NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management

These NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.

Crop Production and Management NCERT Solutions for Class 8 Science Chapter 1

Class 8 Science Chapter 1 Crop Production and Management Textbook Exercise Questions and Answers

Page 13-15

Question 1.
Select the correct word from the following list and fill in the blanks.
float, water, crop, nutrients, preparation
a. The same kind of plants grown and cultivated on a large scale at a place is called ……………….
b. The first step before growing crops is ………………. of the soil.
c. Damaged seeds would ………………. on top of water.
d. For growing a crop, sufficient sunlight and ………………. and ………………. from the soil are essential.
Answer:
a. crop,
b. preparation,
c. float,
d. water, nutrients.

Question 2.
Match items in column A with those in

Column A Column B
(i) Kharif crops (a) Food for cattle
(ii) Rabi crops (b) Ureaandsuper phosphate
(iii) Chemical fertilisers (c) Animal excreta, cow dung, urine and plant waste
(iv) Organic manure (d) Sheat, gram, pea
(e) Paddy and maize

Answer:
(i) → (e),
(ii) → (d),
(iii) → (b),
(iv) → (c)

Question 3.
Give two examples of each:
a. Kharif crop
b. Rabi crop
Answer:
a. Paddy and maize,
b. Wheat and mustard.

Question 4.
Write a paragraph in your own words on each of the following.
a. Preparation of soil
b. Sowing
c. Weeding
d. Threshing
Answer:
a. Preparation of soil: The basic step before the cultivation of a crop is the preparation of the soil. It involves loosening the soil resulting in deeper penetration of the roots. This process increases the growth of several microbial organisms, earthworms, etc., which enrich the soil with humus and other essential nutrients of the soil. Tilling of soil brings the rich nutrients of the soil to the top surface. Basically, plants require nutrients for their proper growth and functioning. The process of loosening the soil is called tilling or ploughing the soil. Ploughing takes place with the help of a bull and appropriate equipment like plough, hoe or cultivator. This helps the plants to completely utilise the nutrients obtained from the soil for their growth.

b. Sowing: Sowing is an important process in the production of crops. The process of placing the seeds in the soil for the growth of the plants is sowing. Seed selection is important for better growth of the plant. The net production of the crop, i.e., yield is improved through sowing. It is done traditionally by a tool or a seed drill. The tool is funnel-shaped and was used traditionally for seed sowing in the soil. Nowadays, seed sowing is done through a tractor by the usage of seed drills. The seeds are dispersed uniformly in the soil through this tool and are sown at a particular depth. This new method of sowing is time-saving and also ensures seed protection from the birds.

c. Weeding: The unwanted plants in the crops are called weeds. These weeds absorb the nutrients from the soil. So it is necessary to remove them. Weeds are either removed manually or by mechanical tools. The process of removal of weeds is called weeding. Some chemicals like 2,4-D are also used to kill the weeds. Weedicides are sprayed to get of weeds.

d. Threshing: It is the process of separating the grains or seeds from chaff. This process takes place after the harvesting of the crop. It generally takes place with the help of a machine known as ‘combine’. This machine is a combination of both harvester and thresher. It cleans the harvested grains from chaff.

NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management

Question 5.
Explain how fertilisers are different from manure.
Answer:

Fertiliser Manure
1. Fertilisers are commercially available plant nutrients. 1. Manure is a natural substance prepared by the decomposition of animal excreta and plant wastes.
2. They can be organic or inorganic in nature. 2. Manure is known to have a large quantity of organic materials and very little amount of plant nutrients.
3. They ensure healthy growth and development of plants by providing them with nitrogen, phosphorus, potassium, etc. 3. They help in enriching the soil with organic matter and nutrients.
4. The addition of fertilisers to the soil requires special guidelines such as dose time, post addition precautions, etc., to be followed. 4. The addition of manure does not require any special guidelines.
5. A fertiliser does not provide any humus to the soil. 5. Manure provides humus to the soil and increases soil
6. Its excessive use causes water pollution. It cannot replenish the organic matter of soil. 6. It protects the environment and helps in recycling the farm waste.

Question 6.
What is irrigation? Describe two methods of irrigation which conserve water.
Answer:
Plants need plenty of water to grow. Farmers need to supply water to the crops at regular intervals. This practice is called irrigation. Two methods of irrigation which conserve water are as follows:

a. Sprinkler System: The sprinkler system is composed of a series of pipelines. Vertical sprinklers are fitted at suitable gaps on the pipes. Water is pushed through the pipes with the help of a pump. The nozzle of the sprinkler keeps on rotating. It results in a jet of water being sprinkled on plants. Sprinkler system is ideal for irrigation on uneven land.

b. Drip Irrigation: In this system, pipes are laid near the base and along the queue of plants. The pipes have small holes at frequent gaps. The holes facilitate gradual dripping of water on the base of plants. This method is ideal for areas which are suffering from shortage of water.

Question 7.
If wheat is sown in the kharif season, what would happen? Discuss.
Answer:
Kharif come during rainy season hence it is not a wise idea to grow wheat in Kharif season. Crop of wheat requires moderate temperature, moderate amount of water and a long period of frost-free days. If wheat is grown in kharif season it may not grow properly because of very high temperature. Some of the plants may also get damaged due to flooding. This will result in poor yield.

Question 8.
Explain how soil gets affected by the continuous plantation of crops in a field.
Answer:
We know that plants take nutrients from the soil and thus exhaust the soil from most of the nutrients with passage of time. Thus, continuous plantation of crops in the field results in loss of fertility of the soil. The soil may become infertile in the long run because the soil does not get enough time to replenish its lost nutrients.

Question 9.
What are weeds? How can we control them?
Answer:
Any unwanted plant which grows along with crops is called weed. Removal of weeds is called weeding. Weeding is usually done manually by using a trowel. Weeds are also removed during ploughing. Weedicides are the chemicals which destroy weeds. 2, 4-D is an example of weedicide. Weedicides are sprayed before flowering and seeding in weeds.

NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management

Question 10.
Arrange the following boxes in proper order to make a flow chart of sugarcane crop production.
NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management 1
Answer:
Flow chart of the production:
NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management 2

Question 11.
Complete the following cross word puzzle with the help of clues given below.
Down
1. Providing water to the crops.
2. Keeping crop grains for a long time under proper conditions.
5. Certain plants of the same kind grown on a large scale.
Across
3. A machine used for cutting the matured crop.
4. A rabi crop that is also one of the pulses.
6. A process of separating the grain from chaff.
NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management 3
Answer:
1. Irrigation
2. Storage
3. Harvester
4. Gram
5. Crop
6. Winnowing

NCERT Extended Learning Activities and Projects

Question 1.
Sow some seeds in the soil and arrange to water them by drip irrigation. Observe daily.
a. Do you think it can save water?
b. Note the changes in the seed.
Hint:
a. Yes, it will save water because in the drip irrigation method, pipes are laid near the base and along the queue of plants. The pipes have small holes at frequent gaps. The holes facilitate gradual dripping of water on the base of plants. This method is ideal for areas which are suffering from shortage of water.

b. We can see the change in seed day by day. As long as we give proper care and sunlight to the seed, it grows properly. Adding manure/fertiliser to the soil will help the seed to grow faster.

Question 2.
Collect different types of seeds and put them in small bags. Label them.
Hint:
Seeds should be as dry as possible when you collect them. Pick a dry day when there isn’t too much wind as many seeds are very light and can easily be blown away.

Question 3.
Collect pictures of some other agricultural machines and paste them in a file. Write their names and uses.
Hint:
The following agricultural machines are used nowadays:
Shredders and cutters, wheel tractor-scrapper, cotton harvester, tillage planter, drag harrow, sprayer.

NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management

Question 4.
Visit a farm, nursery or a garden nearby. Gather information about
a. importance of seed selection.
b. method of irrigation.
c. effect of extreme cold and extreme hot weather on the plants.
d. effect of continuous rain on the plants.
e. fertilisers/manure used.
Hint:
a. By removing the inferior seeds, the farmer is able to grow stronger and healthier seedlings. While seed selection is mainly aimed at obtaining healthier seeds, it can also be used to maintain and improve the quality of the crop variety. In a crop field, farmers may observe differences in traits between plants.

b. There are two types of modem irrigation methods:

  1. Sprinkler irrigation is a method of irrigation in which water is sprayed or sprinkled through the air in the form of rain-like drops.
  2. In drip irrigation method, pipes are laid near the base and along the queue of plants. The pipes have small holes at frequent gaps. The holes facilitate gradual dripping of water on the base of plants.

c. Extreme heat will slow down the growth and also increase moisture loss in the plants. The temperatures for optimal growth vary with the type of plant. Extremely hot or cold soil temperatures can also hamper the plant growth and seed germination.

d. Rainwater drains out nutrients and minerals that the plant needs to survive from the soil. If it rains continuously, the soil will lose its fertility and the plants won’t get the required nutrients. Plants get destroyed due to excess of rain.

e. Fertilisers supply specific type of nutrients to the plant. Fertilisers are the chemicals which add minerals like potassium, phosphorus and nitrates to soil. They use manure because it is a cheap fertiliser and environment- friendly. Fertilisers are used because they increase crop production.

Activity 1

Objective: To observe the effect of manure and fertilisers on the growth of plants.
Materials Required: Three empty flower pots, soil, cow dung manure, urea fertiliser, water and some gram seeds.
Procedure:

  • Take three empty flower pots and mark them A, B, and C.
  • Put some ordinary soil in pot A. Add some soil mixed with little cow-dung manure in pot B and take some soil mixed with a little urea fertiliser in pot C.
  • Pour the same amount of water in all the three flower pots.
  • Now take some gram seeds and germinate them.
  • Select equal sized seedlings of gram.
  • Plant these seedlings in each of the three flower pots.
  • Keep the flower pots in a sunny place and water them daily.
  • Observe and compare the growth of seedlings in the three flower pots after 7 to 10 days.

NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management 4
Observations:

  • The pot A containing ordinary soil shows slow and poor growth.
  • The pot B containing manure shows better growth.
  • The pot C containing the fertiliser shows the fastest growth.

Conclusion: This activity shows that manure and fertilisers are essential for better growth of plants.

iv. Irrigation: Plants need plenty of water to grow. Farmers need to supply water to the crops at regular intervals. This practice is called irrigation. Different types of crops require different amount and frequency of irrigation. Kharif crops need more water than rabi crops.

Sources of Irrigation: Wells, tube-wells, ponds, lakes, rivers, canals, etc., are the sources of irrigation.

Traditional Methods of Irrigation: In the traditional methods, human or animal labour is used. Following are some traditional methods of irrigation:
a. Moat (pulley-system): This is composed of a pulley and a rope. A bucket is tied to one end of the rope. Another end of the rope is pulled through over the pulley in order to draw water.
NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management 5

b. Chain Pump: Chain pump is composed of a wheel which is turned with the help of a chain. Many circular discs are fitted along with the chain. Movement of discs along with the chain helps in drawing water.
NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management 6

c. Dhekli: Dhekli is composed of a long wooden beam which turns around a lever. A bucket is fitted at the longer end of the beam. The shorter end is pressed and raised by foot to fill and lift water.
NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management 7

d. Rahat: Rahat is also called Persian wheel because its concept came from Persia. Rahat is composed of a big wheel with buckets fitted on the rim. Rahat is turned with the help of cattle, which helps in drawing water from a reservoir.
NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management 8
Manual pumps are now being replaced by motor-driven pumps. Such motors are powered either by electricity or by diesel engine.

Modern Methods of Irrigation: There are two modem methods of irrigation as follows:
a. Sprinkler System: The sprinkler system is composed of a series of pipelines. Vertical sprinklers are fitted at suitable gaps on the pipes. Water is pushed through the pipes with the help of a pump. The nozzle of the sprinkler keeps on rotating. It results
NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management 9

b. Drip Irrigation: In this system, pipes are laid near the base and along the queue of plants. The pipes have small holes at frequent gaps. The holes facilitate gradual dripping of water on the base of plants or directly on the roots. This method is ideal for areas which are suffering from shortage of water.
NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management 10

v. Protection from Weeds
Weeds: Any unwanted plant which grows along with the main crop is called weed.
Weeding: The removal of weeds is called weeding. Weeding is necessary because weeds affect the growth of the crop by competing with the crop plants for water, nutrients, space and light.
Weed Control: 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. These chemicals do not damage the crops.

vi. Harvesting: The cutting of crop after it is mature is called harvesting. In harvesting, the crops are pulled out or cut close to the ground. Harvesting is done manually by sickle or by a machine.

Threshing: In the harvested crop, the seed grains need to be separated from the chaff with the help of a machine called ‘combine’. It is in fact a combined harvester and thresher. This process is called threshing.
Winnowing: Separation of grains and chaff in small land holdings is called winnowing. Winnowing is done manually or by machines.
NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management 11

vii. Storage: Grains obtained by threshing are dried in the Sun. The dried grains are stored in gunny bags and placed in properly ventilated cemented halls, known as godowns. Farmers keep dried grains in jute bags or metallic bins or mud bins. Large scale storage of grains is done in silos and granaries. For storing large quantities of grains in big godowns, specific chemical treatments are used to protect them from pests and microorganisms.
NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management 12

  • Food from Animals: Animals are an important source of food for us. Many animals are reared for milk. Some animals are reared for meat, e.g., goats and poultry. Fish is an important source of meat. Honey is obtained from honeybees.
  • Animal Husbandry: Food is obtained from animals for which animals are reared and provided with proper food, shelter and care. When done on a large scale, it is called animal husbandry.

Class 8 Science Chapter 1 Crop Production and Management Additional Important Questions and Answers

Very Short Answer Type Questions

Question 1.
What is agriculture?
Answer:
Cultivation of plants and rearing of animals for food and other beneficial products and services is called agriculture.

Question 2.
What is a crop?
Answer:
When plants of the same kind are grown and cultivated at one place on a large scale, it is called a crop.

Question 3.
Which agricultural practice comes first: harvesting or weeding?
Answer:
Weeding.

NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management

Question 4.
What is sowing?
Answer:
Putting seeds in soil is called sowing.

Question 5.
What are fertilisers?
Answer:
Fertilisers are chemicals which contain a particular plant nutrient.

Question 6.
What is irrigation?
Answer:
The process of supplying water to crops at regular intervals is called irrigation.

Question 7.
What are weeds?
Answer:
Unwanted plants which grow along with the crops are called weeds.

Question 8.
What is winnowing?
Answer:
Separation of grains from chaff with the help of blowing wind is called winnowing.

Question 9.
What is manure?
Answer:
Manure is an organic substance prepared by the decomposition of plants and animals waste.

Question 10.
What are manures and fertilisers used for?
Answer:
Manures and fertilisers are used to maintain the fertility of the soil and enhance crop yield.

NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management

Question 11.
Write any two uses of hoe.
Answer:

  1. It is used to remove the weeds,
  2. It is used to loosen the soil.

Question 12.
What do you mean by storage?
Answer:
The process of keeping the grains viable for a longer time by saving them from moisture, insects, rats and microorganisms is called storage.

Question 13.
Mention three animals which provide meat.
Answer:
Goat, pig and poultry.

Question 14.
What do you mean by animal husbandry?
Answer:
Animal husbandry is the process of rearing animals by providing them proper food, shelter and care at a large scale.

Question 15.
Why is it necessary to dry grains before storage?
Answer:
The grains are properly dried in the Sun to reduce the moisture in them. This prevents the attack by insects, pests, fungi and bacteria. Moisture changes colour of grains and they lose their germination capacity.

Question 16.
Write some sources of irrigation.
Answer:
Wells, tube wells, ponds, rivers and canals are the main sources of irrigation.

Question 17.
Which oil is obtained from fish and which vitamin is it rich in?
Answer:
Cod liver oil is obtained from fish which is rich in vitamin D.

Short Answer Type Questions

Question 1.
What is humus? How is it formed?
Answer:
Humus is an organic matter rich in nutrients. It is formed by the microbial action on dead and decaying animal bodies and leaves. It is generally formed on those spots where there are denser layers of trees. The soil below it becomes dark having more number of bacteria. These bacteria decompose the decaying organic matter and convert it into manure.

NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management

Question 2.
Explain the traditional method of sowing.
Answer:
Traditionally, the tool used for sowing is shaped like a funnel. The seeds to be sown are filled into the funnel and passed down through two or three pipes, having sharp ends. These sharp ends pierce into the soil and place the seeds in the soil. Broadcasting is another method in which seeds are simply scattered in the soil manually by hands.

Question 3.
Explain the modern method of sowing.
Answer:
The modem method of sowing seeds is through a seed drill. The seed drill is powered by a tractor and it helps to sow the seeds uniformly at proper distances and depths. It also ensures that seeds, once dropped, get covered by the soil after sowing. This prevents the wastage of seeds caused due to damage by the birds. It also saves time and labour and ensures a uniform spreading of the seeds.

Question 4.
What is the significance of ploughing?
Answer:
Significance of ploughing:

  • This allows the roots to penetrate deep into the soil.
  • Loose soil allows the root tips to breathe easily when they go deep into the soil.
  • It allows proper mixing of nutrients and humus into the soil.
  • Loosening of soil brings nutrients and minerals to the top and thus plants are able to utilise these minerals.
  • Loosened soil promotes the growth of organisms like earthworms and microbes which are the farmers’ friends as they further turn and loosen the soil and add humus to it.

Question 5.
What are the advantages of fertilisers?
Answer:
Advantages of fertilisers:

  • Fertilisers give quicker results as compared to the manure.
  • Use of fertilisers has helped farmers in significantly improving the farm yield.

Question 6.
What is the difference between kharif and rabi crops?
Answer:

Kharif Crops Rabi Crops
1. They are monsoon or rainy season crops. 1. They are non­monsoon or winter season crops.
2. These crops are grown in hot and wet conditions. 2. These crops are grown in cold and nearly dry conditions.
3. These crops are sown in the beginning of rainy season in June-July 3. These crops are sown in October- November when monsoon has retreated.
4. These crops are harvested during September-October at the end of monsoon. 4. These crops are harvested in March-April before the advent of hot season.
5. Examples: Paddy, maize, groundnut, soybean, green gram, cotton, black gram., etc. 5. Examples: Wheat, barley, gram, mustard, linseed, pea., etc.

NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management

Question 7.
What do you understand by the fertility of soil? Mention any four methods of replenishment of soil fertility.
Answer:
The ability of soil to supply all the essential plant nutrients to a crop and provide suitable soil structure to support the growth of plants is called soil fertility. The soil fertility can be replenished or regained by the following methods:

  • By keeping the field uncultivated for one or two seasons.
  • By putting manure and fertilisers in the soil.
  • By practising crop rotation.
  • By practising multiple cropping (or mixed cropping).

Question 8.
Why is an earthworm called a farmer’s friend?
Answer:
Earthworms are considered to be ‘friends of farmers’. They are eco-friendly organisms. Earthworms loosen the soil by burrowing deep into it. This is similar to tilling of the soil. Earthworms consume animal and plant wastes and release organic matter as excreta. This excreta of earthworms increases soil fertility. It improves the water holding capacity of the soil. The process of using worms to decompose animal and plant wastes is called vermicomposting. The manure produced after decomposing of wastes in this manner is called vermicompost.

Question 9.
What are the various methods for the improvement of crops?
Answer:
Following are the ways for the improvement of crops:

  • Improved fertility of the soil.
  • Protection against pests and weeds.
  • Better transport and storage facility.
  • Introduction of high yielding variety of seeds (HYV seeds).
  • Use of improved irrigation methods.

Question 10.
What are the advantages of levelling?
Answer:
Advantages of levelling:

  • It compresses the loosened top soil, thus decreasing erosion.
  • It helps in uniform distribution of water.
  • It helps in proper sowing and uniform growth of crop plants.

Question 11.
What is the use of soil for the cultivation of plants?
Answer:
Importance of the soil in agriculture:

  • Soil fixes up the plants in the land. It holds the roots firmly and anchors the plant.
  • It retains water which is absorbed by plants as a vital nutrient.
  • It provides space for useful animals, such as earthworms, which turn up the soil and make it fertile.
  • Soil, being porous, provides enough air to plants and organisms for respiration.

Question 12.
Write a short note on the storage of crops.
Answer:
Proper storage of harvested crop is important to prevent damage from moisture and pests. Grains are Sun dried before being stored. Grains are stored in silos. Silos can be of varying heights, ranging from one metre to several metres. Fruits and vegetables are stored in cold storage. Suitable pesticides are used while storing grains. Neem leaves are also used as pesticides.

NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management

Question 13.
What are the advantages of using manure?
Answer:
The advantages of manure:

  • Manure increases nutrients in soil and soil fertility.
  • It improves soil texture.
  • It improves water retaining capacity of the soil.
  • It is free of any toxic material and thus is environment friendly.

Question 14.
Explain the method of preparing of manure by the farmer.
Answer:
Manure is prepared by decomposition of plant and animal waste. Farmers dump the farm waste in the field and leave it to decompose. Sometimes, the farm waste may be covered with a layer of soil to hasten the process of decomposition. Sometimes, farmers take the help of earthworms to hasten the process. Farmers also make compost pits to prepare manure.

Question 15.
Write two disadvantages of fertilisers.
Answer:
Disadvantages of fertilisers:

  • Excessive use of fertilisers can make the soil infertile.
  • Harmful chemicals in fertilisers pollute the soil and groundwater.

Question 16.
Explain the traditional methods of irrigation.
Answer:
In traditional methods, human or animal labour is used. The various traditional ways are:

  • Moat (pulley system): This is composed of a pulley and a rope. A bucket is tied to one end of the rope. Another end of rope is pulled through over the pulley in order to draw water.
  • Chain pump: Chain pump is composed of a wheel which is turned with the help of a chain. Many circular discs are fitted along with the chain. Movement of discs along with the chain helps in drawing water.
  • Dhekli: Dhekli is composed of a long wooden beam which turns around a lever. A bucket is fitted at the longer end of the beam. The shorter end is pressed and raised by foot to fill and lift the water.
  • Rahat: Rahat is also called Persian wheel because its concept came from Persia. Rahat is composed of a big wheel with buckets fitted on the rim. Rahat is turned with the help of cattle, which helps in drawing water from a reservoir.

Question 17.
Write the importance of irrigation.
Answer:
The importance of irrigation is as follows:

  • Plants contain nearly 90% water.
  • Water is essential for germination of seeds.
  • Water is essential for proper growth of plants.
  • Water is essential for proper development of flowers, fruits and seeds.
  • Water protects the plants from frost and also from the hot air currents.

Question 18.
What is harvesting?
Answer:
Harvesting involves cutting and gathering of the mature crop from the fields. Traditionally, harvesting is done manually by using sickles. Combine harvesters are used on large farms. A combine harvester does harvesting and threshing at one go.

NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management

Question 19.
A group of science club students made a compost pit in their school. They collected all the bio-degradable waste from the school canteen and used it to prepare the compost.
a. Give two wastes that can be used for making the compost and two wastes obtained from canteen which cannot be used for the compost making?
b. What is the other important component required for making the compost?
Answer:
a. The two wastes that can be used for the compost are vegetable and fruit peel and the two wastes obtained from canteen which cannot be used for the compost are plastic and polythene.
b. Bacteria present in the soil are used as component for making compost.

Long Answer Type Questions

Question 1.
Explain the various agricultural practices.
Answer:
The following practices are used in agriculture:
a. Preparation of soil: The first step of cultivation is preparation of soil. This is done by loosening and turning the soil. A plough is used for this purpose. If the soil becomes too hard then farmer may resort to watering the soil before ploughing. Traditionally, animal-drawn ploughs have been used by farmers. Nowadays, tractor-drawn ploughs are used for this purpose.

b. Sowing: Seeds are sown in the field after ploughing. A farmer needs to separate the damaged seeds from the good ones. The seeds should be sown at proper gaps and at proper depth. This ensures adequate sunlight, moisture, air and nutrients to the growing plants.

c. Adding manure and fertilisers: We know that plants take nutrients from the soil and thus exhaust the soil of most of the nutrients with passage of time. Manures and fertilisers need to be added to the soil to replenish soil nutrients. Manure and fertilisers are essential to increase the crop production.

d. Irrigation: Plants need plenty of water to grow. Farmers need to supply water to crops at regular intervals. This practice is called irrigation. Different types of crops require different amount and frequency of irrigation. Kharif crops need more water than rabi crops.

e. Harvesting: Harvesting involves cutting the mature crop. Traditionally, harvesting is done manually by using sickles. Combine harvesters are used on large farms. A combine harvester does harvesting and threshing at one go.

f. Storage: Proper storage of harvested crop is necessary to prevent damage from moisture and pests. Grains are generally dried in the Sun before being stored. Silos of different sizes are used for storing grains. Fruits, vegetables and other perishable items are stored in cold storage. Pesticides are also used while storing grains.

Question 2.
Explain various methods of harvesting in our country.
Answer:
Harvesting is the process of cutting and gathering of the ripened crop. In harvesting, crops are pulled out or cut close to the ground.

There are two modes of harvesting:
a. Manual mode of harvesting: In India, most of the harvesting is done manually and sickle is the only tool that is used for this purpose. The sickles are of two types, namely, plain and saw-shaped (serrated). The serrated sickles are used for cutting paddy and wheat crops.

b. Mechanical harvesting: Machines such as reapers, threshers and even combine harvesters are used. The harvesting with the help of machines enables the farmers to complete the process within a short period and thus the loss of crop due to untimely rains and storms can be saved to a large extent. This also gives farmers sufficient time to prepare the field for the next sowing.

NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management

Question 3.
Explain fallow field and crop rotation as methods of replenishing soil nutrients.
Answer:
a. Fallow Field: When the field is left uncultivated for a season or two, it is called fallow land. Leaving the field fallow allows the soil to recuperate nutrients through natural processes.

b. Crop Rotation: This involves growing a legume crop between two successive cereal crops. Rhizobium bacteria live in the root nodules of legume plants. These bacteria help in nitrogen fixation in soil. Thus, legume plants facilitate replenishment of nutrients in the soil.

Question 4.
Describe the tools for loosening and turning of soil.
Answer:
The tools for loosening and turning of soil are:
a. Plough: A plough is composed of ploughshare and ploughshaft. The ploughshare is made of iron and is triangular in shape. The ploughshaft is made of wood and is very long. It is harnessed to a pair of bullocks or other cattle with the help of a beam which remains perpendicular to the ploughshaft.

b. Hoe: The hoe is used for levelling the soil and for removing weeds. It is made of iron or wood. It is a long beam with a handle. Sometimes a heavy and flat beam of wood is utilised as a hoe. In the iron hoe; a sharp blade is fixed on one end. A hoe is usually pulled by animals but sometimes it is pulled by a tractor as well.

c. Cultivator: A cultivator is composed of a series of iron discs or ploughshares which are fitted on an iron frame. Cultivator is pulled by a tractor. Cultivator helps in tilling a large area in less time. It is ideal for big-sized farms.

Picture-Based Questions

Question 1.
Draw a labelled diagram of a hoe. Also state the function of a hoe.
Answer:
NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management 13
It is a simple tool which is used for removing weeds and for loosening the soil.

Question 2.
Observe the given picture. Recognise it and write its function.
NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management 14
Answer:
The given figure is of a cultivator driven by a tractor. In today’s time, the ploughing is done by a cultivator driven by a tractor. It reduces labour and time.

NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management

Question 3.
a. Draw a diagram of a plough and label the following parts.
(i) Ploughshaft (ii) Ploughshare
b. Write the function of a plough.
c. Name the animals which are used to draw the plough.
Answer:
a.
NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management 15

b. The primary purpose of ploughing is to turn over the upper layer of the soil, bringing fresh nutrients to the surface, while burying weeds and the remains of previous crops and allowing them to break down and improve soil fertility.

c. The plough is drawn by a pair of bulls or other animals like horse, camel, etc.

Question 4.
Observe the given figure and identify it. Write its function.
NCERT Solutions for Class 8 Science Chapter 1 Crop Production and Management 16
Answer:
The given figure is sprinkler system of irrigation. This is a modem method of irrigation. In this method, horizontal pipes having rotating nozzles in their top are used to sprinkle water on the crops.

error: Content is protected !!