Alternative fuels, known as non-conventional or advanced fuels, are any materials or substances that can be used as fuels, other than conventional fuels. Conventional fuels include: fossil fuels (petroleum (oil), coal, propane, and natural gas), as well as nuclear materials such as uranium and thorium, as well as artificial radioisotope fuels that are made in nuclear reactors, and store their energy.
Some well-known alternative fuels include biodiesel, bioalcohol (methanol, ethanol, butanol), chemically stored electricity (batteries and fuel cells), hydrogen, non-fossil methane, non-fossil natural gas, vegetable oil, and other biomass sources.
Traditional vehicle fuels petrol and diesel are, of course, produced from oil, whereas alternative fuels come from a variety of sources. Oil has a couple of key disadvantages, not least the fact that it is in limited supply and takes millions of years to be produced. There are also environmental considerations as fossil fuels release large amounts of harmful greenhouse gases. It is therefore important to look at alternative fuel today in order to better protect the environment and to replace the diminishing oil supplies.
Alternative fuel covers a number of options which are listed below and more details on which can be found on other pages of this site. Most of the options for alternative fuels are not derived from fossil fuels.
Biodiesel - Produced from the oil of crops such as rapeseed or from waste cooking oils. This results in a significant reduction in carbon emissions.
Bioethanol - Produced from starch plants such as corn, sugar plants or trees.
Biogas - A mixture of methane and carbon dioxide from landfill sites or produced using anaerobic digestion. This results in a 60% reduction in carbon emissions.
Fuel cell - A fuel cell uses hydrogen and oxygen to produce electricity.
LPG - A blend of propane and butane produced from oil refining and methane gas fields. This has slightly higher carbon emissions than diesel but 80% lower nitrous oxide emissions.
Natural Gas - Mainly methane extracted from oil and gas fields. This has a 5% reduction in carbon emissions compared to diesel and 80% lower nitrous oxide emissions.
Pure Plant Oil - produced by crushing and filtering crops such as rapeseed. It is thought that carbon emissions from well to wheel will be slightly lower than those for diesel.
Appropriate technology is an ideological movement (and its manifestations) originally articulated as "intermediate technology" by the economist Dr. Ernst Friedrich "Fritz" Schumacher in his influential work, Small is Beautiful. Though the nuances of appropriate technology vary between fields and applications, it is generally recognized as encompassing technological choice and application that is small-scale, labor-intensive, energy-efficient, environmentally sound, and locally controlled. Both Schumacher and many modern-day proponents of appropriate technology also emphasize the technology as people-centered.
Appropriate technology is most commonly discussed in its relationship to economic development and as an alternative to transfers of capital-intensive technology from industrialized nations to developing countries.
Appropriate technology has been used to address issues in a wide range of fields. Well-known examples of appropriate technology applications include: bike- and hand-powered water pumps (and other self-powered equipment), the universal nut sheller, self-contained solar-powered light bulbs and streetlights, and passive solar building designs. Today appropriate technology is often developed using open source principles, which have led to open-source appropriate technology (OSAT) and thus many of the plans of the technology can be freely found on the Internet.
SUSTAINABLE DEVELOPMENT IN DEVELOPING COUNTRIES!
appropriate technology - brings technology to poor villages and can transform lives due to it being sustainable and no one needing to be dependent on lare companies
SOLAR ENERGY
WIND ENERGY
Monday 26 March 2012
Thursday 22 March 2012
renewable and NON renewable resources
Powerpoint:
http://www.childrensuniversity.manchester.ac.uk/interactives/science/energy/renewable.asp
PDF:
http://www.childrensuniversity.manchester.ac.uk/interactives/science/energy/discovermore/renewable.pdf
What are the sources of energy?
Energy are broadly classifies into two main groups: renewable and Non-renewable.
Renewable Energy
Renewable energy is energy which is generated from natural sources i.e. sun, wind, rain, tides and can be generated again and again as and when required. They are available in plenty and by far most the cleanest sources of energy available on this planet. For eg: Energy that we receive from the sun can be used to generate electricity. Similarly, energy from wind, geothermal, biomass from plants, tides can be used this form of energy to another form.
Here are some of the pros and cons of using renewable sources of energy:-
Pros
The sun, wind, geothermal, ocean energy are available in the abundant quantity and free to use.
The non-renewable sources of energy that we are using are limited and are bound to expire one day.
Renewable sources have low carbon emissions, therefore they are considered as green and environment friendly.
Renewable helps in stimulating the economy and creating job opportunities. The money that is used to build these plants can provide jobs to thousands to lakhs of people.
You don't have to rely on any third country for the supply of renewable sources as in case of non-renewable sources.
Renewable sources can cost less than consuming the local electrical supply. In the long run, the prices of electricity are expected to soar since they are based on the prices of crude oil, so renewable sources can cut your electricity bills.
Various tax incentives in the form of tax waivers, credit deductions are available for individuals and businesses who want to go green.
Cons
It is not easy to set up a plant as the initial costs are quite steep.
Solar energy can be used during the day time and not during night or rainy season.
Geothermal energy which can be used to generate electricity has side effects too. It can bring toxic chemicals beneath the earth surface onto the top and can create environmental changes.
Hydroelectric provide pure form of energy but building dams across the river which is quite expensive can affect natural flow and affect wildlife.
To use wind energy, you have to rely on strong winds therefore you have to choose suitable site to operate them. Also, they can affect bird population as they are quite high.
Non-Renewable Energy
Non-Renewable energy is energy which is taken from the sources that are available on the earth in limited quantity and will vanish fifty-sixty years from now. Non-renewable sources are not environmental friendly and can have serious affect on our health. They are called non-renewable because they cannot be re-generated within a short span of time. Non-renewable sources exist in the form of fossil fuels, natural gas, oil and coal.
Here are some of the pros and cons of using non-renewable sources of energy:-
Pros
Non-renewable sources are cheap and easy to use. You can easily fill up your car tank and power your motor vehicle.
You can use small amount of nuclear energy to produce large amount of power.
Non-renewable have little or no competition at all. For eg: if you are driving a battery driven car your battery gets discharged then you won't be able to charge it in the middle if the road rather it is easy to find a gas pumping station.
They are considered as cheap when converting from one type of energy to another.
Cons
Non-renewable sources will expire some day and we have to us our endangered resources to create more non-renewable sources of energy.
The speed at which such resources are being utilized can have serious environmental changes.
Non-renewable sources release toxic gases in the air when burnt which are the major cause for global warming.
Since these sources are going to expire soon, prices of these sources are soaring day by day.
Why should we conserve energy?
Energy needs to be conserved to protect our environment from drastic changes, to save the depleting resources for our future generations. The rate at which the energy is being produced and consumed can damage our world in many ways. In other words, it helps us to save the environment. We can reduce those impacts by consuming less energy. The cost of energy is rising every year. It is important for us to realize how energy is useful to us and how can we avoid it getting wasted.
To start saving energy is not a big thing at all. We can start saving the energy from our home itself, just by turning off the lights during day hours, washing clothes in cold water or using public transport instead of using our own vehicle and later can implement these things on much wider scale at society level, then at city level then district level and finally at country level. You might notice a small change in your monthly bills by implementing these changes as they would be getting decreased more and more. With so many alternatives and so many techniques about there, if millions of people like us start doing these things, it will help us to save much more money and also help the environment.
A non-renewable resource is a natural resource which cannot be produced, grown, generated, or used on a scale which can sustain its consumption rate, once depleted there is no more available for future needs. Also considered non-renewable are resources that are consumed much faster than nature can create them. Fossil fuels (such as coal, petroleum, and natural gas), nuclear power (uranium) and certain aquifers are examples. In contrast, resources such as timber (when harvested sustainably) or metals (which can be recycled) are considered renewable resources.
Fossil fuel:
A temporary oil drilling rig in Western Australia
Further information: Oil depletion
Natural resources such as coal, petroleum (crude oil) and natural gas take thousands of years to form naturally and cannot be replaced as fast as they are being consumed. Eventually natural resources will become too costly to harvest and humanity will need to find other sources of energy.
At present, the main energy source used by humans are non-renewable fossil fuels, as a result of continual use since the first internal combustion engine in the 17th century, the fuel is still in high demand with conventional infrastructure and transport which are fitted with the combustion engine. The continual use of fossil fuels at the current rate will increase global warming and cause more severe climate change.
Renewable energy is energy which comes from natural resources such as sunlight, wind, rain, tides, and geothermal heat, which are renewable (naturally replenished). About 16% of global final energy consumption comes from renewables, with 10% coming from traditional biomass, which is mainly used for heating, and 3.4% from hydroelectricity. New renewables (small hydro, modern biomass, wind, solar, geothermal, and biofuels) accounted for another 3% and are growing very rapidly. The share of renewables in electricity generation is around 19%, with 16% of global electricity coming from hydroelectricity and 3% from new renewables.
Renewable sources:
Wind power
Hydropower
Solar energy
Biomass
Biofuel
Geothermal energy
http://www.childrensuniversity.manchester.ac.uk/interactives/science/energy/renewable.asp
PDF:
http://www.childrensuniversity.manchester.ac.uk/interactives/science/energy/discovermore/renewable.pdf
What are the sources of energy?
Energy are broadly classifies into two main groups: renewable and Non-renewable.
Renewable Energy
Renewable energy is energy which is generated from natural sources i.e. sun, wind, rain, tides and can be generated again and again as and when required. They are available in plenty and by far most the cleanest sources of energy available on this planet. For eg: Energy that we receive from the sun can be used to generate electricity. Similarly, energy from wind, geothermal, biomass from plants, tides can be used this form of energy to another form.
Here are some of the pros and cons of using renewable sources of energy:-
Pros
The sun, wind, geothermal, ocean energy are available in the abundant quantity and free to use.
The non-renewable sources of energy that we are using are limited and are bound to expire one day.
Renewable sources have low carbon emissions, therefore they are considered as green and environment friendly.
Renewable helps in stimulating the economy and creating job opportunities. The money that is used to build these plants can provide jobs to thousands to lakhs of people.
You don't have to rely on any third country for the supply of renewable sources as in case of non-renewable sources.
Renewable sources can cost less than consuming the local electrical supply. In the long run, the prices of electricity are expected to soar since they are based on the prices of crude oil, so renewable sources can cut your electricity bills.
Various tax incentives in the form of tax waivers, credit deductions are available for individuals and businesses who want to go green.
Cons
It is not easy to set up a plant as the initial costs are quite steep.
Solar energy can be used during the day time and not during night or rainy season.
Geothermal energy which can be used to generate electricity has side effects too. It can bring toxic chemicals beneath the earth surface onto the top and can create environmental changes.
Hydroelectric provide pure form of energy but building dams across the river which is quite expensive can affect natural flow and affect wildlife.
To use wind energy, you have to rely on strong winds therefore you have to choose suitable site to operate them. Also, they can affect bird population as they are quite high.
Non-Renewable Energy
Non-Renewable energy is energy which is taken from the sources that are available on the earth in limited quantity and will vanish fifty-sixty years from now. Non-renewable sources are not environmental friendly and can have serious affect on our health. They are called non-renewable because they cannot be re-generated within a short span of time. Non-renewable sources exist in the form of fossil fuels, natural gas, oil and coal.
Here are some of the pros and cons of using non-renewable sources of energy:-
Pros
Non-renewable sources are cheap and easy to use. You can easily fill up your car tank and power your motor vehicle.
You can use small amount of nuclear energy to produce large amount of power.
Non-renewable have little or no competition at all. For eg: if you are driving a battery driven car your battery gets discharged then you won't be able to charge it in the middle if the road rather it is easy to find a gas pumping station.
They are considered as cheap when converting from one type of energy to another.
Cons
Non-renewable sources will expire some day and we have to us our endangered resources to create more non-renewable sources of energy.
The speed at which such resources are being utilized can have serious environmental changes.
Non-renewable sources release toxic gases in the air when burnt which are the major cause for global warming.
Since these sources are going to expire soon, prices of these sources are soaring day by day.
Why should we conserve energy?
Energy needs to be conserved to protect our environment from drastic changes, to save the depleting resources for our future generations. The rate at which the energy is being produced and consumed can damage our world in many ways. In other words, it helps us to save the environment. We can reduce those impacts by consuming less energy. The cost of energy is rising every year. It is important for us to realize how energy is useful to us and how can we avoid it getting wasted.
To start saving energy is not a big thing at all. We can start saving the energy from our home itself, just by turning off the lights during day hours, washing clothes in cold water or using public transport instead of using our own vehicle and later can implement these things on much wider scale at society level, then at city level then district level and finally at country level. You might notice a small change in your monthly bills by implementing these changes as they would be getting decreased more and more. With so many alternatives and so many techniques about there, if millions of people like us start doing these things, it will help us to save much more money and also help the environment.
A non-renewable resource is a natural resource which cannot be produced, grown, generated, or used on a scale which can sustain its consumption rate, once depleted there is no more available for future needs. Also considered non-renewable are resources that are consumed much faster than nature can create them. Fossil fuels (such as coal, petroleum, and natural gas), nuclear power (uranium) and certain aquifers are examples. In contrast, resources such as timber (when harvested sustainably) or metals (which can be recycled) are considered renewable resources.
Fossil fuel:
A temporary oil drilling rig in Western Australia
Further information: Oil depletion
Natural resources such as coal, petroleum (crude oil) and natural gas take thousands of years to form naturally and cannot be replaced as fast as they are being consumed. Eventually natural resources will become too costly to harvest and humanity will need to find other sources of energy.
At present, the main energy source used by humans are non-renewable fossil fuels, as a result of continual use since the first internal combustion engine in the 17th century, the fuel is still in high demand with conventional infrastructure and transport which are fitted with the combustion engine. The continual use of fossil fuels at the current rate will increase global warming and cause more severe climate change.
Renewable energy is energy which comes from natural resources such as sunlight, wind, rain, tides, and geothermal heat, which are renewable (naturally replenished). About 16% of global final energy consumption comes from renewables, with 10% coming from traditional biomass, which is mainly used for heating, and 3.4% from hydroelectricity. New renewables (small hydro, modern biomass, wind, solar, geothermal, and biofuels) accounted for another 3% and are growing very rapidly. The share of renewables in electricity generation is around 19%, with 16% of global electricity coming from hydroelectricity and 3% from new renewables.
Renewable sources:
Wind power
Hydropower
Solar energy
Biomass
Biofuel
Geothermal energy
Monday 19 March 2012
transnational company, newly industralised country
NIC:
http://www.slideshare.net/guest0edc68/newly-industrialised-countries
TNC:
http://www.grips.ac.jp/csids/perspectives/perspective03.pdf
http://www.slideshare.net/guest0edc68/newly-industrialised-countries
TNC:
http://www.grips.ac.jp/csids/perspectives/perspective03.pdf
Thursday 15 March 2012
INC
Multinational Companies:
Head off - MEDC
Branch Plants - LEDC
ADVANTAGES:
no tarrifs
cheap labour
health and safety is lower
incentives
raw material
DISADVANTAGES:
language/ culture
time zones
exchange rates
amount of skilled labour
safety
Head off - MEDC
Branch Plants - LEDC
ADVANTAGES:
no tarrifs
cheap labour
health and safety is lower
incentives
raw material
DISADVANTAGES:
language/ culture
time zones
exchange rates
amount of skilled labour
safety
Monday 12 March 2012
System of manufacturing
old system:
power supply - near by
new system:
power - national grid - plug in - socket (plug in)
FOOTLOOSE
PAGE 18C
1. metal, wheels, engine
2. due to high demand for resources and enables quicker production
b) due to low moving cost
c) so that they have room to produce the car and to expand
d) so that they get all areas of the production in the factory covered
HIGH TECH INDUSTRYS IN LEDC's
High Technology Industry
These icons indicate that teacher’s notes or useful web addresses are available in the Notes Page.
This icon indicates that the slide contains activities created in Flash. These activities are not editable.
For more detailed instructions, see the Getting Started presentation.
What is high-tech industry?
Where does high-tech industry locate?
What factors influence the location of high-tech industry?
What is a science park?
What pressures are created by the growth of high-tech industry?
High-technology industry
High-technology industry involves a highly-skilled workforce and its products require a high proportion of research and development.
High-technology industry is relatively footloose since access to raw materials is not very important. The ‘raw materials’ that are required are usually lightweight electronic components.
What is high-tech industry?
Where does high-tech industry locate?
What factors influence the location of high-tech industry?
What is a science park?
What pressures are created by the growth of high-tech industry?
High-technology industry
Where does high-tech industry locate?
The largest concentration of high-tech industries is found in Silicon Valley.
Silicon Valley is the nickname for the high-tech heartland of the United States. It is located between San Francisco and San Jose, California.
M4 Corridor
Cambridge and the M11 corridor
Where does high-tech industry locate in the UK?
High-tech industry in the UK
What is high-tech industry?
Where does high-tech industry locate?
What factors influence the location of high-tech industry?
What is a science park?
What pressures are created by the growth of high-tech industry?
High-technology industry
Bangalore has been called the Silicon Valley of India. Over 160,000 people are currently employed in the technology sector and this number is expected to exceed 200,000 in 2005, which will rival Silicon Valley.
Electronics City in Bangalore is India’s first science park. It is home to about 100 companies including Siemens, Hewlett Packard and Motorola. Infoys was the first Indian firm to float on the US Stock Exchange.
What is high-tech industry?
Where does high-tech industry locate?
What factors influence the location of high-tech industry?
What is a science park?
What pressures are created by the growth of high-tech industry?
Learning objectives
High-technology industry
A science park is a planned industrial complex which contains quaternary companies while a business park can also contain manufacturing companies.
Business park
Science park
What is a science park?
Cambridge Science Park
What is high-tech industry?
Where does high-tech industry locate?
What factors influence the location of high-tech industry?
What is a science park?
What pressures are created by the growth of high-tech industry?
Learning objectives
High-technology industry
Trinity College
Local residents in Milton
Logatech (a small high-tech company)
Greenworld (an environmental group)
Local farmer
Trinity and Trinity Hall are planning to develop a 22 acre plot to the west of their site. It will attract further high-tech industries to the area.
What pressures do you think will be created as a result? Decide what the viewpoints of the following will be:
Growth of high-tech industry
Growth of high-tech industry
Trinity College expansion proposals
Using map information only, give three reasons why a science park located at site A.
List two other factors that influence the location of science parks.
There are proposals to create a new science park at site B. Explain why some people may be against its development.
Study the map.
Examination question
High-technology industry
High technology industry involves a highly-skilled workforce and its products require a high proportion of research and development.
The largest concentration of high-tech industries can be found in Silicon Valley, USA. In the UK, the M4 corridor is an attractive location for high-tech industry.
Bangalore is the centre of high-tech industry in India.
High technology industry is relatively footloose.
Factors behind location include: a highly-skilled workforce, proximity to research centres and attractive environments.
A science park is a planned industrial complex which contains quaternary companies such as Cambridge Science Park.
The growth of the high-tech industry can bring advantages and disadvantages.
High-tech sectors
The sector approach classifies industries according their technology intensity, product approach according to finished products.
Aerospace
Artificial Intelligence
Biotechnology
Software
Electrical Engineering
Photonics
Nanotechnology
Nuclear Physics
Robotics
Telecommunications
High-tech industries
Further analysis from OECD has indicated that using research intensity as an industry classification indicator is also possible. The OECD does not only take the manufacturing but also the usage rate of technology into account.
power supply - near by
new system:
power - national grid - plug in - socket (plug in)
FOOTLOOSE
PAGE 18C
1. metal, wheels, engine
2. due to high demand for resources and enables quicker production
b) due to low moving cost
c) so that they have room to produce the car and to expand
d) so that they get all areas of the production in the factory covered
HIGH TECH INDUSTRYS IN LEDC's
High Technology Industry
These icons indicate that teacher’s notes or useful web addresses are available in the Notes Page.
This icon indicates that the slide contains activities created in Flash. These activities are not editable.
For more detailed instructions, see the Getting Started presentation.
What is high-tech industry?
Where does high-tech industry locate?
What factors influence the location of high-tech industry?
What is a science park?
What pressures are created by the growth of high-tech industry?
High-technology industry
High-technology industry involves a highly-skilled workforce and its products require a high proportion of research and development.
High-technology industry is relatively footloose since access to raw materials is not very important. The ‘raw materials’ that are required are usually lightweight electronic components.
What is high-tech industry?
Where does high-tech industry locate?
What factors influence the location of high-tech industry?
What is a science park?
What pressures are created by the growth of high-tech industry?
High-technology industry
Where does high-tech industry locate?
The largest concentration of high-tech industries is found in Silicon Valley.
Silicon Valley is the nickname for the high-tech heartland of the United States. It is located between San Francisco and San Jose, California.
M4 Corridor
Cambridge and the M11 corridor
Where does high-tech industry locate in the UK?
High-tech industry in the UK
What is high-tech industry?
Where does high-tech industry locate?
What factors influence the location of high-tech industry?
What is a science park?
What pressures are created by the growth of high-tech industry?
High-technology industry
Bangalore has been called the Silicon Valley of India. Over 160,000 people are currently employed in the technology sector and this number is expected to exceed 200,000 in 2005, which will rival Silicon Valley.
Electronics City in Bangalore is India’s first science park. It is home to about 100 companies including Siemens, Hewlett Packard and Motorola. Infoys was the first Indian firm to float on the US Stock Exchange.
What is high-tech industry?
Where does high-tech industry locate?
What factors influence the location of high-tech industry?
What is a science park?
What pressures are created by the growth of high-tech industry?
Learning objectives
High-technology industry
A science park is a planned industrial complex which contains quaternary companies while a business park can also contain manufacturing companies.
Business park
Science park
What is a science park?
Cambridge Science Park
What is high-tech industry?
Where does high-tech industry locate?
What factors influence the location of high-tech industry?
What is a science park?
What pressures are created by the growth of high-tech industry?
Learning objectives
High-technology industry
Trinity College
Local residents in Milton
Logatech (a small high-tech company)
Greenworld (an environmental group)
Local farmer
Trinity and Trinity Hall are planning to develop a 22 acre plot to the west of their site. It will attract further high-tech industries to the area.
What pressures do you think will be created as a result? Decide what the viewpoints of the following will be:
Growth of high-tech industry
Growth of high-tech industry
Trinity College expansion proposals
Using map information only, give three reasons why a science park located at site A.
List two other factors that influence the location of science parks.
There are proposals to create a new science park at site B. Explain why some people may be against its development.
Study the map.
Examination question
High-technology industry
High technology industry involves a highly-skilled workforce and its products require a high proportion of research and development.
The largest concentration of high-tech industries can be found in Silicon Valley, USA. In the UK, the M4 corridor is an attractive location for high-tech industry.
Bangalore is the centre of high-tech industry in India.
High technology industry is relatively footloose.
Factors behind location include: a highly-skilled workforce, proximity to research centres and attractive environments.
A science park is a planned industrial complex which contains quaternary companies such as Cambridge Science Park.
The growth of the high-tech industry can bring advantages and disadvantages.
High-tech sectors
The sector approach classifies industries according their technology intensity, product approach according to finished products.
Aerospace
Artificial Intelligence
Biotechnology
Software
Electrical Engineering
Photonics
Nanotechnology
Nuclear Physics
Robotics
Telecommunications
High-tech industries
Further analysis from OECD has indicated that using research intensity as an industry classification indicator is also possible. The OECD does not only take the manufacturing but also the usage rate of technology into account.
Monday 5 March 2012
Industry
Industrial sectors
Main article: Industrial organization
Further information: Industrial loan company
Clark's Sector Model (1950)
Farming- The secondary sector,involving refinery refining,construction,and manufacturing;The Tertiary sector,which deals with services (such as law and medicine) and distribution of manufactured goods;And the Quaternary sector, a relatively new type of knowledge industry focusing on technological R&D research,design and development such as computer programming, and biochemistry. A fifth, quinary, sector has been proposed encompassing nonprofit activities. The economy is also broadly separated into public sector and private sector, with industry generally categorized as private. Industries are also any business or manufacturing. Industries can be classified on the basis of raw materials, size and ownership.
Raw Materials: Industries may be agriculture based, Marine based, Mineral based, Forest based.
Size: It refers to the amount of capital invested, number of people employed and the volume of production.
Ownership: Industries can be classified into private sector, state owned or public sector, joint sector and co-operative sector
Industry in the sense of manufacturing became a key sector of production and labour in European and North American countries during the Industrial Revolution, which upset previous mercantile and feudal economies through many successive rapid advances in technology, such as the steel and coal production. It is aided by technological advances, and has continued to develop into new types and sectors to this day. Industrial countries then assumed a capitalist economic policy. Railroads and steam-powered ships began speedily establishing links with previously unreachable world markets, enabling private companies to develop to then-unheard of size and wealth. Following the Industrial Revolution, perhaps a third of the world's economic output is derived from manufacturing industries—more than agriculture's share.
Many developed countries and many developing/semi-developed countries (People's Republic of China, India etc.) depend significantly on industry. Industries, the countries they reside in, and the economies of those countries are interlinked in a complex web of interdependence.
Industry is divided into four sectors. They are:
Sector Definition
Primary This involves the extraction of resources directly from the Earth, this includes farming, mining and logging. They do not process the products at all. They send it off to factories to make a profit.
Secondary This group is involved in the processing products from primary industries. This includes all factories—those that refine metals, produce furniture, or pack farm products such as meat.
Tertiary This group is involved in the provision of services. They include teachers, managers and other service providers.
Quaternary This group is involved in the research of science and technology. They include scientists.
As a country develops people move away from the primary sector to secondary and then to tertiary.
There are many other different kinds of industries, and often organized into different classes or sectors by a variety of industrial classifications.
Industry classification systems used by the government[which?] commonly divide industry into three sectors: agriculture, manufacturing, and services. The primary sector of industry is agriculture, mining and raw material extraction. The secondary sector of industry is manufacturing. The tertiary sector of industry is service production. Sometimes, one talks about a quaternary sector of industry, consisting of intellectual services such as research and development (R&D).
Market-based classification systems such as the Global Industry Classification Standard and the Industry Classification Benchmark are used in finance and market research. These classification systems commonly divide industries according to similar functions and markets and identify businesses producing related products.
Industries can also be identified by product: chemical industry, petroleum industry, automotive industry, electronic industry, meatpacking industry, hospitality industry, food industry, fish industry, software industry, paper industry, entertainment industry, semiconductor industry, cultural industry, poverty industry
labor-intensive industry - capital-intensive industry
light industry - heavy industry
Declining industries
Main article: Deindustrialisation
Historically certain manufacturing industries have gone into a decline due to various economic factors, including the development of replacement technology or the loss of competitive advantage. An example of the former is the decline in carriage manufacturing when the automobile was mass-produced.
A recent trend has been the migration of prosperous, industrialized nations toward a post-industrial society. This is manifested by an increase in the service sector at the expense of manufacturing, and the development of an information-based economy, the so-called informational revolution. In a post-industrial society, manufacturing is relocated to economically more favourable locations through a process of off-shoring.
The major difficulty for people looking to measure manufacturing industries outputs and economic effect is finding a measurement which is stable historically. Traditionally, success has been measured in the number of jobs created. The lowering of employee numbers in the manufacturing sector has been assumed to be caused by a decline in the competitiveness of the sector. The truth however is that it has been caused by the introduction of the lean manufacturing process. Eventually, this will lead to competing product lines being managed by one of two people, as is already the case in the cigarette manufacturing industry.
Related to this change is the upgrading of the quality of the product being manufactured. While it is easy to produce a low tech, low skill product, the ability to manufacture high quality products is limited to companies with a high skilled staff.
[edit]Society
Main article: Industrial society
An industrial society can be defined in many ways. Today, industry is an important part of most societies and nations. A government must have some kind of industrial policy, regulating industrial placement, industrial pollution, financing and industrial labor.
Primary - Secondary - Tertiary
Main article: Industrial organization
Further information: Industrial loan company
Clark's Sector Model (1950)
Farming- The secondary sector,involving refinery refining,construction,and manufacturing;The Tertiary sector,which deals with services (such as law and medicine) and distribution of manufactured goods;And the Quaternary sector, a relatively new type of knowledge industry focusing on technological R&D research,design and development such as computer programming, and biochemistry. A fifth, quinary, sector has been proposed encompassing nonprofit activities. The economy is also broadly separated into public sector and private sector, with industry generally categorized as private. Industries are also any business or manufacturing. Industries can be classified on the basis of raw materials, size and ownership.
Raw Materials: Industries may be agriculture based, Marine based, Mineral based, Forest based.
Size: It refers to the amount of capital invested, number of people employed and the volume of production.
Ownership: Industries can be classified into private sector, state owned or public sector, joint sector and co-operative sector
Industry in the sense of manufacturing became a key sector of production and labour in European and North American countries during the Industrial Revolution, which upset previous mercantile and feudal economies through many successive rapid advances in technology, such as the steel and coal production. It is aided by technological advances, and has continued to develop into new types and sectors to this day. Industrial countries then assumed a capitalist economic policy. Railroads and steam-powered ships began speedily establishing links with previously unreachable world markets, enabling private companies to develop to then-unheard of size and wealth. Following the Industrial Revolution, perhaps a third of the world's economic output is derived from manufacturing industries—more than agriculture's share.
Many developed countries and many developing/semi-developed countries (People's Republic of China, India etc.) depend significantly on industry. Industries, the countries they reside in, and the economies of those countries are interlinked in a complex web of interdependence.
Industry is divided into four sectors. They are:
Sector Definition
Primary This involves the extraction of resources directly from the Earth, this includes farming, mining and logging. They do not process the products at all. They send it off to factories to make a profit.
Secondary This group is involved in the processing products from primary industries. This includes all factories—those that refine metals, produce furniture, or pack farm products such as meat.
Tertiary This group is involved in the provision of services. They include teachers, managers and other service providers.
Quaternary This group is involved in the research of science and technology. They include scientists.
As a country develops people move away from the primary sector to secondary and then to tertiary.
There are many other different kinds of industries, and often organized into different classes or sectors by a variety of industrial classifications.
Industry classification systems used by the government[which?] commonly divide industry into three sectors: agriculture, manufacturing, and services. The primary sector of industry is agriculture, mining and raw material extraction. The secondary sector of industry is manufacturing. The tertiary sector of industry is service production. Sometimes, one talks about a quaternary sector of industry, consisting of intellectual services such as research and development (R&D).
Market-based classification systems such as the Global Industry Classification Standard and the Industry Classification Benchmark are used in finance and market research. These classification systems commonly divide industries according to similar functions and markets and identify businesses producing related products.
Industries can also be identified by product: chemical industry, petroleum industry, automotive industry, electronic industry, meatpacking industry, hospitality industry, food industry, fish industry, software industry, paper industry, entertainment industry, semiconductor industry, cultural industry, poverty industry
labor-intensive industry - capital-intensive industry
light industry - heavy industry
Declining industries
Main article: Deindustrialisation
Historically certain manufacturing industries have gone into a decline due to various economic factors, including the development of replacement technology or the loss of competitive advantage. An example of the former is the decline in carriage manufacturing when the automobile was mass-produced.
A recent trend has been the migration of prosperous, industrialized nations toward a post-industrial society. This is manifested by an increase in the service sector at the expense of manufacturing, and the development of an information-based economy, the so-called informational revolution. In a post-industrial society, manufacturing is relocated to economically more favourable locations through a process of off-shoring.
The major difficulty for people looking to measure manufacturing industries outputs and economic effect is finding a measurement which is stable historically. Traditionally, success has been measured in the number of jobs created. The lowering of employee numbers in the manufacturing sector has been assumed to be caused by a decline in the competitiveness of the sector. The truth however is that it has been caused by the introduction of the lean manufacturing process. Eventually, this will lead to competing product lines being managed by one of two people, as is already the case in the cigarette manufacturing industry.
Related to this change is the upgrading of the quality of the product being manufactured. While it is easy to produce a low tech, low skill product, the ability to manufacture high quality products is limited to companies with a high skilled staff.
[edit]Society
Main article: Industrial society
An industrial society can be defined in many ways. Today, industry is an important part of most societies and nations. A government must have some kind of industrial policy, regulating industrial placement, industrial pollution, financing and industrial labor.
Primary - Secondary - Tertiary
Thursday 1 March 2012
Overnutrition
Overnutrition is a form of malnutrition in which nutrients are oversupplied relative to the amounts required for normal growth, development, and metabolism. Overnutrition is a type of malnutrition where there are more nutrients than required for normal growth.
The term can refer to:
obesity, brought on by general overeating of foods high in caloric content, as well as:
the oversupply of a specific nutrient or categories of nutrients, such as mineral or vitamin poisoning, due to excessive intake of dietary supplements or foods high in nutrients (such as liver), or nutritional imbalances caused by various fad diets.
For mineral excess, see:
Iron poisoning, and
low sodium diet (excess sodium).
The term can refer to:
obesity, brought on by general overeating of foods high in caloric content, as well as:
the oversupply of a specific nutrient or categories of nutrients, such as mineral or vitamin poisoning, due to excessive intake of dietary supplements or foods high in nutrients (such as liver), or nutritional imbalances caused by various fad diets.
For mineral excess, see:
Iron poisoning, and
low sodium diet (excess sodium).
undernutrition
When individuals are undernourished, they can no longer maintain natural bodily capacities, such as growth, resisting infections and recovering from disease, learning and physical work, and pregnancy and lactation in women. Poor feeding of infants and young children, especially the lack of optimal breastfeeding and responsive complementary feeding, along with such illnesses as diarrhoea, pneumonia, malaria and HIV/AIDS, often exacerbated by helminths, are major causes of undernutrition.2
The second target of MDG 1 is to reduce the proportion of people who suffer from hunger by half between 1990 and 2015. The indicator by which progress is measured – and the focus of this report card – is the prevalence of underweight in children under five, specifically, the percentage of children aged 0–59 months who fall below minus two standard deviations from the median weight for age of the standard reference population.
Estimates for underweight prevalence are based on the most recent data available to UNICEF for years between 1996 and 2005 from 110 countries, covering 98 per cent of the developing world’s under-five population. Trend analysis is based on a subset of 73 countries with available trend data for 1990–2004, covering 86 per cent of children in developing countries.
The second target of MDG 1 is to reduce the proportion of people who suffer from hunger by half between 1990 and 2015. The indicator by which progress is measured – and the focus of this report card – is the prevalence of underweight in children under five, specifically, the percentage of children aged 0–59 months who fall below minus two standard deviations from the median weight for age of the standard reference population.
Estimates for underweight prevalence are based on the most recent data available to UNICEF for years between 1996 and 2005 from 110 countries, covering 98 per cent of the developing world’s under-five population. Trend analysis is based on a subset of 73 countries with available trend data for 1990–2004, covering 86 per cent of children in developing countries.
Malnutrition
Malnutrition is the condition that results from taking an unbalanced diet in which certain nutrients are lacking, in excess (too high an intake), or in the wrong proportions.[1][2]
A number of different nutrition disorders may arise, depending on which nutrients are under or overabundant in the diet.
The World Health Organization cites malnutrition as the greatest single threat to the world's public health.[3] Improving nutrition is widely regarded as the most effective form of aid.[3][4] Emergency measures include providing deficient micronutrients through fortified sachet powders, such as peanut butter, or directly through supplements.[5][6] The famine relief model increasingly used by aid groups calls for giving cash or cash vouchers to the hungry to pay local farmers instead of buying food from donor countries, often required by law, as it wastes money on transport costs.[7][8]
There are various methods used to gauge the degree of malnutrition, including the Gomez Classification. This classifies as 1st, 2nd or 3rd degree malnutrition according to the percentage of normal body weight a person is.
Long term measures include fostering nutritionally dense agriculture by increasing yields, while making sure negative consequences affecting yields in the future are minimized.[9]
Recent efforts include aid to farmers.[10] However, World Bank strictures restrict government subsidies for farmers, while the spread of fertilizer[11] use may adversely affect ecosystems and human health[12] and is hampered by various civil society groups.
Mortality
According to Jean Ziegler(the United Nations Special Rapporteur on the Right to Food for 2000 to March 2008), mortality due to malnutrition accounted for 58% of the total mortality in 2006: "In the world, approximately 62 million people, all causes of death combined, die each year. One in twelve people worldwide is malnourished.[14] In 2006, more than 36 million died of hunger or diseases due to deficiencies in micronutrients".[15]
According to the World Health Organization, malnutrition is by far the biggest contributor to child mortality, present in half of all cases.[3] Six million children die of hunger every year.[16] Underweight births and inter-uterine growth restrictions cause 2.2 million child deaths a year. Poor or non-existent breastfeeding causes another 1.4 million. Other deficiencies, such as lack of vitamin A or zinc, for example, account for 1 million. Malnutrition in the first two years is irreversible. Malnourished children grow up with worse health and lower educational achievements. Their own children also tend to be smaller. Malnutrition was previously seen as something that exacerbates the problems of diseases as measles, pneumonia and diarrhea. But malnutrition actually causes diseases as well, and can be fatal in its own right.[3]
[edit]Causes
Malnutrition increases the risk of infection and infectious disease; for example, it is a major risk factor in the onset of active tuberculosis.[17] In communities or areas that lack access to safe drinking water, these additional health risks present a critical problem. Lower energy and impaired function of the brain also represent the downward spiral of malnutrition as victims are less able to perform the tasks they need to in order to acquire food, earn an income, or gain an education.
Nutrients Deficiency Excess
Food energy Starvation, Marasmus Obesity, diabetes mellitus, Cardiovascular disease
Simple carbohydrates none diabetes mellitus, Obesity
Complex carbohydrates none Obesity
Saturated fat low sex hormone levels [18] Cardiovascular disease
Trans fat none Cardiovascular disease
Unsaturated fat none Obesity
Fat Malabsorption of Fat-soluble vitamins, Rabbit Starvation (If protein intake is high) Cardiovascular disease (claimed by some)
Omega 3 Fats Cardiovascular disease Bleeding, Hemorrhages
Omega 6 Fats none Cardiovascular disease, Cancer
Cholesterol none Cardiovascular disease
Protein kwashiorkor Rabbit starvation
Sodium hyponatremia Hypernatremia, hypertension
Iron Iron deficiency: Anemia Cirrhosis, heart disease
Iodine Iodine deficiency: Goiter, hypothyroidism Iodine Toxicity (goiter, hypothyroidism)
Vitamin A Vitamin A deficiency: Xerophthalmia and Night Blindness, low testosterone levels Hypervitaminosis A (cirrhosis, hair loss)
Vitamin B1 Beri-Beri
Vitamin B2 Ariboflavinosis: Cracking of skin and Corneal Ulceration
Vitamin B3 Pellagra dyspepsia, cardiac arrhythmias, birth defects
Vitamin B12 Pernicious anemia
Vitamin C Scurvy diarrhea causing dehydration
Vitamin D Rickets Hypervitaminosis D (dehydration, vomiting, constipation)
Vitamin E nervous disorders Hypervitaminosis E (anticoagulant: excessive bleeding)
Vitamin K Vitamin K deficiency: Haemorrhage
Calcium Osteoporosis, tetany, carpopedal spasm, laryngospasm, cardiac arrhythmias Fatigue, depression, confusion, anorexia, nausea, vomiting, constipation, pancreatitis, increased urination
Magnesium Magnesium deficiency: Hypertension Weakness, nausea, vomiting, impaired breathing, and hypotension
Potassium Hypokalemia, cardiac arrhythmias Hyperkalemia, palpitations
Boron Boron deficiency
Manganese Manganese deficiency
[edit]Psychological
Malnutrition, in the form of iodine deficiency, is "the most common preventable cause of mental impairment worldwide."[19] Even moderate iodine deficiency, especially in pregnant women and infants, lowers intelligence by 10 to 15 I.Q. points, shaving incalculable potential off a nation’s development.[19] The most visible and severe effects — disabling goiters, cretinism and dwarfism — affect a tiny minority, usually in mountain villages. But 16 percent of the world’s people have at least mild goiter, a swollen thyroid gland in the neck.[19]
Protein-calorie malnutrition can cause cognitive impairments. For humans, "critical period varies from the final third of gestation to the first 2 years of life".[20]
Research indicates that improving the awareness of nutritious meal choices and establishing long-term habits of healthy eating has a positive effect on a cognitive and spatial memory capacity, potentially increasing a student's potential to process and retain academic information.
Some organizations have begun working with teachers, policymakers, and managed food service contractors to mandate improved nutritional content and increased nutritional resources in school cafeterias from primary to university level institutions. Health and nutrition have been proven to have close links with overall educational success.[21] Currently less than 10% of American college students report that they eat the recommended five servings of fruit and vegetables daily.[22] Better nutrition has been shown to have an impact on both cognitive and spatial memory performance; a study showed those with higher blood sugar levels performed better on certain memory tests.[23] In another study, those who consumed yogurt performed better on thinking tasks when compared to those who consumed caffeine free diet soda or confections.[24] Nutritional deficiencies have been shown to have a negative effect on learning behavior in mice as far back as 1951.[25]
"Better learning performance is associated with diet induced effects on learning and memory ability".[26]
The "nutrition-learning nexus" demonstrates the correlation between diet and learning and has application in a higher education setting.
"We find that better nourished children perform significantly better in school, partly because they enter school earlier and thus have more time to learn but mostly because of greater learning productivity per year of schooling."[27]
91% of college students feel that they are in good health while only 7% eat their recommended daily allowance of fruits and vegetables.[22]
Nutritional education is an effective and workable model in a higher education setting.[28][29]
More "engaged" learning models that encompass nutrition is an idea that is picking up steam at all levels of the learning cycle.[30]
There is limited research available that directly links a student's Grade Point Average (G.P.A.) to their overall nutritional health. Additional substantive data is needed to prove that overall intellectual health is closely linked to a person's diet, rather than just another correlation fallacy.
Nutritional supplement treatment may be appropriate for major depression, bipolar disorder, schizophrenia, and obsessive compulsive disorder, the four most common mental disorders in developed countries.[31] Supplements that have been studied most for mood elevation and stabilization include eicosapentaenoic acid and docosahexaenoic acid (each of which are an omega-3 fatty acid contained in fish oil, but not in flaxseed oil), vitamin B12, folic acid, and inositol.
[edit]Cancer
Cancer is now common in developing countries. According a study by the International Agency for Research on Cancer, "In the developing world, cancers of the liver, stomach and esophagus were more common, often linked to consumption of carcinogenic preserved foods, such as smoked or salted food, and parasitic infections that attack organs." Lung cancer rates are rising rapidly in poorer nations because of increased use of tobacco. Developed countries "tended to have cancers linked to affluence or a 'Western lifestyle' — cancers of the colon, rectum, breast and prostate — that can be caused by obesity, lack of exercise, diet and age."[32]
[edit]Metabolic syndrome
Several lines of evidence indicate lifestyle-induced hyperinsulinemia and reduced insulin function (i.e. insulin resistance) as a decisive factor in many disease states. For example, hyperinsulinemia and insulin resistance are strongly linked to chronic inflammation, which in turn is strongly linked to a variety of adverse developments such as arterial microinjuries and clot formation (i.e. heart disease) and exaggerated cell division (i.e. cancer). Hyperinsulinemia and insulin resistance (the so-called metabolic syndrome) are characterized by a combination of abdominal obesity, elevated blood sugar, elevated blood pressure, elevated blood triglycerides, and reduced HDL cholesterol. The negative impact of hyperinsulinemia on prostaglandin PGE1/PGE2 balance may be significant.
The state of obesity clearly contributes to insulin resistance, which in turn can cause type 2 diabetes. Virtually all obese and most type 2 diabetic individuals have marked insulin resistance. Although the association between overweight and insulin resistance is clear, the exact (likely multifarious) causes of insulin resistance remain less clear. Importantly, it has been demonstrated that appropriate exercise, more regular food intake and reducing glycemic load (see below) all can reverse insulin resistance in overweight individuals (and thereby lower blood sugar levels in those who have type 2 diabetes).
Obesity can unfavourably alter hormonal and metabolic status via resistance to the hormone leptin, and a vicious cycle may occur in which insulin/leptin resistance and obesity aggravate one another. The vicious cycle is putatively fuelled by continuously high insulin/leptin stimulation and fat storage, as a result of high intake of strongly insulin/leptin stimulating foods and energy. Both insulin and leptin normally function as satiety signals to the hypothalamus in the brain; however, insulin/leptin resistance may reduce this signal and therefore allow continued overfeeding despite large body fat stores. In addition, reduced leptin signalling to the brain may reduce leptin's normal effect to maintain an appropriately high metabolic rate.
There is a debate about how and to what extent different dietary factors— such as intake of processed carbohydrates, total protein, fat, and carbohydrate intake, intake of saturated and trans fatty acids, and low intake of vitamins/minerals—contribute to the development of insulin and leptin resistance. In any case, analogous to the way modern man-made pollution may potentially overwhelm the environment's ability to maintain homeostasis, the recent explosive introduction of high glycemic index and processed foods into the human diet may potentially overwhelm the body's ability to maintain homeostasis and health (as evidenced by the metabolic syndrome epidemic).[citation needed]
[edit]Hyponatremia
Excess water intake, without replenishment of sodium and potassium salts, leads to hyponatremia, which can further lead to water intoxication at more dangerous levels. A well-publicized case occurred in 2007, when Jennifer Strange died while participating in a water-drinking contest.[33] More usually, the condition occurs in long-distance endurance events (such as marathon or triathlon competition and training) and causes gradual mental dulling, headache, drowsiness, weakness, and confusion; extreme cases may result in coma, convulsions, and death. The primary damage comes from swelling of the brain, caused by increased osmosis as blood salinity decreases. Effective fluid replacement techniques include Water aid stations during running/cycling races, trainers providing water during team games such as Soccer and devices such as Camel Baks which can provide water for a person without making it too hard to drink the water.
[edit]Overeating vs. hunger
Although a lot of the focus regarding malnutrition centers around undernourishment, overeating is also a form of malnutrition. Overeating is much more common in the United States,[34] where for the majority of people, access to food is not an issue. The issue in these developed countries is choosing the right kind of food. Fast food is consumed more per capita in the United States than in any other country. The reason for this mass consumption of food is the affordability and accessibility. Oftentimes the fast food, low in cost and nutrition, is high in calories and heavily promoted. When these eating habits are combined with increasingly urbanized, automated, and more sedentary lifestyles, it becomes clear why gaining weight is difficult to avoid.[35]
However, overeating is also a problem in countries where hunger and poverty persist. In China, consumption of high-fat foods has increased while consumption of rice and other goods has decreased.[36] Overeating leads to many diseases, such as heart disease and diabetes, that may result in death.
[edit]Causes
Major causes of malnutrition include poverty and food prices, dietary practices and agricultural productivity, with many individual cases being a mixture of several factors. Malnutrition can also be a consequence of other health issues such as gastroenteritis[37] or chronic illness,[38] especially the HIV/AIDS pandemic[39] Clinical malnutrition, such as in cachexia, is a major burden also in developed countries.
[edit]Poverty and food prices
As much as food shortages may be a contributing factor to malnutrition in countries with lack of technology, the FAO (Food and Agriculture Organization) has estimated that eighty percent of malnourished children living in the developing world live in countries that produce food surpluses.[36] The economist Amartya Sen observed that, in recent decades, famine has always a problem of food distribution and/or poverty, as there has been sufficient food to feed the whole population of the world. He states that malnutrition and famine were more related to problems of food distribution and purchasing power.[40]
It is argued that commodity speculators are increasing the cost of food. As the real estate bubble in the United States was collapsing, it is said that trillions of dollars moved to invest in food and primary commodities, causing the 2007–2008 food price crisis.[41]
The use of biofuels as a replacement for traditional fuels may leave less supply of food for nutrition and raises the price of food.[42] The United Nations special rapporteur on the right to food, Jean Ziegler proposes that agricultural waste, such as corn cobs and banana leaves, rather than crops themselves be used as fuel.[43]
[edit]Dietary practices
A lack of breastfeeding can lead to malnutrition in infants and children. Possible reasons for the lack in the developing world may be that the average family thinks bottle feeding is better.[44] The WHO says mothers abandon it because they do not know how to get their baby to latch on properly or suffer pain and discomfort.[45]
Deriving too much of one's diet from a single source, such as eating almost exclusively corn or rice, can cause malnutrition. This may either be from a lack of education about proper nutrition, or from only having access to a single food source.
Many tend to think malnutrition only in terms of hunger, however, overeating is also a contributing factor as well. Many parts of the world have access to a surplus of non-nutritious food, in addition to increased sedentary lifestyles. In turn, this has created a universal epidemic of obesity. Yale psychologist Kelly Brownell calls this a "toxic food environment” where fat and sugar laden foods have taken precedent over healthy nutritious foods. Not only does obesity occur in developed countries, problems are also occurring in developing countries in areas where income is on the rise.[36]
[edit]Agricultural productivity
Food shortages can be caused by a lack of farming skills such as crop rotation, or by a lack of technology or resources needed for the higher yields found in modern agriculture, such as nitrogen fertilizers, pesticides and irrigation. As a result of widespread poverty, farmers cannot afford or governments cannot provide the technology. The World Bank and some wealthy donor countries also press nations that depend on aid to cut or eliminate subsidized agricultural inputs such as fertilizer, in the name of free market policies even as the United States and Europe extensively subsidized their own farmers.[13][46] Many, if not most, farmers cannot afford fertilizer at market prices, leading to low agricultural production and wages and high, unaffordable food prices.[13] Reasons for the unavailability of fertilizer include moves to stop supplying fertilizer on environmental grounds, cited as the obstacle to feeding Africa by the Green Revolution pioneer Norman Borlaug.[11]
[edit]Future threats
There are a number of potential disruptions to global food supply that could cause widespread malnutrition.
Climate change is of great importance to food security. With 95% of all malnourished peoples living in the relatively stable climate region of the sub-tropics and tropics. According to the latest IPCC reports, temperature increases in these regions are "very likely."[47] Even small changes in temperatures can lead to increased frequency of extreme weather conditions.[47] Many of these have great impact on agricultural production and hence nutrition. For example, the 1998–2001 central Asian drought brought about an 80% livestock loss and 50% reduction in wheat and barley crops in Iran.[48] Similar figures were present in other nations. An increase in extreme weather such as drought in regions such as Sub-Saharan would have even greater consequences in terms of malnutrition. Even without an increase of extreme weather events, a simple increase in temperature reduces the productiveness of many crop species, also decreasing food security in these regions.[47][49]
Colony collapse disorder is a phenomenon where bees are dying in large numbers.[50] Since many agricultural crops worldwide are pollinated by bees, this represents a serious threat to the supply of food.[51]
An epidemic of stem rust on wheat caused by race Ug99 is currently spreading across Africa and into Asia and, it is feared, could wipe out more than 80% of the world’s wheat crops.[52][53]
[edit]Management
Main articles: Ready-to-Use Therapeutic food and famine relief
Fighting malnutrition, mostly through fortifying foods with micronutrients (vitamins and minerals), improves lives at a lower cost and shorter time than other forms of aid, according to the World Bank.[54] The Copenhagen Consensus, which look at a variety of development proposals, ranked micronutrient supplements as number one.[4][55] However, roughly $300m of aid goes to basic nutrition each year, less than $2 for each child below two in the 20 worst affected countries.[3] In contrast, HIV/AIDS, which causes fewer deaths than child malnutrition, received $2.2 billion—$67 per person with HIV in all countries.[3]
[edit]Emergency measures
Micronutrients can be obtained through fortifying foods.[4] Fortifying foods such as peanut butter sachets (see Plumpy'Nut) and Spirulina have revolutionized emergency feeding in humanitarian emergencies because they can be eaten directly from the packet, do not require refrigeration or mixing with scarce clean water, can be stored for years and, vitally, can be absorbed by extremely ill children.[5] The United Nations World Food Conference of 1974 declared Spirulina as 'the best food for the future' and its ready harvest every 24 hours make it a potent tool to eradicate malnutrition. Additionally, supplements, such as Vitamin A capsules or Zinc tablets to cure diarrhea in children, are used.[6]
There is a growing realization among aid groups that giving cash or cash vouchers instead of food is a cheaper, faster, and more efficient way to deliver help to the hungry, particularly in areas where food is available but unaffordable.[7] The UN's World Food Program, the biggest non-governmental distributor of food, announced that it will begin distributing cash and vouchers instead of food in some areas, which Josette Sheeran, the WFP's executive director, described as a "revolution" in food aid.[7][8] The aid agency Concern Worldwide is piloting a method through a mobile phone operator, Safaricom, which runs a money transfer program that allows cash to be sent from one part of the country to another.[7]
However, for people in a drought living a long way from and with limited access to markets, delivering food may be the most appropriate way to help.[7] Fred Cuny stated that "the chances of saving lives at the outset of a relief operation are greatly reduced when food is imported. By the time it arrives in the country and gets to people, many will have died."[56] US Law, which requires buying food at home rather than where the hungry live, is inefficient because approximately half of what is spent goes for transport.[55] Fred Cuny further pointed out "studies of every recent famine have shown that food was available in-country — though not always in the immediate food deficit area" and "even though by local standards the prices are too high for the poor to purchase it, it would usually be cheaper for a donor to buy the hoarded food at the inflated price than to import it from abroad."[57] Ethiopia has been pioneering a program that has now become part of the World Bank's prescribed recipe for coping with a food crisis and had been seen by aid organizations as a model of how to best help hungry nations. Through the country's main food assistance program, the Productive Safety Net Program, Ethiopia has been giving rural residents who are chronically short of food, a chance to work for food or cash. Foreign aid organizations like the World Food Program were then able to buy food locally from surplus areas to distribute in areas with a shortage of food.[58] Not only has Ethiopia been pioneering a program but Brazil has also established a recycling program for organic waste that benefits farmers, urban poor, and the city in general. City residents separate organic waste from their garbage, bag it, and then exchange it for fresh fruit and vegetables from local farmers. As a result, this reduces its countries waste and the urban poor get a steady supply of nutritious food.[35]
[edit]Long-term measures
Main article: food security
The effort to bring modern agricultural techniques found in the West, such as nitrogen fertilizers and pesticides, to Asia, called the Green Revolution, resulted in decreases in malnutrition similar to those seen earlier in Western nations. This was possible because of existing infrastructure and institutions that are in short supply in Africa, such as a system of roads or public seed companies that made seeds available.[59] Investments in agriculture, such as subsidized fertilizers and seeds, increases food harvest and reduces food prices.[13][60] For example, in the case of Malawi, almost five million of its 13 million people used to need emergency food aid. However, after the government changed policy and subsidies for fertilizer and seed were introduced against World Bank strictures, farmers produced record-breaking corn harvests as production leaped to 3.4 million in 2007 from 1.2 million in 2005, making Malawi a major food exporter.[13] This lowered food prices and increased wages for farm workers.[13] Proponents for investing in agriculture include Jeffrey Sachs, who has championed the idea that wealthy countries should invest in fertilizer and seed for Africa’s farmers.[10][13]
Breast-feeding education helps. Breastfeeding in the first two years and exclusive breastfeeding in the first six months could save 1.3 million children’s lives.[61] In the longer term, firms are trying to fortify everyday foods with micronutrients that can be sold to consumers such as wheat flour for Beladi bread in Egypt or fish sauce in Vietnam and the iodization of salt.[5]
Restricting population size is a proposed solution. Thomas Malthus argued that population growth could be controlled by natural disasters and voluntary limits through “moral restraint.”[62] Robert Chapman suggests that an intervention through government policies is a necessary ingredient of curtailing global population growth.[63] However, there are many who believe that the world has more than enough resources to sustain its population. Instead, these theorists point to unequal distribution of resources and under- or unutilized arable land as the cause for malnutrition problems.[64][65] For example, Amaryta Sen advocates that, “no matter how a famine is caused, methods of breaking it call for a large supply of food in the public distribution system. This applies not only to organizing rationing and control, but also to undertaking work programmes and other methods of increasing purchasing power for those hit by shifts in exchange entitlements in a general inflationary situation.”[40] One suggested policy framework to resolve access issues is termed food sovereignty, the right of peoples to define their own food, agriculture, livestock, and fisheries systems in contrast to having food largely subjected to international market forces. Food First is one of the primary think tanks working to build support for food sovereignty. Neoliberals advocate for an increasing role of the free market. Another possible long term solution would be to increase access to health facilities to rural parts of the world. These facilities could monitor undernourished children, act as supplemental food distribution centers, and provide education on dietary needs. These types of facilities have already proven very successful in countries such as Peru and Ghana.[66][67] New technology in agricultural production also has great potential to combat under nutrition.[68] By improving agricultural yields, farmers could reduce poverty by increasing income as well as open up area for diversification of crops for household use. The World Bank itself claims to be part of the solution to malnutrition, asserting that the best way for countries to succeed in breaking the cycle of poverty and malnutrition is to build export-led economies that will give them the financial means to buy foodstuffs on the world market.
When aiming to prevent rather than treat overeating, which is also a form of malnutrition, starting in the school environment would be the perfect place as this is where the education children receive today will help them choose healthier foods during childhood, as well as into adulthood. As seen in Singapore, if we increase nutrition in school lunch programs and physical activity for children and teachers, obesity can be reduced by almost 30–50%
A number of different nutrition disorders may arise, depending on which nutrients are under or overabundant in the diet.
The World Health Organization cites malnutrition as the greatest single threat to the world's public health.[3] Improving nutrition is widely regarded as the most effective form of aid.[3][4] Emergency measures include providing deficient micronutrients through fortified sachet powders, such as peanut butter, or directly through supplements.[5][6] The famine relief model increasingly used by aid groups calls for giving cash or cash vouchers to the hungry to pay local farmers instead of buying food from donor countries, often required by law, as it wastes money on transport costs.[7][8]
There are various methods used to gauge the degree of malnutrition, including the Gomez Classification. This classifies as 1st, 2nd or 3rd degree malnutrition according to the percentage of normal body weight a person is.
Long term measures include fostering nutritionally dense agriculture by increasing yields, while making sure negative consequences affecting yields in the future are minimized.[9]
Recent efforts include aid to farmers.[10] However, World Bank strictures restrict government subsidies for farmers, while the spread of fertilizer[11] use may adversely affect ecosystems and human health[12] and is hampered by various civil society groups.
Mortality
According to Jean Ziegler(the United Nations Special Rapporteur on the Right to Food for 2000 to March 2008), mortality due to malnutrition accounted for 58% of the total mortality in 2006: "In the world, approximately 62 million people, all causes of death combined, die each year. One in twelve people worldwide is malnourished.[14] In 2006, more than 36 million died of hunger or diseases due to deficiencies in micronutrients".[15]
According to the World Health Organization, malnutrition is by far the biggest contributor to child mortality, present in half of all cases.[3] Six million children die of hunger every year.[16] Underweight births and inter-uterine growth restrictions cause 2.2 million child deaths a year. Poor or non-existent breastfeeding causes another 1.4 million. Other deficiencies, such as lack of vitamin A or zinc, for example, account for 1 million. Malnutrition in the first two years is irreversible. Malnourished children grow up with worse health and lower educational achievements. Their own children also tend to be smaller. Malnutrition was previously seen as something that exacerbates the problems of diseases as measles, pneumonia and diarrhea. But malnutrition actually causes diseases as well, and can be fatal in its own right.[3]
[edit]Causes
Malnutrition increases the risk of infection and infectious disease; for example, it is a major risk factor in the onset of active tuberculosis.[17] In communities or areas that lack access to safe drinking water, these additional health risks present a critical problem. Lower energy and impaired function of the brain also represent the downward spiral of malnutrition as victims are less able to perform the tasks they need to in order to acquire food, earn an income, or gain an education.
Nutrients Deficiency Excess
Food energy Starvation, Marasmus Obesity, diabetes mellitus, Cardiovascular disease
Simple carbohydrates none diabetes mellitus, Obesity
Complex carbohydrates none Obesity
Saturated fat low sex hormone levels [18] Cardiovascular disease
Trans fat none Cardiovascular disease
Unsaturated fat none Obesity
Fat Malabsorption of Fat-soluble vitamins, Rabbit Starvation (If protein intake is high) Cardiovascular disease (claimed by some)
Omega 3 Fats Cardiovascular disease Bleeding, Hemorrhages
Omega 6 Fats none Cardiovascular disease, Cancer
Cholesterol none Cardiovascular disease
Protein kwashiorkor Rabbit starvation
Sodium hyponatremia Hypernatremia, hypertension
Iron Iron deficiency: Anemia Cirrhosis, heart disease
Iodine Iodine deficiency: Goiter, hypothyroidism Iodine Toxicity (goiter, hypothyroidism)
Vitamin A Vitamin A deficiency: Xerophthalmia and Night Blindness, low testosterone levels Hypervitaminosis A (cirrhosis, hair loss)
Vitamin B1 Beri-Beri
Vitamin B2 Ariboflavinosis: Cracking of skin and Corneal Ulceration
Vitamin B3 Pellagra dyspepsia, cardiac arrhythmias, birth defects
Vitamin B12 Pernicious anemia
Vitamin C Scurvy diarrhea causing dehydration
Vitamin D Rickets Hypervitaminosis D (dehydration, vomiting, constipation)
Vitamin E nervous disorders Hypervitaminosis E (anticoagulant: excessive bleeding)
Vitamin K Vitamin K deficiency: Haemorrhage
Calcium Osteoporosis, tetany, carpopedal spasm, laryngospasm, cardiac arrhythmias Fatigue, depression, confusion, anorexia, nausea, vomiting, constipation, pancreatitis, increased urination
Magnesium Magnesium deficiency: Hypertension Weakness, nausea, vomiting, impaired breathing, and hypotension
Potassium Hypokalemia, cardiac arrhythmias Hyperkalemia, palpitations
Boron Boron deficiency
Manganese Manganese deficiency
[edit]Psychological
Malnutrition, in the form of iodine deficiency, is "the most common preventable cause of mental impairment worldwide."[19] Even moderate iodine deficiency, especially in pregnant women and infants, lowers intelligence by 10 to 15 I.Q. points, shaving incalculable potential off a nation’s development.[19] The most visible and severe effects — disabling goiters, cretinism and dwarfism — affect a tiny minority, usually in mountain villages. But 16 percent of the world’s people have at least mild goiter, a swollen thyroid gland in the neck.[19]
Protein-calorie malnutrition can cause cognitive impairments. For humans, "critical period varies from the final third of gestation to the first 2 years of life".[20]
Research indicates that improving the awareness of nutritious meal choices and establishing long-term habits of healthy eating has a positive effect on a cognitive and spatial memory capacity, potentially increasing a student's potential to process and retain academic information.
Some organizations have begun working with teachers, policymakers, and managed food service contractors to mandate improved nutritional content and increased nutritional resources in school cafeterias from primary to university level institutions. Health and nutrition have been proven to have close links with overall educational success.[21] Currently less than 10% of American college students report that they eat the recommended five servings of fruit and vegetables daily.[22] Better nutrition has been shown to have an impact on both cognitive and spatial memory performance; a study showed those with higher blood sugar levels performed better on certain memory tests.[23] In another study, those who consumed yogurt performed better on thinking tasks when compared to those who consumed caffeine free diet soda or confections.[24] Nutritional deficiencies have been shown to have a negative effect on learning behavior in mice as far back as 1951.[25]
"Better learning performance is associated with diet induced effects on learning and memory ability".[26]
The "nutrition-learning nexus" demonstrates the correlation between diet and learning and has application in a higher education setting.
"We find that better nourished children perform significantly better in school, partly because they enter school earlier and thus have more time to learn but mostly because of greater learning productivity per year of schooling."[27]
91% of college students feel that they are in good health while only 7% eat their recommended daily allowance of fruits and vegetables.[22]
Nutritional education is an effective and workable model in a higher education setting.[28][29]
More "engaged" learning models that encompass nutrition is an idea that is picking up steam at all levels of the learning cycle.[30]
There is limited research available that directly links a student's Grade Point Average (G.P.A.) to their overall nutritional health. Additional substantive data is needed to prove that overall intellectual health is closely linked to a person's diet, rather than just another correlation fallacy.
Nutritional supplement treatment may be appropriate for major depression, bipolar disorder, schizophrenia, and obsessive compulsive disorder, the four most common mental disorders in developed countries.[31] Supplements that have been studied most for mood elevation and stabilization include eicosapentaenoic acid and docosahexaenoic acid (each of which are an omega-3 fatty acid contained in fish oil, but not in flaxseed oil), vitamin B12, folic acid, and inositol.
[edit]Cancer
Cancer is now common in developing countries. According a study by the International Agency for Research on Cancer, "In the developing world, cancers of the liver, stomach and esophagus were more common, often linked to consumption of carcinogenic preserved foods, such as smoked or salted food, and parasitic infections that attack organs." Lung cancer rates are rising rapidly in poorer nations because of increased use of tobacco. Developed countries "tended to have cancers linked to affluence or a 'Western lifestyle' — cancers of the colon, rectum, breast and prostate — that can be caused by obesity, lack of exercise, diet and age."[32]
[edit]Metabolic syndrome
Several lines of evidence indicate lifestyle-induced hyperinsulinemia and reduced insulin function (i.e. insulin resistance) as a decisive factor in many disease states. For example, hyperinsulinemia and insulin resistance are strongly linked to chronic inflammation, which in turn is strongly linked to a variety of adverse developments such as arterial microinjuries and clot formation (i.e. heart disease) and exaggerated cell division (i.e. cancer). Hyperinsulinemia and insulin resistance (the so-called metabolic syndrome) are characterized by a combination of abdominal obesity, elevated blood sugar, elevated blood pressure, elevated blood triglycerides, and reduced HDL cholesterol. The negative impact of hyperinsulinemia on prostaglandin PGE1/PGE2 balance may be significant.
The state of obesity clearly contributes to insulin resistance, which in turn can cause type 2 diabetes. Virtually all obese and most type 2 diabetic individuals have marked insulin resistance. Although the association between overweight and insulin resistance is clear, the exact (likely multifarious) causes of insulin resistance remain less clear. Importantly, it has been demonstrated that appropriate exercise, more regular food intake and reducing glycemic load (see below) all can reverse insulin resistance in overweight individuals (and thereby lower blood sugar levels in those who have type 2 diabetes).
Obesity can unfavourably alter hormonal and metabolic status via resistance to the hormone leptin, and a vicious cycle may occur in which insulin/leptin resistance and obesity aggravate one another. The vicious cycle is putatively fuelled by continuously high insulin/leptin stimulation and fat storage, as a result of high intake of strongly insulin/leptin stimulating foods and energy. Both insulin and leptin normally function as satiety signals to the hypothalamus in the brain; however, insulin/leptin resistance may reduce this signal and therefore allow continued overfeeding despite large body fat stores. In addition, reduced leptin signalling to the brain may reduce leptin's normal effect to maintain an appropriately high metabolic rate.
There is a debate about how and to what extent different dietary factors— such as intake of processed carbohydrates, total protein, fat, and carbohydrate intake, intake of saturated and trans fatty acids, and low intake of vitamins/minerals—contribute to the development of insulin and leptin resistance. In any case, analogous to the way modern man-made pollution may potentially overwhelm the environment's ability to maintain homeostasis, the recent explosive introduction of high glycemic index and processed foods into the human diet may potentially overwhelm the body's ability to maintain homeostasis and health (as evidenced by the metabolic syndrome epidemic).[citation needed]
[edit]Hyponatremia
Excess water intake, without replenishment of sodium and potassium salts, leads to hyponatremia, which can further lead to water intoxication at more dangerous levels. A well-publicized case occurred in 2007, when Jennifer Strange died while participating in a water-drinking contest.[33] More usually, the condition occurs in long-distance endurance events (such as marathon or triathlon competition and training) and causes gradual mental dulling, headache, drowsiness, weakness, and confusion; extreme cases may result in coma, convulsions, and death. The primary damage comes from swelling of the brain, caused by increased osmosis as blood salinity decreases. Effective fluid replacement techniques include Water aid stations during running/cycling races, trainers providing water during team games such as Soccer and devices such as Camel Baks which can provide water for a person without making it too hard to drink the water.
[edit]Overeating vs. hunger
Although a lot of the focus regarding malnutrition centers around undernourishment, overeating is also a form of malnutrition. Overeating is much more common in the United States,[34] where for the majority of people, access to food is not an issue. The issue in these developed countries is choosing the right kind of food. Fast food is consumed more per capita in the United States than in any other country. The reason for this mass consumption of food is the affordability and accessibility. Oftentimes the fast food, low in cost and nutrition, is high in calories and heavily promoted. When these eating habits are combined with increasingly urbanized, automated, and more sedentary lifestyles, it becomes clear why gaining weight is difficult to avoid.[35]
However, overeating is also a problem in countries where hunger and poverty persist. In China, consumption of high-fat foods has increased while consumption of rice and other goods has decreased.[36] Overeating leads to many diseases, such as heart disease and diabetes, that may result in death.
[edit]Causes
Major causes of malnutrition include poverty and food prices, dietary practices and agricultural productivity, with many individual cases being a mixture of several factors. Malnutrition can also be a consequence of other health issues such as gastroenteritis[37] or chronic illness,[38] especially the HIV/AIDS pandemic[39] Clinical malnutrition, such as in cachexia, is a major burden also in developed countries.
[edit]Poverty and food prices
As much as food shortages may be a contributing factor to malnutrition in countries with lack of technology, the FAO (Food and Agriculture Organization) has estimated that eighty percent of malnourished children living in the developing world live in countries that produce food surpluses.[36] The economist Amartya Sen observed that, in recent decades, famine has always a problem of food distribution and/or poverty, as there has been sufficient food to feed the whole population of the world. He states that malnutrition and famine were more related to problems of food distribution and purchasing power.[40]
It is argued that commodity speculators are increasing the cost of food. As the real estate bubble in the United States was collapsing, it is said that trillions of dollars moved to invest in food and primary commodities, causing the 2007–2008 food price crisis.[41]
The use of biofuels as a replacement for traditional fuels may leave less supply of food for nutrition and raises the price of food.[42] The United Nations special rapporteur on the right to food, Jean Ziegler proposes that agricultural waste, such as corn cobs and banana leaves, rather than crops themselves be used as fuel.[43]
[edit]Dietary practices
A lack of breastfeeding can lead to malnutrition in infants and children. Possible reasons for the lack in the developing world may be that the average family thinks bottle feeding is better.[44] The WHO says mothers abandon it because they do not know how to get their baby to latch on properly or suffer pain and discomfort.[45]
Deriving too much of one's diet from a single source, such as eating almost exclusively corn or rice, can cause malnutrition. This may either be from a lack of education about proper nutrition, or from only having access to a single food source.
Many tend to think malnutrition only in terms of hunger, however, overeating is also a contributing factor as well. Many parts of the world have access to a surplus of non-nutritious food, in addition to increased sedentary lifestyles. In turn, this has created a universal epidemic of obesity. Yale psychologist Kelly Brownell calls this a "toxic food environment” where fat and sugar laden foods have taken precedent over healthy nutritious foods. Not only does obesity occur in developed countries, problems are also occurring in developing countries in areas where income is on the rise.[36]
[edit]Agricultural productivity
Food shortages can be caused by a lack of farming skills such as crop rotation, or by a lack of technology or resources needed for the higher yields found in modern agriculture, such as nitrogen fertilizers, pesticides and irrigation. As a result of widespread poverty, farmers cannot afford or governments cannot provide the technology. The World Bank and some wealthy donor countries also press nations that depend on aid to cut or eliminate subsidized agricultural inputs such as fertilizer, in the name of free market policies even as the United States and Europe extensively subsidized their own farmers.[13][46] Many, if not most, farmers cannot afford fertilizer at market prices, leading to low agricultural production and wages and high, unaffordable food prices.[13] Reasons for the unavailability of fertilizer include moves to stop supplying fertilizer on environmental grounds, cited as the obstacle to feeding Africa by the Green Revolution pioneer Norman Borlaug.[11]
[edit]Future threats
There are a number of potential disruptions to global food supply that could cause widespread malnutrition.
Climate change is of great importance to food security. With 95% of all malnourished peoples living in the relatively stable climate region of the sub-tropics and tropics. According to the latest IPCC reports, temperature increases in these regions are "very likely."[47] Even small changes in temperatures can lead to increased frequency of extreme weather conditions.[47] Many of these have great impact on agricultural production and hence nutrition. For example, the 1998–2001 central Asian drought brought about an 80% livestock loss and 50% reduction in wheat and barley crops in Iran.[48] Similar figures were present in other nations. An increase in extreme weather such as drought in regions such as Sub-Saharan would have even greater consequences in terms of malnutrition. Even without an increase of extreme weather events, a simple increase in temperature reduces the productiveness of many crop species, also decreasing food security in these regions.[47][49]
Colony collapse disorder is a phenomenon where bees are dying in large numbers.[50] Since many agricultural crops worldwide are pollinated by bees, this represents a serious threat to the supply of food.[51]
An epidemic of stem rust on wheat caused by race Ug99 is currently spreading across Africa and into Asia and, it is feared, could wipe out more than 80% of the world’s wheat crops.[52][53]
[edit]Management
Main articles: Ready-to-Use Therapeutic food and famine relief
Fighting malnutrition, mostly through fortifying foods with micronutrients (vitamins and minerals), improves lives at a lower cost and shorter time than other forms of aid, according to the World Bank.[54] The Copenhagen Consensus, which look at a variety of development proposals, ranked micronutrient supplements as number one.[4][55] However, roughly $300m of aid goes to basic nutrition each year, less than $2 for each child below two in the 20 worst affected countries.[3] In contrast, HIV/AIDS, which causes fewer deaths than child malnutrition, received $2.2 billion—$67 per person with HIV in all countries.[3]
[edit]Emergency measures
Micronutrients can be obtained through fortifying foods.[4] Fortifying foods such as peanut butter sachets (see Plumpy'Nut) and Spirulina have revolutionized emergency feeding in humanitarian emergencies because they can be eaten directly from the packet, do not require refrigeration or mixing with scarce clean water, can be stored for years and, vitally, can be absorbed by extremely ill children.[5] The United Nations World Food Conference of 1974 declared Spirulina as 'the best food for the future' and its ready harvest every 24 hours make it a potent tool to eradicate malnutrition. Additionally, supplements, such as Vitamin A capsules or Zinc tablets to cure diarrhea in children, are used.[6]
There is a growing realization among aid groups that giving cash or cash vouchers instead of food is a cheaper, faster, and more efficient way to deliver help to the hungry, particularly in areas where food is available but unaffordable.[7] The UN's World Food Program, the biggest non-governmental distributor of food, announced that it will begin distributing cash and vouchers instead of food in some areas, which Josette Sheeran, the WFP's executive director, described as a "revolution" in food aid.[7][8] The aid agency Concern Worldwide is piloting a method through a mobile phone operator, Safaricom, which runs a money transfer program that allows cash to be sent from one part of the country to another.[7]
However, for people in a drought living a long way from and with limited access to markets, delivering food may be the most appropriate way to help.[7] Fred Cuny stated that "the chances of saving lives at the outset of a relief operation are greatly reduced when food is imported. By the time it arrives in the country and gets to people, many will have died."[56] US Law, which requires buying food at home rather than where the hungry live, is inefficient because approximately half of what is spent goes for transport.[55] Fred Cuny further pointed out "studies of every recent famine have shown that food was available in-country — though not always in the immediate food deficit area" and "even though by local standards the prices are too high for the poor to purchase it, it would usually be cheaper for a donor to buy the hoarded food at the inflated price than to import it from abroad."[57] Ethiopia has been pioneering a program that has now become part of the World Bank's prescribed recipe for coping with a food crisis and had been seen by aid organizations as a model of how to best help hungry nations. Through the country's main food assistance program, the Productive Safety Net Program, Ethiopia has been giving rural residents who are chronically short of food, a chance to work for food or cash. Foreign aid organizations like the World Food Program were then able to buy food locally from surplus areas to distribute in areas with a shortage of food.[58] Not only has Ethiopia been pioneering a program but Brazil has also established a recycling program for organic waste that benefits farmers, urban poor, and the city in general. City residents separate organic waste from their garbage, bag it, and then exchange it for fresh fruit and vegetables from local farmers. As a result, this reduces its countries waste and the urban poor get a steady supply of nutritious food.[35]
[edit]Long-term measures
Main article: food security
The effort to bring modern agricultural techniques found in the West, such as nitrogen fertilizers and pesticides, to Asia, called the Green Revolution, resulted in decreases in malnutrition similar to those seen earlier in Western nations. This was possible because of existing infrastructure and institutions that are in short supply in Africa, such as a system of roads or public seed companies that made seeds available.[59] Investments in agriculture, such as subsidized fertilizers and seeds, increases food harvest and reduces food prices.[13][60] For example, in the case of Malawi, almost five million of its 13 million people used to need emergency food aid. However, after the government changed policy and subsidies for fertilizer and seed were introduced against World Bank strictures, farmers produced record-breaking corn harvests as production leaped to 3.4 million in 2007 from 1.2 million in 2005, making Malawi a major food exporter.[13] This lowered food prices and increased wages for farm workers.[13] Proponents for investing in agriculture include Jeffrey Sachs, who has championed the idea that wealthy countries should invest in fertilizer and seed for Africa’s farmers.[10][13]
Breast-feeding education helps. Breastfeeding in the first two years and exclusive breastfeeding in the first six months could save 1.3 million children’s lives.[61] In the longer term, firms are trying to fortify everyday foods with micronutrients that can be sold to consumers such as wheat flour for Beladi bread in Egypt or fish sauce in Vietnam and the iodization of salt.[5]
Restricting population size is a proposed solution. Thomas Malthus argued that population growth could be controlled by natural disasters and voluntary limits through “moral restraint.”[62] Robert Chapman suggests that an intervention through government policies is a necessary ingredient of curtailing global population growth.[63] However, there are many who believe that the world has more than enough resources to sustain its population. Instead, these theorists point to unequal distribution of resources and under- or unutilized arable land as the cause for malnutrition problems.[64][65] For example, Amaryta Sen advocates that, “no matter how a famine is caused, methods of breaking it call for a large supply of food in the public distribution system. This applies not only to organizing rationing and control, but also to undertaking work programmes and other methods of increasing purchasing power for those hit by shifts in exchange entitlements in a general inflationary situation.”[40] One suggested policy framework to resolve access issues is termed food sovereignty, the right of peoples to define their own food, agriculture, livestock, and fisheries systems in contrast to having food largely subjected to international market forces. Food First is one of the primary think tanks working to build support for food sovereignty. Neoliberals advocate for an increasing role of the free market. Another possible long term solution would be to increase access to health facilities to rural parts of the world. These facilities could monitor undernourished children, act as supplemental food distribution centers, and provide education on dietary needs. These types of facilities have already proven very successful in countries such as Peru and Ghana.[66][67] New technology in agricultural production also has great potential to combat under nutrition.[68] By improving agricultural yields, farmers could reduce poverty by increasing income as well as open up area for diversification of crops for household use. The World Bank itself claims to be part of the solution to malnutrition, asserting that the best way for countries to succeed in breaking the cycle of poverty and malnutrition is to build export-led economies that will give them the financial means to buy foodstuffs on the world market.
When aiming to prevent rather than treat overeating, which is also a form of malnutrition, starting in the school environment would be the perfect place as this is where the education children receive today will help them choose healthier foods during childhood, as well as into adulthood. As seen in Singapore, if we increase nutrition in school lunch programs and physical activity for children and teachers, obesity can be reduced by almost 30–50%
Diversification
Farm diversification is when a farm branches out from traditional farming by adding new money making activities. This can be in place of or in addition to its traditional farming pursuits. Farm diversification can involve anything, from adding pastured poultry and organic beef production to starting a bed and breakfast in the barn or setting up a local tourist attraction. In short farm diversification usually involves a shift from traditional farming activities into non farm projects.
When considering what to diversify into many farmers find it helpful to consider:
Under used resources - many farms have unused buildings and farm resources. Farms that successfully diversify are often able to put their existing farm assets to use. Making a list of your existing farm under utilised resources is a useful first step in working out potential ideas.
Unfilled local demand - being able to meet a local demand for a product or service that is not currently being met may offer an opportunity to broaden your farms horizons into new business areas.
Existing skills and expertise - playing to your existing farming experience and knowledge increases your likelihood of success. It also makes it easier to make the transition from traditional farm to rural enterprise.
Area of interest - make a note of any business ideas that interest you. Following up on these means that you're more likely to put in the extra hours and effort required to make your rural enterprise a success.
When considering what to diversify into many farmers find it helpful to consider:
Under used resources - many farms have unused buildings and farm resources. Farms that successfully diversify are often able to put their existing farm assets to use. Making a list of your existing farm under utilised resources is a useful first step in working out potential ideas.
Unfilled local demand - being able to meet a local demand for a product or service that is not currently being met may offer an opportunity to broaden your farms horizons into new business areas.
Existing skills and expertise - playing to your existing farming experience and knowledge increases your likelihood of success. It also makes it easier to make the transition from traditional farm to rural enterprise.
Area of interest - make a note of any business ideas that interest you. Following up on these means that you're more likely to put in the extra hours and effort required to make your rural enterprise a success.
Monday 27 February 2012
Types of Irrigation
Types of Irrigation
There are mainly 5 kinds of irrigation facility
1 Surface irrigation
2 Localized irrigation
2.1 Drip, or trickle irrigation
3 Sprinkler irrigation
3.1 Center pivot irrigation
3.2 Lateral move (Side roll, Wheel line) irrigation
4 Sub-irrigation
5 Manual irrigation using buckets or watering cans
Surface irrigation
In surface irrigation systems water is moving over the land by simple gravity flow in order to wet it and to infiltrate into the soil. They can be subdivided into furrow, borderstrip or basin irrigation.
Localized irrigation
Localized irrigation is a system where water is distributed under low pressure through a piped network, in a pre-determined pattern, and applied as a small discharge to each plant or adjacent to it. Drip irrigation, spray or micro-sprinkler irrigation and bubbler irrigation belong to this category of irrigation methods.
Sprinkler irrigation
In sprinkler or overhead irrigation, water is piped to one or more central locations within the field and distributed by overhead high-pressure sprinklers or guns. A system utilizing sprinklers, sprays, or guns mounted overhead on permanently installed risers is often referred to as a solid-set irrigation system. Higher pressure sprinklers that rotate are called rotors and are driven by a ball drive, gear drive, or impact mechanism. Rotors can be designed to rotate in a full or partial circle. Guns are similar to rotors, except that they generally operate at very high pressures of 40 to 130 lbf/in² (275 to 900 kPa) and flows of 50 to 1200 US gal/min (3 to 76 L/s), usually with nozzle diameters in the range of 0.5 to 1.9 inches (10 to 50 mm). Guns are used not only for irrigation, but also for industrial applications such as dust suppression and logging.
There are mainly 5 kinds of irrigation facility
1 Surface irrigation
2 Localized irrigation
2.1 Drip, or trickle irrigation
3 Sprinkler irrigation
3.1 Center pivot irrigation
3.2 Lateral move (Side roll, Wheel line) irrigation
4 Sub-irrigation
5 Manual irrigation using buckets or watering cans
Surface irrigation
In surface irrigation systems water is moving over the land by simple gravity flow in order to wet it and to infiltrate into the soil. They can be subdivided into furrow, borderstrip or basin irrigation.
Localized irrigation
Localized irrigation is a system where water is distributed under low pressure through a piped network, in a pre-determined pattern, and applied as a small discharge to each plant or adjacent to it. Drip irrigation, spray or micro-sprinkler irrigation and bubbler irrigation belong to this category of irrigation methods.
Sprinkler irrigation
In sprinkler or overhead irrigation, water is piped to one or more central locations within the field and distributed by overhead high-pressure sprinklers or guns. A system utilizing sprinklers, sprays, or guns mounted overhead on permanently installed risers is often referred to as a solid-set irrigation system. Higher pressure sprinklers that rotate are called rotors and are driven by a ball drive, gear drive, or impact mechanism. Rotors can be designed to rotate in a full or partial circle. Guns are similar to rotors, except that they generally operate at very high pressures of 40 to 130 lbf/in² (275 to 900 kPa) and flows of 50 to 1200 US gal/min (3 to 76 L/s), usually with nozzle diameters in the range of 0.5 to 1.9 inches (10 to 50 mm). Guns are used not only for irrigation, but also for industrial applications such as dust suppression and logging.
Irrigation
Irrigation may be defined as the science of artificial application of water to the land or soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall. Additionally, irrigation also has a few other uses in crop production, which include protecting plants against frost,[1] suppressing weed growing in grain fields[2] and helping in preventing soil consolidation.[3] In contrast, agriculture that relies only on direct rainfall is referred to as rain-fed or dryland farming. Irrigation systems are also used for dust suppression, disposal of sewage, and in mining. Irrigation is often studied together with drainage, which is the natural or artificial removal of surface and sub-surface water from a given area.
Irrigation is also a term used in medical/dental fields to refer to flushing and washing out anything with water or another liquid.
Types
Basin flood irrigation of wheat.
Irrigation of land in Punjab, Pakistan.
Various types of irrigation techniques differ in how the water obtained from the source is distributed within the field. In general, the goal is to supply the entire field uniformly with water, so that each plant has the amount of water it needs, neither too much nor too little.The modern methods are efficient enough to achieve this goal.
[edit]Surface
Main article: Surface irrigation
In surface irrigation systems, water moves over and across the land by simple gravity flow in order to wet it and to infiltrate into the soil. Surface irrigation can be subdivided into furrow, borderstrip or basin irrigation. It is often called flood irrigation when the irrigation results in flooding or near flooding of the cultivated land. Historically, this has been the most common method of irrigating agricultural land.
Where water levels from the irrigation source permit, the levels are controlled by dikes, usually plugged by soil. This is often seen in terraced rice fields (rice paddies), where the method is used to flood or control the level of water in each distinct field. In some cases, the water is pumped, or lifted by human or animal power to the level of the land.
[edit]Localized
Brass Impact type sprinkler head
Localized irrigation is a system where water is distributed under low pressure through a piped network, in a pre-determined pattern, and applied as a small discharge to each plant or adjacent to it. Drip irrigation, spray or micro-sprinkler irrigation and bubbler irrigation belong to this category of irrigation methods.[25]
[edit]Drip
Main article: Drip Irrigation
Drip Irrigation - A dripper in action
Grapes in Petrolina, just possible in this semi arid area due to drip irrigation.
Drip irrigation, also known as trickle irrigation, functions as its name suggests.In this system water falls drop by drop just at the position of roots. Water is delivered at or near the root zone of plants, drop by drop. This method can be the most water-efficient method of irrigation[26], if managed properly, since evaporation and runoff are minimized.
In modern agriculture, drip irrigation is often combined with plastic mulch, further reducing evaporation, and is also the means of delivery of fertilizer. The process is known as fertigation.
Drip Irrigation Layout and its parts
Deep percolation, where water moves below the root zone, can occur if a drip system is operated for too long or if the delivery rate is too high. Drip irrigation methods range from very high-tech and computerized to low-tech and labor-intensive. Lower water pressures are usually needed than for most other types of systems, with the exception of low energy center pivot systems and surface irrigation systems, and the system can be designed for uniformity throughout a field or for precise water delivery to individual plants in a landscape containing a mix of plant species. Although it is difficult to regulate pressure on steep slopes, pressure compensating emitters are available, so the field does not have to be level. High-tech solutions involve precisely calibrated emitters located along lines of tubing that extend from a computerized set of valves.
[edit]Sprinkler
Sprinkler irrigation of blueberries in Plainville, New York, United States.
In sprinkler or overhead irrigation, water is piped to one or more central locations within the field and distributed by overhead high-pressure sprinklers or guns. A system utilizing sprinklers, sprays, or guns mounted overhead on permanently installed risers is often referred to as a solid-set irrigation system. Higher pressure sprinklers that rotate are called rotors and are driven by a ball drive, gear drive, or impact mechanism. Rotors can be designed to rotate in a full or partial circle. Guns are similar to rotors, except that they generally operate at very high pressures of 40 to 130 lbf/in² (275 to 900 kPa) and flows of 50 to 1200 US gal/min (3 to 76 L/s), usually with nozzle diameters in the range of 0.5 to 1.9 inches (10 to 50 mm). Guns are used not only for irrigation, but also for industrial applications such as dust suppression and logging.
A traveling sprinkler at Millets Farm Centre, Oxfordshire, United Kingdom.
Sprinklers can also be mounted on moving platforms connected to the water source by a hose. Automatically moving wheeled systems known as traveling sprinklers may irrigate areas such as small farms, sports fields, parks, pastures, and cemeteries unattended. Most of these utilize a length of polyethylene tubing wound on a steel drum. As the tubing is wound on the drum powered by the irrigation water or a small gas engine, the sprinkler is pulled across the field. When the sprinkler arrives back at the reel the system shuts off. This type of system is known to most people as a "waterreel" traveling irrigation sprinkler and they are used extensively for dust suppression, irrigation, and land application of waste water. Other travelers use a flat rubber hose that is dragged along behind while the sprinkler platform is pulled by a cable. These cable-type travelers are definitely old technology and their use is limited in today's modern irrigation projects.
[edit]Center pivot
Main article: Center pivot irrigation
A small center pivot system from beginning to end
The hub of a center-pivot irrigation system.
Rotator style pivot applicator sprinkler.
Center pivot irrigation is a form of sprinkler irrigation consisting of several segments of pipe (usually galvanized steel or aluminum) joined together and supported by trusses, mounted on wheeled towers with sprinklers positioned along its length. The system moves in a circular pattern and is fed with water from the pivot point at the center of the arc. These systems are found and used in all parts of the world and allow irrigation of all types of terrain. Newer systems have drop sprinkler heads as shown in the image that follows.
Center pivot with drop sprinklers. Photo by Gene Alexander, USDA Natural Resources Conservation Service.
Most center pivot systems now have drops hanging from a u-shaped pipe attached at the top of the pipe with sprinkler heads that are positioned a few feet (at most) above the crop, thus limiting evaporative losses. Drops can also be used with drag hoses or bubblers that deposit the water directly on the ground between crops. Crops are often planted in a circle to conform to the center pivot. This type of system is known as LEPA (Low Energy Precision Application). Originally, most center pivots were water powered. These were replaced by hydraulic systems (T-L Irrigation) and electric motor driven systems (Reinke, Valley, Zimmatic). Many modern pivots feature GPS devices.[citation needed]
Wheel line irrigation system in Idaho. 2001. Photo by Joel McNee, USDA Natural Resources Conservation Service.
[edit]Lateral move (side roll, wheel line)
A series of pipes, each with a wheel of about 1.5 m diameter permanently affixed to its midpoint and sprinklers along its length, are coupled together at one edge of a field. Water is supplied at one end using a large hose. After sufficient water has been applied, the hose is removed and the remaining assembly rotated either by hand or with a purpose-built mechanism, so that the sprinklers move 10 m across the field. The hose is reconnected. The process is repeated until the opposite edge of the field is reached. This system is less expensive to install than a center pivot, but much more labor intensive to operate, and it is limited in the amount of water it can carry. Most systems utilize 4 or 5-inch (130 mm) diameter aluminum pipe. One feature of a lateral move system is that it consists of sections that can be easily disconnected. They are most often used for small or oddly shaped fields, such as those found in hilly or mountainous regions, or in regions where labor is inexpensive.
[edit]Sub-irrigation
Subirrigation also sometimes called seepage irrigation has been used for many years in field crops in areas with high water tables. It is a method of artificially raising the water table to allow the soil to be moistened from below the plants' root zone. Often those systems are located on permanent grasslands in lowlands or river valleys and combined with drainage infrastructure. A system of pumping stations, canals, weirs and gates allows it to increase or decrease the water level in a network of ditches and thereby control the water table.
Sub-irrigation is also used in commercial greenhouse production, usually for potted plants. Water is delivered from below, absorbed upwards, and the excess collected for recycling. Typically, a solution of water and nutrients floods a container or flows through a trough for a short period of time, 10–20 minutes, and is then pumped back into a holding tank for reuse. Sub-irrigation in greenhouses requires fairly sophisticated, expensive equipment and management. Advantages are water and nutrient conservation, and labor-saving through lowered system maintenance and automation. It is similar in principle and action to subsurface drip irrigation.
[edit]Manual using buckets or watering cans
These systems have low requirements for infrastructure and technical equipment but need high labor inputs. Irrigation using watering cans is to be found for example in peri-urban agriculture around large cities in some African countries.
[edit]Automatic, non-electric using buckets and ropes
Besides the common manual watering by bucket, an automated, natural version of this also exist. Using plain polyester ropes combined with a prepared ground mixture can be used to water plants from a vessel filled with water.[27][28][29]
The ground mixture would need to be made depending on the plant itself, yet would mostly consist of black potting soil, vermiculite and perlite. This system would (with certain crops) allow to save expenses as it does not consume any electricity and only little water (unlike sprinklers, water timers, ...). However, it may only be used with certain crops (probably mostly larger crops that do not need a humid environment; perhaps e.g. paprikas).[citation needed]
[edit]Using water condensed from humid air
In countries where at night, humid air sweeps the countryside, water can be obtained from the humid air by condensation onto cold surfaces. This is for example practiced in the vineyards at Lanzarote using stones to condense water or with various fog collectors based on canvas or foil sheets.
[edit]Sources of irrigation water
Sources of irrigation water can be groundwater extracted from springs or by using wells, surface water withdrawn from rivers, lakes or reservoirs or non-conventional sources like treated wastewater, desalinated water or drainage water. A special form of irrigation using surface water is spate irrigation, also called floodwater harvesting. In case of a flood (spate) water is diverted to normally dry river beds (wadis) using a network of dams, gates and channels and spread over large areas. The moisture stored in the soil will be used thereafter to grow crops. Spate irrigation areas are in particular located in semi-arid or arid, mountainous regions. While floodwater harvesting belongs to the accepted irrigation methods, rainwater harvesting is usually not considered as a form of irrigation. Rainwater harvesting is the collection of runoff water from roofs or unused land and the concentration of this. Some of Ancient India's water systems were pulled by oxen.
Around 90% of wastewater produced globally remains untreated, causing widespread water pollution, especially in low-income countries. Increasingly, agriculture is using untreated wastewater as a source of irrigation water. Cities provide lucrative markets for fresh produce, so are attractive to farmers. However, because agriculture has to compete for increasingly scarce water resources with industry and municipal users (see Water scarcity below), there is often no alternative for farmers but to use water polluted with urban waste, including sewage, directly to water their crops. There can be significant health hazards related to using water loaded with pathogens in this way, especially if people eat raw vegetables that have been irrigated with the polluted water. The International Water Management Institute has worked in India, Pakistan, Vietnam, Ghana, Ethiopia, Mexico and other countries on various projects aimed at assessing and reducing risks of wastewater irrigation. They advocate a ‘multiple-barrier’ approach to wastewater use, where farmers are encouraged to adopt various risk-reducing behaviours. These include ceasing irrigation a few days before harvesting to allow pathogens to die off in the sunlight, applying water carefully so it does not contaminate leaves likely to be eaten raw, cleaning vegetables with disinfectant or allowing fecal sludge used in farming to dry before being used as a human manure.[30] The World Health Organization has developed guidelines for safe water use.
[edit]Water scarcity
A group of brilliant young engineers, restoring and developing the old Mughal irrigation system during the reign of the Mughal Emperor Bahadur Shah II.
Fifty years ago, the common perception was that water was an infinite resource. At that time, there were fewer than half the current number of people on the planet. People were not as wealthy as today, consumed fewer calories and ate less meat, so less water was needed to produce their food. They required a third of the volume of water we presently take from rivers. Today, the competition for water resources is much more intense. This is because there are now more than seven billion people on the planet, their consumption of water-thirsty meat and vegetables is rising, and there is increasing competition for water from industry, urbanisation and biofuel crops. To avoid a global water crisis, farmers will have to strive to increase productivity to meet growing demands for food, while industry and cities find ways to use water more efficiently.[31]
Successful agriculture is dependent upon farmers having sufficient access to water. However, water scarcity is already a critical constraint to farming in many parts of the world. With regards to agriculture, the World Bank targets food production and water management as an increasingly global issue that is fostering a growing debate.[32] Physical water scarcity is where there is not enough water to meet all demands, including that needed for ecosystems to function effectively. Arid regions frequently suffer from physical water scarcity. It also occurs where water seems abundant but where resources are over-committed. This can happen where there is overdevelopment of hydraulic infrastructure, usually for irrigation. Symptoms of physical water scarcity include environmental degradation and declining groundwater. Economic scarcity, meanwhile, is caused by a lack of investment in water or insufficient human capacity to satisfy the demand for water. Symptoms of economic water scarcity include a lack of infrastructure, with people often having to fetch water from rivers for domestic and agricultural uses. Some 2.8 billion people currently live in water-scarce areas.[33]
[edit]How an in-ground irrigation system works
Most commercial and residential irrigation systems are "in ground" systems, which means that everything is buried in the ground. With the pipes, sprinklers, emitters (drippers), and irrigation valves being hidden, it makes for a cleaner, more presentable landscape without garden hoses or other items having to be moved around manually. This does, however, create some drawbacks in the maintenance of a completely buried system.
[edit]Controllers, zones, and valves
Most irrigation systems are divided into zones. A zone is a single irrigation valve and one or a group of drippers or sprinklers that are connected by pipes or tubes. Irrigation systems are divided into zones because there is usually not enough pressure and available flow to run sprinklers for an entire yard or sports field at once. Each zone has a solenoid valve on it that is controlled via wire by an irrigation controller. The irrigation controller is either a mechanical (now the "dinosaur" type) or electrical device that signals a zone to turn on at a specific time and keeps it on for a specified amount of time. "Smart Controller" is a recent term used to describe a controller that is capable of adjusting the watering time by itself in response to current environmental conditions. The smart controller determines current conditions by means of historic weather data for the local area, a soil moisture sensors (water potential or water content), rain sensor, or in more sophisticated systems satellite feed weather station, or a combination of these.
[edit]Emitters and sprinklers
When a zone comes on, the water flows through the lateral lines and ultimately ends up at the irrigation emitter (drip) or sprinkler heads. Many sprinklers have pipe thread inlets on the bottom of them which allows a fitting and the pipe to be attached to them. The sprinklers are usually installed with the top of the head flush with the ground surface. When the water is pressurized, the head will pop up out of the ground and water the desired area until the valve closes and shuts off that zone. Once there is no more water pressure in the lateral line, the sprinkler head will retract back into the ground. Emitters are generally laid on the soil surface or buried a few inches to reduce evaporation losses.
[edit]Problems in irrigation
Main article: Environmental impacts of irrigation
Irrigation can lead to a number of problems:[34]
Competition for surface water rights.
Depletion of underground aquifers.
Ground subsidence (e.g. New Orleans, Louisiana)
Underirrigation or irrigation giving only just enough water for the plant (e.g. in drip line irrigation) gives poor soil salinity control which leads to increased soil salinity with consequent build up of toxic salts on soil surface in areas with high evaporation. This requires either leaching to remove these salts and a method of drainage to carry the salts away. When using drip lines, the leaching is best done regularly at certain intervals (with only a slight excess of water), so that the salt is flushed back under the plant's roots.[35][36]
Overirrigation because of poor distribution uniformity or management wastes water, chemicals, and may lead to water pollution.
Deep drainage (from over-irrigation) may result in rising water tables which in some instances will lead to problems of irrigation salinity requiring watertable control by some form of subsurface land drainage.[37][38]
Irrigation with saline or high-sodium water may damage soil structure owing to the formation of alkaline soil
Irrigation is also a term used in medical/dental fields to refer to flushing and washing out anything with water or another liquid.
Types
Basin flood irrigation of wheat.
Irrigation of land in Punjab, Pakistan.
Various types of irrigation techniques differ in how the water obtained from the source is distributed within the field. In general, the goal is to supply the entire field uniformly with water, so that each plant has the amount of water it needs, neither too much nor too little.The modern methods are efficient enough to achieve this goal.
[edit]Surface
Main article: Surface irrigation
In surface irrigation systems, water moves over and across the land by simple gravity flow in order to wet it and to infiltrate into the soil. Surface irrigation can be subdivided into furrow, borderstrip or basin irrigation. It is often called flood irrigation when the irrigation results in flooding or near flooding of the cultivated land. Historically, this has been the most common method of irrigating agricultural land.
Where water levels from the irrigation source permit, the levels are controlled by dikes, usually plugged by soil. This is often seen in terraced rice fields (rice paddies), where the method is used to flood or control the level of water in each distinct field. In some cases, the water is pumped, or lifted by human or animal power to the level of the land.
[edit]Localized
Brass Impact type sprinkler head
Localized irrigation is a system where water is distributed under low pressure through a piped network, in a pre-determined pattern, and applied as a small discharge to each plant or adjacent to it. Drip irrigation, spray or micro-sprinkler irrigation and bubbler irrigation belong to this category of irrigation methods.[25]
[edit]Drip
Main article: Drip Irrigation
Drip Irrigation - A dripper in action
Grapes in Petrolina, just possible in this semi arid area due to drip irrigation.
Drip irrigation, also known as trickle irrigation, functions as its name suggests.In this system water falls drop by drop just at the position of roots. Water is delivered at or near the root zone of plants, drop by drop. This method can be the most water-efficient method of irrigation[26], if managed properly, since evaporation and runoff are minimized.
In modern agriculture, drip irrigation is often combined with plastic mulch, further reducing evaporation, and is also the means of delivery of fertilizer. The process is known as fertigation.
Drip Irrigation Layout and its parts
Deep percolation, where water moves below the root zone, can occur if a drip system is operated for too long or if the delivery rate is too high. Drip irrigation methods range from very high-tech and computerized to low-tech and labor-intensive. Lower water pressures are usually needed than for most other types of systems, with the exception of low energy center pivot systems and surface irrigation systems, and the system can be designed for uniformity throughout a field or for precise water delivery to individual plants in a landscape containing a mix of plant species. Although it is difficult to regulate pressure on steep slopes, pressure compensating emitters are available, so the field does not have to be level. High-tech solutions involve precisely calibrated emitters located along lines of tubing that extend from a computerized set of valves.
[edit]Sprinkler
Sprinkler irrigation of blueberries in Plainville, New York, United States.
In sprinkler or overhead irrigation, water is piped to one or more central locations within the field and distributed by overhead high-pressure sprinklers or guns. A system utilizing sprinklers, sprays, or guns mounted overhead on permanently installed risers is often referred to as a solid-set irrigation system. Higher pressure sprinklers that rotate are called rotors and are driven by a ball drive, gear drive, or impact mechanism. Rotors can be designed to rotate in a full or partial circle. Guns are similar to rotors, except that they generally operate at very high pressures of 40 to 130 lbf/in² (275 to 900 kPa) and flows of 50 to 1200 US gal/min (3 to 76 L/s), usually with nozzle diameters in the range of 0.5 to 1.9 inches (10 to 50 mm). Guns are used not only for irrigation, but also for industrial applications such as dust suppression and logging.
A traveling sprinkler at Millets Farm Centre, Oxfordshire, United Kingdom.
Sprinklers can also be mounted on moving platforms connected to the water source by a hose. Automatically moving wheeled systems known as traveling sprinklers may irrigate areas such as small farms, sports fields, parks, pastures, and cemeteries unattended. Most of these utilize a length of polyethylene tubing wound on a steel drum. As the tubing is wound on the drum powered by the irrigation water or a small gas engine, the sprinkler is pulled across the field. When the sprinkler arrives back at the reel the system shuts off. This type of system is known to most people as a "waterreel" traveling irrigation sprinkler and they are used extensively for dust suppression, irrigation, and land application of waste water. Other travelers use a flat rubber hose that is dragged along behind while the sprinkler platform is pulled by a cable. These cable-type travelers are definitely old technology and their use is limited in today's modern irrigation projects.
[edit]Center pivot
Main article: Center pivot irrigation
A small center pivot system from beginning to end
The hub of a center-pivot irrigation system.
Rotator style pivot applicator sprinkler.
Center pivot irrigation is a form of sprinkler irrigation consisting of several segments of pipe (usually galvanized steel or aluminum) joined together and supported by trusses, mounted on wheeled towers with sprinklers positioned along its length. The system moves in a circular pattern and is fed with water from the pivot point at the center of the arc. These systems are found and used in all parts of the world and allow irrigation of all types of terrain. Newer systems have drop sprinkler heads as shown in the image that follows.
Center pivot with drop sprinklers. Photo by Gene Alexander, USDA Natural Resources Conservation Service.
Most center pivot systems now have drops hanging from a u-shaped pipe attached at the top of the pipe with sprinkler heads that are positioned a few feet (at most) above the crop, thus limiting evaporative losses. Drops can also be used with drag hoses or bubblers that deposit the water directly on the ground between crops. Crops are often planted in a circle to conform to the center pivot. This type of system is known as LEPA (Low Energy Precision Application). Originally, most center pivots were water powered. These were replaced by hydraulic systems (T-L Irrigation) and electric motor driven systems (Reinke, Valley, Zimmatic). Many modern pivots feature GPS devices.[citation needed]
Wheel line irrigation system in Idaho. 2001. Photo by Joel McNee, USDA Natural Resources Conservation Service.
[edit]Lateral move (side roll, wheel line)
A series of pipes, each with a wheel of about 1.5 m diameter permanently affixed to its midpoint and sprinklers along its length, are coupled together at one edge of a field. Water is supplied at one end using a large hose. After sufficient water has been applied, the hose is removed and the remaining assembly rotated either by hand or with a purpose-built mechanism, so that the sprinklers move 10 m across the field. The hose is reconnected. The process is repeated until the opposite edge of the field is reached. This system is less expensive to install than a center pivot, but much more labor intensive to operate, and it is limited in the amount of water it can carry. Most systems utilize 4 or 5-inch (130 mm) diameter aluminum pipe. One feature of a lateral move system is that it consists of sections that can be easily disconnected. They are most often used for small or oddly shaped fields, such as those found in hilly or mountainous regions, or in regions where labor is inexpensive.
[edit]Sub-irrigation
Subirrigation also sometimes called seepage irrigation has been used for many years in field crops in areas with high water tables. It is a method of artificially raising the water table to allow the soil to be moistened from below the plants' root zone. Often those systems are located on permanent grasslands in lowlands or river valleys and combined with drainage infrastructure. A system of pumping stations, canals, weirs and gates allows it to increase or decrease the water level in a network of ditches and thereby control the water table.
Sub-irrigation is also used in commercial greenhouse production, usually for potted plants. Water is delivered from below, absorbed upwards, and the excess collected for recycling. Typically, a solution of water and nutrients floods a container or flows through a trough for a short period of time, 10–20 minutes, and is then pumped back into a holding tank for reuse. Sub-irrigation in greenhouses requires fairly sophisticated, expensive equipment and management. Advantages are water and nutrient conservation, and labor-saving through lowered system maintenance and automation. It is similar in principle and action to subsurface drip irrigation.
[edit]Manual using buckets or watering cans
These systems have low requirements for infrastructure and technical equipment but need high labor inputs. Irrigation using watering cans is to be found for example in peri-urban agriculture around large cities in some African countries.
[edit]Automatic, non-electric using buckets and ropes
Besides the common manual watering by bucket, an automated, natural version of this also exist. Using plain polyester ropes combined with a prepared ground mixture can be used to water plants from a vessel filled with water.[27][28][29]
The ground mixture would need to be made depending on the plant itself, yet would mostly consist of black potting soil, vermiculite and perlite. This system would (with certain crops) allow to save expenses as it does not consume any electricity and only little water (unlike sprinklers, water timers, ...). However, it may only be used with certain crops (probably mostly larger crops that do not need a humid environment; perhaps e.g. paprikas).[citation needed]
[edit]Using water condensed from humid air
In countries where at night, humid air sweeps the countryside, water can be obtained from the humid air by condensation onto cold surfaces. This is for example practiced in the vineyards at Lanzarote using stones to condense water or with various fog collectors based on canvas or foil sheets.
[edit]Sources of irrigation water
Sources of irrigation water can be groundwater extracted from springs or by using wells, surface water withdrawn from rivers, lakes or reservoirs or non-conventional sources like treated wastewater, desalinated water or drainage water. A special form of irrigation using surface water is spate irrigation, also called floodwater harvesting. In case of a flood (spate) water is diverted to normally dry river beds (wadis) using a network of dams, gates and channels and spread over large areas. The moisture stored in the soil will be used thereafter to grow crops. Spate irrigation areas are in particular located in semi-arid or arid, mountainous regions. While floodwater harvesting belongs to the accepted irrigation methods, rainwater harvesting is usually not considered as a form of irrigation. Rainwater harvesting is the collection of runoff water from roofs or unused land and the concentration of this. Some of Ancient India's water systems were pulled by oxen.
Around 90% of wastewater produced globally remains untreated, causing widespread water pollution, especially in low-income countries. Increasingly, agriculture is using untreated wastewater as a source of irrigation water. Cities provide lucrative markets for fresh produce, so are attractive to farmers. However, because agriculture has to compete for increasingly scarce water resources with industry and municipal users (see Water scarcity below), there is often no alternative for farmers but to use water polluted with urban waste, including sewage, directly to water their crops. There can be significant health hazards related to using water loaded with pathogens in this way, especially if people eat raw vegetables that have been irrigated with the polluted water. The International Water Management Institute has worked in India, Pakistan, Vietnam, Ghana, Ethiopia, Mexico and other countries on various projects aimed at assessing and reducing risks of wastewater irrigation. They advocate a ‘multiple-barrier’ approach to wastewater use, where farmers are encouraged to adopt various risk-reducing behaviours. These include ceasing irrigation a few days before harvesting to allow pathogens to die off in the sunlight, applying water carefully so it does not contaminate leaves likely to be eaten raw, cleaning vegetables with disinfectant or allowing fecal sludge used in farming to dry before being used as a human manure.[30] The World Health Organization has developed guidelines for safe water use.
[edit]Water scarcity
A group of brilliant young engineers, restoring and developing the old Mughal irrigation system during the reign of the Mughal Emperor Bahadur Shah II.
Fifty years ago, the common perception was that water was an infinite resource. At that time, there were fewer than half the current number of people on the planet. People were not as wealthy as today, consumed fewer calories and ate less meat, so less water was needed to produce their food. They required a third of the volume of water we presently take from rivers. Today, the competition for water resources is much more intense. This is because there are now more than seven billion people on the planet, their consumption of water-thirsty meat and vegetables is rising, and there is increasing competition for water from industry, urbanisation and biofuel crops. To avoid a global water crisis, farmers will have to strive to increase productivity to meet growing demands for food, while industry and cities find ways to use water more efficiently.[31]
Successful agriculture is dependent upon farmers having sufficient access to water. However, water scarcity is already a critical constraint to farming in many parts of the world. With regards to agriculture, the World Bank targets food production and water management as an increasingly global issue that is fostering a growing debate.[32] Physical water scarcity is where there is not enough water to meet all demands, including that needed for ecosystems to function effectively. Arid regions frequently suffer from physical water scarcity. It also occurs where water seems abundant but where resources are over-committed. This can happen where there is overdevelopment of hydraulic infrastructure, usually for irrigation. Symptoms of physical water scarcity include environmental degradation and declining groundwater. Economic scarcity, meanwhile, is caused by a lack of investment in water or insufficient human capacity to satisfy the demand for water. Symptoms of economic water scarcity include a lack of infrastructure, with people often having to fetch water from rivers for domestic and agricultural uses. Some 2.8 billion people currently live in water-scarce areas.[33]
[edit]How an in-ground irrigation system works
Most commercial and residential irrigation systems are "in ground" systems, which means that everything is buried in the ground. With the pipes, sprinklers, emitters (drippers), and irrigation valves being hidden, it makes for a cleaner, more presentable landscape without garden hoses or other items having to be moved around manually. This does, however, create some drawbacks in the maintenance of a completely buried system.
[edit]Controllers, zones, and valves
Most irrigation systems are divided into zones. A zone is a single irrigation valve and one or a group of drippers or sprinklers that are connected by pipes or tubes. Irrigation systems are divided into zones because there is usually not enough pressure and available flow to run sprinklers for an entire yard or sports field at once. Each zone has a solenoid valve on it that is controlled via wire by an irrigation controller. The irrigation controller is either a mechanical (now the "dinosaur" type) or electrical device that signals a zone to turn on at a specific time and keeps it on for a specified amount of time. "Smart Controller" is a recent term used to describe a controller that is capable of adjusting the watering time by itself in response to current environmental conditions. The smart controller determines current conditions by means of historic weather data for the local area, a soil moisture sensors (water potential or water content), rain sensor, or in more sophisticated systems satellite feed weather station, or a combination of these.
[edit]Emitters and sprinklers
When a zone comes on, the water flows through the lateral lines and ultimately ends up at the irrigation emitter (drip) or sprinkler heads. Many sprinklers have pipe thread inlets on the bottom of them which allows a fitting and the pipe to be attached to them. The sprinklers are usually installed with the top of the head flush with the ground surface. When the water is pressurized, the head will pop up out of the ground and water the desired area until the valve closes and shuts off that zone. Once there is no more water pressure in the lateral line, the sprinkler head will retract back into the ground. Emitters are generally laid on the soil surface or buried a few inches to reduce evaporation losses.
[edit]Problems in irrigation
Main article: Environmental impacts of irrigation
Irrigation can lead to a number of problems:[34]
Competition for surface water rights.
Depletion of underground aquifers.
Ground subsidence (e.g. New Orleans, Louisiana)
Underirrigation or irrigation giving only just enough water for the plant (e.g. in drip line irrigation) gives poor soil salinity control which leads to increased soil salinity with consequent build up of toxic salts on soil surface in areas with high evaporation. This requires either leaching to remove these salts and a method of drainage to carry the salts away. When using drip lines, the leaching is best done regularly at certain intervals (with only a slight excess of water), so that the salt is flushed back under the plant's roots.[35][36]
Overirrigation because of poor distribution uniformity or management wastes water, chemicals, and may lead to water pollution.
Deep drainage (from over-irrigation) may result in rising water tables which in some instances will lead to problems of irrigation salinity requiring watertable control by some form of subsurface land drainage.[37][38]
Irrigation with saline or high-sodium water may damage soil structure owing to the formation of alkaline soil
Subsistence farming
Subsistence agriculture is self-sufficiency farming in which the farmers focus on growing enough food to feed themselves and their families. The typical subsistence farm has a range of crops and animals needed by the family to eat and clothe themselves during the year. Planting decisions are made principally with an eye toward what the family will need during the coming year, and secondarily toward market prices.
Tony Waters[1] writes: "Subsistence peasants are people who grow what they eat, build their own houses, and live without regularly making purchases in the marketplace." However, despite the primacy of self-sufficiency in subsistence farming, most subsistence farmers also participate in trade to some degree, albeit one or two orders of magnitude less than among consumers in industrial or postindustrial economies.
Most subsistence farmers today live in developing countries. Although their amount of trade as measured in currency is less than that of consumers in developed countries, most have important trade contacts and do trade items that they can produce because of their special skills or their access to resources not available to other subsistence farmers.[2]
Subsistence grain-growing agriculture (predominantly wheat and barley) first emerged during the Neolithic Revolution when humans began to settle in the Nile, Euphrates, and Indus River Valleys. Subsistence agriculture also emerged independently in Mexico where it was based on maize cultivation, and the Andes where it was based on the domestication of the potato. Subsistence agriculture was the dominant mode of production in the world until recently, when market-based capitalism became widespread. Subsistence horticulture may have developed independently in South East Asia and Papua New Guinea.
Subsistence farming continues today in large parts of rural Africa,[3] and parts of Asia and Latin America. Subsistence agriculture had largely disappeared in Europe by the beginning of World War I, and in North America with the movement of sharecroppers and tenant farmers out of the American South and Midwest during the 1930s and 1940s.[1] As recently as the 1950s, it was still common on family farms in North America and Europe to grow most of the family's own food and make much of its own clothing, although sales of some of the farm's production earned enough currency to buy certain staples, typically including sugar; coffee and tea; petroleum distillates (petrol, kerosene, fuel oil); textile products such as bolts of cloth, needles, and thread; medicines; hardware products such as nails, screws, and wire; and a few discretionary items such as candy or books. Many of the preceding items, as well as occasional services from physicians, veterinarians, blacksmiths, and others, were often bought with barter rather than currency. In Central and Eastern Europe subsistence and semi-subsistence agriculture reappeared within the transition economy since about 1990.
Types
Shifting agriculture ('slash and burn' or Jhooming)
In this type of agriculture, a patch of forest land is cleared by a combination of felling and burning, and crops are grown. After 2-3 years the fertility of the soil begins to decline, the land is abandoned and the farmer moves to clear a fresh piece of land elsewhere in the forest and the process continues. While the land is left fallow the forest regrows in the cleared area and soil fertility and biomass is restored. After a decade or more, the farmer may return to the first piece of land. This form of agriculture is sustainable at low population densities, but higher population loads require more frequent clearing which prevents soil fertility from recovering, opens up more of the forest canopy, and encourages scrub at the expense of large trees, eventually resulting in deforestation and heavy erosion.
While this 'slash and burn' technique may describe the method for opening new land, commonly the farmers in question have in existence at the same time smaller fields, sometimes merely gardens, near the homestead there they practice intensive 'non-shifting" techniques until shortage of fields where they can employ "slash and burn" to clear land and (by the burning) provide fertilizer (ash). Such gardens nearer the homestead often regularly receive household refuse, the manure of any household chickens or goats, and compost piles where refuse is thrown initially just to get it out of the way. However, such farmers often recognize the value of such compost and apply it regularly to their smaller fields. They also may irrigate part of such fields if they are near a source of water.
In some areas of tropical Africa, at least, such smaller fields may be ones in which crops are grown on raised beds. Thus farmers practicing 'slash and burn' agriculture are often much more sophisticated agriculturalists than the term "slash and burn" "subsistence" farmers suggest.
Changes
- High yield varieties
- Irrigation
- Land reform
- Appropriate technology
Tony Waters[1] writes: "Subsistence peasants are people who grow what they eat, build their own houses, and live without regularly making purchases in the marketplace." However, despite the primacy of self-sufficiency in subsistence farming, most subsistence farmers also participate in trade to some degree, albeit one or two orders of magnitude less than among consumers in industrial or postindustrial economies.
Most subsistence farmers today live in developing countries. Although their amount of trade as measured in currency is less than that of consumers in developed countries, most have important trade contacts and do trade items that they can produce because of their special skills or their access to resources not available to other subsistence farmers.[2]
Subsistence grain-growing agriculture (predominantly wheat and barley) first emerged during the Neolithic Revolution when humans began to settle in the Nile, Euphrates, and Indus River Valleys. Subsistence agriculture also emerged independently in Mexico where it was based on maize cultivation, and the Andes where it was based on the domestication of the potato. Subsistence agriculture was the dominant mode of production in the world until recently, when market-based capitalism became widespread. Subsistence horticulture may have developed independently in South East Asia and Papua New Guinea.
Subsistence farming continues today in large parts of rural Africa,[3] and parts of Asia and Latin America. Subsistence agriculture had largely disappeared in Europe by the beginning of World War I, and in North America with the movement of sharecroppers and tenant farmers out of the American South and Midwest during the 1930s and 1940s.[1] As recently as the 1950s, it was still common on family farms in North America and Europe to grow most of the family's own food and make much of its own clothing, although sales of some of the farm's production earned enough currency to buy certain staples, typically including sugar; coffee and tea; petroleum distillates (petrol, kerosene, fuel oil); textile products such as bolts of cloth, needles, and thread; medicines; hardware products such as nails, screws, and wire; and a few discretionary items such as candy or books. Many of the preceding items, as well as occasional services from physicians, veterinarians, blacksmiths, and others, were often bought with barter rather than currency. In Central and Eastern Europe subsistence and semi-subsistence agriculture reappeared within the transition economy since about 1990.
Types
Shifting agriculture ('slash and burn' or Jhooming)
In this type of agriculture, a patch of forest land is cleared by a combination of felling and burning, and crops are grown. After 2-3 years the fertility of the soil begins to decline, the land is abandoned and the farmer moves to clear a fresh piece of land elsewhere in the forest and the process continues. While the land is left fallow the forest regrows in the cleared area and soil fertility and biomass is restored. After a decade or more, the farmer may return to the first piece of land. This form of agriculture is sustainable at low population densities, but higher population loads require more frequent clearing which prevents soil fertility from recovering, opens up more of the forest canopy, and encourages scrub at the expense of large trees, eventually resulting in deforestation and heavy erosion.
While this 'slash and burn' technique may describe the method for opening new land, commonly the farmers in question have in existence at the same time smaller fields, sometimes merely gardens, near the homestead there they practice intensive 'non-shifting" techniques until shortage of fields where they can employ "slash and burn" to clear land and (by the burning) provide fertilizer (ash). Such gardens nearer the homestead often regularly receive household refuse, the manure of any household chickens or goats, and compost piles where refuse is thrown initially just to get it out of the way. However, such farmers often recognize the value of such compost and apply it regularly to their smaller fields. They also may irrigate part of such fields if they are near a source of water.
In some areas of tropical Africa, at least, such smaller fields may be ones in which crops are grown on raised beds. Thus farmers practicing 'slash and burn' agriculture are often much more sophisticated agriculturalists than the term "slash and burn" "subsistence" farmers suggest.
Changes
- High yield varieties
- Irrigation
- Land reform
- Appropriate technology
Commercial Farming
Commercial agriculture is large-scale production of crops for sale, intended for widespread distribution to wholesalers or retail outlets. In commercial farming crops such as wheat, maize, tea, coffee, sugarcane, cashew, rubber, banana, cotton are harvested and sold into world markets. Commercial agriculture includes livestock production and livestock grazing.
Due to the expensive nature of capital formation and implementation of technological processes, the landowners of such farms are often large agricultural corporations (especially in developing countries). Large-scale commercial farming, in terms of some of its processes, may be conceptually not very different from large industrial enterprises; United Fruit Company (now Chiquita Brands International) is an example. Commercial farming is most commonly found in advanced industrialized nations.
The harvested crop may be processed on-site (or shipped to a processing facility belonging to the farm owners) and then sold to a wholesaler as a complete product, or it may be sold as-is for further processing elsewhere.
Commercial agriculture differs significantly from subsistence agriculture, as the main objective of commercial agriculture is achieving higher profits through economies of scale, specialization, introduction of capital-intensive farming techniques, labour-saving technologies, and maximization of crop yields per hectare through synthetic and natural resources (fertilizers, hybrid seeds, irrigation, etc.). Whereas subsistence agriculture is an economic model in which most members of a population work in agriculture to feed themselves, with limited need for trade, commercial agriculture is a type of agriculture suited to industrial or postindustrial economic models, in which most members of a population do not work in agriculture, are fed by others (the few who do work in agriculture), and purchase their food and fiber as consumers, with currency.
Development
Commercial farming is a progression from diversified (sometimes called mixed) farming, where the farmer's intention is to produce goods for sale primarily for widespread consumption by others. The farmer may acquire a sufficiently large amount of arable land and/or sufficiently advanced technology. In advanced countries, there is also investment in expensive capital equipment like tractors, harvesters and so forth. At this point, it may become more profitable for the farmer to specialize and focus on one or a few particular crops due to economies of scale. This may be further augmented by higher levels of technology that might significantly reduce the risk of poor harvests. Thus, the key difference between commercial farming and less-developed forms of agriculture is the new emphasis on capital formation, scientific progress and technological development, as opposed to a reliance mainly on natural resource utilization that is common to subsistence and diversified agriculture.
Types
There are types of commercial agriculture:
Intensive Commercial Farming: A system of agriculture in which relatively large amounts of capitol or labour and applied to relatively smaller areas of land. It is practiced in countries where the population pressure is reducing the size of landholdings. The State of West Bengal in India provides one of the best examples of intensive commercial farming.
Extensive Commercial Farming: It is a system of agriculture in which relatively small amounts of capital or labour investment are applied to relatively large areas of land. At times, the land is left fallow to regain its fertility. It is mostly mechanized as labour is very expensive or may not be available at all. It usually occurs at the margin of the agricultural system, at a great distance from market or on poor land of limited potential. It is practiced usually in the tarai regions of southern Nepal. Crops grown are sugarcane, rice and wheat.
Plantation Agriculture: Plantation is a large farm or estate usually in a tropical or sub-tropical country where crops are grown for sale in distant markets rather than local consumption.
Factors
Commercial agriculture contains six key factors:
1. Location
Commercial farms must move their products to market. Farms need to be located near transportation systems. Trucks, ships, planes, and trains are several ways that products can be moved from where they are grown or made to where customers can buy them.
2. Climate
A farm's soil, as well as the climate of the region in which it is located, determine what crops will grow there or whether the land can support livestock. The temperature and rainfall can also determine the type of crop grown. For example, oranges must be grown in a hot climate. They will not grow if the temperature is too cold.
3. Raw Materials
A commercial farm depends on raw material. For example, a farmer will plant grain to get wheat. A farmer will have dairy cows to produce milk. Seeds and animals are two examples of raw materials used in commercial agriculture.
4. Market Forces
Supply and demand are important for selling agricultural products. If there is a high demand for a product and low supply, the price will be increased.
5. Labour
People who work on farms provide different types of labour. Labour is needed to plant crops, as well as to harvest them. This is important because some produce, such as grapes, need to be hand harvested.
6. Transportation
Movement of agricultural products to market depends on transportation systems. For example, produce is shipped by rail in special refrigerated cars, then shipped across the ocean. Some crops. such as fruit, must get to the market quickly, or else they will rot; crops like these are often shipped shorter distances or are sold in the regions where they are grown.
Changes
- produce more food
- increased investment
- greater use of chemicals
- genetically improved seeds and animals are being introduced
- increased farm size
- increased field size
- mechanisation - starting to use more machinery
Due to the expensive nature of capital formation and implementation of technological processes, the landowners of such farms are often large agricultural corporations (especially in developing countries). Large-scale commercial farming, in terms of some of its processes, may be conceptually not very different from large industrial enterprises; United Fruit Company (now Chiquita Brands International) is an example. Commercial farming is most commonly found in advanced industrialized nations.
The harvested crop may be processed on-site (or shipped to a processing facility belonging to the farm owners) and then sold to a wholesaler as a complete product, or it may be sold as-is for further processing elsewhere.
Commercial agriculture differs significantly from subsistence agriculture, as the main objective of commercial agriculture is achieving higher profits through economies of scale, specialization, introduction of capital-intensive farming techniques, labour-saving technologies, and maximization of crop yields per hectare through synthetic and natural resources (fertilizers, hybrid seeds, irrigation, etc.). Whereas subsistence agriculture is an economic model in which most members of a population work in agriculture to feed themselves, with limited need for trade, commercial agriculture is a type of agriculture suited to industrial or postindustrial economic models, in which most members of a population do not work in agriculture, are fed by others (the few who do work in agriculture), and purchase their food and fiber as consumers, with currency.
Development
Commercial farming is a progression from diversified (sometimes called mixed) farming, where the farmer's intention is to produce goods for sale primarily for widespread consumption by others. The farmer may acquire a sufficiently large amount of arable land and/or sufficiently advanced technology. In advanced countries, there is also investment in expensive capital equipment like tractors, harvesters and so forth. At this point, it may become more profitable for the farmer to specialize and focus on one or a few particular crops due to economies of scale. This may be further augmented by higher levels of technology that might significantly reduce the risk of poor harvests. Thus, the key difference between commercial farming and less-developed forms of agriculture is the new emphasis on capital formation, scientific progress and technological development, as opposed to a reliance mainly on natural resource utilization that is common to subsistence and diversified agriculture.
Types
There are types of commercial agriculture:
Intensive Commercial Farming: A system of agriculture in which relatively large amounts of capitol or labour and applied to relatively smaller areas of land. It is practiced in countries where the population pressure is reducing the size of landholdings. The State of West Bengal in India provides one of the best examples of intensive commercial farming.
Extensive Commercial Farming: It is a system of agriculture in which relatively small amounts of capital or labour investment are applied to relatively large areas of land. At times, the land is left fallow to regain its fertility. It is mostly mechanized as labour is very expensive or may not be available at all. It usually occurs at the margin of the agricultural system, at a great distance from market or on poor land of limited potential. It is practiced usually in the tarai regions of southern Nepal. Crops grown are sugarcane, rice and wheat.
Plantation Agriculture: Plantation is a large farm or estate usually in a tropical or sub-tropical country where crops are grown for sale in distant markets rather than local consumption.
Factors
Commercial agriculture contains six key factors:
1. Location
Commercial farms must move their products to market. Farms need to be located near transportation systems. Trucks, ships, planes, and trains are several ways that products can be moved from where they are grown or made to where customers can buy them.
2. Climate
A farm's soil, as well as the climate of the region in which it is located, determine what crops will grow there or whether the land can support livestock. The temperature and rainfall can also determine the type of crop grown. For example, oranges must be grown in a hot climate. They will not grow if the temperature is too cold.
3. Raw Materials
A commercial farm depends on raw material. For example, a farmer will plant grain to get wheat. A farmer will have dairy cows to produce milk. Seeds and animals are two examples of raw materials used in commercial agriculture.
4. Market Forces
Supply and demand are important for selling agricultural products. If there is a high demand for a product and low supply, the price will be increased.
5. Labour
People who work on farms provide different types of labour. Labour is needed to plant crops, as well as to harvest them. This is important because some produce, such as grapes, need to be hand harvested.
6. Transportation
Movement of agricultural products to market depends on transportation systems. For example, produce is shipped by rail in special refrigerated cars, then shipped across the ocean. Some crops. such as fruit, must get to the market quickly, or else they will rot; crops like these are often shipped shorter distances or are sold in the regions where they are grown.
Changes
- produce more food
- increased investment
- greater use of chemicals
- genetically improved seeds and animals are being introduced
- increased farm size
- increased field size
- mechanisation - starting to use more machinery
Thursday 26 January 2012
Deserts and Desertification
- A desert is a landscape or region that receives an extremely low amount of precipitation, less than enough to support growth of most plants. Most deserts have an average annual precipitation of less than 400 millimetres
- A common definition distinguishes between true deserts, which receive less than 250 millimetres of average annual precipitation, and semideserts or steppes, which receive between 250 millimetres (10 in) and 400 to 500 millimetres (16 to 20 in).
- Desertification is the degradation of land in drylands.
- Caused by a variety of factors, such as climate change and human activities, desertification is one of the most significant global environmental problems.
- The world's great deserts were formed by natural processes interacting over long intervals of time. During most of these times, deserts have grown and shrunk independent of human activities.
- Dryland ecosystems are already very fragile, and can rarely sustain the increased pressures that result from intense population growth. Many of these areas are inappropriately opened to development, when they cannot sustain human settlements.
- The most common cause of desertification is the over cultivation of desert lands.
- A common definition distinguishes between true deserts, which receive less than 250 millimetres of average annual precipitation, and semideserts or steppes, which receive between 250 millimetres (10 in) and 400 to 500 millimetres (16 to 20 in).
- Desertification is the degradation of land in drylands.
- Caused by a variety of factors, such as climate change and human activities, desertification is one of the most significant global environmental problems.
- The world's great deserts were formed by natural processes interacting over long intervals of time. During most of these times, deserts have grown and shrunk independent of human activities.
- Dryland ecosystems are already very fragile, and can rarely sustain the increased pressures that result from intense population growth. Many of these areas are inappropriately opened to development, when they cannot sustain human settlements.
- The most common cause of desertification is the over cultivation of desert lands.
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