"application rates depending on the soil fertility, usually as measured by a soil test and according to the particular crop. Legumes, for example, fix nitrogen from the atmosphere and generally do not require nitrogen fertilizer. Fertilizers are applied to crops both as solids and as liquid. About 90% of fertilizers are applied as solids. The most widely used solid inorganic fertilizers are urea, diammonium phosphate and potassium chloride. Solid fertilizer is typically granulated or powdered. Often solids are available as prills, a solid globule. Liquid fertilizers comprise anhydrous ammonia, aqueous solutions of ammonia, aqueous solutions of ammonium nitrate or urea."
"atmospheric nitrogen. This is achieved by a number of diazotrophs. One way this can occur is in the nodules in the roots of legumes that contain symbiotic bacteria of the genera ""Rhizobium"", ""Mesorhizobium"", ""Sinorhizobium"", ""Bradyrhizobium"", and ""Azorhizobium"". A lichen is a symbiosis of a macroscopic fungus with photosynthetic microbial algae or cyanobacteria. Microorganisms are useful in producing foods, treating waste water, creating biofuels and a wide range of chemicals and enzymes. They are invaluable in research as model organisms. They have been weaponised and sometimes used in warfare and bioterrorism. They are vital to agriculture through their roles in maintaining"
"in the atmosphere as well as oxidation by methane consuming bacteria in Earth’s soils. Soils act as a major sink for atmospheric methane through the methanotrophic bacteria that reside within them. This occurs with two different types of bacteria. ""High capacity-low affinity"" methanotrophic bacteria grow in areas of high methane concentration, such as waterlogged soils in wetlands and other moist environments. And in areas of low methane concentration, ""low capacity-high affinity"" methanotrophic bacteria make use of the methane in the atmosphere to grow, rather than relying on methane in their immediate environment. Forest soils act as good sinks for atmospheric"
"fossil fuel and biomass combustion. In agroecosystems, fertilizer application has increased microbial nitrification (aerobic process in which microorganisms oxidize ammonium [NH] to nitrate [NO]) and denitrification (anaerobic process in which microorganisms reduce NO to atmospheric nitrogen gas [N]). Both processes naturally leak nitric oxide (NO) and nitrous oxide (NO) to the atmosphere. Of particular concern is NO, which has an average atmospheric lifetime of 114–120 years, and is 300 times more effective than CO as a greenhouse gas. NO produced by industrial processes, automobiles and agricultural fertilization and NH emitted from soils (i.e., as an additional byproduct of nitrification) and"
"human land uses often add more, especially from anaerobic soil, artificial wetlands such as rice fields, and from the guts of farm animals, especially ruminants such as cattle and sheep. Gardeners may cause extra methane to be added to the atmosphere in several ways: Nitrous oxide, NO, is a natural part of the nitrogen cycle, but human land uses often add more. Gardeners may cause extra nitrous oxide to be added to the atmosphere by: Black carbon is not a gas, but it acts like a greenhouse gas because it can be suspended in the atmosphere and absorb heat. Gardeners"
"good fertilizer. Humus is called the ""higher"" decomposition of organic matter. The compost humus is used as fertilizer, both organic. Organic matter decomposes via aerobic or Anaerobic digestion means. Call ""composting"" aerobic cycle (high presence of oxygen) decomposition of organic matter. Called ""digestion"" anaerobic cycle (with no or little presence of oxygen) decomposition of organic matter. The compost is naturally obtained by decomposing aerobic (with oxygen) of organic waste and plant debris, animal excrement and slurry, through the mass reproduction of thermophilic aerobic bacteria that are present naturally in any place (later the continue fermentation the other species of bacteria,"
"organism was recently discovered in the rainforests of northern Patagonia, and has the unique capability of converting cellulose into medium-length hydrocarbons typically found in diesel fuel. Many other fungi that can degrade cellulose and other polymers have been observed to produce molecules that are currently being engineered using organisms from other kingdoms, suggesting that fungi may play a large role in the bio-production of fuels in the future (reviewed in ). Microbial gastrointestinal flora in a variety of animals have shown potential for the production of biofuels. Recent research has shown that TU-103, a strain of ""Clostridium"" bacteria found in"
"In such zones, chemosynthetic microbes provide energy and carbon to the other organisms. Other microbes are decomposers, with the ability to recycle nutrients from other organisms' waste products. These microbes play a vital role in biogeochemical cycles. The nitrogen cycle, the phosphorus cycle, the sulphur cycle and the carbon cycle all depend on microorganisms in one way or another. For example, the nitrogen gas which makes up 78% of the earth's atmosphere is unavailable to most organisms, until it is converted to a biologically available form by the microbial process of nitrogen fixation. Due to the high level of horizontal"
"by their incorporation into the microbes' living cells, where it is temporarily sequestered in the form of amino acids and protein. Nitrate may also be lost from the soil when bacteria metabolise it to the gases N and NO. The loss of gaseous forms of nitrogen to the atmosphere due to microbial action is called ""denitrification"". Nitrogen may also be ""leached"" from the soil if it is in the form of nitrate or lost to the atmosphere as ammonia due to a chemical reaction of ammonium with alkaline soil by way of a process called ""volatilisation"". Ammonium may also be"
"coke was recovered and used as fertiliser. Finally, the chemical basis of nutrients delivered to the soil in manure was understood and in the mid-19th century chemical fertilisers were applied. However, the dynamic interaction of soil and its life forms still awaited discovery. In 1856 J. Thomas Way discovered that ammonia contained in fertilisers was transformed into nitrates, and twenty years later Robert Warington proved that this transformation was done by living organisms. In 1890 Sergei Winogradsky announced he had found the bacteria responsible for this transformation. It was known that certain legumes could take up nitrogen from the air"
"microbes for their own growth. As these microbes are ingested or die, nitrogen is added to the soil. Nitrogen is also mineralized from the degradation of proteins and nucleic acids in litter. This mineralized nitrogen is also added to the soil. Due to these processes, the rate of nitrogen added to the soil is coupled with rates of microbial respiration. Studies have shown that rates of soil respiration were associated with rates of microbial turnover and nitrogen mineralization. Alterations of the global cycles can further act to change the climate of the planet. As stated earlier, the CO released by"
"can be fed with energy crops such as maize silage or biodegradable wastes including sewage sludge and food waste. During the process, the micro-organisms transform biomass waste into biogas (mainly methane and carbon dioxide) and digestate. There are two key processes: mesophilic and thermophilic digestion which is dependent on temperature. In experimental work at University of Alaska Fairbanks, a 1000-litre digester using psychrophiles harvested from ""mud from a frozen lake in Alaska"" has produced 200–300 liters of methane per day, about 20%–30% of the output from digesters in warmer climates. The air pollution produced by biogas is similar to that"
"for oil refineries, and the fuel source in hydrogen vehicles. Protein rich animal and fish feed is produced by feeding natural gas to Methylococcus capsulatus bacteria on commercial scale. Natural gas is also used in the manufacture of fabrics, glass, steel, plastics, paint, and other products. Natural gas is mainly composed of methane. After release to the atmosphere it is removed by gradual oxidation to carbon dioxide and water by hydroxyl radicals () formed in the troposphere or stratosphere, giving the overall chemical reaction + 2 → + 2. While the lifetime of atmospheric methane is relatively short when compared"
"element required for growth by all biological systems. While extremely common (80% by volume) in the atmosphere, dinitrogen gas () is generally biologically inaccessible due to its high activation energy. Throughout all of nature, only specialized bacteria and Archaea are capable of nitrogen fixation, converting dinitrogen gas into ammonia (), which is easily assimilated by all organisms. These prokaryotes, therefore, are very important ecologically and are often essential for the survival of entire ecosystems. This is especially true in the ocean, where nitrogen-fixing cyanobacteria are often the only sources of fixed nitrogen, and in soils, where specialized symbioses exist between"
"are shed or are eaten, the nitrogen in those tissues becomes available to animals and microbes. Microbial decomposition releases nitrogen compounds from dead organic matter in the soil, where plants, fungi, and bacteria compete for it. Some soil bacteria use organic nitrogen-containing compounds as a source of carbon, and release ammonium ions into the soil. This process is known as nitrogen mineralization. Others convert ammonium to nitrite and nitrate ions, a process known as nitrification. Nitric oxide and nitrous oxide are also produced during nitrification. Under nitrogen-rich and oxygen-poor conditions, nitrates and nitrites are converted to nitrogen gas, a process"
"of nitrifying bacteria, and the nitrate compounds for gunpowder (see this topic for more) were historically produced, in the absence of mineral nitrate sources, by means of various fermentation processes using urine and dung. Nitrates are found in fertilizers. As a byproduct of lightning strikes in earth's nitrogen-oxygen rich atmosphere, nitric acid is produced when nitrogen dioxide reacts with water vapor. Nitrates are mainly produced for use as fertilizers in agriculture because of their high solubility and biodegradability. The main nitrate fertilizers are ammonium, sodium, potassium, and calcium salts. Several million kilograms are produced annually for this purpose. The second"
"often with a second metal, usually molybdenum but sometimes vanadium. Microorganisms that can fix nitrogen are prokaryotes (both bacteria and archaea, distributed throughout their respective domains) called diazotrophs. Some higher plants, and some animals (termites), have formed associations (symbiosis) with diazotrophs. Nitrogen can be fixed by lightning converting nitrogen and oxygen into (nitrogen oxides). may react with water to make nitrous acid or nitric acid, which seeps into the soil, where it makes nitrate, which is of use to growing plants. Nitrogen in the atmosphere is highly stable and nonreactive due to there being a triple bond between atoms in"
"anaerobes, or facultatively anaerobes (can alter between the oxygen dependent and oxygen independent types of metabolisms), including ""Achromobacter"" and ""Pseudomonas"". The purification process caused by oxygen-free conditions converts nitrates and nitrites in soil into nitrogen gas or into gaseous compounds such as nitrous oxide or nitric oxide. In excess, denitrification can lead to overall losses of available soil nitrogen and subsequent loss of soil fertility. However, fixed nitrogen may circulate many times between organisms and the soil before denitrification returns it to the atmosphere. The diagram above illustrates the nitrogen cycle. Actinobacteria are critical in the decomposition of organic matter"
"respiration and consequently produce nitrogen gas, which is inert and unavailable to plants. Dissimilatory nitrate reduction to ammonium (DNRA), or nitrate/nitrite ammonification, is an anaerobic respiration process. Microbes which undertake DNRA oxidise organic matter and use nitrate as an electron acceptor, reducing it to nitrite, then ammonium (NO→NO→NH). Both denitrifying and nitrate ammonification bacteria will be competing for nitrate in the environment, although DNRA acts to conserve bioavailable nitrogen as soluble ammonium rather than producing dinitrogen gas. In this biological process, nitrite and ammonia are converted directly into molecular nitrogen (N) gas. This process makes up a major proportion of"
"leguminous crops. ""Azotobacter"" can be used with crops like wheat, maize, mustard, cotton, potato and other vegetable crops. ""Azospirillum"" inoculations are recommended mainly for sorghum, millets, maize, sugarcane and wheat. Blue green algae belonging to a general cyanobacteria genus, ""Nostoc"" or ""Anabaena"" or ""Tolypothrix"" or ""Aulosira"", fix atmospheric nitrogen and are used as inoculations for paddy crop grown both under upland and low-land conditions. ""Anabaena"" in association with water fern ""Azolla"" contributes nitrogen up to 60 kg/ha/season and also enriches soils with organic matter. Other types of bacteria, so-called phosphate-solubilizing bacteria, such as ""Pantoea agglomerans"" strain P5 or ""Pseudomonas putida"""
"soils to make calcium carbonate cement. This cement could then be used to make bricks and other building materials. The ability for ""S.ureae"" to convert urea to ammonia has important potential applications in the production of biofuels and fertilizers. Ammonia is currently being actively researched as a carbon-alternative fuel source. The high octane rating (110-130) and its relative safety when compared to gasoline make it an ideal replacement for current gasoline. Traditional methods of generating ammonia for fertilizer rely heavily on the use of natural gas; in fact, to produce the ammonia needed for current fertilizer demands accounts for an"
"as a nitrogen-release fertilizer. Urea has the highest nitrogen content of all solid nitrogenous fertilizers in common use. Therefore, it has the lowest transportation costs per unit of nitrogen nutrient. Many soil bacteria possess the enzyme urease, which catalyzes conversion of urea to ammonia (NH) or ammonium ion (NH) and bicarbonate ion (HCO). Thus urea fertilizers rapidly transform to the ammonium form in soils. Among the soil bacteria known to carry urease, some ammonia-oxidizing bacteria (AOB), such as species of ""Nitrosomonas"", can also assimilate the carbon dioxide the reaction releases to make biomass via the Calvin cycle, and harvest energy"
"slow sand filter. Anaerobic digestion by methanogens generate useful methane gas as a by-product. Microorganisms are used in fermentation to produce ethanol, and in biogas reactors to produce methane. Scientists are researching the use of algae to produce liquid fuels, and bacteria to convert various forms of agricultural and urban waste into usable fuels. Microorganisms are used to produce many commercial and industrial chemicals, enzymes and other bioactive molecules. Organic acids produced on a large industrial scale by microbial fermentation include acetic acid produced by acetic acid bacteria such as ""Acetobacter aceti"", butyric acid made by the bacterium ""Clostridium butyricum"","
"by oxidizing ammonia (the other product of urease) to nitrite, a process termed nitrification. Nitrite-oxidizing bacteria, especially ""Nitrobacter"", oxidize nitrite to nitrate, which is extremely mobile in soils because of its negative charge and is a major cause of water pollution from agriculture. Ammonium and nitrate are readily absorbed by plants, and are the dominant sources of nitrogen for plant growth. Urea is also used in many multi-component solid fertilizer formulations. Urea is highly soluble in water and is therefore also very suitable for use in fertilizer solutions (in combination with ammonium nitrate: UAN), e.g., in 'foliar feed' fertilizers. For"
"The other 2 molecules are used to regenerate xylulose 5-phosphate. As key players in the carbon cycle, methylotrophs work to reduce global warming primarily through the uptake of methane and other greenhouse gases. In aqueous environments, methanogenic bacteria produce 40-50% of the world's methane. Symbiosis between methanogens and methanotrophic bacteria greatly decreases the amount of methane released into the atmosphere. The use of methylotrophs in the agricultural sector is another way in which they can potentially impact the environment. Traditional chemical fertilizers supply nutrients not readily available from soil but have effects such as decreased crop yield, poor soil quality"
"chemical oxygen demand (22). Hydrogen and methane can both be used as alternatives to fossil fuels in internal combustion engines or for power generation. Like MFCs or bioethanol production plants, MECs have the potential to convert waste organic matter into a valuable energy source. Hydrogen can also be combined with the nitrogen in the air to produce ammonia, which can be used to make ammonium fertilizer. Ammonia has been proposed as a practical alternative to fossil fuel for internal combustion engines. Microbial electrolysis cell A microbial electrolysis cell (MEC) is a technology related to Microbial fuel cells (MFC). Whilst MFCs"
"into a usable form to be taken up by plants. Between 5x10 and 10x10 g per year are fixed by lightning strikes, but most fixation is done by free-living or symbiotic bacteria known as diazotrophs. These bacteria have the nitrogenase enzyme that combines gaseous nitrogen is the with hydrogen to produce ammonia, which is converted by the bacteria into other organic compounds. Most biological nitrogen fixation occurs by the activity of Mo-nitrogenase, found in a wide variety of bacteria and some Archaea. Mo-nitrogenase is a complex two-component enzyme that has multiple metal-containing prosthetic groups. An example of free-living bacteria is"
"Apart from gas fields, an alternative method of obtaining methane is via biogas generated by the fermentation of organic matter including manure, wastewater sludge, municipal solid waste (including landfills), or any other biodegradable feedstock, under anaerobic conditions. Rice fields also generate large amounts of methane during plant growth. Methane hydrates/clathrates (ice-like combinations of methane and water on the sea floor, found in vast quantities) are a potential future source of methane. Cattle belch methane accounts for 16% of the world's annual methane emissions to the atmosphere. One study reported that the livestock sector in general (primarily cattle, chickens, and pigs)"
"or later crops. Intercropping with a legume has the potential to decrease the need for applied fertilizer. Commercial inoculants of ""Bradyrhizobium"" are available. These can be applied as a peat or liquid directly to the seed before planting. Bradyrhizobium Bradyrhizobium is a genus of Gram-negative soil bacteria, many of which fix nitrogen. Nitrogen fixation is an important part of the nitrogen cycle. Plants cannot use atmospheric nitrogen (N); they must use nitrogen compounds such as nitrates. ""Bradyrhizobium"" species are Gram-negative bacilli (rod-shaped) with a single subpolar or polar flagellum. They are common soil-dwelling micro-organisms that can form symbiotic relationships with"
"fungi are believed to produce chloroform in soil. Chloroform volatilizes readily from soil and surface water and undergoes degradation in air to produce phosgene, dichloromethane, formyl chloride, carbon monoxide, carbon dioxide, and hydrogen chloride. Its half-life in air ranges from 55 to 620 days. Biodegradation in water and soil is slow. Chloroform does not significantly bioaccumulate in aquatic organisms. Chloroform was synthesized independently by several investigators circa 1831: In industry, chloroform is produced by heating a mixture of chlorine and either chloromethane or methane. At 400–500 °C, a free radical halogenation occurs, converting these precursors to progressively more chlorinated compounds:"
"atmosphere — N gas comprises nearly 79% of air. However, N is unavailable for use by most organisms because there is a triple bond between the two nitrogen atoms in the molecule, making it almost inert. In order for nitrogen to be used for growth it must be “fixed” (combined) in the form of ammonium (NH) or nitrate (NO) ions. The weathering of rocks releases these ions so slowly that it has a negligible effect on the availability of fixed nitrogen. Therefore, nitrogen is often the limiting factor for growth and biomass production in all environments where there is a"
"as nitrogen and protecting against pests and disease, while reducing the need for water and other inputs. Some approaches may even allow agriculture in soils that were never considered viable. The group of bacteria called rhizobia live inside the roots of legumes and fix nitrogen from the air into a biologically useful form. Mycorrhizae or root fungi form a dense network of thin filaments that reach far into the soil, acting as extensions of the plant roots they live on or in. These fungi facilitate the uptake of water and a wide range of nutrients. Up to 30% of the"
"to regenerate NAD from NADH. Electrons are transferred to ferredoxin, which in turn is oxidized by hydrogenase, producing H. Hydrogen gas is a substrate for methanogens and sulfate reducers, which keep the concentration of hydrogen low and favor the production of such an energy-rich compound, but hydrogen gas at a fairly high concentration can nevertheless be formed, as in flatus. As an example of mixed acid fermentation, bacteria such as ""Clostridium pasteurianum"" ferment glucose producing butyrate, acetate, carbon dioxide, and hydrogen gas: The reaction leading to acetate is: Glucose could theoretically be converted into just CO and H, but the"