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Controlled-release Fertiliser
224px, Methylene diurea (MDU) is component of the most popular controlled-release fertilizers. A controlled-release fertiliser (CRF) is a granulated fertiliser that releases nutrients gradually into the soil (i.e., with a controlled release period). Controlled-release fertilizer is also known as controlled-availability fertilizer, delayed-release fertilizer, metered-release fertilizer, or slow-acting fertilizer. Usually CRF refers to nitrogen-based fertilizers. Slow- and controlled-release involve only 0.15% (562,000 tons) of the fertilizer market (1995). History Controlled-nitrogen-release technologies based on polymers derived from combining urea and formaldehyde were first produced in 1936 and commercialized in 1955. The early product had 60 percent of the total nitrogen cold-water-insoluble, and the unreacted (quick-release) less than 15%. Methylene ureas, e.g. methylene diurea, were commercialized in the 1960s and 1970s, having 25% and 60% of the nitrogen as cold-water-ins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methylene Diurea
Methylene diurea (MDU) is the organic compound with the formula CH2(NHC(O)NH2)2. It is a white water-soluble solid. The compound is formed by the condensation of formaldehyde with urea. Methylene diurea is the substrate for the enzyme methylenediurea deaminase. Applications MDU is an intermediate in the production of urea-formaldehyde resins. Together with dimethylene triurea, MDU is a component of some controlled-release fertilizer 224px, Methylene diurea (MDU) is component of the most popular controlled-release fertilizers. A controlled-release fertiliser (CRF) is a granulated fertiliser that releases nutrients gradually into the soil (i.e., with a controlled release period ...s.{{Ullmann, doi= 10.1002/14356007.n10_n01 , title= Fertilizers, 2. Types , year=2009 , last1=Dittmar , first1=Heinrich , last2=Drach , first2=Manfred , last3=Vosskamp , first3=Ralf , last4=Trenkel , first4=Martin E. , last5=Gutser , first5=Reinhold , last6=Steffens , first6=Günter References F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
N-(n-butyl)thiophosphoric Triamide
''N''-(''n''-Butyl)thiophosphoric triamide (NBPT) is the organophosphorus compound with the formula SP(NH2)2(NHC4H9). A white solid, NBPT is an "enhanced efficiency fertilizer", intended to limit the release of nitrogen-containing gases following fertilization. Regarding its chemical structure, the molecule features tetrahedral phosphorus bonded to sulfur and three amido groups. Use NBPT functions as an inhibitor of the enzyme urease. Urease, pervasive in soil microorganisms, converts urea into ammonia, which is susceptible to volatilization if produced faster than it can utilized by plants. Approximately 0.5% by weight NBPT is mixed with the urea. See also * Phenyl phosphorodiamidate Phenyl phosphorodiamidate is an organophosphorus compound with the formula C6H5OP(O)(NH2)2. A white solid, it is used as an inhibitor of urease, an enzyme that accelerates the hydrolysis of urea. In this way, phenyl phosphorodiamidate enhances th ..., another urease inhibitor References {{D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seed Ball
Seed balls, also known as earth balls or , consist of seeds rolled within a ball of clay and other matter to assist gemination. They are then thrown into vacant lots and over fences as a form of 'guerilla gardening'. Matter such as humus and compost are often placed around the seeds to provide microbial inoculants. Cotton-fibres or liquefied paper are sometimes added to further protect the clay ball in particularly harsh habitats. An ancient technique, it was re-discovered by Japanese natural farming pioneer Masanobu Fukuoka. Development of technique The technique for creating seed balls was rediscovered by Japanese natural farming pioneer Masanobu Fukuoka. The technique was also used, for instance, in ancient Egypt to repair farms after the annual spring flooding of the Nile. In modern times, during the period of the Second World War, this Japanese government plant scientist working in a government lab, Fukuoka, who lived on the mountainous island of Shikoku, wanted to fin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urea
Urea, also known as carbamide, is an organic compound with chemical formula . This amide has two amino groups (–) joined by a carbonyl functional group (–C(=O)–). It is thus the simplest amide of carbamic acid. Urea serves an important role in the metabolism of nitrogen-containing compounds by animals and is the main nitrogen-containing substance in the urine of mammals. It is a colorless, odorless solid, highly soluble in water, and practically non-toxic ( is 15 g/kg for rats). Dissolved in water, it is neither acidic nor alkaline. The body uses it in many processes, most notably nitrogen excretion. The liver forms it by combining two ammonia molecules () with a carbon dioxide () molecule in the urea cycle. Urea is widely used in fertilizers as a source of nitrogen (N) and is an important raw material for the chemical industry. In 1828 Friedrich Wöhler discovered that urea can be produced from inorganic starting materials, which was an important conceptual miles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isobutylidenediurea
Isobutylidenediurea (abbreviated IBDU) is an organic compound with the formula (CH3)2CHCH2. It is a derivative of urea (OC(NH2)2), which itself is highly soluble in water, but IBDU is not. It functions as a controlled-release fertiliser owing to its low solubility, which limits the rate of its hydrolysis to urea, which is a fast-acting fertiliser. It is produced by the condensation reaction of isobutyraldehyde and two equivalents of urea: : (CH3)2CHCHO + 2 OC(NH2)2 → (CH3)2CHCH2 + H2O The controlled-release process is the reverse of the above reaction, which only occurs after the IBDU dissolves. Related materials A number of CRF's have been developed based on urea. Related to IBDU is crotonylidene diurea (Crotodur). Simpler are various urea-formaldehyde materials such as ureaform Urea-formaldehyde (UF), also known as urea-methanal, so named for its common synthesis pathway and overall structure, is a nontransparent thermosetting resin or polymer. It is produced ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urease
Ureases (), functionally, belong to the superfamily of amidohydrolases and phosphotriesterases. Ureases are found in numerous bacteria, fungi, algae, plants, and some invertebrates, as well as in soils, as a soil enzyme. They are nickel-containing metalloenzymes of high molecular weight. These enzymes catalyze the hydrolysis of urea into carbon dioxide and ammonia: : (NH2)2CO + H2O CO2 + 2NH3 The hydrolysis of urea occurs in two stages. In the first stage, ammonia and carbamic acid are produced. The carbamate spontaneously and rapidly hydrolyzes to ammonia and carbonic acid. Urease activity increases the pH of its environment as ammonia is produced, which is basic. History Its activity was first identified in 1876 by Frédéric Alphonse Musculus as a soluble ferment. In 1926, James B. Sumner, showed that urease is a protein by examining its crystallized form. Sumner's work was the first demonstration that a protein can function as an enzyme and led eventually to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrification
''Nitrification'' is the biological oxidation of ammonia to nitrite followed by the oxidation of the nitrite to nitrate occurring through separate organisms or direct ammonia oxidation to nitrate in comammox bacteria. The transformation of ammonia to nitrite is usually the rate limiting step of nitrification. Nitrification is an important step in the nitrogen cycle in soil. Nitrification is an aerobic process performed by small groups of autotrophic bacteria and archaea. Microbiology Ammonia oxidation The oxidation of ammonia into nitrite (also known as nitritation) is performed by two groups of organisms, ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA). AOB AOB can be found among the Betaproteobacteria and Gammaproteobacteria. Since discovery of AOA in 2005, two isolates have been cultivated: ''Nitrosopumilus maritimus'' and ''Nitrososphaera viennensis''. In soils the most studied AOB belong to the genera '' Nitrosomonas'' and '' Nitrococcus''. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soluble
In chemistry, solubility is the ability of a substance, the solute, to form a solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form such a solution. The extent of the solubility of a substance in a specific solvent is generally measured as the concentration of the solute in a saturated solution, one in which no more solute can be dissolved. At this point, the two substances are said to be at the solubility equilibrium. For some solutes and solvents, there may be no such limit, in which case the two substances are said to be "miscible in all proportions" (or just "miscible"). The solute can be a solid, a liquid, or a gas, while the solvent is usually solid or liquid. Both may be pure substances, or may themselves be solutions. Gases are always miscible in all proportions, except in very extreme situations,J. de Swaan Arons and G. A. M. Diepen (1966): "Gas—Gas Equilibria". ''Journal of Chemical Physics'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBDU
Isobutylidenediurea (abbreviated IBDU) is an organic compound with the formula (CH3)2CHCH2. It is a derivative of urea (OC(NH2)2), which itself is highly soluble in water, but IBDU is not. It functions as a controlled-release fertiliser owing to its low solubility, which limits the rate of its hydrolysis to urea, which is a fast-acting fertiliser. It is produced by the condensation reaction of isobutyraldehyde and two equivalents of urea: : (CH3)2CHCHO + 2 OC(NH2)2 → (CH3)2CHCH2 + H2O The controlled-release process is the reverse of the above reaction, which only occurs after the IBDU dissolves. Related materials A number of CRF's have been developed based on urea. Related to IBDU is crotonylidene diurea (Crotodur). Simpler are various urea-formaldehyde materials such as ureaform, which consists of methylene diurea Methylene diurea (MDU) is the organic compound with the formula CH2(NHC(O)NH2)2. It is a white water-soluble solid. The compound is formed by the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crotonylidene Diurea
Crotonylidene diurea (CDU) is an organic compound formed by the condensation of crotonaldehyde with two equivalents of urea. It is a white, water-soluble solid. CDU is a component of some controlled-release fertilizer 224px, Methylene diurea (MDU) is component of the most popular controlled-release fertilizers. A controlled-release fertiliser (CRF) is a granulated fertiliser that releases nutrients gradually into the soil (i.e., with a controlled release period ...s.{{Ullmann, doi= 10.1002/14356007.n10_n01 , title= Fertilizers, 2. Types , year=2009 , last1=Dittmar , first1=Heinrich , last2=Drach , first2=Manfred , last3=Vosskamp , first3=Ralf , last4=Trenkel , first4=Martin E. , last5=Gutser , first5=Reinhold , last6=Steffens , first6=Günter References Fertilizers Horticulture Ureas Nitrogen heterocycles Heterocyclic compounds with 1 ring ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urease
Ureases (), functionally, belong to the superfamily of amidohydrolases and phosphotriesterases. Ureases are found in numerous bacteria, fungi, algae, plants, and some invertebrates, as well as in soils, as a soil enzyme. They are nickel-containing metalloenzymes of high molecular weight. These enzymes catalyze the hydrolysis of urea into carbon dioxide and ammonia: : (NH2)2CO + H2O CO2 + 2NH3 The hydrolysis of urea occurs in two stages. In the first stage, ammonia and carbamic acid are produced. The carbamate spontaneously and rapidly hydrolyzes to ammonia and carbonic acid. Urease activity increases the pH of its environment as ammonia is produced, which is basic. History Its activity was first identified in 1876 by Frédéric Alphonse Musculus as a soluble ferment. In 1926, James B. Sumner, showed that urease is a protein by examining its crystallized form. Sumner's work was the first demonstration that a protein can function as an enzyme and led eventually to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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