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Chapter 12: IMPROVEMENT IN FOOD RESOURCES

Food supplies proteins, carbohydrates, fats, vitamins and minerals. They are required for body development, growth and health.

Agriculture and animal husbandry provides food.

India needs more than a quarter of a billion tonnes of grain every year. But there is only limited land area for cultivation. So increasing the production efficiency of crops and livestock is essential.

Green revolution increased food-grain production and White revolution increased milk production.

But these also led to intensive use of natural resources, causing environmental damage. Hence, food production should be increased without degrading environment.

Scientific management practices, including mixed farming, intercropping, and integrated farming should be adopted for high yields and sustained livelihoods.

IMPROVEMENT IN CROP YIELDS

- Cereals like wheat, rice, maize, millets, and sorghum provide carbohydrates for energy.

- Pulses like gram, pea, black gram, green gram, pigeon pea and lentil provide protein.

- Oil seeds like soyabean, ground nut, sesame, castor, mustard, linseed and sunflower provide fats.

- Vegetables, spices and fruits provide vitamins, minerals, small amounts of proteins, carbohydrates and fats.

- Food crops like berseem, oats or sudan grass are grown for livestock.

- Different crops require different climatic conditions, temperature and photoperiods (duration of sunlight) for their growth, flowering and completion of life cycle.

- The crops which are grown in rainy season (June to October i.e., kharif season) are called kharif crops. E.g., Paddy, soyabean, pigeon pea, maize, cotton, green gram and black gram.

- The crops which are grown in the winter season (November to April i.e., rabi season) are called rabi crops. E.g., wheat, gram, peas, mustard, linseed etc.

- In India, there has been four times increase in the production of food grains from 1952 to 2010 with only 25% increase in the cultivable land area.

- 3 stages of farming:

· Choice of seeds for planting.

· Nurturing of the crop plants.

· Protection of growing and harvested crops from loss.

- Major groups of activities for improving crop yields:

• Crop variety improvement

• Crop production improvement

• Crop protection management.

CROP VARIETY IMPROVEMENT

- It depends on finding a crop variety that yield well. This includes breeding for characteristics like disease resistance, better response to fertilisers, product quality, and high yield.

- Hybridisation is a way to incorporate desirable characters into crop varieties. It is the crossing of genetically dissimilar plants. Hybridisation may be

· Intervarietal: Between different varieties.

· Interspecific: Between 2 species of the same genus.

· Intergeneric: Between different genera.

- Another way of improving the crop is by introducing a gene that would provide the desired characteristic. This results in genetically modified crops.

- New varieties must produce high yields under various environmental conditions.

- Good quality seeds are essential for farmers, ensuring uniform germination under the same conditions.

- Cultivation practices and crop yield depend on weather, soil quality and water availability. Varieties that withstand diverse climates (such as drought and flood situations) and tolerant to high soil salinity are useful.

Key factors for variety improvement:

· Higher yield: To increase the productivity per acre.

· Improved quality: Depends on the crop. E.g., Baking quality in wheat, protein quality in pulses, oil quality in oilseeds and preserving quality in fruits and vegetables.

· Biotic and abiotic resistance: Development of varieties resistant to biotic (diseases, insects and nematodes) and abiotic (drought, salinity, water logging, heat, cold and frost) stresses.

· Change in maturity duration: Shorter crop duration helps to grow multiple rounds of crops in a year. It also reduces the cost of crop production. Uniform maturity simplifies harvesting and minimizes losses.

· Wider adaptability: Varieties that grow in various environmental and climatic conditions stabilise production.

· Desirable agronomic characteristics: Tallness and profuse branching are desirable for fodder crops. Dwarfness is desired in cereals, so that less nutrients are consumed. Thus they give higher productivity.

CROP PRODUCTION MANAGEMENT

Production practices are at different levels - ‘no cost’, ‘low cost’ and ‘high cost’.

(i) NUTRIENT MANAGEMENT

- Nutrients are supplied to plants by air, water and soil.

- Some nutrients are required in large quantities. They are called macro-nutrients. Other nutrients are needed in small quantities. They are called micro-nutrients.

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

- Deficiency of nutrients affects plant’s physiological processes like reproduction, growth and susceptibility to diseases.

- To increase the yield, soil can be enriched by adding nutrients through manure and fertilizers.

MANURE

- It contains organic matter and some nutrients.

- It is prepared by the decomposition of animal excreta and plant waste.

- It enriches soil with nutrients and organic matter and increase soil fertility. The organic matter improves the soil structure. This involves increasing the water holding capacity in sandy soils. In clayey soils, the organic matters help in drainage and avoid water logging.

- Manure reduces excessive fertilizer use and recycles farm waste, protecting the environment.

- Based on the kind of biological material used, manure can be classified as:

1. Compost and vermicompost: The process in which farm waste material like livestock excreta (cow dung, etc.), vegetable waste, animal refuse, domestic waste, sewage waste, straw, eradicated weeds etc. is decomposed in pits is known as composting.

The compost is rich in organic matter and nutrients.

Compost prepared by using earthworms hastens the decomposition of plant and animal refuse. This is called vermicompost.

2. Green manure: Before sowing crop seeds, plants like sun hemp or guar are grown and then ploughed into the soil as mulch. This green manure enriches the soil with nitrogen and phosphorus.

FERTILIZERS

- These are commercially produced nutrients supplying

nitrogen, phosphorus & potassium for better vegetative growth (leaves, branches, flowers) and higher yields in high-cost farming.

- They should be applied with proper dose, timing, and pre- and post-application precautions to avoid wastage and water pollution. E.g., fertilizers may be washed away by excessive irrigation. This causes water pollution.

- Overuse of fertilizers reduce soil fertility by depleting organic matter and harming soil microorganisms.

- Fertilizers offer short-term benefits, but manure provides long-term soil fertility.

- Organic farming is a farming system with minimal or no use of chemicals as fertilizers, herbicides, pesticides, etc., and with a maximum input of organic manures, recycled farm-wastes and use of bio-agents.

The bio-agents include culture of blue green algae (biofertilizers), neem leaves or turmeric in grain storage (bio-pesticides).

Organic farming depends on healthy cropping systems such as mixed cropping, inter-cropping and crop rotation. These are beneficial in insect, pest and wheat control besides providing nutrients.

(ii) IRRIGATION

- Indian agriculture relies on rain-fed systems, making crop success dependent on timely and sufficient monsoons. Poor rainfall leads to crop failure, while timely irrigation increases yields.

- Irrigation reduces dependence on rain, especially in drought-prone areas with light soils that retain less water. Scientists have developed drought-tolerant crop varieties.

- India’s irrigation methods:

· Wells: 2 types - dug wells and tube wells.

Dug well: Water is collected from water bearing strata.

Tube wells: Water is tapped from the deeper strata.

· Canals: An elaborate and extensive irrigation system in which they receive water from one or more reservoirs or rivers. The main canal is divided into branch canals to irrigate fields.

· River Lift Systems: Water is directly drawn from the rivers to supplement irrigation in areas close to rivers. It is useful in areas where canal flow is insufficient or irregular due to inadequate reservoir release.

· Tanks: Small storage reservoirs, which intercept and store the run-off of smaller catchment areas.

- Rainwater harvesting and watershed management, including check-dams, are fresh initiatives to boost water availability, raising groundwater levels and reducing soil erosion.

(iii) CROPPING PATTERNS

· Mixed cropping: Growing two or more crops simultaneously on the same land.

E.g., wheat + gram, or wheat + mustard, or groundnut + sunflower. This reduces risk and gives some insurance against failure of one of the crops.

· Inter-cropping: Growing two or more crops simultaneously on the same field in a definite pattern.

A few rows of one crop alternate with a few rows of a second crop, E.g., soyabean + maize, or finger millet (bajra) + cowpea (lobia).

Crops are selected based on their different nutrient needs. This ensures maximum nutrient utilisation, and prevents pests and diseases from affecting all plants of the same crop. Thus, both crops give better yields.

Intercropping

· Crop rotation: The growing of different crops on a piece of land in a pre-planned succession.

The choice of crops depends on the availability of moisture and irrigation. If done properly, it allows two or three harvests per year with good yields.

CROP PROTECTION MANAGEMENT

- Weeds, insect pests & diseases may damage field crops.

- Weeds are unwanted plants in the cultivated field. E.g., Xanthium (gokhroo), Parthenium (gajar ghas), Cyperinus rotundus (motha). They compete for food, space and light and take up nutrients reducing the crop growth.

- Insect pests attack the plants in 3 ways:

· They cut the root, stem and leaf.

· They suck the cell sap from various plant parts.

· They bore into stem and fruits.

- Plant diseases are caused by pathogens like bacteria, fungi, and viruses, which can spread through soil, water, and air.

Prevention and control of weeds, insects & diseases:

· Pesticides such as herbicides, insecticides, and fungicides are used on crops or for seed and soil treatment. However, excessive use can harm plants and animals, leading to environmental pollution.

· Mechanical removal of weeds.

· Preventive methods like proper seed bed preparation, timely sowing, intercropping and crop rotation help in weed control.

· Preventive measures against pests: Use of resistant varieties and summer ploughing (fields are ploughed deep in summers to destroy weeds and pests).

STORAGE OF GRAINS

Factors causing storage losses in agricultural produce:

· Biotic: Insects, rodents, fungi, mites and bacteria.

· Abiotic: Inappropriate moisture and temperatures in the place of storage.

These factors cause degradation in quality, loss in weight, poor germinability, discolouration of produce.

Preventive and control measures:

· Strict cleaning of the produce before storage.

· Drying of the produce in sunlight and then in shade.

· Fumigation using chemicals that can kill pests.

ANIMAL HUSBANDRY

- It is the scientific management of animal livestock.

- It includes feeding, breeding and disease control.

- Animal-based farming includes cattle, goat, sheep, poultry and fish farming.

CATTLE FARMING

- Cattle husbandry serves two purposes - milk production and draught labour for agricultural work such as tilling, irrigation and carting.

- Indian cattle include two species- Bos indicus (cows) and Bos bubalis (buffaloes).

- Milk-producing females are called milch animals (dairy animals). Cattles used for farm labour are called draught animals.

- Milk production can be increased by increasing the lactation period.

- Exotic or foreign breeds (E.g., Jersey, Brown Swiss) are selected for long lactation periods, while local breeds (E.g., Red Sindhi, Sahiwal) show excellent diseases resistance. The two can be cross-bred to get animals with both the desired qualities.

- Proper cleaning and shelter are essential for humane farming, animal health, and the production of clean milk.

- Animals need regular brushing to remove dirt and loose hair. They should be sheltered in well-ventilated roofed sheds to protect from rain, heat and cold. The floor should be sloped for dryness and easy cleaning.

- Food requirements of dairy animals are 2 types:

a. Maintenance requirement: Food required to support a healthy life.

b. Milk producing requirement: Food required during the lactation period.

- Animal feed includes:

· Roughage: It is largely fibre.

· Concentrates: These are low in fibre and contain relatively high levels of proteins and other nutrients.

- Besides food, feed additives containing micronutrients promote the health and milk output of dairy animals.

- Cattle suffer from various diseases which reduce milk production and may cause death.

- Cattle parasites include

· External parasites: They live on the skin and cause skin diseases.

· Internal parasites: Worms affect stomach and intestine. Flukes damage the liver.

- Vaccinations protect farm animals from major viral and bacterial diseases.

Animal Products	Nutritional value in Per cent (%)
Animal Products	Fat	Protein	Sugar	Minerals	Water	Vitamins
Milk (Cow)	3.60	4.00	4.50	0.70	87.20	B₁, B₂, B₁₂, D, E
Egg	12.00	13.00	Trace amount	1.00	74.00	B₂, D
Meat	3.60	21.10	Trace amount	1.10	74.20	B₂, B₁₂
Fish	2.50	19.00	Trace amount	1.30	77.20	Niacin, D, A

POULTRY FARMING

- It is the farming of domestic fowl for egg production and chicken meat.

- Improved poultry breeds are developed to produce layers (for eggs) and broilers (for meat).

- The cross-breeding programmes between Indian (indigenous, E.g., Aseel) and foreign (exotic, E.g., Leghorn) breeds aims to develop new varieties for the following desirable traits:

· Number and quality of chicks.

· Dwarf broiler parent for commercial chick production.

· Summer adaptation capacity/ tolerance to high temperature.

· Low maintenance requirements.

· Reduced size of the egg-laying bird with ability to utilise more fibrous cheaper diets formulated using agricultural by-products.

EGG AND BROILER PRODUCTION

- Broiler chickens are fed with vitamin-rich supplementary feed for good growth rate and feed efficiency. They are managed to prevent mortality and maintain feathering and carcass quality, and are sent to market for meat.

- Management practices for good production:

· Maintenance of temperature and hygienic conditions in housing and poultry feed.

· Prevention and control of diseases and pests.

- Broilers have different housing, nutritional, and environmental needs compared to egg layers.

- Broiler feed is protein-rich with adequate fat and high levels of vitamins A and K.

- Poultry fowl suffer from diseases caused by virus, bacteria, fungi, parasites, and nutritional deficiencies. Preventative measures include:

· Proper cleaning, sanitation & spraying of disinfectants.

· Vaccination.

FISH PRODUCTION

- Fish is a cheap source of animal protein for our food.

- Fish production includes the finned true fish and shellfish such as prawns and Molluscs.

- There are two ways of obtaining fish.

· Capture fishing: From natural resources.

· Culture fishery: Fish farming.

(i) MARINE FISHERIES

- India’s marine fishery resources include 7500 km of coastline and the deep seas.

- Popular marine fishes: Pomphret, mackerel, tuna, sardines, and Bombay duck.

- Marine fish are caught using various nets from fishing boats. Yields are increased by locating schools of fish using satellites and echo-sounders.

- Some marine fish of high economic value are also farmed in seawater. E.g., finned fishes like mullets, bhetki, and pearl spots, shellfish such as prawns, mussels and oysters as well as seaweed.

- Oysters are also cultivated for the pearls they make.

- As marine fish stocks become depleted, increasing demand for fish can be met through culture fisheries, called mariculture.

(ii) INLAND FISHERIES

- Inland fisheries use fresh water resources like canals, ponds, reservoirs, rivers, and brackish water resources (estuaries & lagoons). Although capture fishing occurs here, most fish production comes from aquaculture.

- Fish culture can be combined with rice cultivation, where fish are grown in paddy fields.

- Intensive fish farming uses composite fish culture systems, involving both local and imported species. Here, five or six fish species are stocked in a single pond. They are selected for their different food habits – surface feeders (e.g., Catlas), middle-zone feeders (e.g., Rohus), bottom feeders (e.g., Mrigals and Common Carps), and weed feeders (e.g., Grass Carps). It ensures efficient use of all food resources in the pond without competition, thereby increasing fish yield.

- A challenge in composite fish culture is that many fish breed only during the monsoon. Also, wild-caught fish seed may be mixed with other species. To ensure quality seed availability, hormonal stimulation techniques have been developed to breed fish in ponds.

BEE-KEEPING

It is an agricultural enterprise of rearing honeybees for honey and wax.

Beehives are the source of wax. It is used in medicines.

The local bee varieties used for commercial honey production are Apis cerana indica (Indian bee), A. dorsata (rock bee) and A. florae (little bee).

The Italian bee variety, A. mellifera, is introduced which has high honey collection capacity, lower stinging, stay in a beehive for long periods, and breed very well.

For commercial honey production, bee farms or apiaries are established.

The quality and taste of honey depend on the pasturage, or the flowers available for nectar and pollen collection.

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12. Improvement in Food Resources | Class 9 Science | PDF and Web notes

IMPROVEMENT IN CROP YIELDS

ANIMAL HUSBANDRY