Answers for NCERT Class VIII Chapter 1 – Crop Production and Management.

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Crop Production and Management Answers

Question 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 crop.

b) The first step before growing crops is preparation of the soil.

c) Damaged seeds would float on top of water.

d) For growing a crop, sufficient sunlight and water and nutrients from the soil are essential.

Question 2: Match items in column A with those in column B.

(i) Kharif crops     (e) Paddy and maize

(ii) Rabi crops       (d) Wheat, gram, pea

(iii) Chemical fertilisers   (b) Urea and super phosphate

(iv) Organic manure (c) Animal excreta, cow dung, urine and plant waste.

Question 3: Give two examples of each.

a) Kharif crop – Paddy, maize

(b) Rabi crop – Wheat, gram

Question 4: Write a paragraph in your own words on each of the following.

(a) Preparation of soil: It is the first step to be followed before growing a crop. The most important task is to loosening the soil, so that the roots penetrate deep into it. The loosening of the soil helps in the growth of several microbes, earthworms etc., which enrich the soil with humus and other essential nutrients, required for proper growth and functioning.

The process of loosening is called tilling or ploughing the soil. Tilling of soil brings the nutrient-rich soil to the top.

(b) Sowing: Sowing is another important step in crop production. It is the process of placing the seed in or on the soil for future growth. The seeds that are selected for growing should be of good quality. This will improve the net yield of the crop.

Sowing is usually done with the help of either a traditional tool or a seed drill. The traditional tool were shaped like a funnel.

Nowadays, seed drills that make the use of tractors are used for sowing seeds. This tool disperses seeds uniformly and sows seeds at proper depth. Sowing by this method saves time and also protects the seeds from birds.

(c)Weeding: Undesirable plants that grow along with the crop are known as weeds. Weeds compete with the crop for nutrients, light, and space which reduce productivity.

Weeding is the process of removing these weeds. Xanthium, Parthenium, etc. are some common weeds.

Some important weeding methods are:

(i) Weeds can be controlled using weedicides. It is a chemical, which is sprayed in the fields to kill all available weeds. Weedicides are not harmful to crops.

(ii) Tilling before sowing of crops also helps in removing weeds. Tilling uproots the weeds.

(iii) The manual method of removing weeds is with the help of a khurpi. It involves regular uprooting or cutting of weeds close to the ground.

(d)Threshing: Threshing is the process of separating grains or seeds from chaff. It is done after harvesting the crop. It is usually carried out with the help of a machine known as ‘Combine’. This machine is a combination of harvester and thresher. It harvests plants as well as cleans grains.

Question 5: Explain how fertilisers are different from manure.

Question 6: What is irrigation? Describe two methods of irrigation which conserve water.

Answer: The supply of water to crops at regular intervals is called irrigation. The time and frequency of irrigation varies from crop to crop, soil to soil and season to season.

Two methods of irrigation which help in conservation of water are:

a) Sprinkler system: This system is useful on uneven land. Perpendicular pipes, having rotating nozzles on top, are joined to the main pipeline at regular intervals. Water is allowed to flow under pressure so it escapes from the rotating nozzles and is sprinkled on the crop as if it is raining.

(ii) Drip system : Water falls drop by drop directly near the roots. It
is the best technique for watering fruit 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  and does not require too much water for its growth. If wheat is sown in kharif season, the crop may wilt as it cannot tolerate excess water.

Wheat crop requires cooler climate which is not available during kharif season. Also, the crop requires light of medium intensity which is not available during kharif season. As a result, the produce will decrease and the quality of grains will not be satisfactory. Therefore, wheat should not be sown in the kharif season.

Question 8: Explain how soil gets affected by the continuous plantation of crops in a field.

Answer: Continuous plantation of crops in a field makes the soil poor in certain nutrients such as nitrogen, phosphorus, potassium, etc. Plants require nutrients for their proper growth and functioning. When a farmer continues to grow crops one after the other, then all nutrients available in the soil reduce and the crop yield decreases.

Question 9: What are weeds? How can we control them?

Answer:

Undesirable plants that grow along with the crop are known as weeds. Weeds compete with the crop for nutrients, light, and space which reduce productivity.

Weeding is the process of removing these weeds. Xanthium, Parthenium, etc. are some common weeds.

Some important weeding methods are:

(i) Weeds can be controlled using weedicides. It is a chemical, which is sprayed in the fields to kill all available weeds. Weedicides are not harmful to crops.

(ii) Tilling before sowing of crops also helps in removing weeds. Tilling uproots the weeds.

(iii) The manual method of removing weeds is with the help of a khurpi. It involves regular uprooting or cutting of weeds close to the ground.