NCERT PRACTICE QUESTIONS
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 _____________ from the soil are essential.
Ans.- (a) crop. (b) preparation (c) float (d) water and nutrients
2. Match items in column A with those in column B.
Ans.-
(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 wastes. |
3. Give two examples of each.
(a) Kharif crop (b) Rabi crop
Ans.- Kharif crops- Maize and Paddy, Rabi crops- Wheat and Pea
4. 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 the soil is the first step in agriculture. Preparation of the soil is done to loosen the soil, which is essential for the root penetration into the soil. This allows the roots to breathe easily. Loosening of the soil allows the growth of earthworms and microorganisms, which will help to keep the soil fertile by adding humus to the soil. Loosening of soil also brings nutrient-rich soil to the top layer, which is essential for the growth of plants.
b) Sowing is an important process in crop production. First, healthy seeds are selected before sowing. After selecting healthy seeds sowing is done by either traditional methods or by using equipment’s seed drill.
c) Removal of unnecessary plants from the field is called weeding. Weeds compete with crop plants for nutrients and water. This will reduce the yield of the desired crops. Weeds also interfere while harvesting and gets mixed with crops. Some weeds are poisonous to animals and humans. Tilling is a common method which helps removal of weeds before sowing crops, manual methods like physical removal of plants are used to remove weeds. Weedicides are sprayed to get rid of weeds, but this method may affect the health of farmers because of chemicals used as weedicides.
d) Process of separating the chaff from the crop is known as threshing. Threshing is carried by a machine called ‘combine’ which is a harvester as well as a thresher. Threshing is also done by winnowing where to blow of wind is used to separate the chaff from crops.
5. Explain how fertilizers are different from manure.
Ans.-
Fertilizer | Manure |
Fertilizer is a man-made inorganic salt. | Manure is a natural substance obtained by the decomposition of cattle dung and plant residues. |
Fertilizer is prepare in factors. | Manure provides a lot of humus to the soil. |
Fertilizer does not provide any humus to the soil. | Manure provides a lot of humus to the soil. |
Fertilizers are very rich in plant nutrients like nitrogen, phosphorus and potassium. | Manure is relatively less rich in plant nutrients. |
6. What is irrigation? Describe two methods of irrigation which conserve water.
Ans.-
ü Traditional Methods - Ones that use cattle and human labor: They are cheaper but less efficient. These include- pully system, chain pump etc. To lift water, pumps can be powered by - diesel, biogas, electricity, and solar energy.
ü Modern Methods - They are best for saving water.
ü Two main irrigation methods in use today are -
n Sprinkler System- It has perpendicular pipes, with rotating nozzles on top, joined to the main pipeline at regular intervals. Water flows through the main pipeline under pressure. it escapes from rotating nozzles and sprinkles on the crop like rain. This method is best for places where land is uneven and sufficient water is not available.
n Drip System- Mostly best for places where availability of water is poor. water falls drop-by-drop directly near the roots of the crop. there is no wastage of water at all. often used in fruit plants, gardens, and trees.
7. If wheat is sown in the Kharif season, what would happen? Discuss.
Ans.- Wheat crops may get destroyed if sown in Kharif season because of unfavorable temperature, pests and adaptable conditions for the plants to grow.
8. Explain how soil gets affected by the continuous plantation of crops in a field.
Ans.- Plants require nutrients for their growth. Without optimum nutrients plants will die. Continuous plantation of crops results in depletion of certain nutrients like Nitrogen, Phosphorus, Potassium etc. This results in the decrease of yield due to loss of nutrients hence there should be a gap between crops in order to get a good yield.
9. What are weeds? How can we control them?
Ans.- Weeds are the unwanted plants that grow along with the crops. Its removal is a must for the better growth of the crops. These can be controlled by spraying certain chemicals, called weedicides. For example 2, 4-dichlorophenoxyacetic acid and metolachlor.
10. Arrange the following boxes in proper order to make a flow chart of sugarcane crop production.
Ans.-
11. Complete the following word puzzle with the help of clues given below.
Ans.-
Junior Science Topic - Crop Production And Management. Chapter notes, video lectures, power point presentation and NCERT exercise solution. (Class 8, CBSE syllabus, chapter 01)
By - EduPorm India - The Educational Platform
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