NCERT Exemplar for Class 8 Science Solutions Chapter 1 Crop Production and Management

Multiple Choice Questions

1. Which one of the following conditions is not essential to grow maize?

1. High temperature 

2. Humidity 

3. Low temperature

4. Rainfall

Ans: (c) Low Temperature

Explanation: The kharif crop is  produced at high temperatures.To grow maize low temperature is not necessarily required as it is a kharif crop. 

2. Propagation of ginger is generally done using

1. Seed 

2. Stem (rhizome) 

3. root

4. leaf

Ans: (b) Stem (rhizome) 

Explanation: Since the ginger is modified underground stem and it does not propagate by leaves, roots or seeds hence the propagation of ginger is done using stem (rhizome). 

3. Which of the following statements is not true for organic manure?

1. It enhances water holding capacity of soil. 

2. It has a balance of all plant nutrients.

3. It provides humus to soil. 

4. It improves texture of soil

Ans: (b) It has a balance of all plant nutrients.

Explanation: The organic manure keeps a balance in all plant nutrients. It can be produced from the decomposition of animal and plant wastes which are rich in organic nutrients. But this also depends on the soil quality whether the soil is deficient in nature or more nutrient. 

4. The term used for the process of separation of grains from chaff is

1. Sieving 

2. Threshing 

3. winnowing

4. hand picking

Ans: (b) Threshing

Explanation: Threshing is the term which is used for the process of separation of grains from chaff. This process takes place with the help of a machine known as Combine. The Combine helps to remove the inedible chaff and stores the edible grains. 

5. Read the statements given below.

(i) Seeds require moisture for germination.

(ii) Plants can absorb nutrients mostly in dissolved form.

(iii) Irrigation protects crops from both frost and hot air currents.

(iv) Irrigation improves soil texture.

Choose the combination of statements which indicate the need to irrigate crops.

1. i and ii 

2. i, ii, iii

3. i, ii, iii, iv 

4. i and iii

Ans: (a) i and ii 

Explanation: The seeds require moisture for the process of germination. Plants can largely absorb nutrients in soluble form. Irrigation is the process of providing water to plants. In the irrigation plants absorb the necessary nutrients in the dissolved form through their root hair. 

6. Which of the following tools would a farmer use to remove weeds from the field?

1. Hoe 

2. Plough

3. Axe

4. Cultivator

Ans: (a) Plough

Explanation: The tool which will help the farmers to remove weeds from the field is hoe. This toll has a sharp blade which is pulled by the animals in the field. 

7. Which of the following is not true for fertilizers?

1. They increase the yield.

2. Their excessive use disturbs the balance of nutrients in soil.

3. They are generally used in small quantities.

4. They are environment friendly.

Ans: (b) Their excessive use disturbs the balance of nutrients in soil.

Explanation: The fertilizers are not friendly to the environmental conditions. This plays a role in decreasing the fertility of soil. This also pollutes the water and soil due to their harmful chemicals. Using fertilizers also damages human health. 

8. Given below are statements about the harmful effects of weeds on crop plants.

(i) They interfere in harvesting.

(ii) They help crop plants to grow healthily.

(iii) They compete with crop plants for water, nutrients, space and light.

(iv) They affect plant growth.

Choose the correct combination of statements.

1. i, iii, iv 

2. iii only

3. iii, iv

4. i, ii, iii, iv

Ans: (a) i, iii, iv

Explanation: The weeds interfere in the process of harvesting. The weed often grows with the crops and helps to reduce the effect of sunlight but also is an important nutrient from reaching to the roots and stems of the crop which results in a bad crop. 

9. The process of loosening and turning of soil is called

1. Irrigation and manuring 

2. Digging and winnowing 

3. tilling and ploughing

4. harvesting and storage

Ans: (c) tilling and ploughing

Explanation: The process of loosening and turning of soil is known as the tilling and ploughing. It takes place by a tool which is generally made with wood and iron. 

10. The monsoon season in our country is during the months

1. April to December 

2. June to September

3. November to March

4. January to May

Ans: (b) June to September

Explanation: The monsoon season in our country is from the month November to the month March. 

11. The system of irrigation where in water is supplied drop by drop near the roots of plants, is called

1. Pulley system 

2. Drip system

3. sprinkler system

4. lever system

Ans: (b) Drip System

Explanation: The drip irrigation system is a type of irrigation in which water is delivered drop by drop near the roots of plants. This technology is employed in irrigation because it conserves water. Drop by drop, water slows towards the root and stem of the crop in the drip system, promoting its growth. It is very effective but yes more time consuming. 

VERY SHORT ANSWER QUESTIONS 

12. Pick out the odd one from the following words given in the box and give reason for it. Give a reason for it.  Plough, Seed Drill, Hoe, Chain Pump, Sickle 

Ans: From the above given tools the seed drill is the odd one out. This is a modern tool which is used for the process of cultivation.  The other tools in the above mentioned list are very traditional and the old methods which are used for the cultivation process. The seed drill is used to sow seed on the same distance and to properly cover it with the soil. The plough is used for the process of tilling, hoe and sickle used for the removal of the weeds, the chain pump is used for the irrigation process of the crops. 

13. If you are given a dry piece of land for cultivation what will you do before sowing the seeds? 

Ans: Before sowing the seeds in a field there are many aspects which can be done which are as follows- 

(i) If the field is dry for irrigation water it. 

(ii) After the watering step, prepare it according to the crop which is going to sow. 

(iii) Properly till it so that the microbes can absorb the necessary moisture and nutrients from the soil. 

14. State whether the following statements are true or false. Correct the false statements. 

(i) Using good quality seed is the only criterion to get high yield. 

Ans: Using good quality seed is the only criterion to get high yield. This statement is false. 

Correct statement: Apart from the good quality seeds one is needed to do a proper agricultural practice also. 

(ii) Growing different crops in different seasons in the same field will deplete the soil of nutrients. 

Ans: Growing different crops in different seasons in the same field will deplete the soil of nutrients. This statement is false. 

Correct statement: By growing different crops in the same field helps to improve the fertility rate of the field. 

(iii) All crop plants are sown as seeds in the field.

Ans: All crop plants are sown as seeds in the field. This statement is true.

(iv) Cells of root nodules of leguminous plants fix nitrogen. 

Ans: Cells of root nodules of leguminous plants fix nitrogen. This statement is false.

Correct statement: A bacteria named rhizobium helps in the fixation of nitrogen. 

(v) Freshly harvested grains must be dried before storing.

Ans: Freshly harvested grains must be dried before storing. This statement is true. 

15. During which months do farmers grow mustard in India? 

Ans: During the month of October and March the farmers grow mustard in India. The mustard is a Rabi crop which farmers start sowing in the beginning of the winter season that is the month of October and November as they need low temperatures. The mustard is harvested in the months of April and May.  

16. Which activity of the farmer can promote growth of earthworms and microbes in the field? 

Ans: Ploughing the soil could aid a farmer in increasing the quantity of earthworms and bacteria in his or her field. The ploughing creates space in soil which leads in aeration and the loose soil helps in the growth of earthworms and microbes.

SHORT ANSWER QUESTIONS 

17. Beera wants to practice crop rotation in his field. Suggest a Rabi crop and a Kharif crop which will replenish his field with nitrogen. Which crop replenishes nitrogen and why? 

Ans: The examples of Rabi crops are pea, wheat, mustard whereas the example of kharif crop is paddy, maize, soyabean. These crops are grown in different temperatures in different seasons, so the rotation of the crops is really very easy. 

18. Match the agricultural implements given in Column A with their use given in Column B.

(i)___; (ii)___; (iii)___; (iv)___ 

Ans: The correct matching is as follows:

19. What are organic foods? 

Ans: The crops which are cultivated without using any of the harmful chemicals, fertilizers, and pesticides and which don’t affect humans or any animals are known as organic foods. These crops can be cultivated by using traditional fertilizers. 

20. From the word puzzle given as Fig. 1.1 Find at least eight words which are ‘farmer’s friends.’ Classify them into living and non living.

Ans:

21. (a) Name the tool used with a tractor for sowing seeds in a field. 

Ans: The Seed Drill is a tool that is used with a tractor. It's used to spread seeds at a uniform spacing. It plants the seeds in the ground and then covers them with dirt. This process is the manual process. 

(b) What are the advantages of using this tool? 

Ans: The advantages of seed drill are as follows- 

It helps to avoid the overcrowding of the seed by sowing it in an equal distance. 

It covers the seed with soil after sowing it due to which the birds and insects cannot eat it. 

It is a fast process and takes less time and labor. 

It helps to increase the yield of the crops by almost nine times. 

22. (a) Name the practice followed for large scale rearing of farm animals. 

Ans: The domestication process of animals and their rearing is called animal husbandry. This process is used to increase the livestock of the pigs, buffalos, horses etc. This practice needs good care and very fine livestock management. 

(b) What facilities are provided to farm animals? 

Ans:  Following are the facilities that are being provided to the animals- 

(i) The water and food. 

(ii) The appropriate shelter facilities for them. 

(iii) The medical Facilities for them. 

(iv)  The good hygienic practices. 

23. Classify the following crops into Kharif and Rabi crops and write in the tabular column given below:

(Maize, paddy, mustard, pea, gram, wheat, groundnut, cotton)

Ans:

LONG ANSWER QUESTIONS 

24. Despite the favorable climatic conditions, a farmer’s crop failed to give good yield. Give the possible reasons for this. 

Ans: The following issues could be possible for the farmer’s failed crop:- 

1. The crop selection wasn't made properly. 

2. The farmer used a bad quality seed. 

3. The weeds of the field were not removed. 

4. There was no proper irrigation of the field. 

25. As a part of eco-club activity students were asked to raise a kitchen garden in the school premises. They were provided with some materials given in the box. List the other materials you would require. How will you plan the garden? Write the steps. 

khurpi, water-can, spade, shovel 

Ans: The materials which are required for a garden are plants from the nursery, seeds, seeding of vegetables, water, and soil. 

The following are the steps required- 

(i) To collect the kitchen waste and make compost from it by cutting it into smaller pieces. 

(ii) A portion of land will be identified with proper sunlight. 

(iii) To dig the soil and level it properly. 

(iv) To sow the seeds into the soil and it should be placed unequal. 

(v) After the sowing process, apply the compost so that no insect can harm the seed. 

(vi) By some intervals, remove the weeds from the field. 

26. Paddy is a major cereal crop in our country. 

a. In which season is paddy cultivated? 

Ans: The paddy is a kharif crop and it is cultivated during the rainy season. 

b. Discuss the methods of sowing. 

Ans: Method: First the seeds of the paddy are grown in a nursery and when they are grown up for sowing, these are taken to the field and planted. Only the healthy seed plants are planted in the field. The damaged and weak plants are useless for the sowing. 

c. What measures must be taken to prevent spoilage and insect attack of harvested grains. 

Ans: The measures which are to be taken to prevent spoilage and insect attack of the harvested grains are as followed- 

To expose them in sunlight by which the moisture is removed from the freshly harvested crops. 

The dried neem leaves are applied on the crops to prevent it from the insects. 

The chemicals and insecticides are also applied. 

The fumigation process is applied to clear the insects.

27. Unscramble the words related to crop production and its management and write in the boxes given beneath them. 

Now, using the circled letters, form one word which is an activity carried out in fields, after maturation of crops. 

Ans:

(i)

(ii)

(iii)

(iv)

28. Below is a conversation between two farmers Heera and Beera. 

Heera : Brother Beera, your maize crops look beautiful! They 

have grown pretty fast. 

Beera : Yes, I have sprayed urea this time. What about you? 

Heera : Well, I am still relying on good old cow dung. I am saving money for buying a tractor. 

Beera : That’s good. Tractor saves a lot of time and labor. 

Heera : Yes, it’s been very labor intensive for me and now these weeds have come up. 

Beera : Try weedicides, they are very effective. 

Now answer the following questions. 

(i) List the practices which are not environment friendly and why? 

Ans: The practices which are not environment friendly and are dangerous in the field are pesticides, fertilizers, weedicides and many other chemical substances. 

(ii) What is the advantage of modern agriculture over traditional ones? 

Ans: By comparing the traditional equipment to the modern equipment the modern equipment is more reliable and user friendly. It requires less time and effort.

(iii) Name one weedicide and the precautions farmers must take during its application. 

Ans: One of the weedicides is 2,4-D. Precautionary in order to avoid inhaling of this chemical while spraying it in the field the farmers should cover their nose and mouth properly. 

29. For discussion 

Despite being one of the growing economies, our country still has a large section of population going hungry and malnourished. Do you think an efficient crop production mechanism is the only solution to this? Discuss in the class what else needs to be done to root out hunger and malnutrition from our country. 

Ans: For a long time agriculture has been the main source of income in India. For many decades, India was an agrarian economy. Apart from this, India has a large number of agricultural consumers. Because of a very high population it becomes necessary for a country like India to maintain the agriculture sector and to work for its benefits. 

The below mentioned methods can be useful for India to make it a vast agrarian country and to reduce its malnutrition- 

1. For the process of breeding and seeding, we should select a high quality seed. This will result in the increase of the crop level and also the crops will produce health. This will be useful for the farmers as well as for the people. 

2. The management and collection of the crops should be done with a very careful manner. 

3. For everyone the crop should be made available. There should not be a discrimininsation by the government between and poor. 

4. The information regarding the better production of the crops and its care should be made available on multiple platforms such as the television and radio. This can be helpful for farmers to understand the variety of crops and its farming. 

30. Terms related to agricultural practice are given below. Rearrange them in the correct sequence. 

harvesting, sowing, manuring, tilling and ploughing, irrigation, de–weeding. 

Ans: The correct arrangement for the given sequence is as follows- 

Tilling and ploughing > Sowing > Manuring > Irrigation > Weeding > Harvesting.

Crop Production and Management

A crop is a group of plants of the same type that are planted and farmed to provide food. This is carried out on a vast tract of arable land. There are many varieties of crops available. The many sorts of crops are as follows:

Rabi Crops: These crops are cultivated from October to March, throughout the winter season.

Kharif Crops: These crops are cultivated from July to October, during the rainy season.

Ploughing and Tilling

It's a process used to loosen and turn the soil. The plough is used in this process.

Plough

• A plough is a device used by farmers for various tasks such as fertilizer application, tilling, and soil loosening.

• It may also be used to apply nutrients to the soil, remove weeds, scrape the dirt, and so forth.

• The triangular iron strip is the ploughshare.

• The essential portion is the ploughshaft, which is fashioned out of a log of wood.

• The shaft has a handle on the opposite end.

• The other end is connected to a beam that is put around the necks of the bulls.

• A pair of oxen and a man may pull a wooden, traditional plough.

• These wooden ploughs have now been replaced with iron ploughs.

Hoe

A hoe is a tool used to dig up the soil and loosen it before planting a sapling to eliminate weeds and loosen the soil.

Cultivator

•  A cultivator is a tool that is mounted to a tractor and aids in soil loosening.

• Although cultivators are quicker than ploughs, they are utilized instead.

Sowing

Sowing is the act of putting seeds into the ground. During this agricultural procedure, adequate care should be followed, such as maintaining the right depth, maintaining the proper distance, and ensuring that the soil is clean, healthy, and free of illness and other pathogens, such as fungus. All of these measures are important for the process of seed germination, which converts seeds into new plants.

Methods Of Sowing

1. Traditional Method

2. Broadcasting

3. Dibbling

4. Drilling

5. Seed dropping behind the plough

6. Transplanting 

7. Hill Dropping

8. Check Row Planting

Quality of seed

• In terms of crop production, seed quality plays a significant role.

• Putting healthy seeds in water is a fantastic way to choose them.

• The hollow seeds of the dead and damaged seeds float on water, but the healthy seeds sink.

Traditional Tools

• Farmers employed traditional implements before the invention of modern agricultural gear.

• Ploughs, shovels, scythes, and pickaxes are examples.

• A funnel-like apparatus was used for sowing the seeds in the past.

• After seeds were placed in this funnel, they were funneled into 2-3 tubes with sharp edges.

• The seeds will be placed in the soil by piercing the ends into the soil.

Seeds Drill

Seed drills are used in conjunction with tractors to plant seeds.

It guarantees that seeds are sown evenly and at a specific depth and covered with soil after planting.

Nursery

• A nursery is a location where young plants and trees are raised before being planted elsewhere.

• The nursery serves as a storage facility for saplings.

Germination

• When a seed is planted in the ground and watered, it will germinate.

• From the seed, a plant emerges and begins to develop.

Manure

The decomposition of dead plants and animals produces manure. They primarily serve as a source of nutrition for the crops. They assist in proper agricultural cultivation. The addition of manure to the soil allows it to store more water. Acids in organic manures break down nutrients in the soil and make them accessible to plants.

Advantages of Manure

• It improves the soil's water-holding capacity.

• It makes the soil porous and allows gases to flow freely.

• The soil improves in texture.

• In the soil, the number of bacteria grows.

Fertilizer

A fertilizer is a chemical product that includes essential elements like nitrogen, potassium, and phosphorus to make soil fruitful. Fertilizers such as urea, potash, and ammonium sulphate are common.

Advantages of Fertilizer

• They are easily transportable and portable.

• Plants quickly absorb fertilizers.

• Many crops, such as wheat, maize, and rice, benefit from fertilizers, boosting and raising their yield.

Disadvantages of using Fertilizer

• An excessive amount of fertilizer can pollute the environment.

• In rare situations, it can also modify the pH of the soil.

Leaving the Land Fallow

• When land is kept fallow for a long boosting and raising time, the nutrients are replenished by the land itself.

• This area can once again be used for agriculture.

Crop Rotation

Crop rotation guarantees that the same crop does not grow indefinitely, preventing soil fertility degradation. One can restore soil fertility by cultivating crops that require various sets of nutrients.

Harvesting

Harvesting refers to the act of cutting the crop once it has reached maturity.

Method of Harvesting

There are two techniques for harvesting.

• The manual approach, which employs the use of a sickle, is the first.

• The mechanical approach, which employs a massive machine known as a harvester, is the second.

Threshing

• The process of threshing separates the grains from the chaff.

• While it may be done manually, a machine that separates all grain seeds is now employed.

Winnowing

• The method of winnowing involves employing the wind to separate grain seeds from the chaff.

• The lighter chaff flies away in the wind while the heavier grains fall to the ground.