Class 08 || Science || 01. Crop Production and Management Solutions

CLASS 8th
01. Crop Production and Management

Exercise

01. 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.

Ans.  (a) crop (b) Preparation, (c) Float, (d) water and nutrients

02. Match items in column A with those in column B.

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

Answer:

Colulumn A	Column B
Kharif crops	Paddy and maize
Rabi crops	Wheat, gram, pea
Chemical fertilisers	Urea and super phosphate
Organic manure	Animal excreta, cow dung, urine and plant waste

03. Give two examples of each.; (a) Kharif crop (b) Rabi crop

Answer:

Kharif crops	Paddy and maize
Rabi crops	Wheat, gram, pea

04. Write a paragraph in your own words on each of the following.

(a) Preparation of soil (b) Sowing (c) Weeding (d) Threshing

Ans. (a) Preparation of soil : - Preparation of soil is the first step of farming. Soil is loosened and turned over. This helps in making the soil more airy so that roots can breathe in air. Moreover, loosening of soil also facilitates better penetration of roots into the soil. Seeds can be easily sown in loosened soil.

(b) Sowing : - The method of putting the seeds into soil is called sowing. Traditionally, seed is sown manually by spreading the seeds by hands. This process is called broadcasting. Seed drills are used when sowing needs to be done on a large scale.

(c) Weeding  : - Removal of weeds is called weeding. Unwanted plants which grow along with the crop are called weeds. They compete for resources; like sunlight, water and air; with the main crop. So, it is necessary to remove weeds for proper growth of crops. Weeding is usually done manually by using hands and sickles. Sometimes weedicides are also sprayed.

(d) Threshing : - Separation of grains from harvested stems is called Threshing. For smaller quantity, threshing is done by hands. For somewhat bigger quantity, threshing is done using animal; especially bullocks. Animals are made to trample over the harvested stock which helps in separation of grains. Threshing machines are used for bigger quantities.

05. Explain how fertilisers are different from manure.

Ans.

Manure			Fertilizer
01	It is natural.	01		It is artificial.
02	They are organic mixture formed by the natural process.	02		They are inorganic mixture formed by industries.
03	It has humus.	03		It has no humus.
04	They improve the soil texture.	04		They do not improve the soil texture.
05	They are not nutrient specific they have less nutrient.	05		They are nutrient specific they have nutrient.
06	They are bulky in size and occupy more space.	06		They are little in size and occupy little space.
07	They remain the structure of the soil.	07		They change the structure of the soil.
08	They provide the medium for the production of microorganisms.	08		They do not provide the medium for the production of microorganisms.
09	It is cheep.	09		It is costly.
10	They are pours.	10		These are not pours.
11	i.e. compost, vermin compost etc.	11		i.e. Urea, NPK etc.

                       

06. What is irrigation? Describe two methods of irrigation which conserve water.

Ans.  Supplying of water to the crop plants at different intervals is known as irrigation.

The source of irrigation is rain water, river, ponds, dame, lakes, ponds, canals and the underground water. The frequency of irrigation varies from crop to crop and irrigation of crop fields influenced by the type of soil.

Traditionally methods of irrigation are moat, chain pump, dhekli and rahat. Modern methods of irrigation is Tube well pump, sprinkle system and drip system. Sprinkle system and drip system methods conserve water in irrigation.

07. If wheat is sown in the kharif season, what would happen? Discuss.

Ans.: The crop of wheat needs mild to moderate temperature and frost free days; along with irrigation but no water logging. Winters are suitable for growing wheat. In the kharif season; which coincides with the peak summer months in India, temperature is at its peak which is not suitable for wheat. Moreover, during rainy season lot of water accumulates in fields which would be harmful for wheat crop. Hence, if wheat is sown in the kharif season; the productivity would be minuscule and would not be profitable for the farmers.

OR

If wheat is sown in the kharif season (from June to October), then the whole crop might get destroyed because of many factors such as lack of optimum temperature, adaptability, availability of pests, etc. Kharif season includes the rainy season, which is not favourable for the growth of wheat crop. Therefore, wheat crop should not be sown during this season.

08. Explain how soil gets affected by the continuous plantation of crops in a field.

Ans. Continuous plantation of crops in a field affects soil fertility. Plants utilize all the nutrients from soil which leads to depletion of nutrients in the soil. As a result, soil fertility reduces drastically.

09. What are weeds? How can we control them?

                                       OR

ó Q. What are weeds and Weedicides? What are main processes of removing weeds?

Ans. The unwanted plants which grown along the crops are known as weeds i.e. Xanthium (gokhroo), Parthenium (Gajar ghas), Cyperinus rotundus (Motha), grass, Amaranths etc.

They compete for water, nutrient and space. They snatched nutrient, water sunlight etc which is necessary to them. Some weeds secret toxic substances and live like a parasite and affect the yield of crop.

Weedicides: - The chemicals use to control the weeds is known as Weedicides i.e. Malathion and 2, 4-D etc. weedicides are diluted with water and sprayed with sprayer.

Weeding or Controlling of Weeds: - Controlling or removing the weed from the fields is called weedding. Weeds can be controlled by removing from the agricultural implements (plough, hero or khurpa), by uprooting, by using the weedicides or tilling the field before crops

10. Arrange the following boxes in proper order to make a flow chart of sugarcane crop production.

Ans. 5. Preparation of soil → 6. Ploughing the field → 7. Manuring → 4. Sowing → 2. Irrigation → 3. Harvesting → 1. Sending crop to sugar factory

11. Complete the following 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.

Ans. Down: 1: IRRIGATION 2: STORAGE 5: CROP Across: Answer: 3: HARVESTOR 4: GRAM  6: WINNOWING

Some Important Question asked in Papers

Q. Write difference between Rabi and Kharif crops with examples.

Q. Name a weedicides.

Q. Give two examples of each Rabi crops and Kharif corps.

Q. Write the difference between Manure and Fertilizer.

Q. Write about the two modern method of irrigation.

Ans. Sprinkling and Canal irrigation.

Q. match the following:

A	B
Cutting of Mature crop	Hoe
Separation of grains and chaff	Harvesting
Tool used for removing weeds and loosening soil.	Ploughing
Process of loosening and turning the soil.	Winnowing

Ans.

A	B
Cutting of Mature crop	Harvesting
Separation of grains and chaff	Winnowing
Tool used for removing weeds and loosening soil.	Hoe
Process of loosening and turning the soil.	Ploughing