Fertilizer (English American) or fertilizer (English spelling difference see) is any material that comes from nature or synthetic (other than stuffy stuff) applied to the soil or to plant tissues to supply one or more plant nutrients essential for plant growth. Many sources of fertilizers exist, both naturally and industrially produced.
Video Fertilizer
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Fertilizer improves plant growth. This goal is met by two ways, which are traditional additives that provide nutrients. The second mode used by some fertilizers is to improve the effectiveness of the soil by modifying water retention and aeration. This article, like much on fertilizers, emphasizes nutritional aspects. Fertilizers usually provide, in various proportions:
- three main macronutrients:
- Nitrogen (N): leaf growth
- Phosphorus (P): Development of roots, flowers, seeds, fruit;
- Potassium (K): Strong growth of stems, movement of water in plants, promotion of flowering and fruiting;
- three secondary macronutrients: calcium (Ca), magnesium (Mg), and sulfur (S);
- micronutrients: copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), zinc (Zn), boron (B). What is sometimes significant are silicon (Si), cobalt (Co), and vanadium (V).
Nutrition needed for healthy plant life is classified according to the elements, but the elements are not used as fertilizers. Instead of compounds containing these elements is the basis of the fertilizer. Macro nutrients are consumed in larger quantities and present in plant tissues in amounts from 0.15% to 6.0% in dry matter (DM) (0% moisture). The plant consists of four main elements: hydrogen, oxygen, carbon, and nitrogen. Carbon, hydrogen and oxygen are widely available as water and carbon dioxide. Although nitrogen forms most of the atmosphere, but in a form that is not available to plants. Nitrogen is the most important fertilizer because nitrogen is present in proteins, DNA and other components (eg, chlorophyll). To be nutritious for crops, nitrogen must be available in a "fixed" form. Only a few bacteria and host plants (especially legumes) can fix atmospheric nitrogen (N 2 ) by converting them to ammonia. Phosphate is required for the production of DNA and ATP, the primary energy carrier in cells, as well as certain lipids.
Micronutrients are consumed in smaller quantities and present in plant tissues in the order of parts per million (ppm), ranging from 0.15 to 400 ppm DM, or less than 0.04% DM. These elements are often present in the active sites of enzymes that perform plant metabolism. Since these elements allow the catalyst (enzyme), its impact far exceeds the percentage by weight.
Maps Fertilizer
Classification
Fertilizers are classified in several ways. They are classified according to whether they provide a single nutrient (eg, K, P, or N), in which case they are classified as "straight fertilizer." "Multinutrient fertilizers" (or "complex fertilizers") provide two or more nutrients, eg N and P. Fertilizers are sometimes classified as inorganic (most of the topics of this article) compared to organic. Inorganic fertilizers do not include carbonaceous materials except ureas. Organic fertilizers usually come from plants or animals that are recycled. Inorganic is sometimes called synthetic fertilizers because various chemical treatments are needed for the manufacture.
Single nut ("straight") fertilizer
The main nitrogen-based direct fertilizer is ammonia or its solution. Ammonium nitrate (NH 4 NO 3 ) is also widely used. Urea is another popular nitrogen source, having the advantage that it is solid and not explosive, unlike ammonia and ammonium nitrate, respectively. A few percent of the nitrogen fertilizer market (4% in 2007) has been met by calcium ammonium nitrate (Ca
The main straight phosphate fertilizer is superphosphate. "Single superphosphate" (SSP) consists of 14-18% P 2 O 5 , again in the form of Ca (H 2 PO 4 ) 2 , but also phosphogypsum (CaSO 4 Ã, Â · Ã, 2H 2 O). Triple superphosphate (TSP) usually consists of 44-48% of P 2 O 5 and there is no gypsum. A single superphosphate mixture and triple superphosphate are called double superphosphates. More than 90% of the typical superfosphate fertilizer dissolves in water.
Multinutrient Fertilizer
This fertilizer is the most common. They consist of two or more components of nutrition.
Binary (NP, NK, PK) fertilizers
The main two component fertilizers provide nitrogen and phosphorus for plants. This is called NP fertilizer. The main NP fertilizers are monoammonium phosphate (MAP) and diammonium phosphate (DAP). The active ingredient in MAP is NH 4 H 2 PO 4 . The active ingredient in DAP is (NH 4 ) 2 HPO 4 . Approximately 85% of MAP and DAP fertilizers dissolve in water.
NPK Fertilizer
NPK fertilizer is a three-component fertilizer that provides nitrogen, phosphorus, and potassium.
The value of NPK is a scoring system that describes the amount of nitrogen, phosphorus, and potassium in the fertilizer. The NPK rating consists of three numbers separated by dashes (for example, 10-10-10 or 16-4-8) that describe the chemical content of the fertilizer. The first number represents the percentage of nitrogen in the product; second number, P 2 O 5 ; third, K 2 O. Fertilizer does not actually contain P 2 O 5 or K 2 O, but the system is a conventional abbreviation for the amount of phosphorus (P) or potassium (K) in the fertilizer. The 50-pound (23 kg) label of fertilizer labeled 16-4-8 contains 8 liters (3.6 kg) of nitrogen (16% of 50 pounds), a phosphorus equivalent of 2 pounds P 2 O 5 (4% of 50 pounds), and 4 pounds K 2 O (8% of 50 pounds). Most fertilizers are labeled according to the N-P-K convention, although the Australian convention, following the N-P-K-S system, adds a fourth number for sulfur, and uses element values ​​for all values ​​including P and K.
Micronutrient
The main micronutrients are molybdenum, zinc, and copper. These elements are provided as a water-soluble salt. Iron presents a special problem as it turns into a bio-available compound at moderate soil pH and phosphate concentration. For this reason, irons are often managed as chelate complexes, for example, EDTA derivatives. Micronutrient requirements depend on the plant. For example, sugar beets seem to require boron, and nuts require cobalt.
Production
Nitrogen fertilizer
Nitrogen fertilizers are made from ammonia (NH 3 ), which is sometimes injected into the soil directly. Ammonia is produced by the Haber-Bosch process. In this energy-intensive process, natural gas (CH 4 ) usually supplies hydrogen, and nitrogen (N 2 ) comes from the air. This ammonia is used as a feedstock for all other nitrogen fertilizers, such as anhydrous ammonium nitrate (NH 4 NO 3 ) and urea (CO (NH 2 ) 2 ).
Deposits of sodium nitrate (NaNO 3 ) (Chile burp) are also found in the Atacama desert in Chile and are one of the nitrogen-rich native fertilizers (1830) used. Still mined for fertilizer.
Phosphate fertilizer
All phosphate fertilizers are obtained by extracting from minerals containing PO 4 3 - anions. In rare cases, fields are treated with crushed minerals, but most of the more soluble salts are produced by chemical treatment of phosphate minerals. The most popular phosphate-containing minerals are referred to collectively as phosphate rocks. The main mineral is fluorapatite Ca 5 (PO 4 ) 3 F (CFA) and Ca hydroxyapatite 5 (PO < sub> 4 ) 3 OH. This mineral is converted into a water-soluble phosphate salt by treatment with sulfur (H 2 SO 4 ) or phosphoric acid (H 3 PO 4 ). The production of large sulfuric acid as an industrial chemical is mainly due to its use as cheap acid in processing phosphate rocks into phosphate fertilizers. The use of a global primer for sulfur and phosphorus compounds is related to this basic process.
In the process of nitrophosphate or Odda process (discovered in 1927), phosphate rocks with a content of up to 20% phosphorus (P) were dissolved with nitric acid (HNO 3 ) to produce a phosphoric acid mixture (H 3 PO 4 ) and calcium nitrate (Ca (NOT 3 ) 2 ). This mixture can be combined with potassium fertilizer to produce a compound fertilizer with three macronutrients N, P and K in a soluble form.
Potassium fertilizer
Potassium is a mixture of potassium minerals used to make potasium (chemical symbol: K) fertilizer. Potas dissolve in water, so the main effort in producing these nutrients from ore involves some purification steps; eg, to remove sodium chloride (NaCl) (ordinary salt). Sometimes potash is referred to as K 2 O, because it is a convenience issue for those explaining the contents of potassium. Even potassium fertilizer is usually potassium chloride, potassium sulfate, potassium carbonate, or potassium nitrate.
Compound fertilizer
Compound fertilizers, which contain N, P, and K, can often be produced by mixing straight fertilizer. In some cases, chemical reactions occur between two or more components. For example, monoammonium and diammonium phosphate, which provide plants with N and P, are produced by neutralizing phosphoric acid (from phosphate rocks) and ammonia: 3 3 PO 4 -> (NH 4 ) H 2 PO 4
Organic fertilizer
"Organic fertilizers" can describe the fertilizer with organic biological origins - that is, fertilizers derived from living or previously live ingredients. Organic fertilizers can also explain commercially available and often packaged products that seek to keep up with the expectations and limitations adopted by "organic farming" and "environmentally friendly" gardening systems associated with the production of food and plants that significantly limit or strictly avoid the use of synthetic. fertilizers and pesticides. "Organic fertilizers" products usually contain acceptable organic ingredients and additives such as nutritious rock powder, ground sea shells (crabs, oysters, etc.), other prepared products such as seaweed or seaweed, and microorganisms and cultivated derivatives.
Organic fertilizers (first definition) include such animal waste, plant waste from agriculture, compost, and processed mud (biosolids). Outside of fertilizers, animal sources can include products from animal slaughter - blood meal, bone meal, feather, skin, nails, and horn are all typical components. Organic materials available to industries such as mud waste may not be accepted as a component of organic farming and gardening, due to factors ranging from residual contaminants to public perceptions. On the other hand, marketed "organic fertilizers" may include, and promote, organically processed materials because they have consumer appeal. No matter the definition or composition, most of these products contain less concentrated nutrients, and nutrients are not easily calculated. They can offer the benefit of building the land as well as appealing to those who try to farm/garden more "naturally".
In terms of volume, peat is the most widely used organic soil change package. Because this form of unconverted coal, which fixes the soil by aeration and absorbs water, does not provide the nutritional value of the plant, it is not the fertilizer as defined at the beginning of the article, but an amendment. Coir, (derived from coco fiber), bark, and sawdust when added to the soil all act the same (but not identical) with peat and are also considered as organic soil amendments - or texturizers - due to their limited nutritional input. Some organic additives can have an inverse effect on nutrients - fresh sawdust can consume soil nutrients because it is damaged, and may decrease soil pH - but these same organic texturizers (as well as compost, etc.) can improve nutrient availability through increased cation exchange, or through enhancement the growth of microorganisms which in turn increases the availability of certain plant nutrients. Organic fertilizers such as compost and manure can be distributed locally without going into industrial production, making actual consumption more difficult to quantify.
Apps
Fertilizers are commonly used to plant all crops, with the application rate dependent on soil fertility, usually measured by soil test and in accordance with the particular plant. Nuts, for example, fix nitrogen from the atmosphere and generally do not require nitrogen fertilizer.
Liquid vs solid
Fertilizer is applied to the plant either as solid or liquid. Approximately 90% of the fertilizer is applied as solids. The most widely used solid inorganic fertilizers are urea, diammonium phosphate and potassium chloride. Solid fertilizers are usually shaped granules or powder. Often solids are available as prills, solid blobs. Liquid fertilizers consist of anhydrous ammonia, aqueous ammonia solution, ammonium nitrate or urea solution. This concentrated product can be diluted with water to form a concentrated liquid fertilizer (eg, UAN). The advantages of liquid fertilizer are its quicker effect and easier coverage. The addition of fertilizer to irrigation water is called "fertigation".
Slow and controlled release fertilizer
Slow and controlled release only involved 0.15% (562,000 tonnes) of the fertilizer market (1995). Their utility comes from the fact that fertilizer is subject to antagonistic processes. In addition to providing nutrients for plants, excess fertilizers can be toxic to the same plant. Competitive with the absorption by plants is the degradation or loss of fertilizer. Microbes reduce a lot of fertilizer, for example by immobilization or oxidation. Furthermore, the fertilizer is lost due to evaporation or washing. Most slow-release fertilizers are derivatives of urea, a direct fertilizer that provides nitrogen. Isobutylidenediurea ("IBDU") and urea-formaldehyde are slowly converting in the soil to free urea, which is rapidly picked up by plants. IBDU is a single compound of formula (CH 3 ) 2 CHCH (NHC (O) NH 2 ) 2 while urea-formaldehyde consists of a mixture of approximate formulas (HOCH 2 NHC (O) NH) n CH 2 .
In addition to being more efficient in utilizing the nutrients used, slow-release technology also reduces the impact on the environment and contamination of subsurface water. Slow release fertilizers (various forms including fertilizer spikes, tabs, etc.) That reduce the problem of "burning" the plant due to excess nitrogen. The coating of the polymer from the fertilizer gives tablets and spikes of 'timing release' or 'phased nutrient release' (SNR) of nutrient fertilizers.
Controlled release fertilizer is a traditional fertilizer packaged in a degraded shell at a certain level. Sulfur is a typical encapsulation material. Other products coated using thermoplastics (and occasionally ethylene-vinyl acetate and surfactants, etc.) to produce the release of urea or other fertilizers diluted by diffusion. "Reactive Layer Coating" can produce thinner, cheaper membrane layers by applying reactive monomers simultaneously to soluble particles. "Multicote" is a process that implements a low-cost fatty acid salt layer with a paraffin top layer.
Foliar app
Leaf manure is applied directly to the leaves. This method is almost always used to apply water-soluble nitrogen fertilizers and is used primarily for high value crops such as fruits.
Chemicals that affect nitrogen uptake
Various chemicals are used to improve the efficiency of nitrogen-based fertilizers. In this way farmers can limit the pollution effects of nitrogen runoff. Nitrification inhibitors (also known as nitrogen stabilizers) suppress the conversion of ammonia to nitrates, anions more susceptible to leaching. 1-Carbamoyl-3-methylpyrazole (CMP), dicyandiamide, nitrapyrin (2-chloro-6-trichloromethylpyridine) and 3,4-Dimethylpyrazole phosphate (DMPP) are very popular. The urease inhibitor is used to slow the conversion of hydrolytic urea to ammonia, which is susceptible to evaporation and nitrification. The conversion of urea to ammonia is catalyzed by an enzyme called ureases. A popular urease inhibitor is N- (n-butyl) thiophosphate triamide (NBPT).
Overfertilization
Careful fertilization technology is important because excess nutrients can be detrimental. Fuel fertilizer can occur when too much fertilizer is applied, resulting in damage or even death of the plant. Fertilizers vary in their tendency to burn roughly according to their salt index.
Statistics
Recently nitrogen fertilizers have stabilized in most developed countries. China despite being the largest producer and consumer of nitrogen fertilizers. Africa has little dependence on nitrogen fertilizers. Agricultural and chemical minerals are very important in the use of the fertilizer industry, which is worth about $ 200 billion. Nitrogen has a significant impact on the use of global minerals, followed by potassium and phosphate. The production of nitrogen has increased dramatically since the 1960s. Phosphate and potassium have increased in price since the 1960s, which is bigger than the consumer price index. Potash is produced in Canada, Russia, and Belarus, together producing more than half of world production. Potassium production in Canada increases in 2017 and 2018 by 18.6%. Conservative estimates report 30 to 50% of the crops associated with natural or synthetic commercial fertilizers. Fertilizer consumption has exceeded the amount of agricultural land in the United States . The global market value is likely to rise to more than US $ 185 billion until 2019. The European fertilizer market will grow to earn revenues. EUR15.3 billion in 2018.
Data on fertilizer consumption per hectare of fertile land in 2012 is published by The World Bank. For the diagram below the values ​​of EU countries have been extracted and presented as kilograms per hectare (pound per acre). Total consumption of fertilizer in the EU is 15.9 million tons for 105 million hectares of arable land (or 107 million hectares of other cultivable land according to other estimates). This figure is equivalent to 151 kg of fertilizer consumed per hectare of average land for EU countries.
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Use of fertilizers is beneficial in providing nutrients to plants even though they have some negative environmental effects. The greater the consumption of fertilizers can affect soil, surface water, and groundwater due to the spread of mineral use. It is important to be aware of the environmental effects in order to use them sparingly.
Water
Phosphorus and nitrogen fertilizer when used generally have enormous environmental effects. This is because the heavy rain caused the fertilizer to be washed into the water channel. Agricultural runoff is a major contributor to the eutrophication of freshwater bodies. For example, in the US, about half of all lakes are eutrophic. The main contributors to eutrophication are phosphate, which is usually a limiting nutrient; High concentrations increase the growth of cyanobacteria and algae, whose deaths consume oxygen. Cyanobacteria blooms ('algal blooms') can also produce harmful toxins that can accumulate in the food chain, and can be harmful to humans.
The nitrogen-rich compounds found in manure runoff are a major cause of serious oxygen depletion in many parts of the ocean, especially in coastal zones, lakes and rivers. The lack of dissolved oxygen produced greatly reduces the ability of these areas to maintain an ocean fauna. The number of dead ocean zones near populated coastlines is increasing. In 2006, the application of nitrogen fertilizers was increasingly controlled in northwestern Europe and the United States. If eutrophication can be reversed, it may take several decades before the accumulation of nitrate in groundwater can be broken down by natural processes.
Nitrate pollution
Only a small portion of the nitrogen-based fertilizer is converted into production and other plant matter. The rest accumulates on the ground or disappears as run-off. High application rates of nitrogen-containing fertilizers combined with high water solubility from nitrate cause increased runoff to the surface of the water as well as leaching into ground water, thus causing groundwater contamination. Excessive use of nitrogen fertilizers (both synthetic and natural) is extremely destructive, as many of the nitrogen not picked up by plants is converted to nitrate that is easily washed.
Nitrate levels above 10 mg/L (10 ppm) in ground water can cause 'blue baby syndrome' (acquired methemoglobinemia). Nutrition, especially nitrates, in fertilizers can cause problems for natural habitats and for human health if they clean the soil into the water stream or wash through the soil into the ground water.
Land
Acidification
Nitrogen-containing fertilizers can cause soil acidification when added. This can lead to a decrease in the availability of nutrients that can be offset by calcification.
Accumulation of toxic elements
Cadmium
The concentration of cadmium in fertilizers containing phosphorus varies greatly and can cause problems. For example, mono-ammonium phosphate fertilizers may have a cadmium content as low as 0.14 mg/kg or as high as 50.9 mg/kg. The phosphate stones used in their preparation can contain as much as 188 mg/kg of cadmium (for example, sludge in Nauru and the Christmas islands). Continuous use of cadmium fertilizers can contaminate the soil (as shown in New Zealand) and crops. The limits of cadmium content of phosphate fertilizers have been considered by the European Commission. Phosphorus-containing fertilizers now choose phosphate rocks based on cadmium content.
Fluoride
Phosphate rocks contain high levels of fluoride. As a result, the widespread use of phosphate fertilizers has increased the concentration of soil fluoride. It has been found that food contamination from fertilizers is not particularly noticed because plants collect less fluoride from the soil; a greater concern is the likelihood of fluoride toxicity in livestock ingesting contaminated soil. Also a possible concern is the effect of fluoride on soil microorganisms.
Radioactive elements
The radioactive content of the fertilizers varies and depends both on their concentration in the primary mineral as well as on the fertilizer production process. Uranium-238 concentrations can range from 7 to 100 pCi/g in phosphate rock and from 1 to 67 pCi/g in phosphate fertilizers. Where a high annual phosphorus fertilizer rate is used, this can produce uranium-238 concentrations in soil and drainage water that are several times larger than those normally present. However, the impact of this increase on the risk to human health from contamination of food radynuclides is very small (less than 0.05 mSv/y).
Other metals
Steel industry waste, recycled into fertilizer for high zinc levels (essential for plant growth), waste can include the following toxic metals: arsenic, cadmium, chromium, and nickel lead. The most common toxic elements in this type of fertilizer are mercury, lead, and arsenic. These potentially hazardous debris can be removed; However, this significantly increases the cost. Extremely pure fertilizers are widely available and may be best known as water-deeply soluble fertilizers containing blue dyes used around households, such as Miracle-Gro. This highly water soluble fertilizer is used in the plant breeding business and is available in larger packages at a much cheaper cost than the retail amount. Some cheap retail granular garden fertilizers are made with high purity materials.
Depletion of depleted minerals
Attention has been directed to decreasing the concentration of elements such as iron, zinc, copper and magnesium in many foods over the last 50-60 years. Intensive farming practices, including the use of synthetic fertilizers, are often suggested as reasons for this decline and organic farming is often suggested as a solution. Although improved yields generated from NPK fertilizers are known to dilute other nutrient concentrations in plants, many measurable reductions can be attributed to the use of plant varieties that are progressively higher yielding foods with lower mineral concentrations than their less productive ancestors.. Therefore, it is not possible organic farming or reduction of fertilizer use will solve the problem; foods with high nutrient density are assumed to be achieved by using older and lower varieties or the development of new improved varieties, nutrient-dense varieties.
Fertilizers, in fact, are more likely to solve the problem of mineral deficiency than to cause them: In Western Australia the deficiency of zinc, copper, manganese, iron and molybdenum was identified as restricting plant growth and broad grasslands in the 1940s and 1950s. The soil in Western Australia is very old, very rusty and lacking in many nutrients and major traces. From now on, these trace elements are routinely added to the fertilizers used in farming in this state. Many other lands around the world lack zinc, causing shortages in plants and humans, and zinc fertilizer is widely used to solve this problem.
Changes in soil biology
High fertilizer levels can cause damage to the symbiotic relationship between plant roots and mycorrhizal fungi.
Energy consumption and sustainability
In the United States in 2004, 317 billion cubic feet of natural gas was consumed in ammonia industrial production, less than 1.5% of total annual US natural gas consumption. The 2002 report shows that ammonia production consumes about 5% of global natural gas consumption, which is somewhat below 2% of world energy production.
Ammonia is produced from natural gas and air. Natural gas costs account for about 90% of the cost of ammonia production. The increase in natural gas prices over the last decade, along with other factors such as rising demand, has contributed to an increase in fertilizer prices.
Contributions for climate change
Greenhouse gases of carbon dioxide, methane and nitrous oxide are produced during the manufacture of nitrogenous fertilizers. The effect can be combined into an equivalent amount of carbon dioxide. The amount varies according to process efficiency. Figures for the UK are more than 2 kilograms equivalent of carbon dioxide for every kilogram of ammonium nitrate. Nitrogen fertilizers can be converted by soil bacteria into nitrous oxide, a greenhouse gas.
Atmosphere
Through increased use of nitrogen fertilizer, which is used at a rate of about 110 million tonnes (N) per year by 2012, adding to the amount of reactive nitrogen already present, nitrogen oxide (N 2 O) has become a greenhouse gas the third most important after carbon dioxide and methane. It has a global warming potential 296 times greater than the same mass of carbon dioxide and also contributes to stratospheric ozone depletion. By changing processes and procedures, it is possible to reduce some, but not all, of these effects on anthropogenic climate change.
Methane emissions from crop fields (especially rice fields) are enhanced by the application of ammonium-based fertilizers. These emissions contribute to global climate change because methane is a potent greenhouse gas.
Rule
In Europe the problem with high nitrate concentrations in run-off is being handled by the EU Nitrates Directive. In the UK, farmers are encouraged to manage their lands more sustainably on 'sensitive farms'. In the US, high concentrations of nitrate and phosphorus in runoff and water drainage are classified as non-point source pollutants because of their origin; This pollution is regulated at the state level. Oregon and Washington, both in the United States, have a fertilizer registration program with an on-line database containing chemical analysis of fertilizers.
In China, there are regulations applied by governments that want to control the N fertilizer used in agriculture. In 2008, the Chinese government has begun to withdraw a portion of the fertilizer subsidy, which also includes contributions to transportation of fertilizers, electricity and the use of natural gas in the industry. Therefore, professional farmers who run large-scale farms have used less fertilizer since then under fertilizer prices to rise. If large-scale farms continue to reduce the use of fertilizer subsidies, they have no choice but to optimize the fertilizer they have, thereby increasing grain yields and benefits.
Two types of agricultural management practices include organic farming and conventional farming. The first encourages soil fertility using local resources to maximize efficiency. Organic farming avoids synthetic agrochemicals. Conventional farming uses all the components that are not used organic farming.
History
The management of soil fertility has been the preoccupation of the peasants for thousands of years. The Egyptians, Romans, Babylonians, and early Germans were all recorded using mineral and or manure to increase their agricultural productivity. Modern science of plant nutrition began in the 19th century and the work of the German chemist, Justus von Liebig, among others. John Bennet Lawes, a British businessman, began experimenting on the effects of various fertilizers on potted plants in 1837, and a year or two later, the experiments were extended to crops in the field. One immediate consequence is that in 1842 he patented a fertilizer formed by treating phosphates with sulfuric acid, and thus was the first to create an artificial fertilizer industry. The following year, he registered the services of Joseph Henry Gilbert, with whom he continued for over half a century on plant-raising trials at the Vegetable Research Institute.
The Birkeland-Eyde process is one of the industrial processes that compete in the early production of nitrogen-based fertilizers. This process is used to fix atmospheric nitrogen (N 2 ) to nitric acid (HNO 3 ), one of several chemical processes commonly referred to as nitrogen fixation. The resulting nitric acid is then used as a nitrate source (NO 3 - ). A factory based on this process was built in Rjukan and Notodden in Norway, combined with the construction of large hydroelectric facilities.
The 1910s and 1920s witnessed the emergence of the Haber process and the Ostwald process. The Haber process produces ammonia (NH 3 ) from methane gas (CH 4 ) and molecular nitrogen (N 2 ). The ammonia from the Haber process is then converted to nitric acid (HNO 3 ) in the Ostwald process. The development of synthetic fertilizers has greatly supported the growth of the global population - it is estimated that almost half the people on Earth today are being fed as a result of the use of synthetic nitrogen fertilizers.
The use of commercial fertilizers has continued to increase in the last 50 years, rising almost 20-fold to 100 million tonnes of nitrogen per year today. Without commercial fertilizer it is estimated that about one third of the food produced now can not be produced. The use of phosphate fertilizers also increased from 9 million tons per year in 1960 to 40 million tons per year in 2000. Corn crops producing 6-9 tons of grain per hectare (2.5 hectares) require 31-50 kilograms (68 -110 lb) phosphate fertilizer to be applied; soybean plants need about half, like 20-25 kg per hectare. Yara International is the largest nitrogen-based fertilizer producer in the world.
The controlled polymer-based nitrogen release technology of combining urea and formaldehyde was first produced in 1936 and commercialized in 1955. The starting product has 60 percent of the total nitrogen that is insoluble in water, and the unreacted (rapid release) is less than 15%. Methylene ureas was commercialized in the 1960s and 1970s, had 25% and 60% nitrogen as water-insoluble urea nitrogen, and unreacted urea nitrogen in the range of 15% to 30%.
In the 1960s, the Tennessee Valley National Compound Fertilizer Development Center began developing sulfur-coated urea; sulfur is used as the main coating material because of its low cost and its value as a secondary nutrient. Usually there are other wax or polymer sealing sulfur; the nature of slow release depends on the degradation of secondary sealants by soil microbes as well as mechanical imperfections (cracks, etc.) on sulfur. They usually provide 6 to 16 weeks of delayed releases in grass applications. When hard polymers are used as secondary layers, their properties are crosses between particles controlled by diffusion and traditional sulfur.
See also
- Agroecology
- Circulus (theory)
- Fertigation
- Food and Agriculture Organization
- The history of organic farming
- Milorganite
- Phosphogypsum
- Land defertilization
References
External links
- Nitrogen to Feed Our Food, Earth Origin, Haber Process
- International Fertilizer Industry Association (IFA)
- Farming Guide, Complete Guide for Fertilizers and Fertilization
- 4R's Nutrition Management Program from The Fertilizer Institute
Source of the article : Wikipedia
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