Students can Download Science Term 3 Chapter 7 Crop Production and Management Questions and Answers, Notes Pdf, Samacheer Kalvi 8th Science Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 8th Science Solutions Term 3 Chapter 7 Crop Production and Management

Samacheer Kalvi 8th Science Crop Production and Management Text Book Exercise

I. Choose the best answer:

8th Science Crop Production And Management Question 1.
The process of placing seeds in the soil is called as ………………..
(a) ploughing
(b) sowing
(c) crop production
(d) crop rotation
Answer:
(b) sowing

8th Standard Science Crop Production And Management Question 2.
Organism that control insects and pests of plant crops is …………………
(a) bio-pesticides
(b) bio-fertilizers
(c) earthworms
(d) neem leaves
Answer:
(a) bio-pesticides

8th Crop Production And Management Question 3.
The method in which water flows over the soil surface and allow it to infiltrate is ………………..
(a) irrigation
(b) surface irrigation
(c) springier irrigation
(d) drip irrigation
Answer:
(b) surface irrigation

Crop Production And Management Class 8 Question 4.
Effective microorganisms preparation is not used in ………………..
(a) seed treatment
(b) foliar spray
(c) soil treatment
(d) bio-predators
Answer:
(a) seed treatment

8th Standard Crop Production And Management Question 5.
Which of the following is not present in Panchakavya?
(a) cow dung
(b) cow’s urine
(c) curd
(d) sugar
Answer:
(d) sugar

II. Fill in the blanks:

  1. The process of actively growing seedling from one place and planting in the main field for further growth is called ………….
  2. …………. is a plant growing where it is not wanted.
  3. The chemicals used for killing the weeds or inhibiting their growth are called as ………….
  4. …………. seed transfer its unique characteristics to the descents.
  5. …………. centers serve as the ultimate link between ICAR and farmers.
  6. Several popular high yielding varieties of major crops have been developed by ………….

Answer:

  1. Transplantation
  2. Weed
  3. herbicides
  4. Heirloom seeds
  5. Krishi Vigyon Kendra
  6. IARi (Indian Agricultural Research Institute)

III. Match the following:

  1. Bio-pesticide – (a) Neem Leaves
  2. Bio-predators – (b) Bacillus thuringiensis
  3. Bio-fertilizer – (c) Control white flies
  4. Bio-indicators – (d) Improve soil fertility
  5. Bio-repellants – (e) Quality of environment

Answer:

  1. b
  2. c
  3. d
  4. e
  5. a

IV. Answer briefly:

Crop Production And Management Answers Question 1.
Define ploughing.
Answer:
Ploughing or tilling is the process of loosening and turning the soil up and down to facilitate the availability of nutrients in the root zone of that cultivating crop.

Samacheer Kalvi 8th Science Guide Question 2.
Name the methods of sowing.
Answer:
The different methods of sowing are

  1. Sowing by hand
  2. Seed drill
  3. Dibbling

Samacheer Kalvi Guru 8th Science Question 3.
What is foliar spray?
Answer:

  1. Foliar feeding is a technique of feeding plants by applying liquid fertilizer directly to their leaves.
  2. Plants are able to absorb essential elements through the stomata in their leaves. Give a brief account on Krishi Vigyon Kendra.

Samacheer Kalvi Guru 8th Question 4.
Give a brief account on Krishi Vigyon Kendra.
Answer:

  1. Krishi Vigyon Kendra is a farm science centre.
  2. This centre serve as a ultimate link between ICAR and farmers.
  3. They operate small farms to test new technologies.
  4. They also provide advice to farmers about weather and pricing of crops.

Samacheer Kalvi Guru 8 Science Question 5.
What is bio-indicator? How does it help human beings?
Answer:

  1. A bio-indicator or biological indicator is any species or group of species whose function or status reveals the qualitative status of the environment.
  2. Biological indicators are used to document and understand changes in Earth’s living systems especially changes caused by the activities of an expanding human population.

Question 6.
What do you mean by weeding?
Answer:
The undesirable plants growing naturally with crop plants are called weeds. The removal of weeds is called weeding.

Question 7.
What is crop rotation?
Answer:
Crop rotation is planting a series of different crops in the same field following a defined order. This helps to maintain fertility of the soil.

Question 8.
What is green manure?
Answer:

  1. Some plants like Sun hemp or guar are grown in the field prior to the sowing of the crop seeds.
  2. These plants gradually decompose and turn into green manure which helps in ensuring the soil in nitrogen and phosphorous.
  3. Application of green manure always enhance the growth and yield of the crops.

V. Answer in detail:

Question 1.
Explain the agricultural practices.
Answer:
8th Science Crop Production And Management Samacheer Kalvi Solutions Term 3 Chapter 7

1. Soil preparation: (LoosenIng of top soil)

  • Ploughing – Process of loosening and turning the soil up and down to facilitate nutrient availability.
  • levelling – Done with leveller and helps in uniform distribution of water for irrigation
  • Basal Nianuring – Increase soil fertility by manuring

2. Sowing of seeds:

  • Hand – Scattering of seeds by hand.
  • Seed Drill – Sowing seeds by iron drills attached to a tractor.
  • Dibbling – Placing seed in furrow or pits or hole by hand.

3. Adding manure and fertilisers:

  • Manure is a substance added to the soil in the form of Nutrients to enhance plant growth.
  • Organic Sources – Plant and animal waste
  • Synthetic Sources – Urea, Super phosphate.

4. Irrigation:
Supply of water to crops:

  • Traditional method – Irrigation done manually.
  • Modem method – Involve two systems. Sprinkler system Drip system

5. Harvesting of crops:

  • Manual harvesting – Harvested without tools. Eg – Groundnut crop, green gram, black gram, house gram.
  • Mechanical method – Harvesting by instruments small sized farms Eg – Sickle.
  • Machine harvesting – Used for large sized farms.

6. Threshing and Winnowing:
Process of separating the grains from their chaffs or pods.

7. Storage:

  • Supply of the produce has to be stored properly.
  • Grains must be free from moisture to avoid growth of microorganism.
  • Need to be dried in Sun before storing.
  • Collected in Gunny bags and stored in go downs.

Question 2.
Give a detailed account on irrigation.
Answer:
Irrigation:

  1. The supply of water to crops at regular intervals is called irrigation.
  2. Source of irrigation – Wells, tube wells, ponds, lakes, rivers, dams and canal.

8th Standard Science Crop Production And Management Samacheer Kalvi Solutions Term 3 Chapter 7

Traditional Methods:

  1. Irrigation is done manually.
  2. Here, a farmer pulls out water from wells or canals by himself or using cattle and carries to farming fields.
  3. Pumps used for lifting water from various sources.
  4. Diesel, biogas, electricity and solar energy are the sources of energy needed to run these pumps.

Modern Methods:

  1. It helps to overcome the problems exist in the traditional methods.
  2. It also facilitates the even distribution of moisture in the field.

Sprinkler system:

  1. Sprinkles water over the crop and helps in an even distribution of water.
  2. This method is advisable in areas facing water scarcity.
  3. Pump is connected to pipes which generate pressure and water is sprinkled through the fine nozzles of pipes.

Drip System:

  1. Here, water is released drop by drop exactly at root zone using a hose or pipe.
  2. This method is effective one in regions where the availability of water is less.

Question 3.
What is weed? Explain the different methods of weed control.
Answer:
8th Crop Production And Management Samacheer Kalvi Science Solutions Term 3 Chapter 7

Weed:
The undesirable plants may grow naturally along with the main crop, and these undesirable plants are called weeds.

Weeding:
The removal of weeds is called weeding. It is an important process because weeds compete with the crop plants for the nutrients, sunlight, water, space and other resources. It results in the undernourishment of crops and it leads to low yield.

Mechanical methods:

  1. Here, weeds are destroyed physically.
  2. Hand pulling or weeding with the help of weeding hole is the oldest and most efficient method for controlling weeds.

Tillage methods:

  1. It is the practical methods of destroying weeds of all categories.
  2. Weeds are buried in the soil and also exposed to Sun heat by deep ploughing.

Crop Rotation:
Proper rotation of crops is followed for controlling crop associated and parasitic weeds.

Summer tillage:
Deep ploughing after harvest of Rabi crop and exposing underground parts of weeds to strong sunlight during summer months is useful for destroying many annual and perennial weeds.

Biological weed control:

  1. Bio agents like insects and pathogens are used to control weeds.
  2. The objectives are not eradication, but reduction and regulation of the weed population.

Chemical methods:

  1. Very effective in certain cases and have great scope in weed control.
  2. The chemicals used for killing the weeds or inhibiting their growth are called herbicides.
  3. Chemicals are mixed with water and sprayed over the crops.

Integrated weed management:

  1. Integrated weed management combines different agronomic practices and herbicides use to manage weeds, so that the reliance on any one weed control technique is reduced.
  2. Mechanical, biological, cultural and chemical methods are included in integrated weed managements.

Samacheer Kalvi 8th Science Crop Production and Management Additional Questions

I. Choose the correct answer:

Question 1.
…………… is a ornamental crop.
(a) Hemp
(b) Euphorbia
(c) Sorghum
(d) sesame
Answer:
(b) Euphorbia

Question 2.
Lichen is a ……………
(a) Bio-pesticide
(b) Bio-indicator
(c) Bio-predator
(d) Bio-fervilizer
Answer:
(b) Bio-indicator

Question 3.
…………… is a bio predator.
(a) Trichoderma
(b) Aphids
(C) Chrysopa spp
(d) Earthworm
Answer:
(c) Chrysopa spp

Question 4.
Neem is a good ……………
(a) Bio-fertilizer
(b) green manure
(c) insect repellant
(d) Bio predator
Answer:
(c) insect repellant

Question 5.
Royal Botanical garden is located in ……………
(a) Chennai
(b) Mumbai
(c) New Delhi is a method of
(d) Kolkatta
Answer:
(d) Kolkatta

Question 6.
…………… is a method of sowing seeds.
(a) Tillage
(b) Winnowing
(c) Weeding
(d) Dibbling
Answer:
(d) Dibbling

II. Fill in the blanks:

  1. Crops sown in rainy season are called ……………
  2. The summer crops are also called …………… crops.
  3. …………… is an example of Rabi crop.
  4. India is the largest producer of …………… in the world.
  5. …………… is a fodder crop.
  6. Placing a seed in a pit or furrow is called ……………
  7. The process of separating the grains from their chaffs is called ……………
  8. Heirloom seeds are also called …………… seeds.
  9. …………… is commonly called Pusa institute.
  10. The first KVK was established in 1974 in ……………
  11. Vermiwash is used as a …………… for crops.
  12. …………… can be used for seed treatment.
  13. …………… is the main source of bio-fertilizer.

Answer:

  1. Kharif
  2. zaid
  3. Wheat
  4. Banana/ Mangoes
  5. Sorghum
  6. Dibbling
  7. Threshing
  8. Organic
  9. IARI
  10. Pondicherry
  11. foliar spray
  12. Pachgavya
  13. Cyanobacteria

III. Match the following:

Question 1.

  1. Paddy – (a) Fodder
  2. Muskmelon – (b) Oil crop
  3. Millet – (c) Zaid crop
  4. Sesame – (d) Food crop

Answer:

  1. d
  2. c
  3. a
  4. b

Question 2.

  1. Nostoc – (a) Pest
  2. Bacillus – (b) Cyanobacteria
  3. Cotton bollworm – (c) Legume
  4. Rhizobium – (d) Bio-pesticide

Answer:

  1. b
  2. d
  3. a
  4. c

IV. Answer briefly:

Question 1.
How are crops classified based an seasons?
Answer:

  1. Kharif crops – Sown in rainy season eg. Paddy.
  2. Rabi crops – Grown in winter season eg. Wheat.
  3. Zaid Crops – Grown in summer season eg. Muskmelon.

Question 2.
What is dibbling?
Answer:
It is a method of sowing seeds in which the seed material is placed in a furrow, pit or hole , spacing with a dibble and covering the same with soil.

Question 3.
Mention the difference between manure and fertilizer.
Answer:
Manure:

  1. It is organic in origin
  2. It does not cause pollution

Fertiliser:

  1. It is synthetic in origin
  2. It causes water and air pollution

Question 4.
Define threshing.
Answer:
The process of separating the grains from their chaffs or pods is called threshing.

Question 5.
Expand the following abbreviations. FCI, ICAR, KVK, IARI
Answer:

  1. FCI – Food Corporation of India.
  2. ICAR – Indian Council of Agricultural Research
  3. KVK – Krishi Vigyon Kendra
  4. IARI – Indian Agricultural Research Institute.

Question 6.
What are seed balls?
Answer:

  1. Seed balls are a mixture of soil, compost and plant seeds.
  2. These balls are thrown into land areas and is a step towards conserving the natural ecosystems.

Question 7.
What are heirloom seeds?
Answer:

  1. An heirloom seed is the seed of plant that has been carefully cultivated and passed down through many generations.
  2. Heirloom seed are harvested, dried and stored so that one can replant them in the following season.

Question 8.
What is bio-control?
Answer:

  1. Bio-control or biological control is a method of controlling pests such as insects, mites, weed and plant diseases using other organisms.
  2. Eg – Bio-predators, bio-pesticides, bio-repellents and bio-fertilizers.

Question 9.
What are bio-pesticides?
Answer:

  1. Bio-pesticides are living organism or their derived parts which are used as bio-control agents to protect crops against insect pests.
  2. Eg. Entomopathegenic viruses.

Question 10.
What are bio-fertilizer?
Answer:

  1. Bio-fertilizers are organisms which bring about soil nutrient enrichment.
  2. Nitrogen fixing microorganisms have the capability of converting free nitrogen into nitrogenous compounds and make the soil fertile.
  3. Eg – Nostoc.

Question 11.
What is Panchgavya?
Answer:

  1. A growth promoter with a combination of five products obtained from the cow, includes cow dung, cow’s urine, milk, curd and ghee.
  2. It is used in seed treatment.

Question 12.
What is a seed bank?
Answer:
Seed bank is a place where seeds are stored in order to preserve genetic diversity.

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