Chapter 15 — Improvement in Food Resources
Welcome to HSLC Guru! This page provides a complete English-medium study guide for ASSEB Class 9 Science Chapter 15 — Improvement in Food Resources. You will find a clear summary of the chapter, full textbook question answers, additional practice questions including MCQs, fill in the blanks and true/false items, plus a handy glossary. Everything has been organised to help you prepare confidently for your school examination based on the ASSEB syllabus.
Summary
The need to increase food production: India is a country with a very large and growing population. To feed all the people, we need to produce more food without damaging our limited natural resources such as land, water and biodiversity. This is called sustainable agriculture. Both crop production (plant sources of food) and animal husbandry (animal sources such as milk, eggs, meat and fish) must be improved. The Green Revolution increased food-grain production while the White Revolution increased milk production. The major activities for crop improvement are choosing better varieties of seeds, managing the crop properly, and protecting it from pests, diseases and weeds.
Crop variety improvement: The yield and quality of a crop depend on the type of variety used. Better varieties are produced by hybridisation, which is the crossing of two genetically dissimilar plants. Hybridisation may be intervarietal (between two varieties), interspecific (between two species of the same genus) or intergeneric (between different genera). Another method is to introduce a desirable gene into a crop to produce a genetically modified (GM) crop. Important factors for which crops are improved include higher yield, better quality, biotic and abiotic resistance, change in maturity duration, wider adaptability and desirable agronomic traits like dwarfness in cereals.
Crop production management — nutrients, irrigation and cropping patterns: Plants need 16 essential nutrients. Air supplies carbon and oxygen, water supplies hydrogen and oxygen, and the soil supplies the remaining 13 nutrients. Of these, six are macronutrients (N, P, K, Ca, Mg, S) and seven are micronutrients (Fe, Mn, B, Zn, Cu, Mo, Cl). Nutrients are added through manures (organic, prepared from animal and plant wastes — compost, vermicompost, green manure) and fertilisers (commercially produced inorganic salts containing N, P, K — called NPK fertilisers). Manures improve soil texture and water-holding capacity but contain less nutrient; fertilisers give more nutrients but, if overused, harm soil structure and pollute water bodies. Irrigation ensures water supply through wells, canals, river-lift systems, tanks and rainwater harvesting. Cropping patterns include mixed cropping (growing two or more crops simultaneously on the same field), intercropping (growing two crops in a definite pattern of rows) and crop rotation (growing different crops on a piece of land in a planned succession) — these help in better use of resources, reduced pest attack and improved soil fertility.
Protection, storage and animal husbandry: Crops must be protected from weeds, insect pests and diseases caused by bacteria, fungi and viruses. Control measures include weedicides, insecticides, resistant varieties, summer ploughing and biological control. After harvesting, grains are stored carefully because biotic factors (insects, rodents, fungi, mites, bacteria) and abiotic factors (moisture, temperature) cause heavy losses. Strict cleaning, proper drying and fumigation are used. Animal husbandry is the scientific management of livestock — cattle (dairy animals like cows and buffaloes for milk and draught animals like bullocks for farm labour), poultry (egg-layers/layers and broilers for meat), fisheries (capture fishing and culture fishery; marine fisheries in seas and inland fisheries in fresh water and brackish water — also called aquaculture; composite fish culture is a common practice) and bee-keeping or apiculture for honey and wax. Integrated farming combines agriculture with animal rearing, fish culture and bee-keeping so that the waste of one becomes the resource of another, increasing total income from a small piece of land.
Textbook Question Answers
1-Mark Questions
Q1. What is hybridisation?
Answer: Hybridisation is the process of crossing between two genetically dissimilar plants to produce a new variety with desired characteristics such as higher yield or disease resistance.
Q2. Name the three types of hybridisation.
Answer: The three types of hybridisation are intervarietal (between different varieties), interspecific (between two species of the same genus) and intergeneric (between different genera).
Q3. What is a genetically modified crop?
Answer: A genetically modified (GM) crop is a crop in which a desirable gene from another organism has been introduced to give it a useful trait such as pest resistance or higher nutritional value.
Q4. Name any two macronutrients required by plants.
Answer: Two macronutrients required by plants are nitrogen (N) and phosphorus (P).
Q5. What does NPK stand for?
Answer: NPK stands for Nitrogen (N), Phosphorus (P) and Potassium (K) — the three major nutrients supplied to plants through chemical fertilisers.
Q6. What is vermicompost?
Answer: Vermicompost is a type of compost prepared by using earthworms to hasten the decomposition of plant and animal refuse into nutrient-rich manure.
Q7. Define mixed cropping.
Answer: Mixed cropping is the practice of growing two or more crops simultaneously on the same piece of land to minimise risk of total crop failure.
Q8. What are broilers?
Answer: Broilers are poultry birds reared specifically for obtaining meat. They grow rapidly and are slaughtered within 6–8 weeks.
Q9. What is apiculture?
Answer: Apiculture is the scientific rearing of honey bees on a large scale to obtain honey and bees-wax.
Q10. Differentiate between layers and broilers in one line.
Answer: Layers are poultry birds raised for egg production, while broilers are raised for chicken meat.
2–3 Mark Questions
Q1. Differentiate between manure and fertiliser (any three points).
Answer: (i) Manure is an organic substance prepared from plant and animal waste, while fertiliser is an inorganic salt prepared in factories. (ii) Manure contains less amount of nutrients but improves soil texture and water-holding capacity; fertiliser contains a high amount of specific nutrients but does not improve soil structure. (iii) Manure is eco-friendly and slow-acting, while fertiliser is fast-acting and may pollute water and soil if overused.
Q2. What are the advantages of intercropping and crop rotation?
Answer: Advantages of intercropping include better utilisation of nutrients, reduced pest and disease incidence, and prevention of total crop failure. Crop rotation maintains soil fertility (especially when leguminous crops are included), reduces pests and weeds, and gives two or three crops from the same land in a year.
Q3. Mention three biotic and three abiotic factors that cause loss of stored grains.
Answer: Biotic factors causing loss of stored grains: insects, rodents and fungi (or mites and bacteria). Abiotic factors: inappropriate moisture, unfavourable temperature and lack of proper aeration in the storage place.
Q4. Why are dairy animals selected with care? Mention two desirable qualities.
Answer: Dairy animals are selected to ensure good milk yield and adaptability to local conditions. Two desirable qualities are (i) a long lactation period (the period after the birth of a calf during which the cow produces milk) and (ii) resistance to diseases along with the ability to tolerate high temperatures of our climate.
Q5. What is composite fish culture? Mention any two advantages.
Answer: Composite fish culture is a system in which a combination of five or six different species of fish (which feed at different levels in a pond, like surface, middle and bottom feeders) is grown in a single fish-pond. Advantages: (i) maximum use of food available in the pond, and (ii) higher fish yield without competition for food.
Q6. What is integrated farming? Why is it useful?
Answer: Integrated farming is a system in which crop production is combined with cattle, poultry, fish farming and bee-keeping on the same farm so that the waste of one component becomes the input for another. It is useful because it gives multiple incomes from the same piece of land, recycles nutrients, reduces costs and improves overall productivity.
5–6 Mark Questions
Q1. Why do we need to improve our crop yield? Discuss the major activities involved in crop improvement.
Answer: India has a very large and rapidly growing population. To meet the food demand of all citizens without bringing more land under cultivation, the productivity of existing farms must be increased. We also need to produce a steady supply of raw materials for industries and to ensure food security and nutritional well-being. The major activities involved in crop improvement are: (i) Crop variety improvement — choosing better-yielding, disease-resistant and locally adaptable varieties through hybridisation and genetic modification; (ii) Crop production management — providing nutrients through manures and fertilisers, ensuring proper irrigation, and following scientific cropping patterns such as mixed cropping, intercropping and crop rotation; and (iii) Crop protection management — protecting crops from weeds, insect pests and pathogens by using resistant varieties, biological control and the careful use of chemicals. Together these steps make agriculture sustainable and profitable.
Q2. Explain the methods of weed, insect-pest and disease control in crops.
Answer: Weeds are unwanted plants growing along with the main crop; they compete with the crop for nutrients, water, space and sunlight, thus reducing the yield. Insect pests damage crops by cutting roots, stems and leaves, sucking cell sap and boring into stems and fruits. Plant diseases are caused by bacteria, fungi and viruses present in soil, water and air. Control methods include: (i) Mechanical methods like hand weeding, summer ploughing and use of harrows; (ii) Cultural methods like proper seedbed preparation, timely sowing, intercropping and crop rotation; (iii) Chemical methods using weedicides, insecticides and fungicides which should be sprayed in correct doses to avoid pollution and resistance; (iv) Biological control using natural enemies; and (v) Use of resistant varieties developed through plant breeding. A balanced combination of these methods, called Integrated Pest Management, is most effective.
Q3. Describe the practices used in cattle farming and poultry farming.
Answer: Cattle farming is done for two purposes — milk production (dairy animals) and farm labour like tilling, irrigation and carting (draught animals). The cattle commonly milked in India are cows (Bos indicus) and buffaloes (Bos bubalis). To increase milk yield, exotic high-yielding breeds such as Jersey and Brown Swiss are crossed with local breeds such as Red Sindhi and Sahiwal. Cattle require proper shelter, balanced feed (containing roughage and concentrates), regular cleaning, brushing and timely vaccination against diseases caused by viruses, bacteria and parasites. Poultry farming is done to raise domestic fowl for eggs (layers) and meat (broilers). Cross-breeding between Indian breeds (e.g. Aseel) and foreign breeds (e.g. Leghorn) gives birds with desirable traits such as more chicks, dwarf size, high feed efficiency and tolerance to high temperature. Broilers need protein-rich and fat-rich feed with adequate vitamins; layers need calcium-rich feed for shell formation. Strict hygiene, good ventilation and regular vaccination keep both layers and broilers healthy.
Q4. What do you understand by fish production? Differentiate between capture fishing and culture fishery and between marine and inland fisheries.
Answer: Fish production includes the catching and rearing of finned and shell fish for food. There are two main ways of obtaining fish — capture fishing (catching fish from natural water bodies such as rivers, lakes and seas) and culture fishery or aquaculture (rearing fish in controlled conditions in ponds, tanks and confined sea-water enclosures). On the basis of source of water, fisheries are classified as: Marine fisheries — carried out in seas and oceans, where popular fish are pomfret, mackerel, tuna, sardines and Bombay duck; large schools of fish are located using satellites and echo-sounders. Inland fisheries — carried out in freshwater (rivers, ponds, canals) and brackish water (river estuaries, lagoons). Inland fish farming is more productive when composite fish culture is used. Fish production is important because fish provides cheap, high-quality animal protein.
Q5. What is bee-keeping? Mention the qualities of a good honey-producing bee variety. Why is the location of an apiary important?
Answer: Bee-keeping or apiculture is the maintenance of bee hives for the production of honey, as well as bees-wax used in industries (cosmetics, polishes, medicines). It needs little investment and gives an additional income to farmers. Indian local varieties such as Apis cerana indica, Apis dorsata and Apis florae are commonly reared, but the Italian bee Apis mellifera is preferred because it has high honey-collection capacity, stings less, stays in a hive for a long period and breeds well. The qualities of a good honey-producing bee variety are: (i) high honey-collection capacity, (ii) less stinging nature, (iii) stays in the given beehive for long periods, and (iv) breeds well. The location of the apiary is important because the value, taste and quantity of honey depend on the kind of flowers (pasturage) available to the bees in the surrounding area; flowers like litchi, kashmir, sunflower, etc., give the honey its characteristic flavour.
Additional Practice Questions
Multiple Choice Questions (MCQs)
Q1. Which of the following is a Kharif crop?
(a) Wheat (b) Mustard (c) Paddy (d) Pea
Answer: (c) Paddy
Q2. NPK in fertilisers stands for —
(a) Nitrogen, Potassium, Phosphorus (b) Nitrogen, Phosphorus, Potassium (c) Nitrogen, Phosphate, Potash (d) None of these
Answer: (b) Nitrogen, Phosphorus, Potassium
Q3. Which of the following is not a method of crop variety improvement?
(a) Hybridisation (b) Genetic modification (c) Crop rotation (d) Selection
Answer: (c) Crop rotation
Q4. Vermicompost is prepared with the help of —
(a) Earthworms (b) Bacteria (c) Algae (d) Honey bees
Answer: (a) Earthworms
Q5. Layers are poultry birds reared for —
(a) Meat (b) Eggs (c) Feathers (d) Fight
Answer: (b) Eggs
Q6. Apis mellifera is a variety of —
(a) Indian honey bee (b) Italian honey bee (c) Rock bee (d) Little bee
Answer: (b) Italian honey bee
Q7. Pomfret, mackerel and sardine are examples of —
(a) Freshwater fish (b) Marine fish (c) Brackish-water fish (d) Pond fish
Answer: (b) Marine fish
Q8. Bullocks used for ploughing fields are an example of —
(a) Dairy animals (b) Draught animals (c) Poultry (d) Pets
Answer: (b) Draught animals
Q9. Growing two crops simultaneously in a definite row pattern is called —
(a) Mixed cropping (b) Intercropping (c) Crop rotation (d) Monocropping
Answer: (b) Intercropping
Q10. Which one of the following is a micronutrient?
(a) Nitrogen (b) Calcium (c) Zinc (d) Magnesium
Answer: (c) Zinc
Fill in the Blanks
Q1. The crops grown in the rainy season are called __________ crops.
Answer: Kharif
Q2. __________ is the rearing of honey bees on a large scale.
Answer: Apiculture (bee-keeping)
Q3. A combination of fish species feeding at different levels in a pond is called __________ fish culture.
Answer: Composite
Q4. Manure is __________ in nature, while fertiliser is __________ in nature.
Answer: Organic; inorganic
Q5. Crossing of two genetically dissimilar plants is called __________.
Answer: Hybridisation
True or False
Q1. Green Revolution increased the production of food grains in India.
Answer: True
Q2. Broilers are reared for egg production.
Answer: False (broilers are reared for meat)
Q3. Wheat and gram are Rabi crops.
Answer: True
Q4. Use of fertilisers improves the texture of the soil.
Answer: False (continuous use of fertilisers harms soil texture; manure improves soil texture)
Q5. Aquaculture is also called culture fishery.
Answer: True
Glossary
| Term | Meaning |
|---|---|
| Hybridisation | Crossing between two genetically dissimilar plants to produce a new variety with desired traits. |
| GM Crop | A crop in which a gene from another organism has been introduced for a desirable feature. |
| Macronutrient | Nutrient required by plants in large amounts (N, P, K, Ca, Mg, S). |
| Micronutrient | Nutrient required by plants in trace amounts (Fe, Mn, B, Zn, Cu, Mo, Cl). |
| Manure | Organic substance prepared from plant and animal wastes; improves soil structure. |
| Fertiliser | Commercially prepared inorganic salt providing specific nutrients (NPK). |
| Vermicompost | Compost prepared with the help of earthworms. |
| Green Manure | Manure obtained by ploughing in fast-growing crops like sun hemp before flowering. |
| Mixed Cropping | Growing two or more crops simultaneously on the same field without a definite pattern. |
| Intercropping | Growing two or more crops simultaneously on the same field in a definite row pattern. |
| Crop Rotation | Growing different crops on the same land in a planned succession. |
| Weeds | Unwanted plants that grow with crops and compete for resources. |
| Animal Husbandry | Scientific management of livestock for milk, meat, eggs, fibre and labour. |
| Dairy Animals | Cattle reared for milk production (cows, buffaloes). |
| Draught Animals | Cattle used for farm labour (bullocks). |
| Layers | Poultry birds reared for egg production. |
| Broilers | Poultry birds reared for meat. |
| Capture Fishing | Catching of fish from natural water bodies. |
| Culture Fishery / Aquaculture | Rearing of fish in controlled conditions like ponds and tanks. |
| Marine Fisheries | Fisheries carried out in seas and oceans. |
| Inland Fisheries | Fisheries carried out in freshwater and brackish water. |
| Composite Fish Culture | Rearing of 5–6 fish species feeding at different levels in the same pond. |
| Apiculture | Bee-keeping for honey and bees-wax. |
| Pasturage | Flowers available to bees for nectar and pollen collection; affects taste and quality of honey. |
| Integrated Farming | Combining crop, cattle, poultry, fish and bee farming on the same farm to recycle waste and increase income. |