CLASS 8

1 Exercises 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  _____________. (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 _____________ and _____________ from the soil  are essential. Answer 1:  (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.  A B (i) Kharif crops (a) Food for cattle (ii) Rabi crops (b) Urea and super phosphate (iii) Chemical fertilis...

Q. 1. Is it necessary to remove weeds from the field time to time? Give reason. Answer: Yes, it necessary to weed out unwanted plants time to time from crop field  because it competes for space, nutrients and sunlight. It decreases the crop yield. Q. 2. The government usually maintain a buffer stock of grains. Why Answer: The government maintains buffer food stock in silos to provide food grain in  case of food shortage due to disaster or natural calamity. Q. 3. Write the advantage of using a cultivator. Answer: Nowadays plowing on large scale is done by cultivator. A cultivator is a tractor￾driven machine. It cost effective and also saves time. The use of cultivator saves labour  and time. Q. 4. Organic foods are harmless. Do you agree? Answer: The food which is grown organically is harmless and healthier because  organic foods are grown without the use of chemical fertilizers and pesticides. Q. 5. Write the name of the equipment which is used to level the tilled la...

Q. 1. What do you understand by the term ‘winnowing’? Answer: Winnowing is a manual method of separating grains from the chaff (covering  of the seed) with the help of wind. Q. 2. The gain seeds are carried out from the chaff with the help of which  machine? Answer: Separation of grain from the chaff is threshing. Threshing is done with the help  of a machine called ‘combine’. This machine is actually a combination of a harvester  and a thresher. Q. 3. Name the government agency which buys food grains from farmers. Answer: Food Corporation of India (FCI) purchase food grain from farmers. Q. 4. Give the other name of milk yielding animals. Answer: The animals such as cow, buffalo, and goat give milk. Milk yielding animals  are called ‘milch animals’. Q. 5. Nutritive honey is obtained from which animal? Answer: Honey is obtained from the honeybee. A honeybee collects a sweet substance  called nectar from flowers to make honey.

Q. 1. In which season, the frequency of irrigation is required at a higher rate? Answer: Watering of crops at regular intervals is called irrigation. The time and  frequency of irrigation depend on types of crop, soil and season. In summer, the  frequency of watering is higher because in summer temperature is high due to which  the rate of evaporation of water from the soil and the leaves increases. Q. 2. Name some sources of irrigation. Answer: The sources of water for irrigation are wells, tube-wells, ponds, lakes, rivers, dams, and canals. Q. 3. In which method of irrigation, there is no wastage of water? Answer: One of the modern methods of irrigation is the Drip system. In this system, the  water falls drop by drop directly near the roots of the plants, hence water is not wasted  at all. Q. 4. Why are unwanted plants harmful? What are they called? Answer: Undesirable plants which grow naturally along with the crop are called weeds. The weeds are harmful bec...

Q. 1. Give the role of manure and fertiliser in the soil. Answer: Manures are substances added to the soil to add organic matter such as  carbon. Hence, manure enhances soil fertility which is dependent on the interaction of  various organisms and reactions. Fertilizers are chemical compounds. It provides  specific nutrient such as nitrogen (N), phosphorus (P) and potassium (K) to the soil.  Fertilizers increase crop production but it harmful for the soil and environment if it is  used continuously. Q. 2. The plants grow fastest if we add fertilisers in the soil, but if we add manure,  plants grow but at a slower rate. Give reason. Answer: Fertilizers are chemical compounds which provide immediate a particular  nutrient to plants and help them grow faster. Whereas manure is low in nutrient content  and it takes a longer time to release nutrients in the soil. As the result plants grow  slowly. But the use of manure improves soil textures, as w...

Q. 1. Name the machine used for sowing seeds. Answer: ‘Seed drill’ is a machine used to sow seeds. Seed drill is a funnel with a long  and hollow. The seeds are put into the funnel and the seeds go down in the soil one by  one. In the large farms mechanised drills attached to the tractors for sowing seeds. Q. 2. The damaged seeds float on the water surface. Give reason. Answer: Damaged seeds become hollow and lighter. Therefore they float on water. Q. 3. Give the meaning of the term ‘broadcasting’ with respect to agriculture. Answer: Broadcasting is a method of seed sowing. In this method, seeds are spread or  sprinkle in the crop field. Example of such crop is coriander. Q. 4. Name one plant of crop that is transplanted from nursery. Answer: Transplantation is a process in which seedlings are grown in a nursery and  then these are transferred to the main field. Examples are Paddy, tomato and chilly. Q. 5. Mention the advantages of transplantation of seedlings into m...

Q. 1. According to season, the crops are divided into how many cropping  patterns? Answer: Based on seasons there are two cropping patterns in India, Kharif and Rabi  crops. (a) Kharif crops are those that are sown in the months of June-July and harvested in  September-October every year. The Kharif crops also sometimes are also called as  ‘summer crops’. Examples of some of the Kharif crops are paddy, maize, sorghum,  sugarcane, and pearl millets. (b) Rabi crops are those that are sown in the months of October-November and  harvested in the month March-April. The Rabi crops also sometimes are also called as  ‘winter crops’. Examples are wheat, oat, barley and pulses, oil seeds. Q. 2. Levelling is done after ploughing. Why? Answer: After ploughing the soil, large lump of soil is left which needs to be levelled.  Levelling is done to ensure uniform distribution of water to every part of the crop field  during irrigation. Levelling helps in see...

Hots (Higher Order Thinking Skills) Q. 1. Why are earthworms considered a farmer’s friend? Ans. Earthworms are considered as a farmer’s friend as they turn and loosen the soil.  This allows the roots to breathe properly. They turn the organic matter in the soil into  humus. Q. 2. Why is it recommended to wash fruits and raw vegetables before eating  them? Ans. It is recommended to wash fruits and raw vegetables before eating them to wash  away harmful chemicals such as insecticides and pesticides which were sprayed while  growing them.

Long Answer Questions Q. 1. 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 [NCERT Exemplar] Ans. The following items are required—seeds and seedlings of vegetable plants from  nursery, kitchen waste, water. Steps for raising the garden: a. Kitchen waste will be collected and composed in a pit. b. A patch of land will be identified for the garden. c. Soil will be dug up and levelled with the help of a spade. d. Sowing of seeds/transplanting of seedlings. Select seeds/seedlings as per the  season. e. Water the plants regularly with a water can. f. Compost will be applied. g. Weeds will be removed periodically with the help of Khurpi. Q. 2. Paddy is a major cereal crop in our country. (i) In which season is paddy cultivated? (ii) D...

Short Answer Questions Q. 1. 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? [NCERT Exemplar] Ans. Kharif: Rice or Soyabean Rabi: Pea or Wheat Pea/Soyabean are legumes that  will fix nitrogen with the help of Rhizobium. Q. 2. Answer the following questions. (i) Name the tool used with a tractor for sowing seeds in a field. (ii) What are the advantages of using this tool? [NCERT Exemplar] Ans. (i) Seed drill. (ii) The advantages are: • Seeds are sown at a uniform distance and depth to avoid overcrowding. • After sowing, seeds are covered by soil which prevent them from being eaten by  birds. • It saves time and labour. Q. 3. Answer the following questions. (i) Name the practice followed for large scale rearing of farm animals. (ii) What facilities are provided to farm animals? [NCERT Exemplar] Ans. (i) Animal husbandry. (ii) Animals are p...

Very Short Answer Questions Q. 1. If you are given a dry piece of land for cultivation what will you do before  sowing the seeds? [NCERT Exemplar] Ans: The field will be watered, tilled and ploughed before sowing seeds. Q. 2. During which months do farmers grow mustard in India? [NCERT Exemplar] Ans. October to March. Q. 3. Which activity of the farmer can promote growth of earthworms and  microbes in the field? [NCERT Exemplar] Ans. Loosening the soil/maintaining high moisture levels in soil. Q. 4. What are organic foods? [NCERT Exemplar] Ans. Crops cultivated without using any chemicals like fertilisers, pesticides,  weedicides, etc. are called organic foods. Q. 5. Why does a farmer rotate crops in a field? Ans. A farmer rotates crops as it maintains fertility of soil, gives better yields and  prevents crop diseases and pests. Q. 6. What do you mean by transplantation? Ans. The process of shifting seedlings from the nursery to the main field is called  transpl...

93. Question Name two crops which are cultivated: (a) by sowing seeds directly into ϐields. (b) by transplanting. Answer (a) Crops wheat and gram can be cultivated by sowing seeds directly into ϐields. (b) Paddy and tomatoes can be cultivated by transplanting. 94. Question Farmers in Northern India grow legumes as fodder in one season and wheat in the next season. (a) What is this practice known as ? (b) How does this practice help in the replenishment of soil? Answer (a) Crop rotation (b) The nitrogen-ϐixing bacteria present in root nodules of leguminous plants is rhizobium bacteria. Rotation of crops (leguminous and non￾leguminous crops) in the same ϐield replenishes the soil with nitrogen naturally and increases the soil fertility. 95. Question A student lists the following agricultural practices for crop production: Irrigation; Removal of weeds; Preparation of soil; Storage of food grains; Sowing; Adding manure and fertilizers Which agricultural practice is missing from the above l...

88. Question Which of the following system of irrigation is preferred for the uneven land? A. chain pump irrigation system B. drip irrigation system C. sprinkler irrigation system D. river irrigation system Answer Sprinkler system is more suitable for uneven land where sufϐicient water is not available. 89. Question The two crops which are not grown by sowing their seeds directly into the soil in large ϐields are: (A) Peas (B) Tomatoes (C) Chillies (D) Maize A. A and B B. B and C C. A and C D. only C Answer The two crops which are not grown by sowing their seeds directly into the soil in large ϐields are tomatoes and chillies. 90. Question The best Technique of Watering the fruit plants and Tree is: A. chain pump system B. sprinkler system C. moat (pulley system) D. drip system Answer In this system, there is a network of narrow pipes with small holes, in the ϐields. When water ϐlows through these pipes, water falls drop by drop just at the position of the roots. So, it is called drip ...

77. Question One of the following crop is not cultivated by sowing its seeds directly into soil. This one is: A. wheat B. gram (charm) C. paddy D. maize (makka) Answer The process of transferring the seedlings from the nursery to the main ϐield by hand is called transplanting or transplantation. Some crops like paddy and many vegetables, the seeds are not directly sown in the ϐield’s soil. 78. Question Tomatoes are cultivated by the practice called: A. transpiration B. translocation C. transportation D. transplantation Answer Paddy, tomatoes and chillies are grown by transplantation. 79. Question Which of the following cannot be provided to the soil by a chemical fertilizer? A. nitrogen B. humus C. potassium D. phosphorus Answer Nitrogen, phosphorus and potassium are chemical which can be provided to the soil by chemical substance called fertilizers whereas humus cannot. It is provided to the soil by natural substance called manure. 80. Question Which of the following is not grown by t...

70 A. Question What is irrigation? Why is irrigation necessary? Answer The supply of water to crops at right time is called irrigation. All the crop plants need water for their growth. Water is important for proper growth and development of ϐlowers, fruits and seeds of plants. Irrigation is necessary for the absorption of nutrients by plants from the soil. Water is absorbed by the plant roots. Along with water, minerals and fertilizers are also absorbed. Irrigation is necessary to provide moisture for gemination of seeds because germination of seeds does not take place under dry conditions. Irrigation is also necessary for healthy crop growth so as to get good yield. Nutrients dissolved in water get transported to each part of the plant. Water also protects the crop from both frost and hot air currents. 70 B. Question Name the various sources of irrigation in our country. Answer The various sources of irrigation in our country are- wells, tubewells, ponds, lakes, rivers, dams and canal...

58. Question What precaution should be taken while spraying weedicides ? Why Answer Weedicides affects the health of farmer. So, weedicides should be used vary carefully. During spraying of weedicides, the nose and mouth of farmer should be covered with a piece of cloth. 59. Question Give any four differences between manures and fertilizers. Answer Differences between manures and fertilizers: 60. Question Deϐine the terms: (i) harvesting, (ii) threshing, and (iii) winnowing. Answer (i) Harvesting: The cutting and gathering of mature food crop like wheat or paddy is known as harvesting. (ii) Threshing: The process of removal of the grains of harvested crop from the chaff is called threshing. (iii) Winnowing: The process in which grains are separated from chaff with the help of wind is called winnowing. 61 A. Question What are the two ways in which food grains are stored on a large scale? Answer Food grains are stored on a large scale in silos and granaries (gunny bags). 61 B. Question W...

51. Question State two beneϐicial effects of -ploughing the ϐields (or loosening and turning the soil). Answer Loosening and turning the soil is very important for cultivation of crops. The loosening and turning the soil by ploughing is beneϐicial because of the following reasons: (i) The loose soil allows the roots to breathe easily even when they go deep into the soil. (ii) The loosened soil helps in the growth of earthworms and microbes present in the soil. 52 A. Question State the function of Food Corporation of India. Answer The government agency like food corporation of India (FCI) buy food grains from farmers and storing them properly so that they can be supplied throughout the country. 52 B. Question What is done to protect tile grains stored in gunny bags in big go downs from damage ? Answer Pesticide solution are sprayed on the gunny bags in big go downs from time to time to protect the grains from damage. 53. Question Deϐine manure. What are the advantages of manure ? Answer...

44. Question What are the two types of crops based on seasons ? Give one e ample of each type. Answer Based on seasons, all crops are classiϐied into two main groups: (i) Kharif crops- The crops which are sown in the rainy season are called kharif crops. Example- paddy, maize. (ii) Rabi crops – The crops grown in winter season are called rabi crops. Examples- wheat, gram, etc. 45. Question Name the various agricultural practices in the right sequence in which they are undertaken by the farmers. Answer The various agricultural practices which they are undertaken by the farmers are: (i) Preparation of soil (ii) Sowing (iii) Adding manure and fertilisers (iv) Irrigation (v) Protecting from weeds (vi) Harvesting (vii) Storage 46. Question Describe brieϐly, how soil is prepared for sowing the seeds. Answer The preparation of soil is the ϐirst step before growing a crop. The soil is prepared for sowing the seeds of crop by ploughing, levelling and manuring. The process of loosening and turni...

40. Question How are weeds removed from the crop ϐields ? Name one implement used for weeding. Answer The removal of weeds from the crop ϐields is known as weeding. It is necessary process as weed competes with the crop plants for water, nutrients and space. Farmers adopt many ways to remove weeds and control their growth. The various ways by which weeds are removed from the crop ϐields are- (i) With hand – In this method, weeds are removed manually by uprooting or cutting them close to the ground. (ii) By using a khurpa – In this method, weeds can be removed by using a implement called khurpa. (iii) By using weedicides- Example- 2, 4-D 41. Question If wheat is sown in the kharif season, what would happen? Discuss. Answer If wheat is sown in the kharif season, it will not grow well as plants cannot tolerate too much water of the rainy season. 42. Question Which of the following are kharif crops and which are rabi crops ? Wheat, Paddy, Gram, Maize, Mustard, Cotion, Soyabean, Linseed, Pe...

37. Question Explain the drip system of irrigation. State two advantages of the drip system of irrigation. Answer In this system, there is a network of narrow pipes with small holes, in the ϐields. When water ϐlows through these pipes, water falls drop by drop just at the position of the roots. So, it is called drip system. Water is not wasted at all. It is the best technique for watering fruit plants, gardens and trees. Advantages: (i) Drip system is very useful in those regions where availability of water is poor. (ii) Drip system provides water to plants drop by drop. So, water is not wasted at all. 38. Question How do the irrigation requirements of a wheat crop differ from that of a paddy crop ? Answer Each crop needs a speciϐic amount of water during its various stages of its growth. The irrigation requirements depend on the nature of crop. Some crops like need more water whereas other crops require less water. For example, paddy crop requires continuous irrigation whereas wheat c...