DAV Class 8 Science Chapter 9 Question Answer – Crop Production and Its Management

The DAV Class 8 Science Book Solutions and DAV Class 8 Science Chapter 9 Question Answer – Crop Production and Its Management are essential study tools for DAV public school students in Class 8.

DAV Class 8 Science Ch 9 Question Answer – Crop Production and Its Management

DAV Class 8 Science Ch 9 Solutions – Crop Production and Its Management

Something To Know

A. Give one word for the following statements:

Question 1.
________ results in loosening and mixing of soil.
Answer:
Ploughing

Question 2
________ compete with crops for nutrients.
Answer:
weeds

Question 3.
________ bacteria, present in the root nodules of ________ plants, help in fixing atmospheric nitrogen.
Answer:
Rhizobium, leguminous

Question 4.
Harvested grains are ________ to reduce moisture content.
Answer:
dried

Question 5.
Removal of anthers from the flowers is known as ________ .
Answer:
emasculation

B. Match the following:

Column I	Column II
(1) Sickle	(a) Threshing
(2) Tractor	(b) Storage
(3) Seed drill	(c) Ploughing
(4) Combine	(d) Harvesting
(5) Silo	(e) Sowing

Answer:

Column I	Column II
(1) Sickle	(d) Harvesting
(2) Tractor	(c) Ploughing
(3) Seed drill	(e) Sowing
(4) Combine	(a) Threshing
(5) Silo	(b) Storage

C. Tick the correct option:

Question 1.
The practice of growing leguminous plants between successive cereal crops is called-
(a) Agriculture
(b) Crop rotation
(c) Cultivation
(d) Transplantation
Answer:
(b) Crop rotation

Question 2.
Which among the following is a Kharif crop?
(a) Wheat
(b) Gram
(c) Barley
(d) Rice
Answer:
(d) Rice

Question 3.
The organic substance obtained from dead plants, animals and their wastes is known as-
(a) Manure
(b) Crumb
(c) Fertilizer
(d) Chaff
Answer:
(a) Manure

Question 4.
The process of separating grain from chaff is known as-
(a) Threshing
(b) Weeding
(c) Tilling
(d) Winnowing
Answer:
(a) Threshing

Question 5.
Crops, which are grown during the rainy season, are known as-
(a) Rabi crops
(b) Leguminous crops
(c) Kharif crops
(d) Cereal crops
Answer:
(c) Kharif crops

D. Answer the following questions in brief:

Question 1.
Why is the use of a seed drill more advantageous as compared to sowing seeds by broadcasting?
Answer:
Seed drill helps in saving time and labour. Hence, seed drill is more advantageous than sowing seeds by broadcasting.

Question 2.
Babu wants to practice crop rotation. Help him by suggesting what kind of crops can be grown between two consecutive cereal crops? Also, provide him names of one Rabi and one Kharif crop that can be used to replenish the nitrogen content of the soil.
Answer:
Babu should grow pulses between two consecutive cereal crops. Groundnut (Kharif) and Pea (Rabi) crops can be used to replenish the nitrogen content of the soil.

Question 3.
If rice is sown in the month of November, how is the produce likely to be impacted? And why?
Answer:
If rice is sown in the month of November, it will not get adequate sunshine, temperature and water. This will result in low productivity of rice crop.

Question 4.
What are crumbs? Why should they be broken?
Answer:
Crumbs are small lumps of soil in a field after ploughing. They need to be broken down so that the soil becomes more airy and seeds can easily enter and germinate through the soil.

Question 5.
Define the term ‘transplantation? List any two advantages it offers to the farmer.
Answer:
Planting seedlings on different plot of land is called transplantation. This method is used for paddy. It helps farmers to select only the healthy plants for farming. This also helps in maintaining adequate gap between consecutive plants so that the plants get proper amount of sunshine and other resources.

E. Answer the following questions:

Question 1.
State the advantages of ploughing the soil and also state the different ways through which it is done.
Answer:
The advantages of ploughing the soil are:

It improves air circulation in soil.
Roots can penetrate deeper into the soil. Thus, plant can have better anchorage in soil.
It increases water retaining capacity of soil.
It helps in removing weeds.
It helps in growth of microbes in soil that is beneficial for farming.

Different Methods of Ploughing are:
By cattle driven plough, and by tractor drawn cultivator.

Question 2.
Both manures and fertilizers replenish soil fertility. Compare and contrast the advantages and disadvantages of using them.
Answer:

Manure	Fertilizer
Slow to act.	Fast to act.
It does not help in providing specific nutrients to plants.	It helps in providing specific nutrients to plants.
Improves soil composition.	It degrades soil composition.
It has a positive impact on ecosystem.	It may be harmful for ecosystem.

Question 3.
Explain how weeds are harmful for plants practiced by farmers. State the different ways of weed removal practiced by farmers.
Answer:
Weeds compete with plants for various resources like sunlight, air, temperature, water, nutrients, etc. Thus, weeds hamper the growth of crops. Some weeds are poisonous and can prove lethal for cattle and humans. Weeds are removed manually by sickle. Weedicides are also sprayed to get rid of weeds.

Question 4.
Give reasons for the following:
(a) Excess water supply can damage crops.
Answer:
Excess water supply results in waterlogging in the field which obstructs air-supply to the roots thus damage the crops.

(b) Grains are not stored without sun-drying.
Answer:
Grains contain moisture which promotes growth of microbes and pests. Sun-drying helps in removing excess moisture from grain. It helps in preventing the growth of microbes and pest during storage. Hence, grains are not stored without sun-drying.

Pesticides are poisonous and can harm cattle and humans.
Pesticides may destroy some useful insects and animals which help in pollination.
Too much of pesticide goes to groundwater and contaminates it.
Harmful chemicals from pesticides end up in food chain which is harmful for animals and humans.

Question 5.
Bhola’s field is ready with a mature wheat crop. List and explain the steps he would have to undertake before selling the grains to the FCI (Food Corporation of India).
Answer:
Bhola will take following steps before selling the grains:
Harvesting: Cutting and gathering of mature crops is called harvesting. Vegetables and fruits are plucked by hand. Cereals and other crops are harvested by sickle.

Threshing: Separating the grains from husk is called threshing. Small amount of harvest is threshed manually. Threshing machine is used for large amounts. Sometimes, combine harvester is used which does harvesting and threshing simultaneously.

Storage: Grains are dried in sun to remove moisture. After that, grains are stored in silos. Perishable items like fruits and vegetables are sent to cold storage.

Question 6.
Define hybridization. List the steps to be followed for obtaining seeds of a hybrid variety.
Answer:
Cross breeding between two varieties of an organism is called hybridization. Steps for obtaining seeds of a hybrid variety are as follows:

Two varieties of plants of desired characteristics are chosen, say A and B.
Anthers from plant A are removed. This process is called emasculation.
Anthers from plant B are taken and its pollen are dusted on stigmas of plant A.
After that, stigmas of plant A are covered with plastic bags. This process is called bagging.

Value Based Questions

The biology teacher was quick to observe the careless and time-wasting attitude of some of her students. She explained to them the need and importance of proper management of time and all other resources in our life. She then told them about the steps that are taken to properly manage the crops after they have ‘grown up’. The students realized the importance of her advice through this interesting comparison.

Question 1.
State the values conveyed by the Biology teacher to her students.
Answer:
Importance of time management

Question 2.
Name the steps taken to manage the crops after they have ‘grown up’.
Answer:
Irrigation, Weeding, Harvesting, Storage

Question 3.
Let the students organise a ‘play’, highlighting the importance of proper management of time/our resources, in our life.
Answer:
Do it yourself

Something To Do

Question 1.
Visit a field, or a park and collect (using protective gloves) around five types of weeds.
Answer:
Do it yourself

Question 2.
Make a list of Kharif and Rabi crops which are grown in your area. Find out if there are any silos in your city.
Answer:
Do it yourself

Question 3.
Frogs play an important role in. the biological control of insects in the agricultural fields. The decrease in population of frogs results in the increase of the population of insects. Try to find out the role of lizards, owls and bats in the biological control of pests.
Answer:
Lizards, owls and bats also feed on insects. Thus, these animals help in getting rid of many pests.

Question 4.
Find out about ‘Organic Farming’. Learn about the activities involved, and the characteristics of plants grown, in ‘organic farming’.
Answer:
Farming without the use of synthetic fertilizers and synthetic pesticides/weedicides is called organic farming. Organic farming involves using manure, biological pest control and biological methods of weed control. The produce of organic farming is free of toxic materials. Organic farming is a sustainable method of farming.

Question 5.
Visit a nearby farm and observe the various agricultural practices being carried out there. Find out the names and uses of the various machines that are used on the farm.
Answer:
Do it yourself

Question 6.
Try to find out the ‘changes that have come about’ between ‘modem’ and ‘traditional’ farming practices.
Answer:
Do it yourself

DAV Class 8 Science Chapter 9 Solutions – Crop Production and Its Management Important Questions and Answers

I. Fill in the blanks:

1. Paddy is a ________ crop.
Answer:
Kharif

2. Wheat is a ________ crop.
Answer:
Rabi

3. Kharif crops are grown in the ________ season.
Answer:
Rainy

4. Rabi crops are grown in the ________ season.
Answer:
Winter

5. NPK stands for ________,________ and ________.
Answer:
Nitrogen, Phosphorus, Potassium

II. Tick the correct answer:

Question 1.
Which of these is a kharif crop?
(a) Maize
(b) Wheat
(c) Mustard
(d) Linseed
Answer:
(a) Maize

Question 2.
Which of these is a Rabi crop?
(a) Paddy
(b) Soyabean
(c) Potato
(d) Millet
Answer:
(c) Potato

Question 3.
Which of these crops is grown by transplantation?
(a) Wheat
(b) Maize
(c) Paddy
(d) Pea
Answer:
(c) Paddy

Question 4.
Which of these is an example of pest?
(a) Sparrow
(b) Rat
(c) Grasshopper
(d) All of these
Answer:
(d) All of these

Question 5.
Which of these tools is used for harvesting?
(a) Sickle
(b) Hoe
(c) Spade
(d) Axe
Answer:
(a) Sickle

III. Answer the following questions:

Question 1.
What do you understand by agriculture?
Answer:
The practice of cultivating land for growing crops is called agriculture. It also includes growing plants for other requirements like fibre, medicines, flowers and ornamental plants.

Question 2.
Define agricultural practices.
Answer:
In order to maintain a steady supply of food, farmers undertake several systematic activities, spread over a period of time for growing crops. These activities are called agricultural practices.

Question 3.
What is crop rotation?
Answer:
Some crops like wheat and rice use lot of nitrogen from the soil. This leads to loss of nitrogenous nutrients from the soil. The lost nitrogen can be replenished by growing a leguminous crop in between two cereal crops. This practice is called crop rotation.

Question 4.
Explain harvesting.
Answer:
Cutting and gathering of crops after maturation is called harvesting. Crops like wheat and paddy are harvested by sickles. Fruits and vegetables are plucked with hands. After harvesting, grains need to be separated from the harvested crop. This is done by the process of threshing. Threshing can be done manually or by using animals or by threshing machines. For large scale farming, combine harvester is used. This is a machine which does harvesting and threshing at one go. After threshing, grains are separated from chaff. This is known as winnowing.

Question 5.
Write a brief note on irrigation.
Answer:
The supply of water to the plants in the field is called irrigation. Irrigation is done with water from various sources like rains, canals, waterways, wells and pumps. Some crops need more water, while some others need less water.

IV. Projects:

Question 1.
Make a list of food grains which are available in your home. Group them as Kharif and Rabi crops.
Answer:
Do it yourself

Question 2.
Make a list of different tools which are used by a farmer during various agricultural practices.
Answer:
Some tools are: plough, sickle, axe, spade, seed drill, etc.