Food Resource

7/28/2019 Food Resource

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FOOD RESOURCES

Food is an essential requirement for the human

survival. Each person has minimum food requirement. The

main components of food are carbohydrates, fats,

proteins, minerals, and vitamins. Food:

It is a Organic matter taken to satisfy appetite.To meet physiological needs for growth, to supplyenergy, to do work, to maintain bodytemperature.

Foods differ in the amount of the nutrients.


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Types of Food Supply

Historically humans have dependent on threesystems for their food supply.

1. Croplands:It mostly produces grains and provide about 76%

of the world's food.

Ex: Rice, wheat, maize, barley, sugarcane, potato, etc.,

Plants:Four crops-wheat, rice, corn, and potato make up

most of the worlds total food production than all othercrops combined.

Grains(mainly rice, wheat, and corn) provide abouthalf the worlds calories.

Fruits &Vegetables are rich in vitamins, Minerals,Dietary fibre and complex carbohydrate.


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2.Rangelands:

It produces food mainly from the

grazing livestock and provide about 17% of theworld's food

Ex: Meat, milk, fruits, etc.,

Livestock:Domesticated animals eg. Cattle, sheep,

goat, camel, etc. People consume meat, eggs,

milk, cheese, and other products ofdomesticated livestock.


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3. Oceans:

Oceanic fisheries supply about 7% of the

world's food.Aquaculture: Marine and fresh water food

contribute to high quality protein In addition,

one third of the worlds fish catch is convertedinto fish meal to feed livestock consumed by

meat eaters.

Fish and sea food contribute about 70million metric tons of high quality protein to

the worlds diet.


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Major Food sources

The earth is provided with more than

thousands of edible plants and animals.However only 15 plants and 8 terrestrial animalspecies supply 90% of our global Intake ofcalories.

Ex: Rice, wheat, maize, potato, barley, sugarcane,pulses, fruits, vegetables, milk, meat, fish andsea food.

Rice, wheat and maize are the major grains,provide more than 50% of the calories peopleconsume.


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WORLD FOOD PROBLEM

World food problems involve complex

interactions among Food production, Populationgrowth, Poverty, Environmental effects,Economic, Political systems, and Ethics.

In 1996, the World Bank estimated that morethan one billion of the worlds people do not

have enough food to lead healthy and productivelives.

Food and Agriculture Organization (FAO)estimates that about 840 million people remainhungry, though the number has been decreasing2.5 million per year over the last eight years.


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The FAO estimation minimum calorific intake on

a global scale is 2,500 calories/day.

Undernourished - < 90% of min requirementseriously under nourished - < 80%

Deficiency or lack of nutrition malnutrition

1. Nutritious (or) nutrition (or) nourished:

To maintain good health and resist disease,

we need large amount of macronutrients such as

carbohydrates, proteins, and fats and smalleramount of micronutrients such as vitamins A, C

and E and minerals such as iron, calcium and

iodine.


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2. Under nutrition (or) under nourished:

People who cannot buy enough food to meet

their basic energy needs (carbohydrates) sufferfrom under nutrition. They receive less than 90%of these minimum dietary calories.

Effect of under nutrition:

Suffer from mental retardation and infectiousdiseases such as measles and diarrohea.

3. Malnutrition (or) malnourished:

Besides the minimum calorie intake we alsoneed proteins, minerals, vitamins, iron andiodine. Deficiency or lack of nutrition often leadsto malnutrition resulting in several diseases.


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The dietary condition caused by an

insufficiency of one or more nutrients in the

diet.

The two most common forms of PEM,

Marasmus and kwashiorkor


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Children in this category are suffer frompermanently stunted growth , mental

retardation, and other developmental disorders.Every year 40 million people (fifty percent of

which are young children between 1 to 5 years)die of undernourishment and malnutrition.

Over nutrition:

In richer countries, the most common dietaryproblem is too many calories. The average daily

calorific intake in North America and Europe isabove 3,500 calories. Over nutrition contributesto overweight ,high blood pressure, heart attack,and other cardiovascular diseases.


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Balanced Diet:

A balanced diet includes a variety of foodsfrom all 5 food groups. ( Grains, Vegetables,Fruits, Meat & dairy products, Sugar & Fats).

It should provide enough calories to

ensure desirable weight and should include allthe necessary daily nutrients.

About 50% of your calories should come

from complex carbohydrates. About 20%should come from proteins. About 30% shouldcome from fats.


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THE EFFECTS OF AGRICULTURE ON THE ENVIRONMENT

A. Local Effects:

These occur at or near the site of farming. It includessoil erosion and increase in sedimentation. It destroys

aquatic life.

B. Regional Effects:

It includes deforestation, desertification, large scalespollution, fertility of the soil is also affected.

C. Global Effects:

These include climatic changes as well as potentially

extensive changes in chemical cycles.


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Overgrazing:

Livestock wealth plays a crucial role in the rural lifeof our country. The live stock grazing on a particularpiece of grassland is called as Overgrazing.

Overgrazing is a process of, "eating away the forestvegetation without giving it a chance to regenerate".

Impact of Overgrazeing:

Land Degradation,

Soil Erosion,

Loss of useful species,

overgrazing vast areas in Arunachal Pradesh andMeghalaya are getting invaded by thorny bushes,weeds etc. Of low fodder value.


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AGRICULTURE

It is an art, science and industry of managing

the growth of plants and animals for human use.Agriculture includes cultivation of the soil,

growing and harvesting crops, breeding and

raising livestock, dairying and forestry.Types of Agriculture

The two major types of agricultural systems are

Traditional agriculture.

Modern agriculture (a) Industrialized agriculture.


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Traditional agriculture

It involves a small plot, simple tools, surface water,organic fertilizers and a mix of crops. They produce

enough food to feed their families and to sell it for theirincome.

Effects (or) impacts of Traditional agriculture

(a) Deforestation: Cutting and burning of trees in forests to

clear the land for cultivation results in loss of forest cover.

(b) Soil erosion: Clearing of forest cover exposes the soil towind and rainfall, resulting in loss of top fertile soil layer.

(c) Loss of nutrients: During cutting and burning of trees, theorganic matter in the soil gets destroyed and most of thenutrients are taken up by the crops within a short period.Thus the soil becomes poor in nutrient, which makes thefarmers shift to another area.


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modern agriculture

It makes use of hybrid seeds of single crop variety, high-tech

equipments, lot of fertilizers, pesticides and water to producelarge amount of single crops.


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Effects (or) impacts of modern agriculture (or)

Adverse effects of agricultural practices (or)

Environmental effects of agriculture1. Problems in using Fertilizer

(a) Micronutrient imbalance:

Most of the chemical fertilizers used inmodem agriculture contain nitrogen, phosphorus

and potassium (N, P, K), which are

macronutrients. When excess of the fertilizersare used in the fields, it causes micronutrient

imbalance.


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(b) Blue Baby syndrome (Nitrate pollution): Whenthe Nitrogenous fertilizers are applied in thefields, they leach deep into the soil andcontaminate, the ground water. The nitrateconcentration in the water gets increased. Whenthe nitrate concentration exceeds 25 mg / lit,

they cause serious health problem called "BlueBaby syndrome". This disease affects infants andleads even to death.

c)Eutrophication: A large proportion of N and P

fertilizers used in crop fields is washed off by therunoff water and reaches the water bodiescausing over nourishment of the lakes. Thisprocess is known as Eutrophication.


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Due to eutrophication lakes get attacked by algal

blooms. The algal species use up the nutrients rapidly

and grow very fast. Since the life time of the algal

species are less they die quickly and pollute the water,

which in turn affect the aquatic life.

Pesticides :

The chemical compounds that are used for thecontrol of pests are called Pesticides

Pest:

Any organism that causes an economic loss ordamage to the physical well being of the plant is a

pest.


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PROBLEMS IN USING PESTICIDES

In order to improve the crop yield, lot of pesticides are

used in the agriculture.

(i) First generation pesticides:

Sulphur, arsenic, lead, or mercury are used to kill the

pests.

(ii) Second generation pesticides:

DDT (Dichloro diphenyl trichloromethane) is used

to kill the pests.

Although these pesticides protect our crops fromhuge losses due to pests, they produce number of side-

effects


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(a) Death of non-target organisms:

Many insecticides not only kill the target species, but

also kill the several non-target species, which are useful to

us.

(b) Producing new pests: Some pests species usually survive

even after the pesticides spray, which generates highly

resistant generations. They are immune (resistant) to alltype of pesticides and are called superpests.

(c) Bio-magnification: Many of the pesticides are non-

biodegradable and keep on concentrateing in the food

chain. These process is called bio-magnification. Thesepesticides in a bio-magnified form is harmful to the

human beings.,


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(d) Risk of cancer:

Pesticides enhance the risks of cancer in two ways.

(i) It directly acts as carcinogens.

(ii) It indirectly suppress the immune system.

Desired qualities of an ideal pesticide

(i) An ideal pesticide must kill only the target species.

(ii) It must be a biodegradable.

(iii) It should not produce new pests.

(iv) It should not produce any toxic pesticide vapour.

(v) Excessive synthetic pesticide should not be used.(vi) Chlorinated pesticides and organophosphate

pesticides are hazardous, so they should not be used.


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WATER LOGGING

Water logging is the land where water stand for most of

the year.

Problems in water logging

During water-logged conditions, pore-voids in the

soil get filled with water and the soil-air gets depleted.

In such a condition the roots of the plants do not get

adequate air for respiration. So, mechanical strength of

the soil decreases and crop yield falls.

Causes of water loggingExcessive water supply to the croplands

Heavy rain.

Poor drainage


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Salinity

The water not absorbed by the soil, undergo

evaporation leaving behind a thin layer ofdissolved salts in the top soil. This process of

accumulation of salts is called salinity of the soil.

The saline soils are characterized by theaccumulation of soluble salts Like sodium

chloride, calcium chloride, magnesium chloride,

sodium sulphate, sodium bicarbonates and

sodium carbonates.

The pH of the water exceeds 8.0 (alkaline).


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Problems in salinity

Most of the water, used for irrigation comes

only from canal or ground, which unlike rainwatercontains dissolved salts.

Under dry climates, the water gets evaporated

leaving behind the salt in the upper portion ofthe soil.

Due to salinity, the soil becomes alkaline and

crop yield decreases


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About 36.6 % of the land area is occupied

by human dwellings, factories, roads, railways,

deserts, mountains, rocks, glaciers and polar

ice marshes.

About 30 % of the total land mass in under

forests.

About 22 % of land is occupied by

meadows and pastures.

Only 11 % of land is suitable for

ploughing.


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SOIL:

Soil is an organized mixture of minerals, organic material,

living organisms, air and water.

It deals with the origin, formation and geographic distribution

of the soil.

Soil is formed by two processes

(i) weathering-breaking down of rock into small particles and

(ii) pedo*-genesis-maturation of soil through development of

humus.

Soil fertility is determined by the inorganic matter, organic

matter, water and air spaces in the soil.

The mineral portion of the soil consists of various mixtures of

sand, silt and clay particles.


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SOIL TEXTURE:

The physical structure of a soil is called soil texture.

It depends upon the % of its mineral particles. Soiltexture determines the porosity and nutritional status

of the soil.

There are three important textural soil types-

sandy, clayey and loamy.

(i) Sandy soils:

Contain < 10 % each of clay and silt + remaining

part is sand. Porous and well aerated, Little waterholding capacity, chemically inert. Generally called

light soils because of the absence of moisture. So it

is unfit for plant growth.


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(ii) Clayey soils:

40 % or more clay. Heavy soils because the soils

are compactly packed with little aeration. small sizedpores, which retain water very firmly. Clayey soils

are rich in nutrients but do not support good plant

growth due to poor aeration.

(iii) Loamy soils:

They contain sand, silt and clay approximately in

the ratio of 2 : 2 : 1. Ideally suited for plant growth

because they possess good aeration, sufficientnutritive salts and good water retaining capacity.


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Composition of Soil:

Soil is composed of five constituents:

(i) mineral matter

(ii) organic matter

(iii) soil water

(iv) soil air

(v) living organisms.


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1. M ineral matter:

Derived from the underlying parent rock by its

weathering and occurs in the soil as particles.The mineral particles are irregular in outline and

therefore enclose spaces called interstices for

circulation of air and water.

Depending upon their size ,soil particles are of following types :

Gravel [ 2.00 -5.00 mm],

Coarse Sand[0.20 -2.00 mm],

Fine Sand[0.02 -0.20 mm], Silt [0.002-0.02 mm],

Clay[ less than 0.002 mm


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2. Organic matter :

It is derived from plant refuse (leaves, twigs, roots),

dead bodies of organisms and their excreta(wastes). Theorganic matter is broken down by microbes and is

converted into dark amorphous substance called humus.

Humus is a very useful substance in the soil. It acts as

natural fertilizer.

3. Soil water:

The spaces between soil particles are occupied by water

or air. The water in the soil is present as capillary water,hygroscopic water, combined water and water vapour.

Soil receives water either by rains or irrigation.


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4. Soil air :

Soil contains air in the pour spaces. In a good soil such as loam

about 20-25 % of the total volume is soil air. The compositionof soil is dependent upon air circulation or connection of the

pore spaces with the soil surface.

In a poorly ventilated soil concentration of O2 decreases while

that of CO2 increases because of the respiration of plant rootsand soil organisms.

High concentration of CO2 in the soil is toxic to the soil

organisms.

O2 in soil is essential for humus formation, nitrification,respiration of microorganisms and activities of roots

(absorption of water and mineral salts).


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5. Soil organisms:

A variety of living organisms such as bacteria, actinomycetea, fungi,

algae, protozoa, nematodes,earthworms occur in the soil. The soil

organisms perform following activities in the soil :

(1) Decomposition of dead organic matter- Saprophytic soil

microorganisms

(2) Nitrogen fixation- Cyanobacteria.

(3) Aeration of the soil - Burrowing (earth digging) insects and worms

(4) Several soil organisms secrete mucus, which help in cementing soil

particles to form soil aggregates.

(5) Some microorganisms chemical substances that have stimulating

effect on the growth of higher plants.(6) Some soil fungi form mycorrhizal association with the roots of

higher plants and assist them in obtaining water and nutrients from

the soil.

(7) Several soil organisms take part in biogeochemical cycles.


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Types of Indian Soils

Soils of India are classified into six major types

based on their nature and compositionRed soils:

@ Red Colour -iron components.

@ Low water retention capacity.@ Poor in N,P,K and organic matter.

@ Andhra Pradesh, Tamilnadu, Bihar, Orissa, U.P. ,West

Bengal.

Black soils:

@ Good for cotton and sugarcane cultivation.

@ Maharashtra, Mysore and Madhya Pradesh.


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Skeletal soils:

@ Also called as Mountain soil

@ Altitude between 2000 m and 3000 m.@ Undergoes land slides and snowfall.

@ North-western hills or the Aravallis

@ Used for forestry and growing potatoes, and subtropicalfruits.

Desert soils:

@ Annual rainfall is less than 50 centimetres.

@ These soils cover 1.4 lakh square kilometres.

@ Desert soils can be reclaimed through good irrigation.

@ Rajasthan, semi-desert areas of Kutch.


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Land Degradation:

Any change in the land that reduces its

condition or quality and hence its productivityor productive potential is called land

degradation.


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D tifi ti


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Desertification

Desertification is a slow process of land degradation

that leads to desert formation.

The destruction of natural vegetation results in

accelerated soil erosion due to the removal of the

vegetation cover.

Erosion of the top fertile soil leads to in loss of soilproductivity and formation of deserts.

The Thar desert in I ndia was formed by destroying

thousands of hectares productive land.

Excessive grazing by livestock is another factor

resulting in desertification especially in Rajasthan.

Many deserts in the world are a result of human

activities.


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i f f i if


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Equitable use of Resources for sustainable Lifestyles

Rate of use of renewable resources do not exceed regeneration rates.

Rate of use of non-renewable resources do not exceed rates of

development of renewable substitutes.

Rate of pollution emission do not exceed assimilative capacities of

the environment.

Aiming to achieve complete reuse, recycle and repair

Reducing fossil fuel use - maximizing the use of energy

conservation measures, shrinking energy intensive sectors and

introducing energy taxes

Improving the quality of materials -to get products which are more

durable, repairable and recyclable and avoiding the use hazardousmaterials

Reducing transportation-providing goods and services as close as

possible to the consumers


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Food Resource