FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
PATENT OF ADDITION TO 840/MUM/2008 (See section 54; rule 13)


1. TITLE OF THE INVENTION:
Improved Sulfur Formulation Suitable For Organic Agriculture
2. APPLICANT(S)

1 2
(a) NAME:
Excel Crop Care Limited
(b) NATIONALITY: Indian
Company
(c) ADDRESS:
184-87 S.V. Road, Jogeshwari (West), Mumbai 400102, Maharashtra, India. (a) NAME:
C. C. Shroff Research Institute
(b) NATIONALITY: Indian
(c) ADDRESS:
Ram House, 2nd Floor, Gaiwadi Industrial Estate, Goregaon (West), Mumbai 400 062, Maharashtra, India
PREAMBLE TO THE DESCRIPTION:
The following complete specification particularly describes modification of manner in which the invention disclosed in application No.840/MUM/2008 is to be performed.


Improved Sulfur Formulation Suitable For Organic Agriculture
FIELD OF INVENTION
This invention relates to manner of using granular formulation of sulfur which is disclosed in 840/MUM/2008 as a plant nutrient.
BACKGROUND AND PRIOR ART
Sulfur is as important as nitrogen for synthesis of amino acids and chlorophyll. It is also essential for utilization of phosphorus and other nutrients. Sulfur plays a vital role in optimizing crop yield and quality. It increases size and weight of grain crops, particularly crops which have high nitrogen requirement, as sulfur enhances nitrogen utilization in plants. Plants do not respond to applied nitrogen in absence of adequate sulfur.
Sulfur is present in soil in both, organic and inorganic forms. It is not available to plants in organic form. As microorganisms present in soil decompose organic matter, the organic sulfur slowly gets converted into sulfate form, which is available to plants.
Generally >90% of soil sulfur is present in the organic matter of the soil. Therefore, soils with less organic matter are deficient in sulfur. Moreover, the available sulfate form of sulfur gets leached from such soils.


Fertilizers such as potassium sulfate, potassium magnesium sulfate, ammonium sulfate, gypsum, elemental sulfur etc. are used to meet sulfur requirement of plants.
Elemental sulfur containing fertilizers provide an advantage of slow-release of sulfur over time as sulfur is gradually converted into available sulfate form. Moreover, elemental sulfur containing fertilizers being most concentrated in sulfur are cost effective as it also saves on transportation cost.
Several forms of elemental sulfur containing fertilizers are known in the art. These include dust form, pellets, granules etc. Granular formulation has advantages over other forms such as ease of handling and using.
WO 2008089568 describes a process for preparing micronized elemental sulphur mixture having a size distribution of 80% less than 20 microns for use as a sulphur based fertilizer. However, dust form is difficult to handle. It has a risk of fire hazard as sulfur dust cloud can ignite with a spark.
If sulfur is used in form of larger particles, the rate of conversion of the same by soil microorganisms into available sulfate form is too slow.
Granules of sulfur and bentonite produced by melting sulfur, mixing with bentonite and granulating, are reported in the literature (US 4133669, US 4569859, WO 2008024007). However, such granules


do not break in a controlled manner. As mentioned in GB 2292140,
pellets of bentonite and fly sulphur produced by wet extrusion are
known in the art. However, particle size of the fly sulphur is not
controlled. Moreover, prolonged use of bentonite reduces
permeability of soil.
A process for production of granular sulfur is disclosed in AU 3485878, wherein molten sulfur is foamed and solidified by cooling whilst in the foamed state and reducing it to particulate form. It is not possible to obtain appropriate particle size by this method.
A method for preparing powdered sulfur is disclosed in US 3891743. In this method, molten sulfur is subjected to oxidizing treatment to get rid of hydrogen sulfide which is responsible for caking. A free-flowing powder of sulfur is thus obtained. However, granular form is preferable to powder form, as the former is much easy to handle.
A formulation of sulfur in form of agglomerated particles is disclosed in WO 2008084495. However, the adjuvants used therein cannot be used in organic agriculture.
CA 2043873 discloses a method for manufacturing granular sulfur using calcium lignosulfate as binder dispersant. The method involves grinding sulfur to particles of 200 U.S. mesh or less, which are separated from larger particles using an air classifier. Sulfur with particle size less than or equal to 200 U.S. mesh are mixed with calcium lignosulfate. The mixture is transported to pan granulator where fine mist of water is applied in order to facilitate agglomeration


to form granules. The granules thus formed fall off the pan granulator and are dried and screened. Off size granules are returned to the mixer. In this method there is a risk of fire hazard during grinding and mixing as it forms combustible explosive mass. The process requires continuous monitoring and provision for shut¬down. Moreover, the size of the granules obtained by this method is not uniform.
Therefore there is a need for a granular formulation of sulfur and a process for manufacturing the same, which overcomes abovementioned disadvantages.
OBJECTS OF INVENTION
The main object of present invention is to provide an eco-friendly granular formulation of sulfur which is non-dusty and easy to handle.
Another object of invention is to provide a granular formulation of sulfur which is cost-effective.
Another object of invention is to provide a simple and non-hazardous process for manufacturing granular formulation of sulfur.
Another object of invention is to provide a granular formulation of sulfur which can be used in organic agriculture as a plant nutrient.


DETAILED DESCRIPTION OF INVENTION
The inventors of present invention have developed a granular formulation of sulfur and a process for manufacturing thereof, using appropriate ratio of sulfur to alkali metal lignosulphonate in such a way that it performs effectively as dispersing as well as binding agent. The formulation when manufactured by said process has desired qualities of being adequately loaded with the active component and at the same time it is dust free, easy to handle and use.
Though technically any alkali metal lignosulphonate can be used to prepare the formulation of present invention, sodium lignosulphonate may be preferred due to economic reasons as well as easy availability thereof.
The granular formulation of present invention may be prepared either by extrusion or by spray-granulation process.
The first method (extrusion) includes the steps of (1) grinding technical sulfur containing at least 1% moisture so as to eliminate fire hazard during the process of particle size reduction (2) adding an eco-friendly dispersing cum binding agent and mixing (3) further reducing the particle size by a suitable process such as air-jet milling so that more than 90% particles become <10 \x (4) adding water and mixing to prepare dough (5) extruding dough to form granules (6) drying the granules preferably at 50-65°C.


The second method (spray-granulation) includes the steps of (1) grinding technical sulfur containing at least 1% moisture so as to eliminate fire hazard during the process of particle size reduction (2) adding an eco-friendly dispersing cum binding agent & water, and mixing to prepare slurry (3) further reducing the particle size by a suitable process such as bead-milling so that more than 90% particles become <10 u (5) passing the slurry through spray granulator to obtain granules.
EXAMPLE-1
81.8 g. Sulfur containing 1% moisture was ground to obtain material passing through 60 mesh. 19.2 g. sodium lignosulphonate was added. The mixture was subjected to air-jet milling for further reduction in particle size to obtain more than 90% of particles with particle size below 10 u. 18 ml water was added to the mixture to prepare dough which was extruded and dried at 55°C to obtain free-flowing granules.
EXAMPLE-2
61.6 g. Sulfur containing 1% moisture was ground to obtain material passing through 60 mesh. 39.4 g. sodium lignosulphonate was added. The mixture was subjected to air-jet milling for further reduction in particle size to obtain more than 90% of particles with particle size below 10 u 16 ml water was added to the mixture to prepare dough which was extruded and dried at 55°C to obtain free-flowing granules.


EXAMPLE-3
71.7 g. Sulfur containing 1% moisture was ground to obtain material
passing through 60 mesh. 29.3 g. sodium lignosulphonate was
added. The mixture was subjected to air-jet milling for further
reduction in particle size to obtain more than 90% of particles with
particle size below 10 μ. 20 ml water was added to the mixture to
prepare dough which was extruded and dried at 55°C to obtain free-
flowing granules.
EXAMPLE-4
91.9 g. Sulfur containing about 1% moisture was ground to obtain material passing through 60 mesh. 9.1 g. sodium lignosulphonate was added. The mixture was subjected to air-jet milling for further reduction in particle size to obtain more than 90% of particles with particle size below 10 μ. 18 ml water was added to the mixture to prepare dough which was extruded and dried at 55°C to obtain free-flowing granules.
EXAMPLE-5
81.8 g. Sulfur containing 1% moisture was ground to obtain material
passing through 60 mesh. 19.2 g. sodium lignosulphonate was
added. 50 ml water was added to prepare slurry. The mixture was
subjected to bead-milling for further reduction in particle size to
obtain more than 90% of particles with particle size below 10 (a. It


was then subjected to spray-granulation and drying at 65°C to obtain free-flowing granules.
EXAMPLE-6
61.6 g. Sulfur containing 1% moisture was ground to obtain material passing through 60 mesh. 39.4 g. sodium lignosulphonate was added. 50 ml water was added to prepare slurry. The mixture was subjected to bead-milling for further reduction in particle size to obtain more than 90% of particles with particle size below 10 u. It was then subjected to spray-granulation and drying at 65°C to obtain free-flowing granules.
EXAMPLE-7
71.7g. Sulfur containing 1% moisture was ground to obtain material passing through 60 mesh. 29.3 g. sodium lignosulphonate was added. 50 ml water was added to prepare slurry. The mixture was subjected to bead-milling for further reduction in particle size to obtain more than 90% of particles with particle size below 10 μ. It was then subjected to spray-granulation and drying at 65°C to obtain free-flowing granules.
EXAMPLE-8
91.9 g. Sulfur containing 1% moisture was ground to obtain material passing through 60 mesh. 9.1 g. sodium lignosulphonate was added. 50 ml water was added to prepare slurry. The mixture was subjected


to bead-milling for further reduction in particle size to obtain more than 90% of particles with particle size below 10 n. It was then subjected to spray-granulation and drying at 65°C to obtain free-flowing granules.
The formulation of present invention can be used as plant nutrient. The application rate should be determined depending on the need and deficiency of sulfur in soil. The formulation can be used by broadcasting on soil or by spraying on soil an aqueous dispersion of the formulation.
Soil application of the formulation of present invention at the rate of 3 Kg/Acre caused an increase in yield by 6 - 15% in paddy.
Results of soil application of the formulation of present invention at the rate of 3 Kg/Acre on paddy of variety Pakistani Basmati are given below:

Treatments No. of tillers/hill Plant
height
(cm) Panicle
length
(cm) No. of
grains/
panicle Wtof 1000 grains (gm) Yield (Q)
Tl 19.8 103 22.7 85 30 11.3(15.3%)
T2 18.1 103 21.2 83 30 10.8(9.8%)
Control 16.2 102.5 19.8 78 29 9.8


Results of soil application of the formulation of present invention at the rate of 3 Kg/ Acre on paddy variety sunder are given below:
Treatments No. of Plant Panicle No. of No. of Yield (Q)
tillers/hill height length grains/ chaffy
(cm) (cm) panicle grains/
panicle
Tl 17 102 25 290 23 24.1(8%)
T2 17 102 24 276 28 23.6(6%)
Control 14~2 101 22 226 36 22.1
The formulation of present invention and the process for manufacturing the same has been already claimed in prior Indian application 840/MUM/2008. The scope of this patent is the manner of using said formulation as a plant nutrient.


CLAIMS

(Dr. Jyotsna P. Kapadia)
Sr. Manager - IP
Excel Crop Care Ltd.
1. A method of providing sulfur as a plant nutrient by broadcasting on soil the granular formulation of sulfur claimed in any of the claims 5 or 10 of the Indian patent application 840/MUM/2008.
2. A method of providing sulfur as a plant nutrient by spraying on soil an aqueous dispersion of granular formulation of sulfur claimed in any of the claims 5 or 10 of the Indian patent application 840/MUM/2008.