CG Board Class 8 Science Chapter 13 Solutions: Food Production and Management (खाद्य उत्पादन एवं प्रबंधन) – 2026-27

No, Ipomea or other unwanted weeds grown randomly in a place cannot be called a crop. A crop is defined as plants of a common variety grown systematically in a large area for a specific purpose (such as food, fiber, or economic yield). Weeds grow uninvited, compete with main crops for nutrients, water, and sunlight, and do not serve the purpose of planned cultivation.

Crops are differentiated into three types based on seasons:

1. Kharif (Autumn) Crops: Grown in the rainy season (sown in June-July, harvested in October-November). Examples: Paddy (rice), maize, moong, urad, sugarcane, and cotton.
2. Rabi (Winter) Crops: Grown in the winter season (sown in October-November, harvested in March-April). Examples: Wheat, gram, mustard, linseed, and peas.
3. Zaid (Summer) Crops: Grown in the summer season (March to June). Examples: Watermelon, muskmelon, cucumber, and gourds.

Traditional Equipment:** Simple wooden plough (traditional plough) driven by bullocks or cattle.

• Modern Equipment: Iron soil overturning plough, tractor-driven cultivator, and harrow.

Beaker C** shows maximum germination because it receives all the essential conditions required for germination: air, adequate moisture (water), soil nutrients, and suitable temperature.

1. Beaker A: Grains did not germinate (or rotted) because it was completely filled with water, which cut off the supply of air (oxygen) necessary for seed respiration.
2. Beaker B: Grains did not germinate because it was kept completely dry without any water/moisture.
3. Beaker D: Grains showed poor or delayed germination because the seeds were buried too deep (6 cm in soil), where sufficient air could not reach them easily.

The favourable conditions required for seed germination are:

1. Adequate moisture (water).
2. Proper supply of air (oxygen).
3. Suitable temperature.
4. Proper depth of sowing in fertile soil.

Fruits and vegetables spoil faster in summer because high temperatures accelerate the rate of ripening and speed up the growth, respiration, and enzymatic action of micro-organisms (bacteria and fungi). In winter, the low temperature retards or stops the growth of micro-organisms and slows down enzymatic processes, keeping them fresh for a longer time.

Weeds:** Unwanted plants that grow naturally alongside crop plants in agricultural fields are called weeds.

• Need for Weed Control: Weed control is necessary because weeds compete with the main crop for water, nutrients, space, and sunlight, thereby reducing crop yield and quality. Some weeds also interfere with harvesting or may be poisonous to humans and animals.

Crops can be protected from pests through the following methods:

1. Chemical Control: Spraying appropriate pesticides, insecticides, and fungicides.
2. Biological Control: Using natural predators and parasites (e.g., Trichogramma parasite, Coccinella predator insect, or birds like cranes and ducks).
3. Cultural Practices: Proper tilling before sowing to expose insect eggs/larvae to sunlight, practicing crop rotation, and adopting mixed cropping.
4. Physical Methods: Installing scarecrows or beating drums to drive away birds and animals.

A combine harvester (or combine) is a modern agricultural machine used simultaneously for two main operations: reaping (harvesting) the standing crop and threshing (separating grain from the crop stalks).

Crop products are stored systematically through the following methods:

1. Dry Grain Storage: Freshly harvested grains are sun-dried to reduce moisture content below safe limits and stored in jute bags, metallic bins, godowns, or large cylindrical structures called silos. At the national level, the Food Corporation of India (FCI) stores grains in large warehouses. Chemical sprays or dried neem leaves are used to prevent pest infestation.
2. Perishable Products Storage: Perishable food items like fruits, vegetables, potatoes, and onions are stored in cold storage units at maintained low temperatures to prevent decay and microbial growth.

(1) Incubators are used in:**

(c) कुक्कुट पालन में (In poultry)

(2) Hybridization is a technique of:

(a) protecting crops from pests.

(b) artificial crossing and producing seeds with required qualities

(c) new technique of irrigation

(d) production of more eggs

(b) वांछित गुणों वाले बीज तैयार करने हेतु कृत्रिम संकरण तकनीक

(3) The carbonic product obtained from the wastes of animals and the decomposed plants is called:

(a) fertilizers

(b) manure

(c) green manure

(d) bio fertilizers

(b) खादों (Manure)

(4) Which is not a method to maintain the fertility of the soil?

(a) crop rotation

(b) mixed cropping

(c) weeding

(d) leaving the land uncultivated for some time

(c) निंदाई/खरपतवार नियंत्रण (Weeding)

(5) Which machine is used for both reaping and threshing?

(a) thresher

(b) tractor

(c) combine

(d) harrow

(c) कंबाइन (Combine)

(1) Kharif crops require more water than rabi crops.**

(2) Pesticides and weedicides are not harmful to human beings.

(3) Earthworms are harmful for crops.

(4) Wheat is the main kharif crop of our country.

(5) There is much carbohydrate and fat in mushroom.

Cows and buffaloes are the primary milk-producing (milch) animals in India. Milk production is the second largest agricultural activity after rice cultivation. For high yield, milch animals require nutritious fodder (green grass, straw, and oil cakes of mustard/cottonseed), clean drinking water, well-ventilated shelters, and proper medical care. Improved hybrid breeds such as Sahiwal, Holstein-Friesian (cows), and Murrah (buffaloes) are reared to boost milk output.

Fish production involves the large-scale breeding, rearing, and management of fish in controlled water bodies (fisheries and ponds). Fish is a rich source of animal protein, and cod/shark liver oils provide Vitamin D. Freshwater fishes include Katla, Rohu, and Mrigal, while saltwater (marine) fishes include Tuna and Cod. Fisheries ensure optimal oxygen, light, and feed to produce high-yield fish varieties rapidly.

The artificial rearing and management of honey bees in specialized wooden boxes to obtain honey and beeswax is called apiculture. Honey contains water, sugars, minerals, and enzymes, and is widely used for medicinal purposes. Inside the bee boxes, queen bees lay eggs, worker bees collect nectar/pollen from flowers, convert it into honey, and store it in honeycombs.

Rearing birds such as chickens and ducks for eggs and meat is known as poultry farming. Hens incubate eggs for 21 days during the hatching period. In commercial poultry farms, artificial incubators provide controlled heat and humidity for large-scale hatching. High-yielding egg-laying layers and meat-producing broilers (e.g., White Leghorn, Rhode Island Red, ILS-82) are fed balanced diets containing limestone and small pebbles to support eggshell formation.

Vermicomposting is the process of using earthworms to decompose organic farm wastes, plant refuse, and dung into nutrient-rich organic manure called vermicompost. Earthworms consume decaying organic matter and digest it, producing worm castings rich in nitrogen, phosphorus, and potassium (NPK). This eco-friendly process cleans the environment and improves soil aeration, making earthworms ‘farmer’s friends’.

Mushroom culture is the scientific cultivation of edible fungi (such as Dhingri and White Button mushrooms) on prepared mediums like boiled/treated wheat husk or straw mixed with mushroom spores. The setup is sealed in perforated polythene bags at 20 degree Celsius to 25 degree Celsius for 2 to 3 weeks until white mycelial balls form, which later sprout umbrella-shaped edible mushrooms rich in protein, vitamins, and minerals.

Cold storage refers to temperature-controlled refrigerated warehouses designed to store perishable agricultural commodities such as fruits, vegetables, potatoes, onions, and ginger. By maintaining low temperatures, cold storage slows down respiration and enzymatic activity in plant tissues and inhibits the proliferation of decay-causing bacteria and fungi, preventing spoilage over long periods.

1. पारंपरिक हल:

• English Structural Explanation: A traditional plough consists of a long wooden beam (shaft) connected to a wooden body (butt) fitted with an iron strip at the tip called the ploughshare. When pulled by a pair of bullocks, the ploughshare pierces into the soil, creating narrow furrows to loosen the ground for sowing.
• Hindi Structural Description: पारंपरिक हल में एक लंबी लकड़ी की बीम (Shaft) होती है जो लकड़ी के मुख्य भाग (Butt) से जुड़ी होती है। इसके निचले त्रिकोणीय सिरे पर लोहे की एक मजबूत पत्ती लगी होती है जिसे फाल (Ploughshare) कहते हैं। बैलों की जोड़ी द्वारा खींचे जाने पर फाल मिट्टी में धँसकर गहरी नाली (कुंड़) बनाता है और मिट्टी को चीरकर ढीला करता है।

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पारंपरिक हल

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[Beam / बैल जोतने का डंडा]

[Wooden Body / मुठिया/मुख्य भाग]

|

|— [लोहे की फाल]

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• English Structural Explanation: A simple seed dropper consists of a funnel attached to a long vertical metallic or bamboo tube. The tube is fixed directly behind the ploughshare of a traditional plough. As the farmer drives the plough, seeds are dropped manually into the funnel, passing through the tube to settle at uniform depth and spacing inside the freshly opened furrow.
• Hindi Structural Description: साधारण बीज ड्रॉपिंग यंत्र (नाई/सीड ड्रिल) में एक कीप (Funnel) होती है जो एक लंबी लोहे या बाँस की नली से जुड़ी होती है। इस नली का निचला सिरा पारंपरिक हल के फाल के ठीक पीछे बंधा होता है। हल चलने के साथ-साथ किसान कीप में बीज डालता जाता है, जो नली से होते हुए मिट्टी की नाली में समान गहराई पर गिरते जाते हैं।

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Simple Seed Dropper / नाई यंत्र

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\_______/ <- कीप

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| <- नली

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[हल के पीछे खुलती नली]

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• English Structural Explanation: A harrow is a heavy soil-tilling frame fitted with multiple curved iron teeth, discs, or blades arranged along parallel bars. Drawn by cattle or tractors, the harrow breaks up large clods of earth left after ploughing, pulverizes the soil surface, uproots shallow weeds, and levels the field evenly.
• Hindi Structural Description: हैरो (Harrow) लोहे का एक भारी फ्रेम होता है जिसमें कई मुड़े हुए लोहे के दांते (Teeth) या डिस्क लगी होती हैं। ट्रैक्टर या पशुओं द्वारा खींचे जाने पर हैरो हल चलाने के बाद बचे हुए मिट्टी के बड़े ढेलों को तोड़ता है, खरपतवारों को उखाड़ता है तथा खेत की मिट्टी को भुरभुरा एवं समतल बनाता है।

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हैरो

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+—————————————+ <- लोहे का ढांचा

| | | | |

/ / / / / <- लोहे के दांते

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Definition:** All preparations, operations, and systematic procedures performed by a farmer sequentially from soil preparation to crop harvesting and storage to achieve maximum yield are called farming methods (or agricultural practices).

• Sequential Steps Involved:

1. Selection of land
2. Preparation of soil/land (ploughing and leveling)
3. Selection of seeds and seed treatment
4. Sowing of seeds
5. Manuring and applying fertilizers
6. Irrigation
7. Weeding and weed control
8. Crop protection (against pests and diseases)
9. Harvesting and threshing
10. Storage

To produce a legume crop (such as gram, peas, or moong) in the school garden, the following steps will be followed sequentially:

1. Selection of Land: Choose a sunny plot in the garden with well-drained soil.
2. Preparation of Soil: Dig and loosen the soil using a spade, break big clods, and level the garden bed.
3. Selection of Seeds & Treatment: Select healthy legume seeds and treat them with appropriate fungicides or Rhizobium culture.
4. Sowing: Sow the treated seeds in lines at a depth of 2 to 3 cm maintaining proper distance.
5. Addition of Manure: Add compost or vermicompost to provide phosphatic organic nutrients.
6. Irrigation: Lightly water the bed to maintain required soil moisture.
7. Weeding: Regularly remove unwanted wild plants by hand or trowel.
8. Crop Protection: Monitor for pests and spray organic bio-pesticides if necessary.
9. Harvesting: Harvest mature pods when they turn yellow/dry.
10. Storage: Dry the extracted seeds thoroughly in the sun and store them in airtight containers.

Preferred Method: The puncture / line-sowing method** (using a seed drill or seed dropper) is preferred over the random spraying (broadcasting) method.

• Reasons:

1. In the puncture method, seeds are deposited at uniform depth and equal intervals, ensuring proper space, air, light, and nutrients for each plant.
2. Seeds get covered properly with soil, protecting them from birds and wind.
3. It prevents wastage of seeds caused by overcrowding.
4. Irrigation, weeding, and harvesting become much easier in line-sown crops.

Hybrid seeds are produced by artificial cross-breeding of two plants possessing different desirable genetic characteristics. They are considered better than normal seeds because:

1. They possess high germinating capacity and produce higher crop yield per unit area.
2. They show high resistance against disease-causing pathogens and insect pests.
3. They adapt better to adverse climatic variations such as drought or excessive heat.
4. They mature faster and produce uniform, superior quality grains.

Crops that are grown first in small nursery beds to raise seedlings and then transplanted into the main field are:

1. Paddy (Rice)
2. Onion
3. Tomato
4. Chilli
5. Cabbage
6. Brinjal (Eggplant)

Two modern, water-saving techniques of irrigation are:

1. Sprinkler (Fountain) Irrigation Method: In this method, water is supplied through a main pipeline under high pressure using a pump, exiting through rotating nozzles attached to vertical pipes. Water falls on standing crops artificially like rain showers. It is extremely effective for sandy soils and uneven land surfaces where traditional flooding is impractical.
2. Drip Irrigation Method: In this method, water is delivered directly near the roots of individual plants drop by drop through a network of narrow closed plastic pipes fitted with emitters. This technique eliminates water evaporation and surface run-off losses completely, making it ideal for fruit orchards, vegetables, and drought-prone regions.

Mushrooms are considered a valuable, high-grade vegetarian food product due to the following nutritional reasons:

1. High Protein Content: They are rich in highly digestible proteins.
2. Rich in Vitamins & Minerals: They contain high amounts of Vitamin B complex, Vitamin C, potassium, and essential trace minerals.
3. High Dietary Fiber: They provide abundant dietary fiber, which aids digestion.
4. Low Fat & Sugar: They are ideal for health-conscious people, diabetics, and cardiac patients.

Crop improvement (or crop variety improvement) refers to the scientific process of developing high-yielding, disease-resistant, and climate-resilient varieties of crops with superior genetic traits. It is primarily achieved through techniques like artificial hybridization, selection, and genetic manipulation to maximize grain quality, shorten crop maturity duration, and ensure food security.

Crop rotation is the practice of growing different types of crops sequentially on the same land over different seasons.

• Mechanism of Action:
• Cereal crops (like wheat, rice, or maize) absorb heavy amounts of nitrogenous nutrients from the soil.
• When a leguminous crop (like gram, peas, or moong) is grown in rotation, symbiotic Rhizobium bacteria residing in their root nodules fix atmospheric nitrogen directly into the soil as nitrates.
• Blue-green algae in waterlogged fields also act as bio-fertilizers.
• This natural nitrogen enrichment restores soil fertility without requiring excessive chemical fertilizers, breaks pest cycles, and maintains balanced soil nutrients.