Fertilizers are chemical compounds given to plants to promote growth; they are usually applied either through the soil, for uptake by plant roots, or by foliar feeding, for uptake through leaves. Fertilizers can be organic (composed of organic matter), or inorganic (made of simple, inorganic chemicals or minerals). They can be naturally occurring compounds such as peat or mineral deposits, or manufactured through natural processes (such as composting) or chemical processes (such as the Haber process). These chemical compounds leave lawns, gardens, and soils looking beautiful as they are given different essential nutrients that encourage plant growth.
They typically provide, in varying proportions, the three major plant nutrients (nitrogen, phosphorus, potassium: N-P-K), the secondary plant nutrients (calcium, sulfur, magnesium) and sometimes trace elements (or micronutrients) with a role in plant or animal nutrition: boron, chlorine, manganese, iron, zinc, copper, molybdenum and (in some countries) selenium.
Both organic and inorganic fertilizers were called "manure" derived from the French expression for manual tillage, but this term is now mostly restricted to organic manure.
Though nitrogen is plentiful in the earth's atmosphere, relatively few plants engage in nitrogen fixation (conversion of atmospheric nitrogen to a biologically useful form). Most plants thus require nitrogen compounds to be present in the soil in which they grow.
It is believed that organic agricultural methods are more environmentally friendly and better maintain soil organic matter levels. There are generally accepted scientific studies that support this supposition.[1] Regardless of the source, fertilization results in increased unharvested plant biomass left on the soil surface and crop residues remaining in the soil. Too much of a vital nutrient can be as detrimental as not enough.[2] "Fertilizer burn" can occur when too much fertilizer is applied, resulting in a drying out of the roots and damage or even death of the plant.[3] Organic fertilizers are just as likely to burn as inorganic fertilizers. If excess nitrogen is present the plants will begin to exude nitrogen from the leafy areas. This is called guttation.
Sunday, December 14, 2008
Saturday, December 13, 2008
Pestisides
A pesticide is a substance or mixture of substances used to kill a pest.[1] A pesticide may be a chemical substance, biological agent (such as a virus or bacteria), antimicrobial, disinfectant or device used against any pest. Pests include insects, plant pathogens, weeds, molluscs, birds, mammals, fish, nematodes (roundworms) and microbes that compete with humans for food, destroy property, spread or are a vector for disease or cause a nuisance. Although there are benefits to the use of pesticides, there are also drawbacks, such as potential toxicity to humans and other animals.
[edit]
Types of pesticides
There are multiple ways of classifying pesticides.
Algicides or Algaecides for the control of algae
Avicides for the control of birds
Bactericides for the control of bacteria
Fungicides for the control of fungi and oomycetes
Herbicides for the control of weeds
Insecticides for the control of insects - these can be Ovicides (substances that kill eggs), Larvicides (substances that kill larvae) or Adulticides (substances that kill adult insects)
Miticides or Acaricides for the control of mites
Molluscicides for the control of slugs and snails
Nematicides for the control of nematodes
Rodenticides for the control of rodents
Virucides for the control of viruses (e.g. H5N1)
Pesticides can also be classed as synthetic pesticides or biological pesticides (biopesticides), although the distinction can sometimes blur.
Broad-spectrum pesticides are those that kill an array of species, while narrow-spectrum, or selective pesticides only kill a small group of species.[2]
A systemic pesticide moves inside a plant following absorption by the plant. With insecticides and most fungicides, this movement is usually upward (through the xylem) and outward. Increased efficiency may be a result. Systemic insecticides which poison pollen and nectar in the flowers may kill needed pollinators such as bees.
Most pesticides work by poisoning pests.[3]
[edit]
Uses
Pesticides are used to control organisms which are considered harmful.[4] For example, they are used to kill mosquitoes that can transmit potentially deadly diseases like west nile virus, yellow fever, and malaria. They can also kill bees, wasps or ants that can cause allergic reactions. Insecticides can protect animals from illnesses that can be caused by parasites such as fleas.[4] Pesticides can prevent sickness in humans that could be caused by mouldy food or diseased produce. Herbicides can be used to clear roadside weeds, trees and brush. They can also kill invasive weeds in parks and wilderness areas which may cause environmental damage. Herbicides are commonly applied in ponds and lakes to control algae and plants such as water grasses that can interfere with activities like swimming and fishing and cause the water to look or smell unpleasant.[5] Uncontrolled pests such as termites and mould can damage structures such as houses.[4] Pesticides are used in grocery stores and food storage facilities to manage rodents and insects that infest food such as grain. Each use of a pesticide carries some associated risk. Proper pesticide use decreases these associated risks to a level deemed acceptable by pesticide regulatory agencies such as the United States Environmental Protection Agency (EPA) and the Pest Management Regulatory Agency (PMRA) of Canada.
Pesticides can save farmers money by preventing crop losses to insects and other pests; in the US, farmers get an estimated four-fold return on money they spend on pesticides.[6] One study found that not using pesticides reduced crop yields by about 10%.[7] Another study,conducted in 1999, found that a ban on pesticides in the United States may result in a rise of food prices, loss of jobs, and an increase in world hunger.[8]
DDT, sprayed on the walls of houses, is an organochloride that has been used to fight malaria since the 1950s. Recent policy statements by the World Health Organization have given stronger support to this approach. [9] Dr. Arata Kochi, WHO's malaria chief, said, "One of the best tools we have against malaria is indoor residual house spraying. Of the dozen insecticides WHO has approved as safe for house spraying, the most effective is DDT."[9] However, since then, an October 2007 study has linked breast cancer from exposure to DDT prior to puberty.[10] Poisoning may also occur due to use of DDT and other chlorinated hydrocarbons by entering the human food chain when animal tissues are affected. Symptoms include nervous excitement, tremors, convulsions or death. Scientists estimate that DDT and other chemicals in the organophosphate class of pesticides have saved 7 million human lives since 1945 by preventing the transmission of diseases such as malaria, bubonic plague, sleeping sickness, and typhus.[2] However, DDT use is not always effective, as resistance to DDT was identified in Africa as early as 1955, and by 1972 nineteen species of mosquito worldwide were resistant to DDT.[11] A study for the World Health Organization in 2000 from Vietnam established that non-DDT malaria controls were significantly more effective than DDT use.[12] The ecological effect of DDT on organisms is an example of bioaccumulation.
[edit]
History
Since before 2500 BCE, humans have utilized pesticides to protect their crops. The first known pesticide was elemental sulfur dusting used in Sumeria about 4,500 years ago. By the 15th century, toxic chemicals such as arsenic, mercury and lead were being applied to crops to kill pests. In the 17th century, nicotine sulfate was extracted from tobacco leaves for use as an insecticide. The 19th century saw the introduction of two more natural pesticides, pyrethrum which is derived from chrysanthemums, and rotenone which is derived from the roots of tropical vegetables.[13]
In 1939, Paul Müller discovered that DDT was a very effective insecticide. It quickly became the most widely-used pesticide in the world.
In the 1940s manufacturers began to produce large amounts of synthetic pesticides and their use became widespread.[14] Some sources consider the 1940s and 1950s to have been the start of the "pesticide era."[15] Pesticide use has increased 50-fold since 1950 and 2.3 million tonnes (2.5 million imperial tons) of industrial pesticides are now used each year.[13] Seventy-five percent of all pesticides in the world are used in developed countries, but use in developing countries is increasing.[2]
In the 1960s, it was discovered that DDT was preventing many fish-eating birds from reproducing, which was a serious threat to biodiversity. Rachel Carson wrote the best-selling book Silent Spring about biological magnification. The agricultural use of DDT is now banned under the Stockholm Convention on Persistent Organic Pollutants, but it is still used in some developing nations to prevent malaria and other tropical diseases by spraying on interior walls to kill or repel mosquitoes
[edit]
Types of pesticides
There are multiple ways of classifying pesticides.
Algicides or Algaecides for the control of algae
Avicides for the control of birds
Bactericides for the control of bacteria
Fungicides for the control of fungi and oomycetes
Herbicides for the control of weeds
Insecticides for the control of insects - these can be Ovicides (substances that kill eggs), Larvicides (substances that kill larvae) or Adulticides (substances that kill adult insects)
Miticides or Acaricides for the control of mites
Molluscicides for the control of slugs and snails
Nematicides for the control of nematodes
Rodenticides for the control of rodents
Virucides for the control of viruses (e.g. H5N1)
Pesticides can also be classed as synthetic pesticides or biological pesticides (biopesticides), although the distinction can sometimes blur.
Broad-spectrum pesticides are those that kill an array of species, while narrow-spectrum, or selective pesticides only kill a small group of species.[2]
A systemic pesticide moves inside a plant following absorption by the plant. With insecticides and most fungicides, this movement is usually upward (through the xylem) and outward. Increased efficiency may be a result. Systemic insecticides which poison pollen and nectar in the flowers may kill needed pollinators such as bees.
Most pesticides work by poisoning pests.[3]
[edit]
Uses
Pesticides are used to control organisms which are considered harmful.[4] For example, they are used to kill mosquitoes that can transmit potentially deadly diseases like west nile virus, yellow fever, and malaria. They can also kill bees, wasps or ants that can cause allergic reactions. Insecticides can protect animals from illnesses that can be caused by parasites such as fleas.[4] Pesticides can prevent sickness in humans that could be caused by mouldy food or diseased produce. Herbicides can be used to clear roadside weeds, trees and brush. They can also kill invasive weeds in parks and wilderness areas which may cause environmental damage. Herbicides are commonly applied in ponds and lakes to control algae and plants such as water grasses that can interfere with activities like swimming and fishing and cause the water to look or smell unpleasant.[5] Uncontrolled pests such as termites and mould can damage structures such as houses.[4] Pesticides are used in grocery stores and food storage facilities to manage rodents and insects that infest food such as grain. Each use of a pesticide carries some associated risk. Proper pesticide use decreases these associated risks to a level deemed acceptable by pesticide regulatory agencies such as the United States Environmental Protection Agency (EPA) and the Pest Management Regulatory Agency (PMRA) of Canada.
Pesticides can save farmers money by preventing crop losses to insects and other pests; in the US, farmers get an estimated four-fold return on money they spend on pesticides.[6] One study found that not using pesticides reduced crop yields by about 10%.[7] Another study,conducted in 1999, found that a ban on pesticides in the United States may result in a rise of food prices, loss of jobs, and an increase in world hunger.[8]
DDT, sprayed on the walls of houses, is an organochloride that has been used to fight malaria since the 1950s. Recent policy statements by the World Health Organization have given stronger support to this approach. [9] Dr. Arata Kochi, WHO's malaria chief, said, "One of the best tools we have against malaria is indoor residual house spraying. Of the dozen insecticides WHO has approved as safe for house spraying, the most effective is DDT."[9] However, since then, an October 2007 study has linked breast cancer from exposure to DDT prior to puberty.[10] Poisoning may also occur due to use of DDT and other chlorinated hydrocarbons by entering the human food chain when animal tissues are affected. Symptoms include nervous excitement, tremors, convulsions or death. Scientists estimate that DDT and other chemicals in the organophosphate class of pesticides have saved 7 million human lives since 1945 by preventing the transmission of diseases such as malaria, bubonic plague, sleeping sickness, and typhus.[2] However, DDT use is not always effective, as resistance to DDT was identified in Africa as early as 1955, and by 1972 nineteen species of mosquito worldwide were resistant to DDT.[11] A study for the World Health Organization in 2000 from Vietnam established that non-DDT malaria controls were significantly more effective than DDT use.[12] The ecological effect of DDT on organisms is an example of bioaccumulation.
[edit]
History
Since before 2500 BCE, humans have utilized pesticides to protect their crops. The first known pesticide was elemental sulfur dusting used in Sumeria about 4,500 years ago. By the 15th century, toxic chemicals such as arsenic, mercury and lead were being applied to crops to kill pests. In the 17th century, nicotine sulfate was extracted from tobacco leaves for use as an insecticide. The 19th century saw the introduction of two more natural pesticides, pyrethrum which is derived from chrysanthemums, and rotenone which is derived from the roots of tropical vegetables.[13]
In 1939, Paul Müller discovered that DDT was a very effective insecticide. It quickly became the most widely-used pesticide in the world.
In the 1940s manufacturers began to produce large amounts of synthetic pesticides and their use became widespread.[14] Some sources consider the 1940s and 1950s to have been the start of the "pesticide era."[15] Pesticide use has increased 50-fold since 1950 and 2.3 million tonnes (2.5 million imperial tons) of industrial pesticides are now used each year.[13] Seventy-five percent of all pesticides in the world are used in developed countries, but use in developing countries is increasing.[2]
In the 1960s, it was discovered that DDT was preventing many fish-eating birds from reproducing, which was a serious threat to biodiversity. Rachel Carson wrote the best-selling book Silent Spring about biological magnification. The agricultural use of DDT is now banned under the Stockholm Convention on Persistent Organic Pollutants, but it is still used in some developing nations to prevent malaria and other tropical diseases by spraying on interior walls to kill or repel mosquitoes
Organic Foods and Health
More About Organic Foods and Health
Organic clothes, organic food, organic cleaning products - the word "organic" seems to be the hottest trend right now.
However, before you jump on the organic bandwagon, it is important to identify the pros and cons of purchasing and consuming organic foods.
It may be hard to identify the differences with an untrained eye.
At the grocery store, both the non-organic and organic fruits and vegetables look fresh and healthy, so why do the organic foods cost as much as twice as much?
The trend has moved beyond the produce aisle and into the shelves of the grocery store aisle, leading to the introduction of drinks, dried fruits, bread, yogurt, cheese and dozens of other food products.
Many Americans harbor increasing concerns about food safety and genetically modified food products.
"Organic" when used on the label of a food product means that the food has been grown on land that has been chemical free for at least three years. Food crops labeled organic must also be grown without the use of pesticides or other chemicals.
Finally, they must be processed and packaged without the use of artificial preservatives, colorings or any other additives.
There are many strong arguments in defending the purchase and consumption of organic food products.
Organic farming does not pose the threat of pesticide and chemical run-off which could contamination watersheds and drinking water, while many traditional modern farming methods do just that.
Organic farms also tend to maintain richer, more sustainable soil through the use of cover crops, crop rotations and composts.
These organic farming methods have been shown to slow soil erosion and it vary the nutrient demands on the soil.
One study analyzing twelve foods concluded that organic foods hold more nutritional value and micronutrients than non-organic foods.
The nutritional pros from organic foods include higher levels of vitamins A, B, C, E, vitamins, elements such as zinc and minerals such as calcium. Organic foods also do not carry the risk of some health complications linked to pesticides and antibiotics.
Organic foods also contain lower levels of heavy metals and virtually no hydrogenated fat which has been linked to heart disease), whereas non-organic processed food can contain both.
Despite the increased nutritional value of organic foods, there are some cons to consuming organic foods.
Manure used in organic compost may be more harmful than the health risks related to pesticides and chemicals used on non-organic farms.
Manure often contains E. coli bacterium, which can spread harmful animal diseases to humans. Furthermore, organic foods are producible at the same rate as non-organic foods. Organic farming methods often produce lower yields than modern intensive methods.
This is why food grown organically can often cost twice as much as food grown on non-organic farms. If large farms started replacing modern farming methods with organic methods, the world may see a food shortage emerge.
Candis Reade is an accomplished niche website developer and author. To learn more about the pros and cons of organic foods, please visit My Organic Markets for current articles and discussions.
Article Source: http://EzineArticles.com/?expert=Candis_Reade
Organic clothes, organic food, organic cleaning products - the word "organic" seems to be the hottest trend right now.
However, before you jump on the organic bandwagon, it is important to identify the pros and cons of purchasing and consuming organic foods.
It may be hard to identify the differences with an untrained eye.
At the grocery store, both the non-organic and organic fruits and vegetables look fresh and healthy, so why do the organic foods cost as much as twice as much?
The trend has moved beyond the produce aisle and into the shelves of the grocery store aisle, leading to the introduction of drinks, dried fruits, bread, yogurt, cheese and dozens of other food products.
Many Americans harbor increasing concerns about food safety and genetically modified food products.
"Organic" when used on the label of a food product means that the food has been grown on land that has been chemical free for at least three years. Food crops labeled organic must also be grown without the use of pesticides or other chemicals.
Finally, they must be processed and packaged without the use of artificial preservatives, colorings or any other additives.
There are many strong arguments in defending the purchase and consumption of organic food products.
Organic farming does not pose the threat of pesticide and chemical run-off which could contamination watersheds and drinking water, while many traditional modern farming methods do just that.
Organic farms also tend to maintain richer, more sustainable soil through the use of cover crops, crop rotations and composts.
These organic farming methods have been shown to slow soil erosion and it vary the nutrient demands on the soil.
One study analyzing twelve foods concluded that organic foods hold more nutritional value and micronutrients than non-organic foods.
The nutritional pros from organic foods include higher levels of vitamins A, B, C, E, vitamins, elements such as zinc and minerals such as calcium. Organic foods also do not carry the risk of some health complications linked to pesticides and antibiotics.
Organic foods also contain lower levels of heavy metals and virtually no hydrogenated fat which has been linked to heart disease), whereas non-organic processed food can contain both.
Despite the increased nutritional value of organic foods, there are some cons to consuming organic foods.
Manure used in organic compost may be more harmful than the health risks related to pesticides and chemicals used on non-organic farms.
Manure often contains E. coli bacterium, which can spread harmful animal diseases to humans. Furthermore, organic foods are producible at the same rate as non-organic foods. Organic farming methods often produce lower yields than modern intensive methods.
This is why food grown organically can often cost twice as much as food grown on non-organic farms. If large farms started replacing modern farming methods with organic methods, the world may see a food shortage emerge.
Candis Reade is an accomplished niche website developer and author. To learn more about the pros and cons of organic foods, please visit My Organic Markets for current articles and discussions.
Article Source: http://EzineArticles.com/?expert=Candis_Reade
The Advantages of Organic Food
You Are What You Eat
Do you really know what goes into your food? Discover the advantages of organic food on this site and see exactly what producers have been adding to your fruit and vegetables to make it less healthy than a few years ago.
In the rush to produce more and more crops to satisfy growing demand producers have had to resort to using a lethal cocktail of pesticides to control disease and insect attack.
Good news for their bank balances perhaps but not good news for your health, this is why you need to be informed of the advantages of organic food.
Did you know that if you consumed an average apple you would be eating over 30 pesticides, even after you have washed it?
The quality of food has definitely gone down since the second world war. For instance, the levels of vitamin C in today's fruit bear no resemblance to the levels found in wartime fruit.
Organic food is known to contain 50% more nutrients, minerals and vitamins than produce that has been intensively farmed. Read more about this here.
You will have to eat more fruit nowadays to make up the deficiency, but unfortunately that means eating more chemicals, more detrimental affects on your health eating something that should be good for you!
Also don't forget about the cocktail of anti-biotics and hormones that cattle and poultry are force fed.
What happens to those chemicals when the animal dies?
Digested and stored in human bodies is the answer, have you seen pictures of animals in severly cramped conditions in battery farms?
It just does not make sense to state that any animal kept in these conditions is healthy and produces high quality food.
If you are as worried as I am about the health of your family then you need to read the articles on this and seriously consider converting your family to the organic lifestyle with the organic food information you are going to learn on this site.
Trust me, once you try some organic produce and taste an apple the way it should be, and perhaps how you recall it tasting in your youth, you will never go back to mass produced fruit again.
Sure there are issues with availability and cost but with a bit of research you should be able to find local stores who stock organic produce.
Also, don't forget about your local farmer, I'm sure you will be able to find one that has seen the light and opened up a farm shop to supply local residents.
You should be able to get some very keen prices from these shops, why not take a look around and see who is offering produce in your area?
Some more startling facts now. Pesticides in food have been linked to many diseases including:
Cancer
Obesity
Altzheimer's
Some birth defects
Not a nice list is it? There are probably others but if you think about it, how can it be okay for you to eat chemicals and not expect some form of reaction in your body. Our bodies are delicately balanced wonderful machines. Any form of foreign chemical is bound to cause irritation at the least.
Please take advantage of the organic food articles and information on this site and do consider taking a closer look at what you are eating. It's for your health after all!
Source : http://www.organicfoodinfo.net
Do you really know what goes into your food? Discover the advantages of organic food on this site and see exactly what producers have been adding to your fruit and vegetables to make it less healthy than a few years ago.
In the rush to produce more and more crops to satisfy growing demand producers have had to resort to using a lethal cocktail of pesticides to control disease and insect attack.
Good news for their bank balances perhaps but not good news for your health, this is why you need to be informed of the advantages of organic food.
Did you know that if you consumed an average apple you would be eating over 30 pesticides, even after you have washed it?
The quality of food has definitely gone down since the second world war. For instance, the levels of vitamin C in today's fruit bear no resemblance to the levels found in wartime fruit.
Organic food is known to contain 50% more nutrients, minerals and vitamins than produce that has been intensively farmed. Read more about this here.
You will have to eat more fruit nowadays to make up the deficiency, but unfortunately that means eating more chemicals, more detrimental affects on your health eating something that should be good for you!
Also don't forget about the cocktail of anti-biotics and hormones that cattle and poultry are force fed.
What happens to those chemicals when the animal dies?
Digested and stored in human bodies is the answer, have you seen pictures of animals in severly cramped conditions in battery farms?
It just does not make sense to state that any animal kept in these conditions is healthy and produces high quality food.
If you are as worried as I am about the health of your family then you need to read the articles on this and seriously consider converting your family to the organic lifestyle with the organic food information you are going to learn on this site.
Trust me, once you try some organic produce and taste an apple the way it should be, and perhaps how you recall it tasting in your youth, you will never go back to mass produced fruit again.
Sure there are issues with availability and cost but with a bit of research you should be able to find local stores who stock organic produce.
Also, don't forget about your local farmer, I'm sure you will be able to find one that has seen the light and opened up a farm shop to supply local residents.
You should be able to get some very keen prices from these shops, why not take a look around and see who is offering produce in your area?
Some more startling facts now. Pesticides in food have been linked to many diseases including:
Cancer
Obesity
Altzheimer's
Some birth defects
Not a nice list is it? There are probably others but if you think about it, how can it be okay for you to eat chemicals and not expect some form of reaction in your body. Our bodies are delicately balanced wonderful machines. Any form of foreign chemical is bound to cause irritation at the least.
Please take advantage of the organic food articles and information on this site and do consider taking a closer look at what you are eating. It's for your health after all!
Source : http://www.organicfoodinfo.net
Organic Food
Organic foods are made according to certain production standards, meaning they are grown without the use of conventional pesticides and artificial fertilizers, free from contamination by human or industrial waste, and processed without ionizing radiation or food additives.[1] If livestock are involved, they must be reared without the routine use of antibiotics and without the use of growth hormones, and generally fed a healthy diet. In most countries, organic produce may not be genetically modified.
Organic food production is a heavily regulated industry, distinct from private gardening for instance. Currently, the European Union, the United States, Canada, Japan and many other countries require producers to obtain special certification in order to market food as organic within their borders.
Historically, organic farms have been relatively small family-run farms[2] — which is why organic food was once only available in small stores or farmers' markets. However, since the early 1990s organic food production has had growth rates of around 20% a year, far ahead of the rest of the food industry, in both developed and developing nations. As of April 2008, organic food accounts for 1-2% of food sales worldwide. Future growth is expected to range from 10-50% annually depending on the country[citation needed].
Source: wikipedia
Organic food production is a heavily regulated industry, distinct from private gardening for instance. Currently, the European Union, the United States, Canada, Japan and many other countries require producers to obtain special certification in order to market food as organic within their borders.
Historically, organic farms have been relatively small family-run farms[2] — which is why organic food was once only available in small stores or farmers' markets. However, since the early 1990s organic food production has had growth rates of around 20% a year, far ahead of the rest of the food industry, in both developed and developing nations. As of April 2008, organic food accounts for 1-2% of food sales worldwide. Future growth is expected to range from 10-50% annually depending on the country[citation needed].
Source: wikipedia
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