similarly, honey and lemon juice as well as honey and cinnamon help in reducing weight.

Energy Source: Honey contains about 64 calories per tablespoon. Therefore, honey is used by many people as a source of energy. On the other hand, aquatic (freshwater and marine) organisms like fish, prawns, crabs, pearls, etc.

Pisciculture- This is the method of fish farming in which fishes are raised in artificial way for breeding and transportation.

Aquaculture- Aquaculture though simply means fish farming, in a broader sense, it is farming of aquatic organisms like fish, prawns, etc., and plants for breeding and rearing.

Mariculture- Mariculture involves the cultivation of only marine organisms, unlike any aquatic organism. This is the method of fish farming which is done usually on a very broader scale means by forming an enclosed section of the ocean.

Type of fisheries

Depending on the type of resources, it may be of the following types-
Capture fisheries: The process of obtaining fish from natural resources like lakes, rivers, ponds, etc. is called capture fishing. Capture fisheries are the exploitation of aquatic organisms without stocking the seed.

Recruitment of the species occurs naturally. This is carried out in the sea, rivers, reservoirs, etc. Fish yield decreases gradually in capture fisheries due to indiscriminate catching of fish including brooders and juveniles.


WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production winnowing type of fisheers


Culture fisheries: It is the production of fish in a given body of water such as ponds, lakes, or reservoirs using scientific methods of feeding, breeding, etc.

so as to enhance the output is called culture fishing-A culture fishery is the cultivation of selected fishes in confined areas with utmost care to get maximum yield.

The seed is stocked, nursed, and reared in confined waters, and then the crop is harvested. Culture takes place in ponds, which are fertilized, and supplementary feeds are provided to fish to get maximum yield.

In order to overcome the problems found in capture fisheries to increase production, considerable attention is being given to the culture fisheries.

Fishing in India: Fishing in India is a major industry in its coastal states, employing over 14 million people. Fish production in India has increased more than tenfold since its independence in 1947.

According to the Food and Agriculture Organization (FAO) of the United Nations, fish output in India doubled between 1990 and 2010.

India is endowed with vast and varied aquatic resources (Marine and Inland) amenable for capture fisheries. India is the third-largest producer of fish and the second-largest producer of inland fish in the world.

The fisheries sector provides employment to over 11 million people engaged fully, partially, or in subsidiary activities pertaining to the sector, with an equally impressive segment of the population engaged in ancillary activities.

The potential of fish production from marine and inland sources has been estimated at 3.9 million tonnes and 4.5 million tonnes, respectively.

Inland Fisheries: Inland waters are aquatic-influenced environments located within land boundaries. This includes those located in coastal areas, even where adjacent to marine environments.

Inland water systems can be fresh, saline, or a mix of the two (brackish water). Inland resources comprise of rivers and canals, estuaries, floodplains, wetlands, lagoons, and reservoirs.

While the marine water bodies are used mainly for capturing fisheries resources, the inland water bodies are widely used both for culture and capture fisheries.

Inland capture fisheries of India have an important place; it contributes to about 30% of the total fish production.


WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production winnowing marine fisheers


Marine Fisheries: The captured marine fishery resource of India comprises a long coastline (8118 km.) and an Exclusive Economic Zone (EEZ) (2.025 sq. km).

Marine capture fisheries play a vital role in India’s economy, providing employment and income to nearly two million people. Out of the total fish production in India, about 70% is obtained from the sea.

This gives the idea that how important is the marine fishery with its great economic and commercial values.

There are two main coastlines in India i.e., the East coast and the West coast. Out of these two the west coast is more productive because of better circulation and more oceanic character of its water.

Several exploratory surveys of fish wealth in the deep water on both coasts have been done which indicates that like coastal fisheries, deep sea fisheries can also be of much commercial and economic value.

Carp Culture

Carp are various species of oily freshwater fish of the family Cyprinidae, a very large group of fish native to Europe and Asia. Carp is a large freshwater fish native to central Asia.

Introductions in many countries have helped to make carp the most widely distributed freshwater fish in the world. They are highly cultured and domesticated in aquaculture for food and ornamental purpose.

Freshwater fishes cultured in India are mainly major carp, minor carp, exotic carp, and other fishes. Fishes like Katla, mrigal, and rohu (rui) are 3 major carps of India. A lot of research, hybridization, reduce breeding have been carried out with carps distressfully.

Indian major carp grow fast and can reproduce even in artificial ponds. v. Minor carps are smaller in size than major carp. They do not produce as many eggs as major carp.

Kalbasu, bata,punti, etc., are minor carps. minor carp fishes grow to a size of 30- 100 2cm. with an average weight of 1 to 1.5 kg. The rate of egg production is very low in these fishes.

When the indigenous fishes are not favored for culture due to economic viability, exotic breeds are selected and cultured. These fishes yield nutritious food and earn foreign exchange.

Examples of exotic carp are silver carp, grass carp, and common carp. Other common freshwater fishes are – lata, maguro, single, koi, Tangra, Boal, tilapia, panda, bhetki, etc. However, these fishes are not carp.


WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production crap fish


Indian Carp culture: Indian aquaculture has been,n growing at a fast pace over the last two d^cpdes, with freshwater aquaculture contributing over 95% of the production.

The three major carps cultured in India, namely, Katla (Catla catla), rohu (Labeo rohita), and mrigal (Cirrhinus mrigala), contribute as much as 87 percent of the total Indian aquaculture production.

Three exotic carp were also introduced, namely, silver carp (Hypophthalmichthys molitrix); grass carp (Ctenopharyngodon idyllic), and common carp (Cyprinus carpio).

There are also several other medium and minor carp species, namely kalbos(Labeo calabash) bata (L. bata), and Puntif Puntius sarana), which are important in aquaculture.

Among catfishes, major (Ciarias batrachus) is the only species that is widely cultured, while the catfish, Singh (Heteropneustes fossilis) is cultured to some extent in the eastern states.

The finfish species of importance include climbing perch koi (Anabas testudineus), lata (Channa striata), and tilapia (Oreochromis mossambicus).

Preparation of pond

Pond preparation involves making the ponds weed and predator-free and generating adequate natural food for the survival and growth of fish.

Spawning: Because of constant temperature and favorable weather conditions, carps spawn all year round in India. Spawning takes place early in the morning when the water surface cools down to about 18 degrees.

The female carp swims near the water’s surface followed by the male carp in nuptial swimming and rubbing each other’s bodies. The female lays an egg and the male releases its milt and the eggs are fertilized.

Three days after fertilization, the eggs begin to hatch. The newly hatched larva (seedling) is about 5.5 mm long, delicate, and transparent, with a yolk sac attached to the belly.

It rarely swims but settles on the bottom or on some floating object. On the second day, the larva starts swimming, and on the third-day swims actively from surface to bottom.

During these stages, the larva or fry gets its nourishment from the yolk sac, which disappears on the third day and the fry now must search for food and eat.

Supplementary fry- feed in the form of hard-boiled egg yolk or powdered milk can be applied on the water surface at this time. When the fry grows slightly larger, about the size of a finger, it is called a fingerling.

Nursery ponds are constructed to rear carp fry or larvae. A normal-sized nursery pond measures 5 x 10 m, with a depth of 0.5 m. Before filling up the water the pond should be cleaned thoroughly to get rid of predators and parasites that may be destructive to the larvae. About 1,500 to 3,000 fries can be stocked in the nursery pond.


WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production winnowing prepation of pond


Rearing ponds where adult carp are cultured until they reach marketable size, are needed, which have dimensions of 15 x 50 m and depth of 1.5 to 2 m.

Rearing ponds should also be thoroughly cleaned before filling them with water. This is done by exposing the bottom and letting it dry thoroughly.

The next step involves the application of fertilizers, which encourages the growth of aquatic plants, moss, and algae, which are important natural food and also lead to the growth of microfauna.

Manure in the form of chicken dropping is the most commonly used being cheaper and more readily available in large quantities. When carp fry reaches a length of about 5 to 7 cm, they are transferred from the nursery pond to the rearing pond and allowed to grow to the adult stage.

Stocking ponds: Ponds are stocked with fish fries of the appropriate size. Fingerlings over 10 cm in size are recommended for stocking in culture ponds.

In composite fish farming, a combination of six species is cultured, namely, Katla, rohu, mrigal, and exotic carp like silver carp, grass carp, and common carp.

Supplementary feeds like groundnut oil cake and rice bran are fed to fishes during culture. At the end of the culture period of say 12 months, the fish will reach the marketable size and fetch attractive prices.

Aeration may be done mechanically to increase the concentration of dissolved oxygen in ponds, by paddle wheel aerators, aspirator aerators, and submersible pond aerators. It is also necessary to replace a certain amount of water at regular intervals.


Harvesting of fish is usually done after a culture period of 10 months to one year. However, fish attaining the marketable size can be harvested periodically depending on several factors,

which also reduces the pressure of density in the ponds and thereby provides sufficient space for the growth of fish.

Induced breeding of carps: Induced fish farming has allowed farmers to breed and raise species that do not naturally reproduce in captivity,

manipulate the timing of reproduction to suit production cycles, get fish to spawn on a predetermined date, and fertilize and incubate eggs under hatchery conditions.

The strategy is to inject the fish with one or more naturally occurring reproductive hormones or synthetic analogs to manipulate the maturation of gonads and ovulation.

Sewage-fed fishery: Increasing population, industrialization, and urbanization have created problems in the form of waste disposal.

Wastes arise from virtually all forms of human activities. The common means of disposal of these materials is to dump them outside the village or city limits, to burn them, or to discharge them into ponds and rivers.

But in recent times things have changed. The use of waste for productive purposes has generated a new idea of waste management. Sewage is a rich nutrient resource, cheaply available around big towns and cities.

It can be well-utilized: for fertilizing paddies, fishponds, and horticulture crops. Waste recycling also helps in maintaining a clean environment.

For fish cult urn sewage water from stabilizing tank well as the water after dilution can be utilized. Air-breathing fishes are more suitable to be cultured In sewage treatment ponds as they can survive In water with lesser dissolved oxygen content.

Fish like maguro, single, lata, tilapia, grass carp, etc., are the species of choice to be considered for culture in sewage-treated ponds.

Numerous species of fish are farmed in the sewage-fed ponds called burls In the East Kolkata wetlands.


WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production induced breeding of craps


Nutritional value of fish

Fish Is a food of excellent nutritional value, providing high-quality protein and a wide variety of vitamins and minerals, including vitamins A and D, phosphorus, magnesium, selenium, and Iodine in marine fish.

Its protein – like that of meat – is easily digestible and favorably complements dietary protein provided by cereals and legumes that are typically consumed in many developing countries.

Fishes may be classed as either whitefish or oily fish. Whlteflsh, such as rohu, Katla, mrigal, etc, contain very little fat (usually less than 1%) whereas oily fish, such as English, panda, etc, contain between 10-25%.

The latter, as a result of Its high-fat content, contains a range of fat-soluble vitamins (A, D, E, and K) and essential fatty acids, all of which are vital for the healthy functioning of the body.

Experts agree that, even in small quantities, fish can have a significant positive impact on improving the quality of dietary protein by complementing the essential amino acids that are often present in low quantities in vegetable-based diets.

But recent research shows that fish is much more than just an alternative source of animal protein. Fish oils in fatty fish are the richest source of a type of fat that is vital to normal brain development in unborn babies and infants. Without adequate amounts of these fatty acids, normal brain development does not take place.

Poultry farming

Poultry farming is the raising of domesticated birds such as chickens, ducks, turkeys, and geese, for the purpose of farming meat or eggs for food. Poultry is farmed in great numbers with chickens being the most numerous.


WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production polutry farming


Advantages of Chicken farming

  1. The initial investment is a little lower than layer farming.
  2. The rearing period is 6-7 weeks only.
  3. More flocks can be taken in the same shed.
  4. Broilers have high feed conversion efficiency i.e. least amount of feed is required for unit body weight gain in comparison to other livestock.
  5. Faster return from the investment.
  6. Demand for poultry meat is more compared to sheep/goat meat.
  7. Important terminologies associated with poultry

Breed: Birds with a common origin, having specific characteristics, such as body shape, that distinguish them from other groups within the same species.

Strain: Chicks having specific characteristics, produced in specific farms by breeding.

Variety: The subdivisions of breeds based on specific characteristics, for example- white Leghorn, brown Leghorn, etc.

Chick: Young chicken of either sex from day 1 to about 5-6 weeks of age.

Grower: Chicken of either sex from 6 weeks to 6 months of age.

Cock: A mature male chicken.

Cockerel: A male chicken from day 1 to about 1 year of age.

Hen: A mature female chicken.

Pullet: A female chicken less than one year of age.

Fowl: Generally refers to larger birds.

Broiler/ Fryer: A young bird of either sex, usually of meat-type breeds up to 8-10 weeks of age and weighing 1.5-2.5 kg. The term broiler is applied to chicks that have especially been bred for rapid growth.

  1. Broiler strains are based on hybrid crosses between Cornish White, New Hampshire, and White Plymouth Rock.
  2. In broiler production there are two main production phases:
  3. keeping of parent stock and production of day-old-chicken and
  4. Growing and finishing of broilers.

Layers: Layers are efficient egg producers, breeds used for egg production in the industrial production system are almost entirely based on the White Leghorn and Rhode Island Red.

  1. Selection and crossbreeding techniques have resulted in productive laying hens producing 15 – 19 kg of eggs per year. In layer production,
  2. sometimes two phases of production are recognized:
  3. growing phase up to approximately 140 days; and
  4. productive phase from 140 – 560 days.


WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production eggs


Culling: The process of eliminating undesirable or non-reproductive animals.

Litter: The accumulation of materials, such as hay, sawdust, etc., to form the bed or floor of an animal farm.

Rooster: A young chick of meat type, weighing more than 1.5 kg.

Mash: A form of completely balanced feed that is finely ground and mixed so that birds can easily consume them and got proper nourishment.

Different Breeds Of Chicken

Different breeds are classified in different ways-

1. According to a place of origin

Mediterranean breeds: They originated in Europe, by the side of the Mediterranean Sea. They are small birds with lightweight but mature early and start egg laying. Examples- leghorn, Minorca, etc.

American breeds: The breeds originated in North America, due to hybridization with different Asiatic and Mediterranean breeds. They yield a considerable good amount of flesh and egg. Examples- are Rhode Island Red, New Hampshire, Plymouth Rock, etc.

English breeds: They are popular for their meat. Example- Sussex, Australia, etc.

Asiatic breeds: These breeds originated in Asia. A few important ones are – Brahma, Cochin, etc. Indian indigenous breeds are – Aseel, Chittagong, Ghagus, etc.

2. According To Utility

Laying breed: They lay about 220 or more eggs per year. Example- Leghorn.

Table breed or Meat breed: They produce a good amount of flesh. Examples- Aseel, Cochin, etc.

Dual breed: They produce both egg and flesh in moderately good amounts. Examples- Rhode Island Red, New Hampshire, etc.

3. According To Weight

Light breed: These breeds have body weights of about 2-3 kg. Example- Leghorn.

Heavy breed: These breeds have body weights of more than 3 kg. Example- Aseel, Brahma, etc

According to broodiness

Sitter: They sit on their eggs i.e., the mother incubates the eggs. Examples- Brahma, Aseel, etc.

1. According to a place of origin

Mediterranean breeds: They originated in Europe, by the side of the Mediterranean Sea. They are small birds with lightweight but mature early and start egg laying. Examples- leghorn, Minorca, etc.

American breeds: The breeds originated in North America, due to hybridization with different Asiatic and Mediterranean breeds. They yield a considerable good amount of flesh and egg. Examples- are Rhode Island Red, New Hampshire, Plymouth Rock, etc.

English breeds: They are popular for their meat. Examples- Sussex, Australia, etc.

Asiatic breeds: These breeds originated in Asia. A few important ones are – Brahma, Cochin, etc. Indian indigenous breeds are – Aseel, Chittagong, Ghagus, etc.

2. According to the utility

Laying breed: They lay about 220 or more eggs per year. Example- Leghorn.

Table breed or Meat breed: They produce a good amount of flesh. Examples- Aseel, Cochin, etc.

Dual breed: They produce both egg and flesh in moderately good amounts. Examples- Rhode Island Red, New Hampshire, etc.

According to weight

Light breed: These breeds have a body weight of about 2-3 kg. Example- Leghorn.

Heavy breed: These breeds have a body weight of more than 3 kg. Example- Aseel, Brahma, etc

4. According to broodiness

Sitter: They sit on their eggs i.e., the mother incubates the eggs. Examples- Brahma, Aseel, etc.

Non-sitter: The mothers do not sit on their eggs. Eggs are generally incubated in artificial incubator machines. Examples- Leghorn, Minorca, etc.

Different systems of fowl or chicken farming Generally different systems of farming are followed by poultry keepers. These may be-

  1. Free range or extensive system
  2. Semi-intensive system
  3. Intensive system:
  4. Battery cage system,
  5. Deep litter system.

1. Free range system

Free-range poultry farming consists of poultry permitted to roam freely instead of being contained in any manner. A free-range chicken must have daytime access to open-air runs for at least half of their life.

Free-range chickens grow slowly. Free-range poultry production requires that the poultry have access to the outside. The birds are to be protected from predatory animals and intruders. At present, due to several disadvantages and a shortage of space, this method is almost obsolete.

2. Semi-intensive system

This system is adopted where the amount of free space available is limited. It is necessary to allow 20-30 square yards per bird of outside run.

The birds are kept in a large enclosed area during the day time and are kept in adjacent farmhouses during the night and in unfavorable weather conditions.

3. Intensive system

This system is usually adopted where land is limited. In this system, the birds are confined to the house entirely with no access to the land outside.

The intensive system may be of the following types-

Battery cage system: Battery cages are a housing system used for various animal production methods, but primarily for egglaying hens.

The name arises from the arrangement of rows and columns of identical cages connected together, sharing common divider walls, as in the cells of a battery.

In a battery cage, the rate of food and water, and the duration and intensity of light are tightly controlled. There is no access to the natural environment, nor any opportunity to conduct natural behaviors such as perching, dust bathing, wing flapping or nesting.

Environmental conditions are automatically controlled, including light duration, which mimics summer day length. This stimulates the birds to continue to lay eggs all year round.


  1. A greater number of birds is reared per unit of area
  2. Facilitates correct maintenance of record
  3. Helps in identifying poor producers and prompt culling
  4. It helps in the production of clean eggs
  5. Easy control of parasitic disease
  6. Prompt steps to control feed wastage.

The cage method of housing is ideal for the area with moderate climate conditions where the day temperature in summer does not high and the temperature does not fall too low.

Egg production of the caged layer was reported to be more than those kept in a deep litter system.

Deep litter system: Deep litter system is commonly used all over the world. Litter is the substance that is used for farm animals to sleep on.

In the deep litter system, the poultry birds are kept in large pens of up to 250 birds each, on the floor covered with litter like straw, sawdust, or dried leaves up to a depth of 6-8 inches.

Deep litter is a method of chicken waste management that calls for droppings and bedding material to compost inside the chicken coop instead of being cleaned out and replaced regularly.

With the deep litter method, a carbon-based litter absorbs nitrogen from chicken droppings, which ferments in an odor-free process to produce rich, valuable humus just as in a traditional compost pile.

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production different system of fowl or chicken farming..


  1. It is economical, hygienic, comfortable, and safe for birds
  2. Controls diseases and vices
  3. It increases the efficiency of production
  4. Materials such as paddy husks, sawdust, dried leaves, chopped straw, and groundnut kernels depending upon the availability can be used as litter materials.
  5. Nutritional value of chicken
  6. Naturally low in sodium.
  7. 100 grams of skinless boneless chicken has 31 grams of protein, or more than half the recommended daily allowance.

A good source of niacin, which aids in metabolism; vitamin B6, important to the immune system and blood sugar; biotin, which aids in cell growth; vitamin Bu, involved in nerve and red blood cell maintenance.

  1. Nutritional value of egg
  2. Contain one of the highest quality proteins of any food.
  3. A large egg contains about 70 calories and 6 grams of protein.
  4. A single egg contains 13 essential nutrients.
  5. Egg proteins contain time-release energy which helps maintain blood glucose levels and makes people feel full and energized longer.


Leave a Comment