Science Class 8 – Chapter 1- Crop Production And Management NCERT Exercise Solutions ( Question-Answer) Provided below.
Exercise –
Q.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 _____________.
Answer – crop
(b) The first step before growing crop is ________________ of the soil.
Answer – preparation.
(c) Damaged seeds would ________on the top of water.
Answer – float
(d) For growing a crop, sufficient sunlight and ____________and ________________from the soil are essential.
Answer – nutrients, water.
Q2. 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 superphosphate |
| (iii) Chemical fertilizers | (c) Animal excreta, cow dung, urine, and plant waste |
| (iv) Organic manure | (d) Wheat, gram, pea |
| (e) Paddy and maize |
Answer-
| A | B |
| (i) Kharif crops | (e) Paddy and maize |
| (ii) Rabi crops | (d) Wheat, gram, pea |
| (iii) Chemical fertilizers | (b) Urea and superphosphate |
| (iv) Organic manure | (c) Animal excreta, cow dung, urine, and plant waste |
Q3. Give two examples of each.
(a) Kharif crop
Answer – Paddy, maize, soybean
(b) Rabi crop
Answer – Wheat, gram, pea.
Q4. 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- It is the first step before growing a crop.
It is one of the most important tasks in agriculture is to turn the soil and loosen it. With the help of this step, roots can penetrate deep into the soil;
When the root goes deep into the soil, the loose soil allows the roots to breathe easily.
The process of loosening and turning of the soil is called tilling or ploughing.
(b) Sowing:- Sowing is the most important process in crop production in which seeds are putting into the soil.
Before sowing, it is most important that seeds are of good quality, clean and healthy.
A funnel is a traditional tool which is used for sowing seed.
Nowadays, “seed drill” is used for showing seed with the help of tractors.
This sows the seeds uniformly at equal distance and depth.
(c) Weeding:- In a field, many other undesirable plants may grow naturally along with the crop which is called weeds.
The process of removal of weeds is called weeding. It is necessary because weeds affect the growth of plants.
(d) Threshing- The process of separation of the grains from the chaff is called threshing.
This process is carried out with the help of a machine called thresher.
Q5. Explain how fertilizers are different from manure.
Answer – There are some differences between fertilizers and manure-
| Fertilizers | Manure |
It is a man-made inorganic salt. It is prepared in factories It doesn’t provide humus to the soil. It is very rich in plant nutrients like nitrogen, phosphorus and potassium. | It is a natural substance which is obtained by decomposition of cattle dung and plant residues. It can be prepared in the field. It provides a lot of humus to the soil. It is relatively less rich in plant nutrient. |
Q6. What is irrigation? Describe two methods of irrigation which conserve water.
Answer – The process of supply of water to the crop at appropriate intervals is called irrigation.
There are two methods of irrigation which conserve water-
(i) Drip System
(ii) Sprinkler System
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(i) Drip System
In this system, the water falls drop by drop directly near the roots of the plant.
Water is not wasted in this system. This technique of irrigation is used in the region where the availability of water is poor.
(ii) Sprinkler System-
In this system, the perpendicular pipes, having a rotating nozzle on top are joined to the main pipeline at regular intervals.
With the help of a pump, the main pipe comes under pressure and allowed to flow of water through the main pipe, which escapes from the rotating nozzles. It gets sprinkled on the crop.
Q7. If wheat is sown in the Kharif season, what would happen? Discuss.
Answer – Wheat is a Rabi crop which is sown in the winter season. (October to March).
It requires less water.
If Wheat is sown in Kharif season, the production of wheat will be decreased.
Q8. Explain how soil gets affected by the continuous plantation of crops in a field.
Answer – If there was a continuous plantation of crops in a field the soil becomes infertile because crop takes nutrients from the soil and soil become poorer in certain nutrients.
Q9. What are the weeds? How can we control them?
Answer – The undesirable plants which grow naturally along with the crop, is called weeds. We can control the weeds by using certain chemicals, called weedicides such as 2-4-D.
These are sprayed in the field to kill the weeds without damage the crops.
Weedicides are diluted with water to extend required and sprayed in the field with sprayer.
Farmers also used tilling before sowing of crops helps in uprooting and killing of weeds, which may then dry up and get mixed with the soil.
Q10. Arrange the following boxes in the proper order to make a flow chart of sugarcane crop production.
Answer –
Q11. 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. The 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 the chaff.
Answer –
Thanks sir
Rihan