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Chapter 15: Improvement In Food Resources
All living organisms require food, which provides essential nutrients like proteins, carbohydrates, fats, vitamins, and minerals for development, growth, and health. Our primary sources of food are plants and animals, obtained through agriculture and animal husbandry.
India, with its large and growing population (over one billion), faces a significant challenge in meeting the increasing food demand. While the land area under cultivation has increased by only about 25% from 1952 to 2010, food grain production has increased fourfold. However, India is already intensely cultivated, limiting the scope for expanding agricultural land. Therefore, there is a pressing need to increase the production efficiency of both crops and livestock.
Past efforts, like the Green Revolution (increasing food grain production) and the White Revolution (improving milk availability and use), have been successful but have also led to more intensive use of natural resources, increasing the risk of environmental degradation. Thus, increasing food production must be done through sustainable practices that do not harm the environment or disrupt ecological balances.
Beyond simply increasing production and storage, addressing malnutrition and hunger requires ensuring that people have access to food and the economic means to purchase it. Since a large portion of the population depends on agriculture for livelihood, increasing their income through enhanced farm productivity is essential.
Achieving higher yields and sustained livelihood requires adopting scientific management practices, potentially combining agriculture with other practices like livestock, poultry, fisheries, or bee-keeping (mixed farming). The key challenge is to determine how to effectively increase yields from crops and livestock.
Improvement In Crop Yields
Different types of crops provide various essential nutrients:
- Cereals (wheat, rice, maize, millets, sorghum): Provide carbohydrates for energy.
- Pulses (gram, pea, black gram, green gram, pigeon pea, lentil): Provide protein.
- Oilseeds (soybean, groundnut, sesame, castor, mustard, linseed, sunflower): Provide fats.
- Vegetables, Spices, Fruits: Provide vitamins and minerals, and small amounts of other nutrients.
Fodder crops (berseem, oats, sudan grass) are cultivated as food for livestock.
Crops are also classified based on the season they are grown:
- Kharif crops: Grown in the rainy season, from June to October (e.g., paddy, soybean, pigeon pea, maize, cotton).
- Rabi crops: Grown in the winter season, from November to April (e.g., wheat, gram, peas, mustard).
Increasing crop yields significantly involves practices across three main stages of farming:
- Choosing suitable seeds for planting.
- Nurturing the growing crop plants.
- Protecting the crops from pests, diseases, and storage losses.
Major areas of focus for improving crop yields are:
- Crop variety improvement.
- Crop production improvement.
- Crop protection management.
Crop Variety Improvement
Selecting or developing crop varieties (strains) with specific desirable traits is a key approach to improving yields. Desirable characteristics can include:
- Higher Yield: Increasing the amount of crop produced per unit area (per acre).
- Improved Quality: Tailoring the quality of the harvested product (e.g., baking quality in wheat, protein content in pulses, oil content in oilseeds, preservation quality in fruits/vegetables).
- Biotic and Abiotic Resistance: Developing varieties that can withstand stresses from living organisms (biotic, e.g., diseases, insects, nematodes) and non-living environmental factors (abiotic, e.g., drought, salinity, water logging, heat, cold, frost). This helps maintain production even under challenging conditions.
- Change in Maturity Duration: Developing crops that mature quickly (shorter duration from sowing to harvesting). This allows farmers to grow multiple crops in a year, increasing overall annual production and reducing production costs. Uniform maturity also makes harvesting easier and reduces post-harvest losses.
- Wider Adaptability: Developing varieties that can thrive under diverse environmental conditions (different climatic zones or soil types). This helps stabilise production and allows a single variety to be grown in various regions.
- Desirable Agronomic Characteristics: Modifying plant structure for specific needs. For fodder crops, traits like tallness and profuse branching are desired for more biomass. For cereals, dwarfness is preferred so the plant invests less energy in stem height and more nutrients are available for grain production.
Desirable characters can be introduced into crop varieties through hybridisation (crossing genetically different plants). This can occur between different varieties (intervarietal), different species of the same genus (interspecific), or even between different genera (intergeneric). Another method is genetic modification, where a specific gene conferring a desired trait is introduced into the crop, resulting in genetically modified crops (GM crops).
For any new variety to be successful, it must perform well under diverse conditions and farmers need access to good quality seeds that germinate reliably.
Crop Production Management
Crop production management involves optimizing the practices used to cultivate crops. Farming practices can vary widely depending on the farmer's resources, particularly financial capacity.
Production practices can be broadly categorised based on the level of financial input:
- No cost production: Minimal or no external inputs used.
- Low cost production: Some basic external inputs are used.
- High cost production: Significant investment in inputs like quality seeds, fertilisers, irrigation, machinery, and protection measures.
Generally, there is a correlation between higher financial inputs and higher yields. A farmer's ability to purchase and apply various inputs significantly influences their cropping system and production levels.
Nutrient Management
Just like humans, plants require essential nutrients for their growth, development, and health. These nutrients are obtained from air, water, and soil.
Plants obtain carbon and oxygen from the air and hydrogen from water. The soil is the primary source of the other thirteen essential nutrients required by plants.
Based on the quantities required by plants, these nutrients are classified as:
- Macronutrients: Required in large quantities (e.g., nitrogen, phosphorus, potassium, calcium, magnesium, sulphur).
- Micronutrients: Required in small quantities (e.g., iron, manganese, boron, zinc, copper, molybdenum, chlorine).
| Source | Nutrients |
|---|---|
| Air | carbon, oxygen |
| Water | hydrogen, oxygen |
| Soil | (i) Macronutrients: nitrogen, phosphorus, potassium, calcium, magnesium, sulphur |
| (ii) Micronutrients: iron, manganese, boron, zinc, copper, molybdenum, chlorine |
Deficiencies of these nutrients can negatively impact plant growth, reproduction, and make them more susceptible to diseases. To increase crop yield, the soil needs to be enriched by supplying these nutrients, typically in the form of manure or fertilisers.
Manure:
- Contains large amounts of organic matter and small quantities of nutrients.
- Prepared by decomposing animal excreta and plant waste.
- Improves soil fertility and increases organic matter content.
- Significantly improves soil structure: increases water holding capacity in sandy soils and improves drainage in clayey soils.
- Environmentally friendly, helps recycle farm waste.
Types of manure include:
- Compost and Vermi-compost: Decomposition of farm waste (animal manure, vegetable waste, etc.) in pits (composting). Vermi-compost uses earthworms to speed up decomposition.
- Green manure: Growing specific plants (like sun hemp, guar) and then ploughing them into the soil before sowing the crop. These plants decompose, enriching the soil with nitrogen and phosphorus.
Fertilisers:
- Commercially produced plant nutrients (e.g., urea, superphosphate, potash).
- Primarily supply macronutrients like nitrogen, phosphorus, and potassium.
- Promote good vegetative growth, leading to healthy plants and are a factor in high yields in intensive farming.
However, fertilisers must be used carefully (correct dose, time, method) to avoid negative impacts. Excess fertilisers can be washed away by irrigation, polluting water bodies. Continuous use can harm soil fertility by reducing organic matter and killing beneficial soil microorganisms. Balancing the short-term yield benefits of fertilisers with the long-term soil health benefits of manure is crucial for sustainable agriculture.
Organic Farming: A farming system that minimises or avoids the use of synthetic chemicals (fertilisers, herbicides, pesticides) and relies heavily on organic inputs (manure, recycled waste, bio-agents like biofertilisers and biopesticides) and healthy cropping systems (mixed cropping, inter-cropping, crop rotation). It aims for sustainable practices that improve soil health and control pests naturally.
Irrigation
In many regions like India, agriculture heavily depends on rainfall, making crops vulnerable to poor monsoons or uneven rainfall distribution (droughts). Ensuring a timely water supply to crops through irrigation at critical growth stages is essential for increasing yields and providing stability in production.
Various irrigation systems are used based on the availability of water resources and climate:
- Wells: Dug wells (tapping shallow water) and tube wells (tapping deeper water) provide groundwater, lifted by pumps.
- Canals: Extensive systems drawing water from reservoirs or rivers, with main canals branching into smaller distributaries to reach fields.
- River Lift Systems: Water is directly pumped from rivers to irrigate nearby areas, used where canal supply is insufficient.
- Tanks: Small reservoirs that collect and store rainwater runoff from smaller areas.
Modern approaches to increase water availability for agriculture include rainwater harvesting and watershed management. Building small check-dams helps stop rainwater runoff, reduce soil erosion, and increase the groundwater level, improving overall water availability in an area.
Cropping Patterns
Different methods of arranging and growing crops on the same land can be employed to maximise yields and benefits.
- Mixed Cropping: Growing two or more crops simultaneously on the same piece of land without a definite pattern (e.g., wheat and gram). This helps reduce the risk of total crop failure if one crop is affected by adverse conditions.
- Inter-cropping: Growing two or more crops simultaneously on the same field in a definite pattern, with rows of one crop alternating with rows of other crops (e.g., soybean and maize in alternating rows). Crops are selected based on different nutrient needs to optimise resource utilisation. This pattern also helps prevent pests and diseases from spreading rapidly across all plants of a single crop in the field, as plants of the other crop act as a barrier.
- Crop Rotation: Growing different crops on the same piece of land in a pre-planned sequence or succession over different seasons or years. The choice of crops and duration of rotation depend on factors like irrigation facilities and climate. Proper crop rotation can help maintain soil fertility (especially by including leguminous crops for nitrogen fixation), control pests and diseases, and allow for growing multiple crops in a year with good harvests.
Crop Protection Management
Protecting crops from damage by pests (weeds, insects) and diseases is crucial for preventing significant yield losses.
- Weeds: Unwanted plants that grow alongside cultivated crops (e.g., Xanthium, Parthenium, Cyperinus rotundus). They compete with the crop for light, space, water, and nutrients, reducing crop growth and yield. Removing weeds early in the crop's life is essential.
- Insect Pests: Insects that attack plants in various ways: cutting roots, stems, or leaves; sucking cell sap; boring into stems or fruits. They directly damage the plant, affecting its health and reducing yield.
- Plant Diseases: Caused by pathogens (bacteria, fungi, viruses) that can spread through soil, water, or air, infecting plants and causing diseases that harm growth and reduce production.
Control Methods:
- Pesticides: Chemical substances used to kill pests. Includes herbicides (kill weeds), insecticides (kill insects), and fungicides (kill fungi). Applied by spraying or treating seeds/soil. However, excessive use of pesticides is harmful to the environment, can kill non-target organisms (beneficial insects, soil microbes), and residue in food can be poisonous to humans and animals.
- Mechanical Removal: Physically removing weeds from fields.
- Preventive Methods: Practices that prevent or reduce pest infestation. Includes proper seed bed preparation, timely sowing, inter-cropping, crop rotation, using pest-resistant crop varieties, and summer ploughing (deep ploughing in summer to expose and kill pests and weed seeds).
Prevention and biological control methods are often preferred over chemical pesticides to reduce environmental harm.
Storage of Grains:
Significant losses can occur after harvesting if grains are not stored properly. Factors responsible for storage losses include:
- Biotic factors: Insects, rodents, fungi, mites, and bacteria.
- Abiotic factors: Inappropriate levels of moisture and temperature in the storage area.
These factors degrade grain quality, cause weight loss, reduce germinability, lead to discolouration, and make the produce less marketable.
To minimise storage losses, preventive and control measures are taken before and during storage:
- Strict cleaning of the grains before storage.
- Proper drying of the produce (first in sunlight, then in shade) to reduce moisture content.
- Fumigation: Using chemical fumigants to kill pests in storage areas or containers.
- Maintaining proper temperature and humidity levels in warehouses.
Animal Husbandry
Animal husbandry is the scientific management of animal livestock, encompassing practices related to feeding, breeding, and disease control. It includes raising cattle, goats, sheep, poultry, and fish for various products.
With increasing population and living standards, the demand for animal products like milk, eggs, and meat is rising. Simultaneously, there is growing awareness about the need for humane treatment of farm animals. Therefore, improving livestock production practices is essential to meet demand sustainably and ethically.
Cattle Farming
Cattle (cows and buffaloes) are farmed for two main purposes: milk production and draught labour (for agriculture and transport).
Milk-producing animals are called milch animals or dairy animals (e.g., cows - Bos indicus, buffaloes - Bos bubalis). Animals used for farm work are called draught animals.
Milk production can be increased by improving the breed and management practices. Milk production depends on the duration of the lactation period (period of milk production after calf birth).
To improve milk production, selective breeding or cross-breeding is done:
- Exotic (foreign) breeds (e.g., Jersey, Brown Swiss) are known for long lactation periods and high milk yields.
- Local (indigenous) breeds (e.g., Red Sindhi, Sahiwal) have excellent resistance to diseases common in India.
Cross-breeding between exotic and local breeds aims to develop new varieties that combine the desirable traits of both: long lactation periods and good disease resistance.
Management Practices in Cattle Farming:
- Proper Cleaning and Shelter: Providing clean, well-ventilated sheds that protect animals from rain, heat, and cold. Floors should be sloping for easy cleaning and drainage. Regular brushing is needed to keep animals clean.
- Feeding: Animals have different food requirements: maintenance requirements (for healthy life) and milk-producing requirements (additional food during lactation). Feed includes roughage (mostly fibre) and concentrates (protein-rich, low fibre). A balanced ration with all necessary nutrients is needed. Feed additives (micronutrients) promote health and milk yield.
- Disease Control: Cattle are susceptible to diseases (caused by bacteria, viruses, parasites, nutritional deficiencies). Diseases reduce milk production and can cause death. Parasites can be external (on skin) or internal (worms, flukes). Prevention includes hygiene, sanitation, disinfectants, and vaccination against major diseases.
Poultry Farming
Poultry farming involves raising domestic fowl (chickens) for egg production and chicken meat.
Improved poultry breeds are developed for specific purposes:
- Layers: Bred for egg production.
- Broilers: Bred for meat production (faster growth rate, better feed efficiency).
Cross-breeding programmes between indigenous (e.g., Aseel) and exotic (e.g., Leghorn) breeds aim for desirable traits:
- Increased number and quality of chicks.
- Developing dwarf broiler parents for commercial production efficiency.
- Improved adaptation and tolerance to high temperatures (summer adaptation).
- Lower maintenance requirements.
- Reducing the size of egg-laying birds while improving their ability to use cheaper, high-fibre diets from agricultural by-products (efficient feed utilisation).
Management Practices in Poultry Farming:
- Housing: Proper temperature, lighting, and hygienic conditions are essential.
- Feeding: Broilers require protein-rich feed with adequate fat and high levels of vitamins (A, K) for rapid growth and good feed efficiency. Layer feed is different, focused on egg production.
- Disease Control: Poultry are susceptible to viral, bacterial, fungal, parasitic, and nutritional deficiency diseases. Regular cleaning, sanitation, disinfection, and timely vaccination are crucial for preventing outbreaks and reducing losses.
Poultry is considered an efficient way to convert low-fibre foodstuff (like agricultural by-products) into nutritious animal protein (eggs and meat) for human consumption.
Fish Production
Fish is a valuable and often cheap source of animal protein. Fish production includes true fish (finned fish) and shellfish (prawns, molluscs).
There are two main ways to obtain fish:
- Capture Fishing: Obtaining fish from natural resources (seas, oceans, rivers, lakes) where they live freely.
- Culture Fishery (Aquaculture): Farming fish in designated water bodies.
Fish production occurs in both marine (seawater) and inland (freshwater and brackish water) ecosystems.
Marine Fisheries
India has an extensive coastline and deep seas rich in marine fish resources. Popular marine varieties include pomfret, mackerel, tuna, sardines, and Bombay duck.
Fish are caught using various types of fishing nets from boats. Technology like satellites and echo-sounders helps locate large schools of fish in the open sea to improve yields.
Due to increasing demand and depletion of natural marine fish stocks, mariculture (farming marine fish and shellfish in seawater) is becoming more important. This includes farming finned fish (mullets, bhetki, pearl spots), shellfish (prawns, mussels, oysters), and even seaweed. Oysters are also cultivated for pearls.
Inland Fisheries
Inland water resources include freshwater bodies (canals, ponds, reservoirs, rivers) and brackish water bodies (estuaries, lagoons) where freshwater mixes with seawater.
While some capture fishing occurs, the yield from inland resources is often higher through aquaculture (fish culture or farming).
Fish culture can sometimes be integrated with other farming, like growing fish in waterlogged paddy fields.
Composite fish culture is an intensive system where multiple fish species (typically 5 or 6) are raised in a single fishpond. The species are carefully selected based on their different food habits to ensure that they do not compete with each other and effectively utilise all available food resources in the pond (surface, middle zone, bottom, weeds). This increases the overall fish yield from the pond.
A challenge in fish farming is the availability of good-quality fish seed, as many species breed only during monsoons, and wild-caught seed can be mixed. To overcome this, methods have been developed to induce breeding of these fish in ponds using hormonal stimulation, ensuring a reliable supply of pure fish seed.
Bee-keeping
Bee-keeping (Apiculture) is the practice of rearing bees, primarily for producing honey and beeswax. It is often undertaken as an agricultural enterprise or an additional income-generating activity for farmers due to its relatively low investment requirement.
Beeswax, besides honey, is a valuable product used in various medicinal and industrial preparations.
Several bee varieties are used for commercial honey production in India:
- Local varieties: Apis cerana indica (Indian bee), A. dorsata (rock bee), A. florae (little bee).
- Exotic variety: Apis mellifera (Italian bee).
The Italian bee (A. mellifera) is commonly used for commercial production due to its desirable characters:
- High honey collection capacity.
- Sting less frequently.
- Stay in beehives for longer periods without swarming.
- Breed very well.
Commercial honey production often involves establishing bee farms called apiaries.
The quality and taste of honey depend on the pasturage, which refers to the availability and type of flowers from which bees collect nectar and pollen. Adequate pasturage is needed for good honey yield, and the specific flowers determine the unique flavour of the honey.
Intext Questions
Page No. 204
Question 1. What do we get from cereals, pulses, fruits and vegetables?
Answer:
Page No. 205
Question 1. How do biotic and abiotic factors affect crop production?
Answer:
Question 2. What are the desirable agronomic characteristics for crop improvements?
Answer:
Page No. 206
Question 1. What are macro-nutrients and why are they called macronutrients?
Answer:
Question 2. How do plants get nutrients?
Answer:
Page No. 207
Question 1. Compare the use of manure and fertilizers in maintaining soil fertility.
Answer:
Page No. 208
Question 1. Which of the following conditions will give the most benefits? Why?
(a) Farmers use high-quality seeds, do not adopt irrigation or use fertilizers.
(b) Farmers use ordinary seeds, adopt irrigation and use fertilizer.
(c) Farmers use quality seeds, adopt irrigation, use fertilizer and use crop protection measures.
Answer:
Page No. 209
Question 1. Why should preventive measures and biological control methods be preferred for protecting crops?
Answer:
Question 2. What factors may be responsible for losses of grains during storage?
Answer:
Page No. 210
Question 1. Which method is commonly used for improving cattle breeds and why?
Answer:
Page No. 211
Question 1. Discuss 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.”
Answer:
Question 1. What management practices are common in dairy and poultry farming?
Answer:
Question 2. What are the differences between broilers and layers and in their management?
Answer:
Page No. 213
Question 1. How are fish obtained?
Answer:
Question 2. What are the advantages of composite fish culture?
Answer:
Question 1. What are the desirable characters of bee varieties suitable for honey production?
Answer:
Question 2. What is pasturage and how is it related to honey production?
Answer:
Exercises
Question 1. Explain any one method of crop production which ensures high yield.
Answer:
Question 2. Why are manure and fertilizers used in fields?
Answer:
Question 3. What are the advantages of inter-cropping and crop rotation?
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Question 4. What is genetic manipulation? How is it useful in agricultural practices?
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Question 5. How do storage grain losses occur?
Answer:
Question 6. How do good animal husbandry practices benefit farmers?
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Question 7. What are the benefits of cattle farming?
Answer:
Question 8. For increasing production, what is common in poultry, fisheries and bee-keeping?
Answer:
Question 9. How do you differentiate between capture fishing, mariculture and aquaculture?
Answer: