CHEMICALS IN AGRICULTURE - WHAT ARE THEY?
In order to understand the effects of chemicals in agriculture we should know about the chemicals used. Chemicals used in agriculture are broadly divided into two categories namely Fertilizers and pesticides. As we are discussing about synthetic chemicals whenever I use the words fertilizers and pesticides it refers to artificially produced synthetic chemicals not other organic or natural minerals that are used as fertilizers and pesticides.
Fertilizers are used to provide necessary nutrients required by plants. Fertilizers mainly provide 6 macronutrients: nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulphur (S); & 7 micronutrients: boron (B), chlorine (Cl), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), and zinc (Zn).Most widely used are is NPK fertilizers such as urea and ammonium nitrate. Most of them are prepared through Haber-Bosch process in which Ammonia is produced as starting reactant. They are used to enhance plant growth in order to increase the crop production.
A pesticide is a substance or combination of different substance whose sole purpose is to prevent, destroy or control the pests. The term pesticide, in broad terms, can also include herbicides (inhibits the growth and reproduction of some harmful plants), insecticides( prevent growth of insects) and fungicides (inhibits the growth of mildews, yeasts, and molds). Pests includes any weeds, insects, fish or any mammals that can destroy crop. The pesticides can protect a crop even if there occurs a 'sudden outburst of pests' and hence ensures increased production. Pesticides can be grouped into different chemical families. Important chemical families include organochlorines, organophosphates, and carbamates. Organochlorine hydrocarbons (e.g. DDT) could be separated into dichlorodiphenylethanes, cyclodiene compounds, and other related compounds. They pose a danger since they are non-bio-degradable and bio-accumulate i.e. get stored in bodies of human and other species.
HISTORY :- WHEN IT STARTED?
Practice of using chemicals in agriculture is directly linked to the method of industrial agriculture. It is the process of mass production of agricultural products and livestock. It includes innovation in agricultural machinery and farming methods, genetic technology, techniques for achieving economies of scale in production, the creation of new markets for consumption, the application of patent protection to genetic information, and global trade.It is the so called ‘modern farming’ we often here. These methods are widespread in developed nations and increasingly prevalent worldwide.
Industrial agriculture started in England during industrial revolution. Use of fertilizers especially NPK started with it. Chemist Justus von Liebig (1803–1883) & Sir John Bennet Lawes (1814–1900) from England, Jean Baptiste Boussingault from France where the first to study about fertilizers. The Englishmen James Fison, Edward Packard, Thomas Hadfield and the Prentice brothers each founded companies in the early 19th century to create fertilizers from bone meal. But there wasn’t much in the way of commercial fertilizers before 1900. Sodium Nitrate was the first popular fertilizer and used in the early 1900′s. In the early decades of the 20th Century, the Nobel prize-winning chemists Carl Bosch of IG Farben and Fritz Haber developed the process that enabled nitrogen to be synthesised cheaply into ammonia, for subsequent oxidation into nitrates and nitrites.So then Ammonium Nitrate came into vogue after World War I.
Use of pesticides started after world war II. Many of the chemicals prepared for war purposes were discovered to be toxic to insects but appeared to have low toxicity to animals and other species. The "first generation" pesticides were largely highly toxic compounds, such as arsenic and hydrogen cyanide. Their use was largely abandoned because they were either too ineffective or too toxic. The "second generation" pesticides largely included synthetic organic compounds. ('Synthetic' here means made by humans -- not naturally occurring, while 'organic' means carbon containing, not to be confused with the popular use of "organic" as in "organic farming".)The first important synthetic organic pesticide was a chlorinated hydrocarboon (or organochlorine): DDT or dichlorodiphenyltrichloroethane . In 1939 Swiss chemist Paul Muller discovered its toxicity towards anthropods soon it was used as insecticide and to prevent malaria. He was awarded the Nobel Prize in Physiology or Medicine in 1948 for this discovery.
The use of chemicals in agriculture in directly linked with the practice of industrial agriculture. Since use of chemicals is integral part of industrial agriculture it is evident that any discussion on the merits and de-merits of using chemicals in agriculture must be done in the larger context of analysing industrial agriculture.
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ReplyDeleteGood piece of information. I will be writing about the current state of agriculture in USA. We have been hearing a lot about the financial crisis in USA caused by fraud done by high officials. But fraud in the States is not just restricted to economic crisis. Many issues regarding agriculture are startling.
ReplyDeleteWhen they are counted, agriculture’s share of the U.S. carbon footprint will be at least 25 to 30%.
Methane and nitrous oxides emissions are more damaging as greenhouse gasses than CO2. Since agriculture is one of the largest producers of methane and nitrous oxide, the extent of the agricultural impact is staggering. Unless bad habits of food production and long distance delivery are changed, dealing with climate change will be difficult.
Factory farming pollutes the ground, river, and ocean water with high amounts of nitrogen, phosphorous, and other fertilizers. High levels of nitrates and nitrites were found community wells that provided drinking water to majority of US population.
In addition to fertilizer pollution of food and water, high amounts of pesticides, antibiotics, and hormones are also in the food, soil, water, and air.
Factory farmers continue to use enormous quantities of the most toxic poisons.
The enormous populations of animals used in farming operations also produce a lot of manure, and massive amounts of methane and nitrous oxide. The largest amount of nitrous oxide comes from fertilizer used on farmland that produces feed for confined animals.
Thus a number of issues remain unfixed. This is a difficult time for farmers to figure out how they can produce their own energy and at the same time reducing its use for consumption. With agriculture being responsible for such a large percentage of fossil fuel consumption, it is essential that resources be invested in alternative energy strategies by farmers, entrepreneurs, and by state and federal government agencies…..”
While I totally agree that going back to basics with gardening (just soil, water, sunlight, and a little TLC is all a garden needs!) I'll never agree with basic, rudimentary "correlations" between increases in certain health issues and pesticide use. It's like saying that the reason why the number of obese people in the US has grown over the same time frame as increased pesticide use is because of the pesticides. Or the number of Vietnamese immigrating to the central US has increased exponentially over the same time frame, so it must be because of pesticide use. In my opinion, the reason we get sicker is from over-medicating (I loathe the overuse of hand sanitizer!!) and diseases getting smarter, as well as an increase in laziness (both of which are scientifically proven).
ReplyDeleteHowever, again, I totally agree that going back to basics with gardening is essential to growing great foods! And, no, it's not as simple as just washing off chemicals!!
usage of chemicals is quite essential for increasing productivity and to reach the demand for food world wide! i dont agree to the fact that entire chemicals having effects on environment to be banned! as being a son of farmer i really know the way how insects,and weeds have effect on crop production..they are quite many insects which destroy the crops with in days...as if the pesticides are not used at that time then total crop will be destroyed resting teardrops in the eyes of farmer.
ReplyDeleteBut there are quite few pesticides which have high impact on environment and on human beings.such pesticides should be banned!!
anyway the older techniques like gardening wont increase the production to the level demanded by the world! but it has it's own advantages!!
so the thing i suggest is usage of gardening techniques and also the usage of pesticides which are less harmful only if there is no other alternative to control insects,weeds..
This bit of information is quite true, but I would like to point out some the present times. Your discussion aims mainly at past instances, there has been significant advancement in the agricultural field in the past 35 years. There have been quite a lot of change in agricultural practices, inputs and chemicals used, machinery used, etc. Hence, the effects are also quite different from the past.
ReplyDeleteAccording to me current agricultural practices involves deliberately maintaining ecosystems in a highly simplified, undisturbed, and nutrient-rich state. Apart from newly developed techniques, the farmers now tend to maximize their output by choosing crops that are favoured in that particular geography. Limiting factors, especially water, mineral nitrogen, and mineral phosphate, are supplied in excess, and pests are actively controlled. These three features of modern agriculture—control of crops and their genetics, of soil fertility via chemical fertilization and irrigation, and of pests (weeds, insects, and pathogens) via chemical pesticides—are the hallmarks of the green revolution and present time agriculture. This has caused four once-rare plants (barley, maize, rice, and wheat) to become the dominant plants on earth as humans became the dominant animal. Indeed, these four annual grasses now occupy, respectively, 67 million hectares, 140 million hectares, 151 million hectares, and 230 million hectares, each, worldwide, which is 39.8% of global cropland. The past 35-40 years have been have been quite determining in agricultural practices of today.
The biggest challenge that I felt in agricultural sector lies that the population is ever increasing but the cultivable land is limited. How should we modify the chemical composition of inputs in order to obtain maximum yield .The agricultural achievements of the past 35 years have been impressive and so have been the achievements in seeds and chemicals. However, predicting the future of the agriculture is not quite reasonable because any small innovation might lead to complete transformation in the practices
This is a very interesting thing that i read. So i thought i would share it in above context -
ReplyDeleteIn a new study suggesting pesticides may be associated with the health and development of children, researchers at the University of California, Berkeley’s School of Public Health have found that prenatal exposure to organophosphate pesticides – widely used on food crops – is related to lower intelligence scores at age 7.
The researchers found that every tenfold increase in measures of organophosphates detected during a mother’s pregnancy corresponded to a 5.5 point drop in overall IQ scores in the 7-year-olds. Children in the study with the highest levels of prenatal pesticide exposure scored seven points lower on a standardized measure of intelligence compared with children who had the lowest levels of exposure.
Well...Most studies of exposure to pesticides and chemicals have been conducted in the developed world. Only a few studies have been undertaken in the developing world, including some studies undertaken in South Africa, in the Western Cape. However, all of these studies have focused on occupational exposure and mainly on male workers. A study in Columbia, which focused on couples and included both male and female workers and their reproductive health, is one of the very few such studies carried out in a developing country. Studies on agricultural chemical exposure and adverse reproductive outcomes have mainly been undertaken in the developed world.
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