8th food production and management (Living Science) solution Download Files 8th food production and management (Cordova Mastering science-8 ) solution Download File
Short Answer Type-I Questions: 1. What is meant by agricultural implements? Ans: Agricultural implements are any kind of machinery or tools used on a farm to help with farming. The best-known example of this kind is the tractor. 2. How do leguminous plants help in maintaining the soil fertility? Ans: Rhizobium bacteria present in the root of legurninous plants convert the atmospheric nitrogen into ammonia into soil, which is used by plants. 3. What is pisciculture? Ans: Rearing of fish is called pisciculture. 4. Why is it important to sow seeds at a correct distance from each other? Ans: Seeds should be shown at a correct distance from each other so that seed get sufficient sunlight, nutrients and water from the soil. 5. Give two precautions that must be taken while sowing seeds. Ans: seeds should be shown with right spacing and at right depth 6. How does winnowing help in separation of grains from husk? Ans: When mixture of grain and chaff dropped on the ground from a height, The heavier seeds fall on the ground where as the lighter chaff gets blown away by the wind and fall at a distance. 7. Why is the spraying of pesticides harmful to us? Ans: The spraying of pesticides cause irritation to skin and respiratory problems. They get mixed with soil and water and absorbed by plants. These then enter our bodies through fruits and vegetables which we eat and cause us harm.. F. Short Answer Type-II Questions: 1. (a) Why is irrigation necessary? (b) Why is the drip system of irrigation a water-economical method? Ans: Rain varies and doesnot always supply the right amount of water at right time. Therefore it is important to supply water regularly to the crops. 2. Define fertilisers. Name any four fertilisers. Ans: Chemical substance that contain one or more nutrients essential for plants eg Urea., Calcium Nitrate, Ammonium Sulfate, Super Phosphate 3. The farmers of a village are celebrating the harvest festival of Baisakhi along with their families. They are dancing and singing traditional songs. (a) What is harvesting? Why do farmers celebrate Baisakhi? (b) What do we learn from celebrating festivals? Ans: (a) Cutting and gathering of mature crops is called harvesting. (b) Farmers celebrate Baisakhi to express gratitude to the Almighty for the bountiful harvest and pray for prosperity and good times in future G. Long Answer Questions: 1. (a) What are weedicides? (b) Name one weedicide. (c) What are the harmful effects of weeds in the crop field? Ans: Weedicides are chemicals that kill weeds (b) 2, 4-D and MCPA or Butachlor (c) Weeds compete with the crop for water mineral and sunlight and therefore reduce crop yield. 2.(a) Differentiate between manure and fertilizers. (b) What are the advantages of using manure? Ans: (a) Answer: Fertiliser A fertiliser is an inorganic salt. A fertiliser is prepared in factories. A fertiliser does not provide any humus to the soil. Fertilisers are very rich in plant nutrients like N,P,K Manure Manure is a natural organic substance Manure can be prepared in the fields. Manure provides a lot of humus to the soil. Manure is relatively less rich in plant nutrients. (b) Organic manure is considered to be better than fertilizers. It is because of the following reasons to be (a) It enhances the water holding capacity of the soil. (b) It makes the soil porous, thus making the exchange of gases easy. (c) It also improves the texture of the soil. (d) It increases the number of friendly microbes. HOTs 1. Why do farmers level the field before sowing? Ans: For the uniform distribution of water and manure in a field, a farmer practices 2. During ploughing why is the land pressed lightly and not tightly? Ans: This is because loose soil allow root to breathe easily and allow root to penetrate deeper .Loose soil also help in the growth of earthworm and microbes that provide nutrients to soil.