Crop production and management NCERT class 8 science chapter 1 in English
Class :-8
Subject:- विज्ञान (Science)
Chapter:- 2
Chapter name: Crop Production and Management
Question 1
Select the correct word from the following list and fill in the blanks.
(float, water, crop, nutrients, preparation)
(a) The same kinds of plants grow and cultivated on a large scale at a place is called............
(b) The first step before growing crop is ---------------of the soil
(c) Damaged seeds would..............on top of water .
(d) For growing crops sufficient sunlight and------------and ...........from the soil are essential.
Answer-(a)-Crop (b)-Preparation (c)-float (d)- water, nutrients
Question 2 Match lines with the column A with those in column B
|
Column A |
Column B |
|
(i)
Kharif crops |
(a) Food
for catle |
|
(ii)
Rabi crops |
(b) Urea
and super phosphate |
|
(iii)
Chemical filter |
(c) Animal
excreta |
|
(iv)
Organic Manure |
(d) Wheat,
gram, pea (e) Paddy
and maize |
Answer-(i)-e , (ii)-d , (iii)-b , (iv)-c
Question-3 Give two example for each
(a) Kharif crop-Paddy, Maize, Soyabean, Groundnut, Cotton etc.
(b) Rabi crop -Wheat, gram, pea, Mustard etc
Question-4 Write a paragraph in your own words on each of the following.
(a) Preparation of soil- The Preparation of soil is the first step before growing a crop . One of the most task in agriculture is to turn the soil and loosen it. This allow the roots to penetrate deep in to soil. The loosened soil helps in the growth of earthworms and microbes which are friends of the farmer and add humus to it . Also, turning and loosening of soil brings the nutrient- rich soil to the top so that plants can use these nutrients .
(b) Sowing -Sowing is the most important part of the crop production. Before sowing good quality of seeds collected. Good quality seeds are clean and healthy seeds of a good verity. Seeds can be sown by seed drill or manually.
(c) Weeding- Weeds are unwanted plants that grows along the crops and removal of the weeds is known as weeding. Weeds can be removed either manually by using tools like Khurpi or by using weedicides like 2,4-D. These are spread in the fields to kills the weeds.
(d) Threshing-The process of separation of grains from the chaff is called threshing . This is carried out with the help of a machine called 'Combine' which is in fact a combined harvester and thresher.
Question-5 Explain how fertilizers are different from manure.
Answer-The main difference between Fertilizer and Manure are as follows;
|
S.No. |
Fertilizers |
Manures |
|
1 |
A Fertilizer is an inorganic salt |
Manure ia a natural substance obtained by the decomposition of cattle
dung, human waste and plant residues. |
|
2 |
A fertilizer is prepared in a factory |
Manure can be prepared in the field |
|
3 |
A fertilizer does not provide any humus to the soil |
Manure provides a lot of humus in the soil |
|
4 |
Fertilizers are very rich in plant nutrients like nitrogen,
phosphorus and potassium. |
Manure is relatively less rich in plant nutrients. |
Question-6 : What is the irrigation? Describe two methods of irrigation which conserve water.
Answer -The supply of water to crops at different intervals is called irrigation. The two method of irrigation which conserve water are as follows :
(i) Sprinkler system- Under this method, 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.
(ii) Drip System-In this system, the water falls drop by drop just at the position of the roots. It is best technique for watering fruits plants, gardens and trees. Water is not wasted at all. It is a boon in regions where availability of water is poor.
Question 7: If wheat is sown in the Kharif season, what would happen? Discuss.
Answer: Wheat is a Rabi crop, hence it requires cold climatic conditions to be grow properly. If it sown in the Kharif season, it it will not grow or may get destroyed due to excessive rains in the Kharif season.
Question 8: Explain how soil get effected by the continuous plantation of crops in a field.
Answer: Soil supplied mineral nutrients to the crop These nutrients are essential for the growth of the plants. Continuous growing of crops in the same field make the soil poorer in certain nutrients. This make the soil unfertile. And then to replenish the soil with nutrients farmer need to add manures to the soil.
Question 9: What are weeds? How can we control them?
Answer: The undesirable plants may grow naturally along with the crops are called weeds. These are many ways to remove weeds and control their growth. Weeds can be removed by uprooting or cutting them close to the ground ,from time by time. This is done with the help of the Khurpi.
Weeds are also control by using certain chemicals, called weedicides like 2,4-D. These are the sprayed in the field to kill the weeds.
Question10: Arrange the following boxes in proper order to make a flow chart of sugarcane crop production.
|
Sending crop to suger factory 1 |
|
Irrrigation 2 |
|
Harvesting 3 |
|
Sowing 4 |
|
Preparation of soil 5 |
|
Ploughing the field 6 |
|
Manuring 7 |
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