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Controlled-release fertiliser

December 18, 2023

A controlled-release fertiliser (CRF) is a granulated fertiliser that releases nutrients gradually into the soil (i.e., with a controlled release period).[2] 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).

Methylene diurea (MDU) is component of the most popular controlled-release fertilizers.[1]

History edit

Controlled-nitrogen-release technologies based on polymers derived from combining urea and formaldehyde were first produced in 1936 and commercialized in 1955.[3] 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-insoluble, and unreacted urea nitrogen in the range of 15% to 30%.

In the 1960s in the U.S., the Tennessee Valley Authority National Fertilizer Development Center began developing sulfur-coated urea. Sulfur was used as the principal coating material because of its low cost and its value as a secondary nutrient.[3] Usually wax or polymer is added to perfect the encapsulation. The slow-release properties depend on the degradation of the secondary sealant by soil microbes as well as mechanical imperfections (cracks, etc.) in the capsule. 6 to 16 weeks of delayed release in turf applications is typical. When a hard polymer is used as the secondary coating, the properties are a cross between diffusion-controlled particles and traditional sulfur-coated.

Advantages edit

Many factors motivate the use of CRF, including more efficient use of the fertilizer. Illustrating the problem, it is estimated that, on average, 16% of conventional nitrogen-based fertilizers is lost by evaporation (as NH3, N2O, N2) or run-off ammonia.[4][5] Another factor favoring CRT protecting crops from chemical damage (fertiliser burn). In addition to their providing the nutrition to plants, excess fertilizers can be poisonous to the same plant. Finally important advantages are economic: fewer applications and the use of less fertiliser overall. The results (yield) is in most cases improved by >10%.

Environmental considerations edit

CRF has the potential to decrease nitrogenous pollution, which leads to eutrophication. The efficient use of nitrogen-base fertilizers is also relevant to the emission of N
2O into the atmosphere each year, of which 36% is due to human activity. The anthropogenic N
2O is produced by microorganisms acting on ammonia faster than the plant can uptake this nutrient.[6]

Implementation edit

The fertiliser is administered either by topdressing the soil, or by mixing the fertiliser into the soil before sowing. Polymer coating of fertilizer ingredients gives tablets and spikes a 'true time-release' or 'staged nutrient release' (SNR) of fertilizer nutrients. NBPT functions as an inhibitor of the enzyme urease.[4] Urease inhibitors, at levels of 0.05 weight percent, are added to urea-based fertilizers to control its conversion to ammonia.[7]

Mechanisms of release edit

 
Crotonylidene diurea is also used as a CRF.
 
Isobutylidenediurea (IBDU) is yet another CRF.[8]

The rate of the release is determined by various main factors: (i) the low solubility of the compounds in the soil moisture, (ii) the breakdown of protective coating applied to fertilizer pellets, and (iii) the conversion of the chemicals into ammonia or similarly effective plant nutrient.[4]

Conventional fertilisers are soluble in water, the nutrients disperse. Because controlled-release fertilisers are not water-soluble, their nutrients disperse into the soil more slowly. The fertiliser granules may have an insoluble substrate or a semi-permeable jacket that prevents dissolution while allowing nutrients to flow outward.

Definitions edit

The Association of American Plant Food Control Officials (AAPFCO) has published the following general definitions (Official Publication 57):

  • Slow- or controlled-release fertilizer: A fertilizer containing a plant nutrient in a form which delays its availability for plant uptake and use after application, or which extends its availability to the plant significantly longer than a reference ‘rapidly available nutrient fertilizer’ such as ammonium nitrate or urea, ammonium phosphate or potassium chloride. Such delay of initial availability or extended time of continued availability may occur by a variety of mechanisms. These include controlled water solubility of the material by semi-permeable coatings, occlusion, protein materials, or other chemical forms, by slow hydrolysis of water-soluble low molecular weight compounds, or by other unknown means.
  • Stabilized nitrogen fertilizer: A fertilizer to which a nitrogen stabilizer has been added. A nitrogen stabilizer is a substance added to a fertilizer which extends the time the nitrogen component of the fertilizer remains in the soil in the urea-N or ammoniacal-N form.
  • Nitrification inhibitor: A substance that inhibits the biological oxidation of ammoniacal-N to nitrate-N.
  • Urease inhibitor: A substance that inhibits hydrolytic action on urea by the enzyme urease.

Examples edit

Most slow-release fertilizers are derivatives of urea, a straight fertilizer providing nitrogen. Isobutylidenediurea ("IBDU") and urea-formaldehyde slowly convert in the soil to urea, which is rapidly uptaken by plants. IBDU is a single compound with the formula (CH3)2CHCH(NHC(O)NH2)2 whereas the urea-formaldehydes consist of mixtures of the approximate formula (HOCH2NHC(O)NH)nCH2.

Controlled release fertilizers are traditional fertilizers encapsulated in a shell that degrades at a specified rate. Sulfur is a typical encapsulation material. Other coated products use thermoplastics (and sometimes ethylene-vinyl acetate and surfactants, etc.) to produce diffusion-controlled release of urea or other fertilizers. "Reactive Layer Coating" can produce thinner, hence cheaper, membrane coatings by applying reactive monomers simultaneously to the soluble particles. "Multicote" is a process applying layers of low-cost fatty acid salts with a paraffin topcoat. Recently, biodegradable polymers as coatings for slow/controlled-release fertilizer have attracted interest for their potential to increase fertilizer/pesticide utilization efficiency and reduce negative environmental effects. [9]

See also edit

References edit

  1. ^ Dittmar, Heinrich; Drach, Manfred; Vosskamp, Ralf; Trenkel, Martin E.; Gutser, Reinhold; Steffens, Günter (2009). "Fertilizers, 2. Types". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.n10_n01.
  2. ^ Gregorich, Edward G.; Turchenek, L. W.; Carter, M. R.; Angers, Denis A., eds. (2001). Soil and Environmental Science Dictionary. CRC Press. p. 132. ISBN 978-0-8493-3115-2. LCCN 2001025292. Retrieved 9 December 2011.
  3. ^ a b J. B. Sartain, University of Florida (2011). . Grounds Maintenance. Archived from the original on 2019-10-29. Retrieved 2020-12-29.
  4. ^ a b c Pan, Baobao; Lam, Shu Kee; Mosier, Arvin; Luo, Yiqi; Chen, Deli (2016). "Ammonia Volatilization from Synthetic Fertilizers and its Mitigation Strategies: A Global Synthesis". Agriculture, Ecosystems & Environment. 232: 283–289. doi:10.1016/j.agee.2016.08.019.
  5. ^ Lam, Shu Kee; Wille, Uta; Hu, Hang-Wei; Caruso, Frank; Mumford, Kathryn; Liang, Xia; Pan, Baobao; Malcolm, Bill; Roessner, Ute; Suter, Helen; Stevens, Geoff; Walker, Charlie; Tang, Caixian; He, Ji-Zheng; Chen, Deli (2022). "Next-generation enhanced-efficiency fertilizers for sustained food security". Nature Food. 3 (8): 575–580. doi:10.1038/s43016-022-00542-7. PMID 37118587. S2CID 251080988.
  6. ^ Sloss, Leslie L. (1992). Nitrogen Oxides Control Technology Fact Book. William Andrew. p. 6. ISBN 978-0-8155-1294-3.
  7. ^ Zaman, M.; Zaman, S.; Quin, B.F; Kurepin, L.V; Shaheen, S.; Nawaz, S.; Dawar, K.M (2014). "Improving Pasture Growth and Urea Efficiency Using N inhibitor, Molybdenum and Elemental Sulphur". Journal of Soil Science and Plant Nutrition. doi:10.4067/S0718-95162014005000020.
  8. ^ C. Nitschke; G. Scherr (2012). "Urea Derivatives". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.o27_o04.
  9. ^ Bi, Siwen; Barinelli, Vincenzo; Sobkowicz, Margaret J. (2020-02-02). "Degradable Controlled Release Fertilizer Composite Prepared via Extrusion: Fabrication, Characterization, and Release Mechanisms". Polymers. 12 (2): 301. doi:10.3390/polym12020301. ISSN 2073-4360. PMC 7077398. PMID 32024294.

Further reading edit

  • Du, Chang-wen; Zhou, Jian-ming; Shaviv, Avi (2006). "Release Characteristics of Nutrients from Polymer-coated Compound Controlled Release Fertilizers". Journal of Polymers and the Environment. 14 (3): 223–230. doi:10.1007/s10924-006-0025-4. S2CID 97049596.

December 18, 2023
controlled, release, fertiliser, controlled, release, fertiliser, granulated, fertiliser, that, releases, nutrients, gradually, into, soil, with, controlled, release, period, controlled, release, fertilizer, also, known, controlled, availability, fertilizer, d. A controlled release fertiliser CRF is a granulated fertiliser that releases nutrients gradually into the soil i e with a controlled release period 2 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 Methylene diurea MDU is component of the most popular controlled release fertilizers 1 Contents 1 History 2 Advantages 2 1 Environmental considerations 2 2 Implementation 3 Mechanisms of release 4 Definitions 5 Examples 6 See also 7 References 8 Further readingHistory editControlled nitrogen release technologies based on polymers derived from combining urea and formaldehyde were first produced in 1936 and commercialized in 1955 3 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 insoluble and unreacted urea nitrogen in the range of 15 to 30 In the 1960s in the U S the Tennessee Valley Authority National Fertilizer Development Center began developing sulfur coated urea Sulfur was used as the principal coating material because of its low cost and its value as a secondary nutrient 3 Usually wax or polymer is added to perfect the encapsulation The slow release properties depend on the degradation of the secondary sealant by soil microbes as well as mechanical imperfections cracks etc in the capsule 6 to 16 weeks of delayed release in turf applications is typical When a hard polymer is used as the secondary coating the properties are a cross between diffusion controlled particles and traditional sulfur coated Advantages editMany factors motivate the use of CRF including more efficient use of the fertilizer Illustrating the problem it is estimated that on average 16 of conventional nitrogen based fertilizers is lost by evaporation as NH3 N2O N2 or run off ammonia 4 5 Another factor favoring CRT protecting crops from chemical damage fertiliser burn In addition to their providing the nutrition to plants excess fertilizers can be poisonous to the same plant Finally important advantages are economic fewer applications and the use of less fertiliser overall The results yield is in most cases improved by gt 10 Environmental considerations edit CRF has the potential to decrease nitrogenous pollution which leads to eutrophication The efficient use of nitrogen base fertilizers is also relevant to the emission of N2 O into the atmosphere each year of which 36 is due to human activity The anthropogenic N2 O is produced by microorganisms acting on ammonia faster than the plant can uptake this nutrient 6 Implementation edit The fertiliser is administered either by topdressing the soil or by mixing the fertiliser into the soil before sowing Polymer coating of fertilizer ingredients gives tablets and spikes a true time release or staged nutrient release SNR of fertilizer nutrients NBPT functions as an inhibitor of the enzyme urease 4 Urease inhibitors at levels of 0 05 weight percent are added to urea based fertilizers to control its conversion to ammonia 7 Mechanisms of release edit nbsp Crotonylidene diurea is also used as a CRF nbsp Isobutylidenediurea IBDU is yet another CRF 8 The rate of the release is determined by various main factors i the low solubility of the compounds in the soil moisture ii the breakdown of protective coating applied to fertilizer pellets and iii the conversion of the chemicals into ammonia or similarly effective plant nutrient 4 Conventional fertilisers are soluble in water the nutrients disperse Because controlled release fertilisers are not water soluble their nutrients disperse into the soil more slowly The fertiliser granules may have an insoluble substrate or a semi permeable jacket that prevents dissolution while allowing nutrients to flow outward Definitions editThe Association of American Plant Food Control Officials AAPFCO has published the following general definitions Official Publication 57 Slow or controlled release fertilizer A fertilizer containing a plant nutrient in a form which delays its availability for plant uptake and use after application or which extends its availability to the plant significantly longer than a reference rapidly available nutrient fertilizer such as ammonium nitrate or urea ammonium phosphate or potassium chloride Such delay of initial availability or extended time of continued availability may occur by a variety of mechanisms These include controlled water solubility of the material by semi permeable coatings occlusion protein materials or other chemical forms by slow hydrolysis of water soluble low molecular weight compounds or by other unknown means Stabilized nitrogen fertilizer A fertilizer to which a nitrogen stabilizer has been added A nitrogen stabilizer is a substance added to a fertilizer which extends the time the nitrogen component of the fertilizer remains in the soil in the urea N or ammoniacal N form Nitrification inhibitor A substance that inhibits the biological oxidation of ammoniacal N to nitrate N Urease inhibitor A substance that inhibits hydrolytic action on urea by the enzyme urease Examples editMost slow release fertilizers are derivatives of urea a straight fertilizer providing nitrogen Isobutylidenediurea IBDU and urea formaldehyde slowly convert in the soil to urea which is rapidly uptaken by plants IBDU is a single compound with the formula CH3 2CHCH NHC O NH2 2 whereas the urea formaldehydes consist of mixtures of the approximate formula HOCH2NHC O NH nCH2 Controlled release fertilizers are traditional fertilizers encapsulated in a shell that degrades at a specified rate Sulfur is a typical encapsulation material Other coated products use thermoplastics and sometimes ethylene vinyl acetate and surfactants etc to produce diffusion controlled release of urea or other fertilizers Reactive Layer Coating can produce thinner hence cheaper membrane coatings by applying reactive monomers simultaneously to the soluble particles Multicote is a process applying layers of low cost fatty acid salts with a paraffin topcoat Recently biodegradable polymers as coatings for slow controlled release fertilizer have attracted interest for their potential to increase fertilizer pesticide utilization efficiency and reduce negative environmental effects 9 See also editSeed ball Coated ureaReferences edit Dittmar Heinrich Drach Manfred Vosskamp Ralf Trenkel Martin E Gutser Reinhold Steffens Gunter 2009 Fertilizers 2 Types Ullmann s Encyclopedia of Industrial Chemistry Weinheim Wiley VCH doi 10 1002 14356007 n10 n01 Gregorich Edward G Turchenek L W Carter M R Angers Denis A eds 2001 Soil and Environmental Science Dictionary CRC Press p 132 ISBN 978 0 8493 3115 2 LCCN 2001025292 Retrieved 9 December 2011 a b J B Sartain University of Florida 2011 Food for turf Slow release nitrogen Grounds Maintenance Archived from the original on 2019 10 29 Retrieved 2020 12 29 a b c Pan Baobao Lam Shu Kee Mosier Arvin Luo Yiqi Chen Deli 2016 Ammonia Volatilization from Synthetic Fertilizers and its Mitigation Strategies A Global Synthesis Agriculture Ecosystems amp Environment 232 283 289 doi 10 1016 j agee 2016 08 019 Lam Shu Kee Wille Uta Hu Hang Wei Caruso Frank Mumford Kathryn Liang Xia Pan Baobao Malcolm Bill Roessner Ute Suter Helen Stevens Geoff Walker Charlie Tang Caixian He Ji Zheng Chen Deli 2022 Next generation enhanced efficiency fertilizers for sustained food security Nature Food 3 8 575 580 doi 10 1038 s43016 022 00542 7 PMID 37118587 S2CID 251080988 Sloss Leslie L 1992 Nitrogen Oxides Control Technology Fact Book William Andrew p 6 ISBN 978 0 8155 1294 3 Zaman M Zaman S Quin B F Kurepin L V Shaheen S Nawaz S Dawar K M 2014 Improving Pasture Growth and Urea Efficiency Using N inhibitor Molybdenum and Elemental Sulphur Journal of Soil Science and Plant Nutrition doi 10 4067 S0718 95162014005000020 C Nitschke G Scherr 2012 Urea Derivatives Ullmann s Encyclopedia of Industrial Chemistry Weinheim Wiley VCH doi 10 1002 14356007 o27 o04 Bi Siwen Barinelli Vincenzo Sobkowicz Margaret J 2020 02 02 Degradable Controlled Release Fertilizer Composite Prepared via Extrusion Fabrication Characterization and Release Mechanisms Polymers 12 2 301 doi 10 3390 polym12020301 ISSN 2073 4360 PMC 7077398 PMID 32024294 Further reading editDu Chang wen Zhou Jian ming Shaviv Avi 2006 Release Characteristics of Nutrients from Polymer coated Compound Controlled Release Fertilizers Journal of Polymers and the Environment 14 3 223 230 doi 10 1007 s10924 006 0025 4 S2CID 97049596 Retrieved from https en wikipedia org w index php title Controlled release fertiliser amp oldid 1188325215, wikipedia, wiki, book, books, library,

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