[go: up one dir, main page]

GB2292140A - Application of sulphur or metals in agriculture - Google Patents

Application of sulphur or metals in agriculture Download PDF

Info

Publication number
GB2292140A
GB2292140A GB9516488A GB9516488A GB2292140A GB 2292140 A GB2292140 A GB 2292140A GB 9516488 A GB9516488 A GB 9516488A GB 9516488 A GB9516488 A GB 9516488A GB 2292140 A GB2292140 A GB 2292140A
Authority
GB
United Kingdom
Prior art keywords
sulphur
weight
inert
particles
filler material
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB9516488A
Other versions
GB2292140B (en
GB9516488D0 (en
Inventor
Michael Thomas Whalley
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
HAYS CHEM DISTR Ltd
Original Assignee
HAYS CHEM DISTR Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by HAYS CHEM DISTR Ltd filed Critical HAYS CHEM DISTR Ltd
Publication of GB9516488D0 publication Critical patent/GB9516488D0/en
Publication of GB2292140A publication Critical patent/GB2292140A/en
Application granted granted Critical
Publication of GB2292140B publication Critical patent/GB2292140B/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C05FERTILISERS; MANUFACTURE THEREOF
    • C05DINORGANIC FERTILISERS NOT COVERED BY SUBCLASSES C05B, C05C; FERTILISERS PRODUCING CARBON DIOXIDE
    • C05D9/00Other inorganic fertilisers
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22FWORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/12Metallic powder containing non-metallic particles
    • CCHEMISTRY; METALLURGY
    • C05FERTILISERS; MANUFACTURE THEREOF
    • C05DINORGANIC FERTILISERS NOT COVERED BY SUBCLASSES C05B, C05C; FERTILISERS PRODUCING CARBON DIOXIDE
    • C05D5/00Fertilisers containing magnesium
    • CCHEMISTRY; METALLURGY
    • C05FERTILISERS; MANUFACTURE THEREOF
    • C05DINORGANIC FERTILISERS NOT COVERED BY SUBCLASSES C05B, C05C; FERTILISERS PRODUCING CARBON DIOXIDE
    • C05D9/00Other inorganic fertilisers
    • C05D9/02Other inorganic fertilisers containing trace elements

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Inorganic Chemistry (AREA)
  • Organic Chemistry (AREA)
  • Agricultural Chemicals And Associated Chemicals (AREA)

Abstract

In a method of producing granular or pulverulent materials containing sulphur, particles of sulphur are mixed with an inert or filler material, preferably bentonite, to form said granular or pulverulent materials. The method of producing such materials may be by including an aqueous solution of a binding material therein, mixing being effected at ambient temperature, preferably in a granulating mixer suitably having an inclined granulating surface. Alternatively, the granular or pulverulent material may be produced by feeding the mixture of sulphur particles and inert or filler material between counter-rotating synchronous rollers where pressure is applied to form material of suitable size. In such method, it is possible to add a metallic soap to the mixture to act as a release agent. The material so produced can then be applied to the land. The method is also applicable to producing granular or pulverulent mixtures containing particles of magnesium, copper, zinc or iron.

Description

APPLICATION OF SULPHUR IN AGRICULTURE The present invention concerns improvements in or relating to the application of sulphur in connection with agricultural usage thereof.
Heretofore, there has been sufficient sulphur applied to the land naturally for agricultural purposes.
Sulphur is required as a plant nutrient by being applied to the land and absorbed therein. Previously, emission from power stations has caused sulphur in the fuel for such power stations to be emitted in the form of sulphur dioxide which falls on the ground as mild sulphurous acid, and is thereafter absorbed.
With the closure of various power stations, coupled with the fact that smoke emissions are now strictly controlled, a sulphur shortage has occurred for agricultural usage.
It is extremely difficult to apply sulphur dust on its own to the land. When handled, sulphur dust generates a very high static electric charge. Should discharge occur as a spark, a temperature in excess of 1900C may be achieved, which is sufficient to ignite the dust cloud.
In an attempt to apply sulphur to the land, consideration has been given to applying same in the form of particles; however, with the small size particles required they are difficult to apply and they are dangerous to handle in confined spaces. Moreover, such fine particles can be blown away by the wind and also special equipment is needed to apply same to the land.
If larger particles are utilised then same can be too big to be effective and are not able to be quickly converted into sulphate ions by bacteria such as Thiobacillus.
One known way to apply sulphur to the ground is to form granules of bentonite and sulphur. Such granules have been produced by melting sulphur and mixing same with bentonite. Such heated mixture is then cooled by passing same through a large spray tower or on a cooled conveyor to enable sufficient residence time for cooling to take place. However, such granules do not break down in any controlled manner. In theory, when the granules are applied to the land and either water supplied thereto or rain descends thereon, the bentonite expands and breaks up the granule thereby exposing the sulphur and enabling same to be washed into the ground; however, due to the formation of the granule by the method referred to above, it takes an extremely long time for the granule to break down when water is applied thereto.Moreover, there is no control over the manner in which the granule will break and therefore there is no guarantee that the sulphur will be released in the required form or amount.
Another known way to apply sulphur to the land is to form pellets of bentonite and fly sulphur by wet extrusion. This method is more effective than the "hot" method previously referred to, but is disadvantaged by the fact that the particle size of the fly sulphur is not controlled, and the process is expensive.
It is an object of the present invention to provide a method for permitting safe and economic application of sulphur to the land in a form which allows controlled bacterial attack.
According to the present invention there is provided a method of producing granular or pulverulent materials containing sulphur, wherein particles of sulphur are mixed with an inert or filler material to form said granular or pulverulent materials.
The present invention also provides a method of application of sulphur to the land, comprising applying the granular or pulverulent material produced by the method outlined above to the land. By appropriate mixing and/or selection of sulphur particle size and/or by suitable sieving of the granular or pulverulent materials so produced, products can be obtained which when applied to the land will have the required amount of sulphur contained therein for the particular application concerned.
In the method of producing granular or pulverulent material in accordance with the invention, any suitable inert or filler material can be utilised, preferably bentonite.
The size of the sulphur particles to be utilised may be selected as appropriate, but are generally in the range of 5 - 130ss. Preferably 90% of the sulphur particles should pass through a 75p sieve. Moreover, a plurality of different size particles of sulphur can be utilised.
In producing granular or pulverulent material in accordance with the present invention, the preferred ranges of materials utilised are 10 to 95% by weight of sulphur particles and 5 to 90% by weight of inert or filler material. Preferred ranges are 70% by weight of sulphur particles and 30% by weight of inert or filler material, more preferably 60% by weight of sulphur particles and 40% by weight of inert or filler material.
The granular or pulverulent material produced is preferably of diameter size lmm to 4mm.
Production of the granular or pulverulent material may be effected by mixing the sulphur particles with the inert or filler material and adding an aqueous solution of a binding material thereto, mixing being effected at ambient temperature. Mixing is preferably effected in a granulating mixer, such mixer preferably having an inclined granulating surface.
When utilising such method of mixing, a blend of 70% by weight of sulphur particles and 30% by weight of inert or filler material would preferably be mixed with 12 to 30% by weight of binding material. Suitable binding material would be starch or lignosulphonate.
An alternative method of producing the granular or pulverulent material would be to feed the mixture of sulphur particles and inert or filler material between counter-rotating synchronous rollers where pressure is applied to form agglomerates or like granular or pulverulent material of suitable size. In order to ensure consistent size of the material so produced, subsequent screening may be necessary. When utilising this method, it is possible to add a metallic soap to the sulphur/inert or filler material formulation.
The basic formulation of sulphur particles and inert or filler material utilised in this embodiment of the invention would be substantially the same as indicated above; however, instead of utilising 12 to 30% by weight of binding material, it is possible to utilise 0.1 to 0.5% by weight of a metallic soap, such as magnesium stearate, to act as a release agent during the process.
Whichever method of mixing is utilised, it is possible, in a preferred embodiment, to choose pre selected size of sulphur particles for incorporation in the final granular or pulverulent material. By utilising appropriate inert or filler material to be mixed with the sulphur particles, granular or pulverulent material is produced which can be broken down quite quickly with water to expose the desired amount of sulphur, of the required particle size, to the land.
As indicated above, it is possible to utilise a plurality of different size particles of sulphur, particularly for example when treating various crops in order to regulate the growth thereof. In such situation, larger particles of sulphur would take a longer time to break down and therefore would be available for a longer period of time. It is also possible to produce granules of varying sizes of sulphur for particular applications.
In this connection, small granules of lmm diameter may be used on golf courses without adversely affecting the path of golf balls on the playing surface, whilst larger granules of 4mm diameter are more suitable for use of farmland.
The granules produced in accordance with the present invention can be applied by conventional techniques without any specific safety requirements or equipment being necessary. When rain falls on the land, the bentonite or other inert or filler material expands, the granule breaks and sulphur is washed into the ground.
By selecting different particle sizes of sulphur in the granules then one can control the rate of bacterial conversion to sulphate ions in the soil.
It has previously been shown that the addition of sulphur (in the form of sulphur fertilisers such as ammonium sulphate) to grassland can significantly improve yields. However, a single application does not always last the whole growing season, as it is more easily leached from the soil. Independent trials carried out on rye-grass in Cumbria demonstrated that one early Spring application of 25kg/hectare of elemental sulphur, with particle size predominantly less than 53M, produced a total increase in dry matter of 1.3 tonnes per hectare over all three cuts, providing a satisfactory source of sulphur for the whole season. This increase of some 11% was achieved despite a low yielding second cut due to abnormally low rainfall between mid-May and the end of July, during the period of the trial.
It is possible to mix other fertilisers and other known materials with the sulphur granules as required.
It will thus be seen that the present invention provides an economic and efficient method of applying sulphur to the land for agricultural purposes. By utilising in a preferred embodiment, particles of sulphur of different sizes in the granule so formed, the yield of plants or crops throughout the year may be improved.
The present invention provides a way of applying small particle size sulphur to the land safely and economically.
Whilst the invention has been described in respect of applying sulphur to the land, it is also possible to utilise the method for applying particles of other trace elements such as magnesium, copper, zinc and iron to the land.
In accordance with a further embodiment of the present invention there is provided a method of producing granular or pulverulent materials containing magnesium, copper, zinc or iron, wherein particles of magnesium, copper, zinc or iron are mixed with an inert or filler material to form said granular or pulverulent material.
The methods of producing such materials will be the same as indicated above in respect of production of granular or pulverulent material containing sulphur.
Moreover, once so produced such granular or pulverulent material can be applied to the land in the same manner as indicated above in respect of application of sulphur to the land.

Claims (24)

1. A method of producing granular or pulverulent materials containing sulphur, wherein particles of sulphur are mixed with an inert or filler material to form said granular or pulverulent materials.
2. A method as claimed in claim 1, in which the inert or filler material utilised is bentonite.
3. A method as claimed in claim 1 or 2, in which the size of the sulphur particles to be utilised are in the range of 5 to 130p.
4. A method as claimed in claim 3, in which 90% of the sulphur particles pass through a 75p sieve.
5. A method as claimed in any preceding claim, in which a plurality of different size particles of sulphur are utilised.
6. A method as claimed in any preceding claim, in which the granular or pulverulent materials produced contain 10 to 95% by weight of sulphur particles and 5 to 90% by weight of inert or filler material, and are of diameter size 1 to 4mm.
7. A method as claimed in claim 6, in which the materials contain 70% by weight of sulphur particles and 30% by weight of inert or filler material, or 60% by weight of sulphur particles and 40% by weight of inert or filler material.
8. A method as claimed in any preceding claim, in which the sulphur particles are mixed with the inert or filler material and an aqueous solution of binding material is added thereto, mixing being effected at ambient temperature.
9. A method as claimed in claim 8, in which mixing is effected in a granulating mixer.
10. A method as claimed in claim 9, in which said granulating mixer has an inclined granulating surface.
11. A method as claimed in claim 8, 9 or 10, in which a blend of 70% by weight of sulphur and 30% by weight of inert or filler material is mixed with 12 to 30% by weight of binding material.
12. A method as claimed in claim 8, 9, 10 or 11, in which the binding material is starch or lignosulphonate.
13. A method as claimed in any one of claims 1 to 7, wherein the mixture of sulphur particles and inert or filler material is fed between counter-rotating synchronous rollers where pressure is applied to form agglomerates or like granular or pulverulent material of suitable size.
14. A method as claimed in claim 13, in which subsequent screening is effected.
15. A method as claimed in claim 13 or 14, wherein a metallic soap is added to the mixture of sulphur particles and inert or filler material to act as a release agent.
16. A method as claimed in claim 15, in which the metallic soap is magnesium stearate.
17. A method as claimed in any one of claims 13 to 16, in which the mixture contains 10 to 95% by weight of sulphur particles and 5 to 90% by weight of inert or filler material.
18. A method as claimed in claim 17, in which the mixture contains 70% by weight of sulphur particles and 30% by weight of inert or filler material, or 60% by weight of sulphur particles and 40% by weight of inert or filler material.
19. A method as claimed in claim 15 or 16, in which the mixture comprises 70% by weight of sulphur particles and 30% by weight of inert or filler material which is mixed with 0.1 to 0.5% by weight of the metallic soap.
20. A modification of the method as claimed in any preceding claim, in which the sulphur particles are replaced by particles of magnesium, copper, zinc or iron.
21. A method of producing granular or pulverulent materials as claimed in any preceding claim, substantially as hereinbefore described.
22. A method of application of sulphur to the land, comprising applying the granular or pulverulent material produced by the method as claimed in any one of claims 1 to 18 to the land.
23. A method as claimed in claim 22, wherein by appropriate mixing and/or selection of sulphur particle size and/or by suitable sieving of the granular or pulverulent material so produced, products are obtained which can be applied to the land with the required amount of sulphur contained therein for the particular application concerned.
24. A method of application of magnesium, copper, zinc or iron to the land, comprising applying the granular or pulverulent material produced by the method of claim 19 to the land.
GB9516488A 1994-08-13 1995-08-11 Application of sulphur in agriculture Expired - Fee Related GB2292140B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9416402A GB9416402D0 (en) 1994-08-13 1994-08-13 Application of sulpher in agriculture

Publications (3)

Publication Number Publication Date
GB9516488D0 GB9516488D0 (en) 1995-10-11
GB2292140A true GB2292140A (en) 1996-02-14
GB2292140B GB2292140B (en) 1998-09-09

Family

ID=10759844

Family Applications (2)

Application Number Title Priority Date Filing Date
GB9416402A Pending GB9416402D0 (en) 1994-08-13 1994-08-13 Application of sulpher in agriculture
GB9516488A Expired - Fee Related GB2292140B (en) 1994-08-13 1995-08-11 Application of sulphur in agriculture

Family Applications Before (1)

Application Number Title Priority Date Filing Date
GB9416402A Pending GB9416402D0 (en) 1994-08-13 1994-08-13 Application of sulpher in agriculture

Country Status (1)

Country Link
GB (2) GB9416402D0 (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003053883A1 (en) * 2001-12-20 2003-07-03 Basf Aktiengesellschaft Method for improving plant growth by application of a mixture of sulfur and complexing agent
WO2008024007A3 (en) * 2006-08-25 2008-07-03 Zaklady Chemiczne Siarkopol Ta Sulphur fertilizer and granulated sulphur fertilizer manufacturing method
AU2007343066A1 (en) * 2007-01-08 2008-07-17 Deepak Pranjivandas Shah Novel agricultural composition
WO2009051496A1 (en) * 2007-10-18 2009-04-23 Robert Hamilton Hall Improvements in and relating to soil treatments
WO2010086395A1 (en) 2009-01-29 2010-08-05 Shell Internationale Research Maatschappij B.V. Sulphur-containing fertilizers and process for the preparation thereof
WO2013098404A1 (en) * 2011-12-29 2013-07-04 Shell Internationale Research Maatschappij B.V. Processes for the manufacture of sulphur-containing compositions and sulphur-containing fertilizer compositions
AU2012216575B2 (en) * 2007-10-18 2013-07-11 Robert Hamilton Hall Improvements in and Relating to Soil Treatments
WO2020250137A1 (en) * 2019-06-12 2020-12-17 Gujarat State Fertilizers and Chemicals Limited Process for preparation of water dispersible fertilizer composition and compositions in powder form made therefrom
AU2021328443B2 (en) * 2020-08-17 2023-11-30 Sml Limited An organic agricultural composition

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB356195A (en) * 1929-06-01 1931-08-31 Eduard Dedolph Composition serving as a fertilizer and agricultural pest destroyer
GB623499A (en) * 1947-05-05 1949-05-18 Adam John Sturges Beer Improvements relating to the pulverizing of sulphur and like materials
GB1032724A (en) * 1963-06-04 1966-06-15 Kalk Chemische Fabrik Gmbh Mixtures of granular or pulverulent components and finely divided phosphates
GB1128192A (en) * 1964-12-04 1968-09-25 Organon Labor Ltd Process for rendering powders free flowing and the thus-obtained powders
GB1175876A (en) * 1966-08-22 1970-01-01 Stauffer Chemical Co Compacted Sulphur and Method of Producing Same
DE1592609B1 (en) * 1964-03-25 1970-02-26 Deutsche Hyperphosphat Gmbh Process for the production of a granulated phosphate fertilizer containing sulfur and optionally potassium salt
GB1213494A (en) * 1967-03-23 1970-11-25 Degussa Prevention of agglomeration of powdered materials
GB2136789A (en) * 1983-03-14 1984-09-26 Stoller Ets Rock phosphate fertilizer composition
WO1990003350A1 (en) * 1988-09-30 1990-04-05 F.P.S. Italiana - Finances Products Services S.R.L. Sulfur-based chemical soil-corrective in the form of pellets for agricultural use

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB356195A (en) * 1929-06-01 1931-08-31 Eduard Dedolph Composition serving as a fertilizer and agricultural pest destroyer
GB623499A (en) * 1947-05-05 1949-05-18 Adam John Sturges Beer Improvements relating to the pulverizing of sulphur and like materials
GB1032724A (en) * 1963-06-04 1966-06-15 Kalk Chemische Fabrik Gmbh Mixtures of granular or pulverulent components and finely divided phosphates
DE1592609B1 (en) * 1964-03-25 1970-02-26 Deutsche Hyperphosphat Gmbh Process for the production of a granulated phosphate fertilizer containing sulfur and optionally potassium salt
GB1128192A (en) * 1964-12-04 1968-09-25 Organon Labor Ltd Process for rendering powders free flowing and the thus-obtained powders
GB1175876A (en) * 1966-08-22 1970-01-01 Stauffer Chemical Co Compacted Sulphur and Method of Producing Same
GB1213494A (en) * 1967-03-23 1970-11-25 Degussa Prevention of agglomeration of powdered materials
GB2136789A (en) * 1983-03-14 1984-09-26 Stoller Ets Rock phosphate fertilizer composition
WO1990003350A1 (en) * 1988-09-30 1990-04-05 F.P.S. Italiana - Finances Products Services S.R.L. Sulfur-based chemical soil-corrective in the form of pellets for agricultural use

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003053883A1 (en) * 2001-12-20 2003-07-03 Basf Aktiengesellschaft Method for improving plant growth by application of a mixture of sulfur and complexing agent
AU2002328996B2 (en) * 2001-12-20 2008-09-04 Basf Se Method for improving plant growth by application of a mixture of sulfur and complexing agent
US7530196B2 (en) 2001-12-20 2009-05-12 Basf Aktiengesellschaft Method for improving plant growth by application of a mixture of sulfur and complexing agent
WO2008024007A3 (en) * 2006-08-25 2008-07-03 Zaklady Chemiczne Siarkopol Ta Sulphur fertilizer and granulated sulphur fertilizer manufacturing method
AU2007343066A1 (en) * 2007-01-08 2008-07-17 Deepak Pranjivandas Shah Novel agricultural composition
WO2008084495A3 (en) * 2007-01-08 2008-10-02 Deepak Pranjivandas Shah Novel agricultural composition
AU2007343066C1 (en) * 2007-01-08 2017-06-08 Deepak Pranjivandas Shah Novel agricultural composition
CN101657395A (en) * 2007-01-08 2010-02-24 迪帕克·普兰吉万达斯·沙阿 Novel agricultural composition
CN101657395B (en) * 2007-01-08 2014-03-12 迪帕克·普兰吉万达斯·沙阿 Agricultural composition
US8241387B2 (en) 2007-01-08 2012-08-14 Deepak Pranjivandas Shah Agricultural composition
AU2012216575B2 (en) * 2007-10-18 2013-07-11 Robert Hamilton Hall Improvements in and Relating to Soil Treatments
AU2008312121B2 (en) * 2007-10-18 2013-07-11 Robert Hamilton Hall Improvements in and relating to soil treatments
WO2009051496A1 (en) * 2007-10-18 2009-04-23 Robert Hamilton Hall Improvements in and relating to soil treatments
US8668759B2 (en) 2009-01-29 2014-03-11 Shell Oil Company Sulphur-containing fertilizers and process for the preparation thereof
WO2010086395A1 (en) 2009-01-29 2010-08-05 Shell Internationale Research Maatschappij B.V. Sulphur-containing fertilizers and process for the preparation thereof
WO2013098404A1 (en) * 2011-12-29 2013-07-04 Shell Internationale Research Maatschappij B.V. Processes for the manufacture of sulphur-containing compositions and sulphur-containing fertilizer compositions
WO2020250137A1 (en) * 2019-06-12 2020-12-17 Gujarat State Fertilizers and Chemicals Limited Process for preparation of water dispersible fertilizer composition and compositions in powder form made therefrom
AU2021328443B2 (en) * 2020-08-17 2023-11-30 Sml Limited An organic agricultural composition

Also Published As

Publication number Publication date
GB9416402D0 (en) 1994-10-05
GB2292140B (en) 1998-09-09
GB9516488D0 (en) 1995-10-11

Similar Documents

Publication Publication Date Title
CA2006751C (en) Homogeneous granular nitrogen fertilizer
US3050383A (en) Fertilizer
US5653782A (en) Process for the manufacture of sulfur-containing fertilizers
US6132484A (en) Wet granulation method for generating fertilizer granules
CA1194334A (en) Foliage fertilisers
CA2265922C (en) Wet granulation method for generating granules
EA007775B1 (en) A process for the manufacture of sulphur-containing ammonium phosphate fertilizers
US4410350A (en) Production of pellets and pellet-containing fertilizer composition
US4183738A (en) Granulation process and products produced thereby
CA2268253C (en) Wet granulation method for generating sulfur granules
CA2091045C (en) Non-destructive recovery of natural nitrogen products
US2798801A (en) Production of pelletized nitrogenous fertilizers
GB2292140A (en) Application of sulphur or metals in agriculture
US20220380272A1 (en) Composite fertiliser systems
US5453277A (en) Method of controlling soil pests
RU2629215C1 (en) Fertiliser and method of its obtaining
WO2009125435A2 (en) Improved sulfur formulation suitable for organic agriculture
US5487772A (en) Carboxylate nutrients and methods for their production and use
US4421545A (en) High strength melamine-urea fertilizer granules
US3313615A (en) Coated fertilizers
SK279194B6 (en) A process for producing a granular agent for conditioning of damaged and/or deficient soils
WO1995021689A1 (en) Granular urea
RU2139270C1 (en) Method of preparing organomineral fertilizer
WO1988010246A1 (en) Process for producing a granular soil conditioner
EP1411036B1 (en) Method of obtaining nitrogenated granular fertilizers with a high microelement content and fertilizers obtained thereby

Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee

Effective date: 19990811