Controlled-release fertiliser

A controlled-release fertiliser (CRF) is a granulated fertiliser that releases nutrients gradually into the soil (i.e., with a controlled release period).[2] The slowness of the release is determined by the low solubility of the chemical compounds in the soil moisture. Since conventional fertilisers are soluble in water, the nutrients can disperse quickly as the fertiliser dissolves. 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.

Isobutylidenediurea (IBDU) is typical controlled-release fertiliser owing to its low solubility.[1]

Definitions

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.

Implementation

The fertiliser is administered either by topdressing the soil, or by mixing the fertiliser into the soil before sowing.

One of the advantages of CRF is reduced incidence of fertiliser burn and dissolution of fertiliser in rainwater. Other important advantages are economic: the need for fewer applications and the use of less fertiliser overall. The results (yield) is in most cases improved by > 10%.

Manufacturers and distributors of slow- and controlled- release fertilizers

In North America, the leading producers and/or suppliers of slow- and controlled- release fertilizers are: Agrium Inc., Koch Agronomic Services, Georgia-Pacific, Growth Products, Helena Chemicals, Kugler Company, Lebanon Seaboard Corp., Lesco Inc., Tessenderlo Kerley and The Scotts Company.
The leading manufacturers and/or suppliers in Western Europe are: ICL-Specialty Fertilizers (The Netherlands), Mivena Specialty Fertilizers (The Netherlands), Ekompany Agro B.V. (The Netherlands), Aglukon (Germany), BASF (Germany), COMPO EXPERT (Germany), Puccioni (Italy) and Sadepan Chimica (Italy).
In Israel the leading manufacturer and supplier is Haifa Chemicals.
The leading manufacturers and/or suppliers in Japan are: Central Union Fertilizer, Chissoasahi Fertilizer11, Co-op Chemical, Katakura Chikkarin, Mitsubishi Chemical, Sumitomo Chemical, Taki Chemical and Ube Agri-Materials.
In China, the leading manufacturers are: Hanfeng Evergreen, Shandong Kingenta Ecological Engineering and Shikefeng Chemical Industry.
In Vietnam, the leading manufacturer and supplier is RYNAN Smart Fertilizers.[3] [4]

1. Urea reaction products/slow-release fertilizers
North America
Liquid Products
Georgia-Pacific	Nitamin® 30L - UF Fertilizer
Tessenderlo Kerley	Formolene-Plus® and several Trisert® - urea-triazone formulations
Helena Chemicals	CoRoN® - UF Solution
Kugler Company	KQ XRN 28-0-0 – UF solution
Growth Products	Nitro-30 – UF solution 30-0-0
Granular Products
Agrium (former Nu-Gro)	Nitroform® – UF formulation Nutralene® – methylene urea IB Nitrogen - IBDU
Western Europe
Aglukon	Plantosan® - granular Methylene-urea - Azolon® granular and Azolon® fluid Methylene-urea - PlantoDur® - NPK fertilizer, N based on UF
COMPO EXPERT	CDU (imported from Japan) - Triabon®- NPK fertilizer based on CDU Floranid® Twin - N-, NK- and NPK-fertilizers, N based on IBDU & CDU
Puccioni (Italy)	Nutritop® - Nutritop® N, Smartfert® Top - NPK and NP fertilizers, based on UF
Sadepan Chimica (Italy)	SirflorTM N38, based on UF SazoleneTM - granular and liquid methylene-urea
China
Hanfeng Evergreen	UF
Japan
Chissoasahi Fertilizer	CDU nitrogen ‘UBER’ - controlled-mineralization CDU (called ‘Hyper CDU’ in Japan) NPK fertilizer based on CDU
Mitsubishi Chemical	IBDU nitrogen ‘Good-IB’ and ‘Super-IB’, based on IBDU NPK fertilizer - based on IBDU
Sun Agro	UF NPK fertilizer based on UF

2. Coated/encapsulated controlled-release fertilizers
North America
Polymer-coated products
Agrium	ESN® Polymer coated urea	Koch Agronomic Services	/>	Sulphur-coated urea (SCU)
Koch Agronomic Services	Duration® CR - Polymer-coated urea POLYON® PCU - polymer-coated urea POLYON® coated MAP and NPK fertilizers
Koch Agronomic Services	SCU® Sulfur-Coated Urea, XCU® - polymer-coated, sulfur-coated urea fertilizer
Western Europe and Israel
Polymer-coated products
ICL - Specialty Fertilizers	Agrocote - PU coated N or K or NP Fertilizers Agroblen® - resin and polymer-coated NPK fertilizers Osmocote® - polymer-coated NPK fertilizers
Aglukon	Plantacote® Polymer coated NPK fertilizers
Mivena BV	Horticote® (Plus) Polymer coated NPK fertilizers Fieldcote® - Polymer coated NPK fertilizers Granucote® - Blend with Duration® CR polymer coated Urea
COMPO EXPERT	Basacote®Plus - polymer-coated NPK fertilizers Basatop® - partly polymer-coated N- and NPK-fertilizers
Ekompany Agro B.V.	Ekote® Polymer fully and partly coated NPK, Urea, Phosphat, Potash, etc. fertilizers for arable crops, open field crops and fruit trees, ornamentals, tree nurseries and turf
Haifa Chemicals	Multicote® - polymer-coated NPK-, NP- and NK- fertilizers CoteNTM – polymer-coated urea Mulitcote® Agri – coated NPK-fertilizers for open field crops and fruit trees Multigreen® – controlled-release turf fertilizers Multigro® – controlled-release fertilizer blends for agricul- ture and horticulture
China
Sulphur-coated products
Shandong Kingenta Ecological Engineering	Syncote®- sulphur-coated urea and NPK-fertilizers
Hanfeng Evergreen
Shikefeng Chemical
Polymer/sulphur-coated products
Shandong Kingenta Ecological Engineering	Syncote®- polymer/sulphur-coated urea
Polymer-coated products
Shandong Kingenta Ecological Engineering	Syncote® - polymer-coated NPK-fertilizers and urea
Japan
Sulphur-coated products
Sun-Agro	S-Coat®- sulphur-coated NPK- fertilizers and urea
Polymer-coated products
Chissoasahi Fertilizer	Meister®- polymer-coated urea (called ‘LP-cote’ in Japan) Nutricote® - polymer-coated NPK fertilizer, magnesium sulphate or calcium nitrate Pile Nutricote® - Nutricote® in paper pile ‘Naebako-makase’ - special Meister® for single basal application in nursery boxes of rice ‘Ikubyou-makase’ – special Nutricote®- for single basal application in nursery pots of horticultural crops
Mitsubishi Chemical	M-coat® - polymer-coated urea
Taki Chemical	Taki-coat® - polymer-coated urea
MC Ferticom	U-coat® - polymer-coated urea
Central Union Fertilizer	Cera-Coat® Polymer-Coated Urea
Co-op Chemical	Co-op coat®- polymer-coated NPK fertilizers
Katakura Chikkarin	Sigma Coat® Polymer-Coated Urea and NPK Fertilizers
Sumitomo Chemical	‘SR-coat’ - polymer-coated urea

Synonyms

Controlled-release fertilizer is also known as controlled-availability fertilizer, delayed-release fertilizer, metered-release fertilizer, or slow-acting fertilizer.

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References

C. Nitschke; G. Scherr (2012). "Urea Derivatives". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.o27_o04.
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.
http://www.rynansmartfertilizers.com
Trenkel, M.E. (2010). Slow- and Controlled release and Stabilized Fertilizers. International Fertilizer Industry Association.