Improvement in Food Resources Class 9 Science Chapter 12 CBSE Notes

Class 9 Improvement in Food Resources Notes explain key ideas about enhancing and managing food production. They cover topics like crop production, animal husbandry, and methods to boost yield. Students learn about improved crop varieties, soil management, and pest control with clear explanations. Diagrams and examples make concepts like crop rotation and hybridization easy to grasp. These class 9 Science notes are perfect for quick revision and exam preparation, helping students score better and understand sustainable agriculture.

CBSE Class 9 Science Chapter 12 Improvement in food Resources PDF

Download the FREE PDF of Class 9 Science Chapter 12 Notes from Infinity Learn, updated as per the latest CBSE syllabus 2025-26 for smart, efficient, and effective learning.

Introduction

India is a populous country with more than one billion people and is still growing. For this surplus population, about 240 million tonnes of grain is required per year. This is possible by farming on more land but there is hardly any scope to increase the area of land under cultivation. Therefore, it is necessary to increase our production efficiency for both crops and livestock.

Efforts to meet the food demand by increasing food production have led to some successes so far. Green revolution and white revolution contributed largely to the increase in food grain production and milk production respectively.

List of All Revolutions

• Black Revolution - Petroleum Production
• Blue Revolution - Fish Production
• Brown Revolution - Leather/non-conventional (India)/Cocoa production
• Golden Fibre Revolution - Jute Production
• Golden Revolution - Fruits/Overall Horticulture development/Honey Production
• Green Revolution - Food grains
• Grey Revolution - Fertilizer
• Pink Revolution - Onion production/Pharmaceutical (India)/Prawn production
• Red Revolution - Meat & Tomato Production
• Round Revolution - Potato
• Silver Fiber Revolution - Cotton
• Silver Revolution - Egg/Poultry Production
• White Revolution (In India: Operation Flood) - Milk/Dairy production
• Yellow Revolution - Oil Seeds production
• Evergreen Revolution - Overall development of Agriculture

Green Revolution

The Green revolution is the movement involving an enormous increase in food production by using the improved varieties of wheat, rice, maize and other cereals. Green revolution in 1960s and 1970s has changed the economic scenario of agriculture in India.

M.S. Swaminathan is known as the father of Green Revolution in India, while N. Borlaug is known as father of Green Revolution.

Operation Flood

Operation Flood, launched in 1970, was project of India's National Dairy Development Board (NDDB), which was the world's biggest dairy development program. It transformed India from a milk-deficient nation into the world's largest milk producer, surpassing the USA in 1998, with about 17 percent of global output in 2010-11. In 30 years it doubled milk available per person, and made dairy farming India's largest self-sustainable employment generator. It was launched to help farmers, direct their own development, placing control of the resources they create in their own hands. All this was achieved not merely by mass production, but by production by the masses.

White Revolution

"Operation Flood started the White Revolution in India and made our country self-sufficient in milk and this was achieved entirely through the cooperative structure. Today around 12 million farmers in more than 22 states across the country own around 250 dairy plants handling around 20 million litres of milk a day. This is a remarkable achievement. While we in India tend to take our achievement for granted, this feat elicited high praise and admiration throughout the world."

"A separate agency called as the India Dairy Corporation (IDC) was created to receive grants of food aid and use it in the Operation Flood, this agency was also headed by the marvelous Dr. Verghese Kurien."

"Milk powder production increased from 22,000 tons in the pre-Operational Flood year to 1,40,000 tons by 1989".

Note: Dr. V. Kurien, founder chairman of the National Dairy Development Board (NDDB), is called the architect of India's modern dairy industry and the father of white revolution.

Blue Revolution

An enormous increase in the fish production as an alternative food resource for human beings, is called Blue Revolution. It occured in 1970s.

Sustainable agriculture, which can be defined as the successful management of resources for agriculture to satisfy the changing human needs, while maintaining or enhancing the quality of environment and conserving natural resources.

For instance, for sustainable agriculture, we have to minimize the use of chemicals as fertilizers (e.g., urea) and insecticides (e.g.., DDT). These toxic chemicals have been replaced by biological means (i.e., manures, biological control, etc.). Such farming practice is often called organic farming.

Types of Crops

Crops is cultivated plant that is grown on a large scale to obtain food, fodder, fibres, timbers, fuel etc. Crop plants, fruits and flowering plants and vegetables are different forms of plantation, under specific term as follows:

1. Agronomy: It deals with the rearing and management of crop plants.
2. Horticulture: It deals with the study of fruits and flowering plants, their growth and management.
3. Olericulation: It deals with the study of vegetables growth and management.

Commercial Classification

It is based on the trade and commerce of agriculture produce.

Food crops: They include rice, wheat, maize pulses, oil seeds, vegetables, etc.

• The cereals such as wheat, rice, maize, etc provide us carbohydrates which gives us energy.
• Pulses such as gram, pea, black gram (urad), green gram (moong), etc give us protein.
• Oil seeds such as soyabean, ground nut, castor, seasame, etc, give us fat.
• Vegetabels, fruits and spices give us a range of vitamins and minerals.

1. Fodder crops: These include oats, sorghum, etc, which are raised as food for the livestock.
2. Cash crops: These include cotton, sugarcane, sugar, beet, tobacco, etc. They are important for country's economy.

Climatic classification

According to the climate requirement, they are classified as Kharif, Rabi, Zaid.

Kharif Crop Vs Rabi Crop

Note: Zaid crops: They are grown on irrigated lands in the short duration between Rabi & Kharif crop season mainly from March to June eg. Seasonal fruits & vegetables like watermelon, cucumber etc.

Improvement In Crop Yield

Our scientists have made it possible to increase the production of food grains four times more from 1960 to 2004 with only 25% increase in the cultivable land area. It been possible by three major activities.

1. Crop variety improvement
2. Crop production management
3. Crop protection management

Crop Variety Improvement

Crop variety improvement is studied under plant breeding. Plant breeding refers the study of improvement of crops by alternating genotypes of the crops to improve their genetic potentialities. Under plant breeding practices, new plants are not produced rather only improved crops are develped under plant breeding techniques. The improved crops are the superior crops with respect to quality and quantity over the existing crops.

Varieties or strains of crops can be selected by breeding for various useful characteristics such as disease resistance, response to fertilisers, product quality and high yields.

Aims and Objectives of Plant Breeding

1. High yield: It is the primary concern of the plant breeder to produce a crop variety having increased productivity per acre. It is achieved by developing and selecting more efficient genotype.
2. Improved quality: Quality improvement is required in grain size, colour, shape and size of flower, early flowering, milling and baking quality of wheat, cooking quality in rice, malting quality of barley, size and flavour of fruits, protein quality in pulses, oil quality in oil seeds, seedless quality of fruits and preserving quality in fruits and vegetables.
3. Biotic and abiotic resistance: Under natural conditions the crop plants are prone to certain biotic (diseases caused by bacteria, fungi, nematodes, etc. or damage caused by insects) and abiotic (drought, salinity, water logging, heat, cold) stresses which cause a great loss of production.
4. Change in maturity duration: Production of a crop can be increased many times by reducing the time duration from sowing to harvesting. It saves time, labour, irrigation, fertilizers and money. By reducing the duration of crop, the farmers can grow many rounds of crops in a year in the same field. Uniform maturity of crop makes the process of harvesting easy and reduces losses during harvesting.
5. Wider adaptability: An ability to withstand the extremes of moisture, drought, temperature and other conditions, by the cultivated plants, is another desirable trait by the breeders. Developing such varieties, which can be grown under different environmental conditions, helps farmers to grow one variety under different climatic conditions in different areas.
6. Desirable agronomic characteristics: Improving food yielding plants by raising a complex of useful characters in them such as high yield, dwarfness, early maturing and other desirable agronomic characters. For example, cotton with long fibres and more fabric strength has been developed through hybridization.
7. Development of novel varieties: Seedless tomatoes, oranges, lemons, seed less plums and peaches are some of the products of breeder's honest efforts which have captured the market.

Plant breeding techniques

There are four main plant breeding techniques. They are:

(i) Introduction: The seeds of a plant with some special features are brought from some place and grown in a new place. This is called introduction. If the plant species survives, it is selected for further cultivation.

(ii) Selection: It is the oldest method of crop improvement, even carried out by the pre-historic human beings. Individual plants or group of plants having desirable characters like disease resistance, product quality, high yields, etc are selected eliminating the undesirable ones.

(iii) Hybridization: It is a technique of plant breeding in which the two plants having desired characters are made to cross and develop seeds.

• Hybrids are first generation crosses between genetically unrelated parents. Hybrids are not always intermediates between their parents, but can show Hybrid Vigour.
• Hybrid Vigour / Heterosis: The superiority of the hybrid over either parent in one or more traits is called heterosis or Hybrid Vigour. Vigour in growth, yield, resistance to disease and pests is agriculturally important. Hybrid vigour has been exploited in commercial crops like maize, sorghum, Petunia, cabbage and cucumber.

Mechanism of Hybridization

The pollen grains of one plant (selected as male) are collected for pollination. The stigma of another plant (selected as female) is dusted with the pollen grains of male plant. After pollination, the fusion of desired male and female gametes results in hybrid embryo having characters of both the plants. The seeds plant are colled and grown in the fields.

Improved high-yielding varieties of crops

Note: Quarantine: All the introduced seeds and plants (and animals) are carefully examined for the presence of weeds, insects and disease causing organisms. This is called as quarantine. It is a legal restriction for unwanted introduction. It is also applied to humans to reduce the risk of entry of a pathogen in the country.

Types of Hybridizations

• (a) Intravarietal hybridization: It is between the two plants of same variety.
• (b) Intervarietal hybridization: It is between two plant belonging to different varieties but same species e.g., Wheat
• (c) Interspecific hybridization: It is between the different species of the same genus e.g., Sugarcane.
• (d) Intergeneric hybridization: It is between different genera e.g., Triticales (Wheat and rye), Pomato (Potato and Tomato)

(iv) Recombinant DNA technology or Genetic Engineering: The above mentioned methods of crop improvement (such as selection and hybridization) involves the complete genome of plants. The latest recombinant DNA technology involves transfer of one or more genes from one plant to another. The plant in which the foreign gene has been introduced is called transgenic plant or genetically modified plant (GMO). For Example: Bt-Brinjal, Bt-Cotton, Flavr saur tomato, etc.

Advantages

1. GM - Varieties can be grown in diverse climatic condition.
2. GM - Varieties tolerant to high soil salinity have been develped.

Crop Production Management

The continous growth of human population and degradation of ecological balance would affect the various aspects of agriculture. So the scientists were of the opinion that food production should increase substantially without disturbing the ecosystem, balanced use of manures and fertilizers, application of chemical and biofertilizers, etc. These practices help in lowering of soil erosion, provide better facility for maximum utilization of nutrients, improve the fertility of soil, enhance crop production and help in eradication of weeds.

Nutrient management

Plant also require nutrients for building their structure and maintaining their body functions. Besides soil, the nutrients are also supplied to plant by air and water. There are 16 elements which are essential for plants.

Nutrients supplied by Air, Water and Soil

Thus, nutrient management refers the supply of macronutrients and micronutrients for the proper growth and life cycle of plants with substainable development.

Differences between macronutrients and micronutrients

Deficiency of Mineral Nutrients

Deficiency of macronutrients affect physiological processes and susceptibility to diseases in plants. Such deficits appear on the plant as symptoms, called deficiency symptoms.

• To overcome the problem of deficiency of mineral nutrients and to increase the yield, the soil can be enriched by supplying these nutrients from the external sources.
• The major materials which are added into the soil to improve and maintain its fertility are grouped under two broad categories - Manures and Fertilisers

Manure

• Manures are partially decomposed organic materials added to the soil to increase the fertility of soil and productivity of crop. They contain almost all the essential nutrients required by the plants.
• The manures are of the following types:

(i) Farm yard manure (FYM)/(Compost): Farm yard manure is made up of dung of farm animals, urine, and crop residues (plant remains) which are allowed to partial decay with the help of microorganisms to form humus.

(ii) Green manure: Prior to the sowing of the crop seeds, many leguminous and non-leguminous crops are grown in the field. They are then mulched by ploughing while they are still young and green. This practice is used to enrich the soil in nitrogen and phosphorus. The most commonly used green manure in India are — Sunn hemp, Sweet clover, Cow-pea, Berseem, Cluster bean, etc.

(iii) Vermi-compost: The earthworms, popularly known as "farmer's friend", have been recently employed to obtain an eco-friendly compost, called "vermi-compost", derived from organic wastes.

(iv) Preparation of vermicompost: The earthworms are commonly used in vermicompsting. Earthworms feed on the organic wastes and utilise only 5% of its content. They discharge the rest along with the soil in the form of their casting. These castings are rich in nutrients and used as manure.

Earthworms are very well known as "Nature's ploughman" which promote soil aeration, crush and mix the soil particles, convert the nutrients into simple forms, act as scavenger of pathogenic bacteria and promote the growth of beneficial bacteria in the soil.

Advantage of Using Manure

• The manure contains many organic substances of biological origin which can be easily degraded and absorbed by the plants.
• It helps in recycling of biological waste (farm waste). The manure loosens the soil, increases its aeration and makes the soil more fertile.
• It increases water holding capacity in sandy soils, drainage in clayey soil and avoids water logging.

Fertilizers

Fertilizers are commercially produced synthetic chemical substances added to the soil to overcome the deficiency of mineral nutrients and to maintain the fertility of soil.

Fertilizers are of the following types:

• Nitrogenous fertilizers: Rich in the nitrogen element e.g., urea, sodium nitrate, ammonium sulphate, ammonium nitrate.
• Phosphatic fertilizers: Rich in phosphorus. These are phosphate and superphosphate. Phosphatic fertilisers are good for better fruit production.
• Potassic fertilizers: Rich in potassium, a macronutrient of the plant e.g., potassium chloride, potassium sulphate and potassium nitrate.
• Complex fertilizers: They contain two or three elements - nitrogen, phosphorus, and potassium e.g.,urea, ammonium phosphate, nitrogen phosphate and diammonium phosphate.

Advantages

1. They enhance the vegetative growth (leaves and stem branches) to make the plants healthy.
2. Fertilizers ensure higher yield.
3. Chemical fertilizers are soluble in water and readily absorbed by plants.

Thus, "fertilizers are a factor in the higher yield of high cost farming.

• Chemical fertilizers enhance the crop yield on one hand and cause environmental hazard on the other. Therefore, these chemical substances must be applied by observing utmost precautions.
• Precautions must be observed during pre-and post-application so that the applied dose must be completely utilized by the plants. The left over residue of these chemicals leads to water pollution.

Comparison between Manures and Fertilizers

Organic Farming

Organic farming is a farming system with minimal or no use of chemicals.

• In place of chemical fertilizers, the use of organic manures, biofertilizers biopesticides, resistant varieties are recommended.
• Biofertilizers are also harmless. They are the microorganisms which bring about soil nutrient enrichment, maximize the ecological benefits and minimize the environmental hazards. For this purpose some bio-agents such as blue green algae (i.e., cyano-bacteria) are used.
• The chemical herbicides and pesticides are replaced by the use of biopesticides (such as neem leaves or turmeric specially during grain storage).

Significance of Organic Farming

• Organic farming prevents soil and water pollution.
• Increase long-term soil fertility.
• It provides nourishment to the useful microbes of the soil.
• It protects from the harmful effects of chemical fertilizers, pesticides, insecticides on the plants.

Irrigation

"Irrigation may be defined as the application of water to the soil for the purpose of supplying moisture essential for plant growth especially during stress periods."

• In India, most of the agriculture is rain-fed, i.e., the productivity of crops in many areas is largely dependent on the timely monsoons and sufficient rainfall spread through most of the growing season.
• Several different kinds of irrigation systems are adopted to supply water to agricultural lands depending on the kinds of wells, canals, rivers and tanks.
• Wells: There are two types of wells, namely dug wells and tube wells. In a dug well, water is collected from water bearing strata. Tube wells can tap water from the deeper strata. From these wells, water is lifted by pumps for irrigation.
• Canals: This is usually an elaborate and extensive irrigation system. In this system canals receive water from one or more reservoirs or from rivers. The main canal is divided into branch canals having further distributaries to irrigate fields.
• River Lift System: In areas where canal flow is insufficient or irregular due to inadequate reservoir release, the lift system is more rational. Water is directly drawn from the rivers for supplementing irrigation in areas close to rivers.
• Tanks: These are small storage reservoirs, which intercept and store the run-off of smaller catchment areas.

Cropping Patterns

In order to get maximum benefit from the piece of land, different patterns of growing crops are followed. These are – Mixed cropping pattern, Intercropping pattern, Crop rotation

Mixed cropping pattern

The practice of growing two or more crops at the same time in a field is called mixed cropping. Usually only one crop (example, wheat, gram, mustard, or sunflower) is grown in the field at a time. If this crop faces some problem such as inadequate climate or attack of disease pathogens or insects, the entire labour and money of the farmer goes waste. This can be avoided by growing two or more crops simultaneously on the same piece of land. Because in the mixed cropping if one crop is damaged by a specific pathogen then the same pathogen will not damage the other crops. Thus, total damage of crops can be prevented by mixed cropping.

Crops Combinations Practiced in Mixed Cropping

The following crops are usually combined during mixed cropping by Indian farmers:

1. Wheat and gram
2. Wheat and mustard
3. Groundnut and sunflower
4. Pigeon pea(arher) and soyabean
5. Maize and urad.

Advantages

• With mixed cropping, the risk of total loss from drought, pests, and diseases is reduced.
• It gives maximum production from small plots. This can help farmers cope with land shortage.
• Including legumes in the cropping pattern helps maintain soil fertility by fixing nitrogen in soil.
• Because of high planting, growth of weeds is suppressed.

Disadvantages

• Difficulty in applying fertiliser to individual crops.
• Difficulty in spraying pesticides on individual crops.
• Harvesting and threshing of crops separately is not easy because seeds of the two crops are mixed and then sown.

Intercropping pattern

The practice of growing two or more crops simultaneously on the same field in a definite pattern.

Crops Combinations Practiced in Intercropping

1. Finger millet (Bajra) + Cow pea (Lobia)
2. Cotton + Moong bean
3. Soya bean + Maize
4. Ground nut + Sun flower
5. Wheat + Mustard

Advantages

• It results in potential increase for total production and farm profitability than when the same crops are grown separately.
• It saves time and labour of the farmer and makes better use of resources.
• Since thereis no mixing of crops, seeds of different crops can be sown separately.
• It reduces soil erosion and protects top soil.
• Specific fertliser, pesticide, and weedicide required for each crop can be applied.
• Each crop can be harvested, threshed, and marketed separately.

Disadvantages

• Yield decreases as the crops differ in their competitive abilities.
• Improved implements cannot be used efficiently.
• Higher amount of fertilizer or irrigation water cannot be utilized properly as the component crops vary in their response of these resources.
• Harvesting is difficult.

Crop rotation

The practice of growing two or more different kinds of crops on piece of land in a pre-planned succession is called crop-rotation.

The disease causing pathogens get their host every year so that they multiply and increase in number. This can be avoided by growing different crops in a pre-planned succession. For example, a mustard crop is alternate with sugarcane which is again alternated with berseem or any other crop.

Depending upon the duration, crop rotation is done for different crop combinations as follows:

• One year rotation
• Two years rotation
• Three years rotation:

However, the availability of moisture and irrigation facilities decide the choice of the crop to be cultivated after one harvest.

Advantages

• The fertility of soil is maintained for a long period by crop rotation.
• Crop production is also maintained with high economic yield.
• Crop rotation helps to control pest infestation and crop infections by pathogens.
• Nutrient recycling occurs, naturally.

Disadvantages

• Requires more equipment.
• May require more skill

Crop Protection Management

Crop protection management deals with the study of weeds, insect pests and diseases that decline the crop production.

• There are two major enemies of biological origin which cause damage to our crop plants and reduce their productivity.
  1. Weeds
  2. Disease inciting agents (pathogens).

Weed and Weed Control Management

A plant species growing spontaneously at unwanted habitat (or in the cultivated field) is called a weed.

Examples:

• Xanthium (gokhroo)
• Parthenium (gajar ghas)
• Cyperus rotundus (motha)
• Amaranthus (chaulai)
• Chenopodium (bathwa)
• Weed damage our crop plants, by competing with them for space, water, light and nutrients.

Methods of weed control are:

(i) Mechanical method: The method includes:

• Handpulling: Uprooting by hands.
• Tillage: Destruction of weeds and reduction of their seeds in the soil is called tillage.
• Flooding: Flooding is a popular method of controlling perennial weeds
• Mowing: Cutting with machines.

(ii) Chemical method:

• Weeds can be also destroyed by spraying weedicides which are chemicals that kill the weeds selectively without causing any harm to the crop.
• The use of weedicides is easy, cheap and less time-consuming.
• Weedicides are toxic chemical therefore farmers spraying these should cover their nose & mouth with cloth.

The common weedicides are:

• 2, 4-D (2, 4-dichlorophenoxy acetic acid).
• 2, 4, 5-T (2, 4, 5-trichlorophenoxy acetic acid).
• MCPA (2-methyl, 4-chlorophenoxy acetic acid).
• Atrazine.

(iii) Biological methods: In this method, a natural energy insects, fish, disease causing organisms or competitive plants of the weed plants is used.

Bioagent:

Ideal characteristics:

• Host specificity
• Ability to kill weed or prevent its reproduction
• Good adaptabillity
• Reproductive capacity at a rate sufficient to maintain control of host
• High ability to disperse successfully and to locate its host plant.

Examples of Bio-agents

(iv) Cultural methods: This method includes proper seed bed preparation, timely sowing of crops, inter cropping and crop rotation also help in weed control.

Some other preventive measures against pests are the use of resistant varieties and summer ploughing in which fields are ploughed deep in summers to destroy weeds and pests.

Insect Pests

Harmful pests of our crop plants are small insects which attack the plant in 3 ways:-

• Chewing insect: They cut the root, stem and leaf and swallow these pieces of plant parts e.g. Locusts, Caterpillar, Grasshopper, etc.
• Sucking insects: They suck the cell sap from various parts of the plant with the help of their needle like hollow mouth parts, e.g. Bugs.
• Internal feeders: They bore into seeds and fruits, live inside and harm the crop yield, e.g. Borers.

Disease Inciting Agents (Pathogens)

• Several diseases of crop are caused by pathogenic organisms which damage the plants and reduce the yield. Main pathogens of crop plants are – fungi, bacteria, viruses, mycoplasmas, nematodes, etc.
• The chemical substances which are used to protect the plants are commonly called pesticides. Depending on the kind of organism they destroy, the chemical substances are known as –
  • (i) Herbicides (used against weeds)
  • (ii) Insecticides (used against insects)
  • (iii) Fungicides (used against fungi)
  • (iv) Bactericides (used against bacteria)
• The chemical pesticides are known to cause poisoning.
• So some other preventive measures such as biological control, use of resistant varieties should be preferred.
• In this regard Integrated pest Management (IPM) favours biological control methods which are ecologically safe, target specific and harmless to other life forms.
• The vegetables and fruits of those plants which are treated with biopesticides have better taste and shine.

Storage of grains

• One of the most important aspect of agriculture is proper storage of harvested grain and other agricultural produce. Proper storage is necessary to get seasonal foods regularly throughout the year.

Factor of Storage grain losses.

There are two main factors responsible for losses during storage.

(i) Biotic factors: The living organisms which influence the storage of grains are called biotic factors. These include insects (Beetle, Weevil, Grain borer, etc.), rodents (Rat, Mouse, Squirrel, etc.), birds, mites, fungi, bacteria, etc.

(ii) Abiotic factors: The non-living environmental factors are called abiotic factors. These include moisture and temperature.

Preventive and Control Measures

(i) Cleaning of the produce before storage: The grains and other agricultural produce should be properly cleaned and dried before their storage. They should be filled in new gunny bags before keeping in godowns, warehouses or stores.

(ii) Drying: It is desirable that the grains and nonperishable food such as flour, sugar, spices and nuts should be dried first in sunlight and then in shade. The moisture content of grains should be below (9%).

(iii) Fumigation: Chemical pesticides are used as fumigants, i.e., the solution of pesticides is converted into fumes. These fumes kill the insect pests and other harmful biological agents. For example, two tablets (3 g each) of aluminium phosphate (black poison) can be used to protect one ton grain.

Other pesticides are BHC (Benzene hexachloride) and malathion.

Solved Exercise

Short Answer Type Questions

1. What do we get from cereals, pulses, fruits and vegetables?

Sol.

• Cereals: Mostly carbohydrates
• Pulses: Mostly proteins
• Fruits: Vitamins, minerals, organic acids.
• Vegetables: Vitamins, minerals, small quantities of proteins, carbohydrates and oil.

2. How do biotic and abiotic factors adversely effect crop production?

Sol. Biotic factors are living organisms that reduce crop productivity due to either directly feeding on them (e.g., insects, rodents) or causing diseases (e.g., nematodes, mycoplasmas, bacteria, viruses, fungi).

Abiotic factors are non-living components of environment that effect growth of crop plants like excess of water (water-logging), scarcity of water drought, salinity, heat, cold or frost. Water logging reduces aeration of soil which is harmful to growth and functioning of roots. In drought, water is not available to meet the requirement of the plants for transpiration, growth and photosynthesis. Frost, cold and heat reduce or inhibit metabolic activities and are, therefore, harmful.

3. What are the desirable agronomic characteristics for crop improvement?

Sol. They are different for different crops.

• Cereals should be dwarf but with large ears. Dwarfness makes their stem stronger. They can withstand lodging affect of strong winds. Nutrient requirement is also less. Large ears produce more grains.
• Legumes should have more pods which generally develop in relation to stem branching. Therefore, more branching and good foliage increase their productivity.

4. How do plants get nutrients?

Sol. Plant obtain nutrients from air, water and soil. Air is the source of carbon and oxygen. Hydrogen is obtained from water. The remaining thirteen elements are taken directly from soil through root absorption.

6. Which of the following conditions will give the most benefits? Why?

Sol.

• Farmers use high quality seed but do not adopt irrigation or use fertilizers.
• Farmers use ordinary seeds, adopt irrigation and use fertilizers.
• Farmers use quality seeds, adopt irrigation, use fertilizers and crop protection measures.

Sol. Farmers are benefitted when they use quality seeds. irrigarion fertilizers and crop protection measures (choice c). Ordinary seeds cannot yield very high due to poor quality while quality seeds without necessary inputs yield low.

7. Why should preventive measures and biological cantrol methods are preferred for protection crops?

Sol. Preventive measures and biological control methods do not allow any measurable loss in quality and quantity of crops. They also do not cause any degradation of the environment. Cost is also very small. Preventive measures protect the crops from pests. Biological control methods eliminate the pests without harming crops and other human interests.

8. What factors may be responsible for huge losses during strorage?

Sol.

1. Abiotic Factors: Excess moisture in grains, dampness and high temperature in storage place.
2. Biotic Factors: Insects, mites, rodents, birds, fungi and bacteria.

Long Answer Type Questions

9. Explain any one method of crop production which ensures high yield.

Sol. Rotation of crops is a method of crop production which ensures high yield. Crop rotation is growing of different crop on the same piece of land in a preplanned succession. Crop rotation is done for one year, two year and three year cycle. Crops chosen are such that they withdraw nutrients from different layers of the soil. Crop rotation involving a leguminous crop ensures that the soil gets naturally enriched with nitrogen. Crop rotation is useful in (i) Weed control. (ii) Reduction in pest infestation. (iii) Elimination of soil borne diseases. (iv) Saving of nitrogen fertilizer (v) Improving soil structure and fertility. (vi) Raising of 2-4 crops in a year from the same land giving higher returns to the farmer. (vii) Yield of individual crops is also higher due to improved soil structure, soil fertility, fewer weeds insects and diseases.

10. Why are manures and fertilizer used in fields

Sol. Manures and fertilizers are added to field mainly to replenish minerals which get depleted due to withdrawal by crop plants and leaching down to lower strata of soil.

(i) Manures add small quantity of all minerals to the soil. They improve soil hydration, soil aeration and activity of soil microorganism, some of which are required for solubilisation of heavy minerals.

(ii) Fertilizers are nutrients specific which contain one or more minerals in concentrated form. They meet the immediate and complete minerals requiremet of high yielding varieties. However, they harm soil structure and cause pollution of crops, soil, ground water and nearby surface waters. A combination of both manure and fertilzers is highly useful.

11. What is genetic manipulation? How is it useful in agricultural practices?

Sol. Genetic manipulation is incorporation of new genes for various traits from other genotypes into a crop variety so as to bring about desired change. It is carried out by means of hybridization, mutation breeding, polyploidy and DNA recombination technology.

Use. See Objectives of crop variety improvement.

12. Both aboitic and biotic factors damage stored grains.

Abiotic Factors.

1. Moisture Content of Grains: Moisture content of grains is generally higher than optimum 14%. Higher moisture content of grains increases their respiration, which heats the grains and reduces their keeping quality. Microorganism, fungi and insects attack such grains.
2. Dampness and Humidity of Air: Dampness of godowns and humidity of air cause growth of moulds over and inside the grains.
3. Temperature: Temperature of 30°C and above is harmful to stored grains due to activity of microorganism, insects, pests and activation of enzymes of the grains.

Biotic Factors.

1. Rodents: Six rats consume food equivalent to an average human being. They damage contamination (by urine, hair and excreta).
2. Birds: Birds are often seen in large number excreta often contains Salmonella, the bacterium causing food poisoning.
3. Insect and Worms: Insects and their larvae feed on stored grains either internally (internal feeders like Pulse Beetle, Rice Weevil, Lesser Grain Borer) or externally Red Flour Beetal). They damage the grains, decrease their quality and cause contamination with webs, cocoos, excreta, dead remains and toxins.
4. Microorganisms: Bacteria, yeasts and moulds attack stored grains and cause their rotting. Rotting brings about discolouration, loss of weight, bad odour and contamination of grains which also lose their ability to germinate.

Unsolved Exercise

Very Short Answer Type Questions

1. Define sustainable agriculture?
2. What are micronutrients?
3. Name some fodder crops raised as food for the livestock.
4. What is 'Zaid'? Give examples.
5. What is green manure? Give example.
6. What are the different types of insect pests harming our crops?
7. What is Plant breeding?

Short Answer Type Questions

8. What is crop rotation? How is it advantageous?
9. Write a short note on organic farming.
10. What are the aims and objectives of plant breeding? Write in detail any two such methods and their advantages.
11. Name three main-activities of crop improvement.
12. What are the different methods of plant breeding?
13. What are the different types of hybridization?
14. Differentiate between Rabi and Kharif crops. Give example.
15. What is mixed cropping and intercropping? Give examples.
16. Write about some preventive and control measures for storage of grains.
17. Write an example, explain the advantages of crop rotation and intercropping.
18. What are genetically modified plants? How are they produced? What are their advantages?

Animal Husbandry

• Animal husbandry is the farming or management of animal livestock which includes various aspects such as animal's shelter, feeding, breeding, health and disease control.
• Good animal husbandry practices are needed to meet out the growing demand of milk, eggs, meat, etc. These practices finally benefit the farmers.
• The farming or management of animal livestock includes -Cattle farming, Poultry farming, Fish farming, Bee keeping.

Cattle Farming

• Cows and bullocks are the major backbone of Indian agriculture and play an important role in the rural economy.
• In India, there are two different species of cattle:
  • Cow (cattle): The scientific name of cow is Bos indicus.
  • Buffalo (Indian water buffalo): The scientific name of buffalo is Bubalus bubalis or Bos Bubalis

Breeds of Cow

• Cattle of native origin are called indigenous breeds, Desi breeds, or Indian breeds.
• Imported high-yielding cattle are called exotic breeds.
• The breeds vary in colour, gait, udder size, nature of the horn, and milk yield.

Cattle farming is done mainly for two purposes – Dairy and Draught animals

(i) Dairy animals: Dairy animals include those animals which are kept for obtaining milk. They are also called milch animals. These include cow, buffalo, goat, camel and yak. Cow and buffalo are good milch animals which provide us milk and milk product. From the nutrition point of view milk is most nearly perfect food available to us as a source of animal protein in vegetarian diet.

Cow (Bos indicus): Cows are main milk producing cattle in India. India holds fifth rank in cow population. There are 26 breeds of cow. Some of them are:

Exotic Cattle

Buffalo (Bos Bubalis): Buffaloes are main milch cattle of India. These are also known as Indian water buffalo. Fat, calcium, phosphorus, protein, carbohydrates, vitamins are abundant in buffalo milk. The important breeds of Indian buffalo are Murrah, Bhadawari, Jaffarabadi, Surti, Mehsana and Nili Ravi.

(ii) Draught animal: Animals used in agriculture and for transport are called draught animals, e.g., Bullocks, Horses, Elephants, Mules, etc.

The draught animals are used for other agricultural practices such as tilling and irrigation.

Milk Production

Production of good quality milk depends on several factors.

(i) Influence of breed: Some exotic breeds like Jeresy cows (native of Jersey, U.S.A) produce on an average of 60 litres of milk in a day whereas local breeds like Red Sindhi and Sahiwal produce average of only 6-8 litres of milk per day. However, the milk of Red Sindhi contains more fat than Brown swiss (exoitc breed).

(ii) Duration of Lactation period: The period from the time the calf is born until the cow ceases to give milk is called the 'Period of lactation'. The lactation period of Red Sindhi cow is 230-345 days whereas lactation period of the exotic breed is longer.

Examples:

• Maximum Lactation period in cow - Red Sindhi (Indigenous breed), Holstein- Friesian (exotic breed)
• Maximum lactation period in buffalo - Mehsana, Switi

(iii) Other factors: Seasonal changes affect milk production such that the quality of milk is better in cold weather and decreases in warm weather. The physical health and variation in feeds also affect milk production.

Breeding for the desired quality

The milk production can be increased by the technique of selective breeding. This is done by cross breeding between a local breed (indigenous) cow and an exotic (foreign) bull.

The local cow is selected for the character of disease resistance. The exotic breed of bull is selected for the character of prolonged period of lactation and high yield of milk.

The breeding may be done by natural method or by artificial insemination (i.e. injecting the semen obtained from the desired bull into reproductive tract of the cow). The desired characters are thus obtained in the next generation.

Some of the cross - breeds are as follows:

• Karan Fries: It is develped as a result of cross between Holstein-Friesian and Tharparkar.
• Karan Swiss: It is develped as a result of cross between Brown Swiss and Sahiwal.
• Ayrshire-Sahiwal: A cross between Ayrshire and Sahiwal has produced a breed called Ayrshire-Sahiwal.

Important Study Materials for Class 9 - Science

Cattle Management

In order to keep the cattle healthy and for the production of clean, hygienic and maximum milk, the following fundamental conditions must be given.

• Proper cleaning of shelter.
• Clean and freshwater supply.
• Well ventilated roofed sheds that protect from rain, heat and cold.
• Suitable temperature in shelter houses.
• Sufficient floor area to provide free body movement.
• Provide nutritious food.
• Proper diagnosis, treatment and vaccination.

Cattle Feeding

The food required by dairy animals is called feed. The dairy animals must get adequate, palatable, laxative, appetizing and balanced ration with sufficient greens and all nutrients in proportionate amounts. They also must get large quantity of water for milk production. Dairy animals require food for two basic purposes:

1. They require food to maintain a healthy body and to perform all life activities.
2. They require specific food to produce milk during lactation period.

Components of cattle feed: A normal feed of dairy animals (cow and buffaloes) consists of kinds of components:

(i) Roughages: This part of cattle feed contains mostly fibers which come from hay (straw of cereals or Bhusa), green fodder (examples, Berseem, Lucerne, Cow pea, etc.) and silage.

(ii) Concentrates: These are mixture of substances less fibres and relatively excess amount of protein, fat, carbohydrates, minerals and vitamins.

Diseases of cattle

Cattle and buffaloes suffer from several diseases which not only cause ill health but reduce the milk production. Some severe diseases, if not properly cared, lead to the death of animal. Therefore, treatment in early stages of the disease is more effective. A healthy animal looks bright, happy, peaceful, active and alert in movement; and enjoys normal appetite and feeds regularly. It ruminates and breathes normally and maintains a proper posture.

Diseases caused by Parasites

The parasites of cattle my be external or internal. The external parasites live on the external skin of the body and causes skin diseases. These include blood-sucking lice, fleas and mites. The internal parasites live inside the body of animals. For example, Ascaris (round worm) lives in the stomach and intestine of dairy animals. Liver flukes (Fasciola) live in the liver and cause great damage.

Diseases caused by Bacteria and Viruses

1. Rinderpest (Cattle Plague): A viral disease that causes fever and mouth ulcers.
2. Foot and mouth disease: A viral disease that causes blisters on the mouth and foot in adult cattle. It reduces milk production.
3. Anthrax: A most fatal bacterial disease.
4. Ring worm: A fungal disease that causes small, circular and discoloured raised patches. Vaccinations are given to farm animals many viral and bacterial disease.

Poultry Farming

Poultry is a class of domesticated fowl (particularly young ones of common domestic fowl) used for food and for their eggs. The common poultry birds are chickens, turkeys, ducks, geese, guinea-fowls and pigeons.

Poultry farming includes housing, rearing, sanitation, disease-control and marketing of poultry birds and their products. The emphasis is being laid to improve the production of good quality eggs and chicken meat. This is done by proper poultry farming and developing improved poultry birds. The tremendous rise in availability of poultry product is called silver revolution.

Purpose of Poultry Farming

There are two main purposes of poultry farming:

1. Production of layers for eggs, and
2. Production of broilers for meat.

• These are good sitters as well as ideal mothers.
• Desi breeds are strong and possess natural immunity against local diseases.

Examples of indigenous breed

Examples of exotic breeds

Variety Improvement through Breeding

Several research programmes are going on all over the country to produce the cross breeds for the following desirable traits:

1. The cross breeds should lay more number of eggs, which produce good quality chickens.
2. The broiler chicks should be small sized (dwarf), so that they yield more and consume less.
3. The cross breeds should be able to adapt the adverse climatic conditions such as high temperature during summers and low temperature during winters.
4. They should require less expenditure for their maintenance.
5. The egg-laying birds should be small in size and consume more fibrous cheaper diets specially formulated for them by using the by-products of agriculture.

Care for Layers and Broilers

Egg laying birds are usually called egg layers or simply layers. They need some special attention as compared to meat-producing broilers. The broilers, however, require somewhat different housing, nutritional and environmental requirements as compared to egg layers.

Disease of Poultry

Poultry birds suffer from a variety of disease caused by

1. Nutritional irregularities (rickets)
2. Viruses (Bird flu, Ranikhet, Dermititis, Fowl pox)
3. Bacteria (Salmonellosis, Tuberculosis, Fowl Cholera)
4. Fungi (Aspergillosis)
5. Parasites (Round worm disease, Taeniasis).

They also have arthropod infestations of lice, fleas, ticks and mites. Tick fever is a very serious disease. These diseases reduce the growth of bird, diminish egg production, decrease fertility and even cause death.

Therefore, the following preventive measure must be taken to avoid the poultry disease:

1. Get disease-free chicks raised in proper sanitary conditions from healthy parents.
2. Clean and disinfect the poultry house by spraying of disinfectants at regular intervals.
3. Give fresh and balanced feed to the birds to avoid nutritional diseases.
4. Avoid overcrowding of the birds, ill ventilation and dampness, because these favour the spread of the diseases.
5. Have newly hatched chicks vaccinated in time. Vaccination prevents the occurrence of infectious diseases. If at all, infection occurs, isolate the sick birds, and burn or bury the birds that die of disease. This will stop further spread of the disease and reduce loss of poultry.

Fish Production

Fish is a cheap source of animal protein for our food that is easily digestible. Fish production includes the finned true fish as well as shellfish such as prawns and molluscs. The process involved in obtaining fish from the source is called fishing, i.e., catching of fish. The two different sources of obtaining fish.

Natural resources (Capture fishery)

It means catching fish from their natural habitat, marine and freshwater.

There are two natural resources for fishing:

(a) Marine fisheries: It is the branch of fisheries concerned with obtaining fish from oceans and seas. The fisherman enters into the sea and catches fish by different kinds of fishing nets and gears operated by fishing vessels. Modern equipments include echo sounders and satellites to locate large school of fish in order to increase fish production from the sea. The common marine-fish varieties are: Pomphrets, Mackerels, Tuna, Sardines, Hilsa, Eel, Bombay duck, etc.

(b) Inland fisheries: Inland fisheries include capture from fresh water resources like rivers, canals, tanks, ponds, lakes, etc as well as brackfish water (saline water from sea mixing with fresh water) resources like estuaries and lagoons.

The common fresh water fish varieties are: Rohu, Catle, kalbasu, Mrigal, Sanghara, Shital, etc.

Fish Farming (Culture fishery)

Fish farming or culture fishery is a kind of business and research activity concerned with the culturing, breeding and production of fishes in marine and fresh water ecosystem. It is otherwise called 'Pisciculture'. The growing of various types of aquatic organisms in water bodies is called Aquaculture.

Comparision between Pisciculture and Aquaculture

Types

(i) Monoculture: Culturing a single species of fish in a pond is called monoculture. In this type of fish farming, the fishes of differnet life staages are cultured together. Carps such as Labeo, Catlo, and Mrigala.

(ii) Monosex culture: Culturing of only one sex of a species of fish in a pond is called monosex culture. When only the male or female individuals are stocked together, all the energy of the fishes is utilised for growth and not for reproduction. Tilapias is frequently used for monosex culture because it attains maturity at an early stage. It continues to grow and attains a bigger size. Others fishes used for monosex culture include rainbow trout and salmon.

Composite Fish Culture System

It is a scientific fish farming where several species of fishes ar being cultured at the same time in the same pond. Both local and imported fish species are used in such system.

Characteristic Features

1. Composite fish culture system has different feeding habits. It reduces competition among them.
2. All the different species of fish live in co-existence and harmonization.
3. It has a combination of five or six fish species in a single fish pond.
4. In the six varieties of fishes, three local or indigenous (rohu, catla and mrigal) and three imported or exotic varities (common carp, silver carp and grass carp) are used in different combination.
5. n the six varieties of fishes, the food is available in all the parts of the pond and all fishes get their sufficient food due to their distribution in different vertical stratification.

In this method, fast-growing compatible species of fishes with different feeding habits are selected and stocked together.

A good example of this method is the culture of a mixture of Chinese carp (silver carp), grass carp, and big head carp. The Chinese carp, eats phytoplankton, the grass carp eats pond vegetation, and the big head carp eats zooplankton. Thus, the available food in the pond is utilised in a better way to enhance the productivity.

Major carps such as catla, rohu, and mrigala are extensively used in the ratio 3:3:4 in polyculture fish farming. Catla, rohu, and mrigala occupy three different strata in the pond, namely surface, column, and bottom, respectively, as such there is no competition among them either for food or for space.

• Problem associated with such composite fish culture is that many of these fish breed only during monsoon.
• Another a major problem in fish farming is the lack of availability of good-quality seed.
• To overcome this problem, ways have now been worked out to breed these fish in ponds using hormonal stimulation. This has ensured the supply of pure fish seed in desired quantities.

Beekeeping

Honey is widely used and therefore bee-keeping for making honey has become an agricultural enterprise. Since bee-keeping needs low investments, farmers use it as an additional income generating activity. In addition to honey, the beehives are a source of wax which is used in various medicinal preparations. The practice of bee keeping is called Apiculture. The place where the bees are raised is called as apiary.

Types of Honeybee

Honeybees are social and polymorphic insects. These are placed in class Insecta and order Hymenoptera. Honeybees may be of indigenous and exotic varieties as follows:

(a) Indigenous Varieties of Honey bees

• Apis cerana indica: It is commonly known as the Indian bee and widely used for culture in India.
• Apis dorsata: It is commonly known as rock bee and builds a large hive on tree branches or under the roof of high buildings.
• Apis florea: It is commonly known as little bee and builds small hives in bushes.

(b) Exotic Varieties of Honeybees

• Apis mellifera: It is commonly known as European bee. Its honey production is less but it is best for domestication due to its docile nature.
• Apis adamsoni: It is commonly known as African bee.

Colony of Honeybees

Do you know

• Ernest Spytzner was the first who noticed communication of bees or bee dances.
• Prof. Karl Van Frisch decoded the language of bee dances and got Nobel Prize, 1973. He has mentioned that the rate of dance is directly proportional to the distance of the food.

From the commercial point of view, Apis mellifera is found to be best species. Because

• The Italian bees have high honey collection capacity.
• They sting somewhat less.
• They stay in a given beehive for long periods, and breed very well.
• For commercial honey production, bee farms or apiaries are established.
• The value or quality of honey depends upon the pasturage, or the flowers available to the bees for nectar and pollen collection. In addition to adequate quantity of pasturage, the kind of flowers available will determine the taste of the honey.

Solved Exercise - Animal Husbandry Section

Short Answer Type Questions

1. What method is commonly used for improving the cattle breeds and why?

Sol. Cross breeding indigenous breeds. Foreign or exotic breeds have higher milk yield and longer lactation period as compared to indigenous breeds. Therefore indigenous breeds should be cross-breed with exotic breeds. The local breeds are hardy and resistant to several diseases. There are two methods of cross breeding-natural and artificial insemination. Artificial insemination is preferred as frozen semen can be transported, required in small quantity and protects the cows from contagious diseases.

2. Discus the implications of the following statement "It is interesting to note that poultry is India's most efficient converter of low fibre food stuff (which is unfit for human consumption) into highly nutritious animal protein food."

Sol. India is basically agriculture society where a lot of wastes are produced during food processing e.g., fish meal, meat, rice bran, etc. They are profitably used in forming poultry feed. In return poultry provides us with egg and meat rich in animal protein.

3. What is the difference between broilers and layer in their management?

Sol. Broilers are fast growing young chicken of 6-10 weeks age which are known for the good quality and taste of their meat. Layers are sexually mature hens which are raised for egg laying.

Broilers are given diet rich in protein, with adequate fat, vitamins A and K. They are provided with best of space, hygiene and temperature. Layer are given inferior equality feed. Light is required for good egg laying.

4. How are fishes obtained?

Sol. There are two methods of obtaining fish, capture fishery (capturing fish) from natural waters and culture fishery in impounded waters. In both cases the fish are caught with the help of nets.

5. What are the advantage of composite fish culture?

Sol.

• There is no competition for food or space amongst different types of fish.
• Food available in different parts of the pond are utilised due to their different food habits and different habitats.
• The fish yield is high as some six types of fish are growing simultaneously.

6. What is pasturage and how it is related to honey production?

Sol. Pasturage is flora or crop available to honey bee for collection of nectar and pollen. Pollen is food for honey bees. Nectar is transformed into honey. The amount and quality of honey depend upon type and extent of pasturage.

Long Answer Type Questions

7. How do good animal husbandry practices benefit farmers?

Sol. Good animal husbandry practices keep the animal healthy and more productive. There is higher yield of animal products-milk, eggs, meat.

1. Shelter: Diseases spread if the animal shelters are dingy and crowded. If they are spacious, hygienic and well lighted, the animals remain healthy.
2. Vaccination: Vaccination of young animal prevents the occurrence of common diseases.
3. Segregation of Sick Animals: When sick animal are noticed, they are immediately segregated. Cleanliness drive is undertaken and the remaining animals are given prophylactic doses of medicines to prevent the spread of disease. The livestock remains healthy and productive.
4. Proper Diet: A proper optimum diet with feed additives enhances growth and yield of animals.
5. Breeding: Breeding for more milk, longer lactation period, more egg laying, better convertibility of food and other good characteristics have allowed various branches animal husbandry to give better yield.

8. What are the benefits of cattle farming?

Sol.

1. Milk: It provides milk. Better breeds and better diet have increased milk availability in India. The phenomenal rise in milk availability is called white revolution. Dr. Verghese Kurien is father of white revolution in India. Today, India produces more milk (over 133 million tonnes) than any other country though pre capita milk availability is still low at 295 gms/day.
2. Utilisation of Spare Time: Farmers and others can utilize their spare time in the morning and evening for cattle farming.
3. Extra Income: Cattle farming provides a good amount of extra income.
4. Fodder: Growing fodder is helpul to farmers as the land is not left vacant. Selling of fodder gives good return.
5. Organic Wastes: Wheat bran, Rice bran, and oil cakes are organic wastes which form a good part of cattle feed.
6. Soil Fertility: Cattle dung is useful ingredient for biogas generation and manure formation.

9. For increasing production what is common in poultry, fisheries and bee-keeping?

Sol. (i) Good quality breeds. (ii) Proper feeds. (iii) Proper accomodation and care.

10. How do you differentiate amongst capture fishing, mariculture and aquaculture.

Sol.