DESC:FORM 2
THE PATENT ACT 1970
&
The Patents Rules, 2003

COMPLETE SPECIFICATION

(See section 10 and rule 13)

1. TITLE OF THE INVENTION: PORTABLE SOIL TESTING KIT

2. APPLICANT

(a) NAME: Dr. S. Riazuddin Ahmed

(b) NATIONALITY: Indian

(c) ADDRESS: D. No. 11-3-744, Mallepally, Hyderabad–500 001, A.P, India

THE FOLLOWING INVENTION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

TECHNICAL FIELD

The disclosed invention primarily relates to the agricultural field. More particularly the invention relates to a portable soil test kit that enables evaluation of soil fertility.

BACKGROUND AND PRIOR ART

The ever increasing population has increased the food demand. In a haste to meet this demand the fertilizer consumption, which started in late 1960, has now reached to an indiscriminate usage stage. As a result, the inherent productivity of the soil is hindered which in turn deteriorates the quality of the crop. This also affects the organic usage due to which water holding capacity, pH, salt concentration, organic carbon, available nutrient contents and other properties of soil have reached to an alarming stage. Especially the concentration of nutrients like Nitrogen, Phosphorus and Potassium and minor elements need to be assessed to ensure that the crops get the required nutrient elements for enhanced quality and quantity. Imbalanced nutrient status of soil affects both crop production and cost of cultivation. Assessment of the soil fertility would also save unwarranted expenditure on fertilizers.

Farmers have been trying various methods to sustain its productivity through external application of farm wastes, green manure and chemical nutrients to supply the required nutrients to the crops. However, the ever increasing demand of productivity per unit area and the narrowing cost benefit ratio has made the farmers more sensitive to the soil fertility status and thereby fertilizer management and soil health. Therefore there arises a need for an efficient technology which would enable one to determine the fertility of the soil by simple and effective means.

In the past, various efforts have been made on these grounds. US Patent no. 6699709 discloses a method for determining gross nitrogen-mineralization rate of a soil sample. However this invention helps in determining the fertility only with respect to nitrogen. However nitrogen content is not the only parameter for fertility assessment. There are other components like sulphur, potassium, phosphorus, calcium and micro nutrients like Zinc, Copper, Iron, Manganese and Boron etc, that contribute in determining the fertility of the soil. Determining the level of all these chemicals in the soil requires sophisticated equipments, lab facilities and experts to conduct the test. Most of the farmers do not take the efforts of testing the soil fertility due to these hazels.

Thus there is a need for a fertility testing kit which is easy to use, carry and enables the estimation of all the essential chemicals in the soil. Realizing this need the inventor has invented a portable soil test kit which helps the farmers carry out the various tests for soil fertility by themselves rather than relying on testing laboratories which is a waste of both time and money.

OBJECTS OF THE PRESENT INVENTION
1. The primary objective of this invention is to provide a soil test kit which enables qualitative assessment of the following parameters in the soil.

a. pH (Soil Reaction)
b. Organic Carbon
c. Available Nitrogen
d. Available Phosphorus
e. Available Potassium
f. Available Sulphur
g. Calcareousness of Soil
h. Available Zinc of Soil
i. Available Iron
j. Available Boron
2. Another objective of this invention is to provide a portable soil test kit that can be easily carried from one place to another and can be handled without difficulty.
3. One further objective of this invention is to provide a portable soil test kit that is simple and can be used by an ordinary person, uneducated farmer with help of Colour charts provided along with the kit.
4. Another objective of this invention is to provide a soil test kit that can assess the fertility of the soil and thus will enable optimum administration of fertilizers.

STATEMENT OF INVENTION
The disclosed invention describes a portable soil test kit containing all constituents required to facilitate qualitative assessment of soil fertility on the basis of various parameters including

1. pH (Soil Reaction)
2. Organic Carbon
3. Available Nitrogen
4. Available Phosphorus
5. Available Potassium
6. Available Sulphur
7. Calcareousness of Soil
8. Available Zinc
9. Available Iron
10. Available Boron

BRIEF DESCRIPTION OF THE DRAWINGS
Fig 1 : pH Colour Chart
Fig 2 : Organic Carbon Colour Chart and Available Nitrogen Colour Chart
Fig 3 : Available Phosphorus colour chart and Available Potassium chart
Fig 4 : Available Sulphur and Available Zinc colour chart
Fig 5 : Available Iron Colour Chart and Available Boron Colour Chart

DETAILED DESCRIPTION OF THE INVENTION
The disclosed invention relates to a portable soil test kit that facilitates qualitative assessment of soil fertility on the basis of various parameters including
1. pH (Soil Reaction)
2. Organic Carbon
3. Available Nitrogen
4. Available Phosphorus
5. Available Potassium
6. Available Sulphur
7. Calcareousness of Soil
8. Available Zinc
9. Available Iron
10. Available Boron

CONTENTS OF THE KIT
The portable soil kit disclosed in this application contains all constituents required to perform the above mentioned tests. It is accommodated in a single kit and is hence easy to carry.
The portable Soil test Kit comprises of the following ingredients,
1. Reagent bottles comprising of the following [101]
a. pH Reagent I, b. pH Reagent II, c. Organic Carbon Reagent I, d. Organic Carbon Reagent II, e. Nitrogen reagent I , f Nitrogen reagent II, g. Phosphorus Reagent I, h. Phosphorus Reagent II, i. Phosphorus Reagent III , j. Phosphorus Reagent IV, k. Potassium Reagent I, 1. Potassium Reagent II, m. Sulphur Reagent I , n. Sulphur Reagent II , o. 3N Hydrochloric Acid p. Zinc Reagent I q. Zinc Reagent II r. Zinc Reagent III s. Iron Reagent I t. Iron Reagent II u. Iron Reagent III V. Iron Reagent IV w. Boron Reagent I X. Boron Reagent II y. Boron Reagent III z. Boron Reagent IV
2. Test tubes (6nos) [102]
3. Test tube stand [103]
4. Measuring cylinders of varied capacity (2nos) [104]
5. Filter paper [105]
6. Glass rod [106]
7. Stirrer [107]
8. Spatulas of varied measures ( 3nos) [108]
9. Beaker [109]
10. Cleaning Brush [110]
11. Rubber corks [111]
12. Wash Bottles [112]
13. Dropper [113]
14. Mixing bottle [114]
15. Activated Charcoal Powder [115]
16. Calcium Carbonate Powder [116]
17. User Manual [117]
18. Colour Chart [118]
19. Distilled Water [119]
20. Test Tubes (Cone Shaped) [120] For Zinc analysis.
21. Watch Glass [121]
22. Hand glosses pain [122]
23. Funnels (2Nos) [123]
Moreover the kit can be easily administered by the user and doesn't need field experts to conduct the tests. Also, the kit does not demand the use of AC or DC Power supply making its use very simple.

Given below are the details required to perform the tests mentioned in the kit.

1. DETERMINATION OF SOIL REACTION (pH)

Preparation of Reagents: Estimation of pH (Soil Reaction) in soil consists of two reagents. The method of preparation of these reagents is as follows. Apart from these two reagents pH estimation requires activated charcoal for decolourization of soil extract to obtain a colourless filtered soil solution.

i. pH Reagent I (0.01 N Calcium Chloride solution) : It can be prepared by Dissolving 1.109 g of dry reagent grade of Calcium chloride in one litre of distilled water.

ii. pH Reagent II: It contains Universal Indicator solution with a pH range of 4.0 to 11.0. It should contain tints of colourless buffers containing 2% indicator. It is commercially available as pure Chemical Universal Indicator solution.

iii. Activated Charcoal: Activated Charcoal is a decolourizing powder, which is commercially pure chemical available. It should be free from phosphorus. A 4% aqueous suspension of activated charcoal should have a pH of 5 to 7.0

Method of testing: Take 5 gm of soil using tea spoon in to a beaker and add a pinch of charcoal. Add 12.5 ml of pH reagent I and shake for 10 minutes using glass rod and filter. To the clear filtrate add 2 drops of pH reagent II and mix the liquid of the test tube. Wait for few seconds for colour development. Match the developed colour with the pH colour chart.

Observation Chart (pH colour chart):

pH
COLOUR

4.0
Red

5.0
Orange

6.0
Yellow

8.0
Dark Green

9.0
Violet

10.0
Dark Violet

II. DETERMINATION OF ORGANIC CARBON

Preparation of Reagents: Estimation of Organic carbon in soil consists of two reagents. The method of preparation of these reagents is as follows.

Organic Carbon Reagent I (1.0 N potassium dichromate): It is prepared by Dissolving 49.04 g of AR grade Potassium Dichromate in one litre of distilled water

Organic Carbon Reagent II: To Concentrated sulphuric acid (H2S04) having a molecular weight of 98.08 g and specific gravity of 1.84; 1.25 g of silver sulphate per 100 ml (to avoid chloride interference) is added. It can be prepared by dissolving 12.5 g of silver sulphate (AgS04) in one litre of concentrated sulphuric acid and stored in amber coloured glass container.
Method of testing: Take 1 gm soil using small spatula in a test tube and add 2 ml of O.C. reagent I using dropper followed by 2 ml of O.C. reagent II. Mix the contents of the test tube and keep aside for 15 min. Match the colour developed with the colour chart.

Observation Chart (Organic Carbon Colour Chart)

RANGE
COLOUR

Low
Yellow

Medium
Dark Yellowish Orange

High
Olive green to Black

III. DETERMINATION OF AVAILABLE NITROGEN

Preparation of Reagents: Estimation of available nitrogen in soil consists of two reagents The method of preparation of these reagents are as follows. Apart from these two reagents available nitrogen estimation requires activated charcoal for decolourization soil extract to obtain a colourless filtered soil solution.

Nitrogen Reagent I (O.OIN Calcium Chloride solution) : It is prepared by dissolving 1.499g of dry reagent grade of Calcium chloride in one litre of distilled water.

Nitrogen Reagent II : Magnesium Oxide (MgO) powder is mixed with Phenolphthalein powder and 10 ml of 5% Phenolphthalein indicator solution. It is prepared by thoroughly mixing 500 g of Magnesium Oxide powder with 100 g of Phenolphthalein powder to which a 5% Phenolphthalein solution is evenly sprayed and whole of this powder mixed thoroughly and stored in scintillation vials. This 5% Phenolphthalein indicator solution is prepared by dissolving 5 g of Phenolphthalein powder in 100 ml of Methanol (CH3 OH).
Activated Charcoal: Activated Charcoal is a decolourizing powder, which is commercially available. It should be free from phosphorus. A 4% aqueous suspension of activated charcoal should have a pH of 5 to 7.0

Method of testing: Take 2 g soil using big spatula in to soil shaking bottle and add 10ml of Nitrogen reagent I using measuring cylinder followed by a pinch of charcoal. Close the bottle with inner and outer lids and shake the contents of the bottle for 10 min and filter. To the clear filtrate add a pinch of Nitrogen reagent II (powder) and shake the contents of the test tube and keep aside for 15 min. Match the developed colour with the Nitrogen colour chart.

Observation Chart (Available Nitrogen Colour Chart)

RANGE
COLOUR

Low
Very light Pink

Medium
Light Pink

H-Medium Dark Pink

M-High Very Dark Pink

High
Reddish Pink

IV. DETERMINATION OF AVAILABLE PHOSPHORUS
Preparation of Reagents: The estimation of available phosphorus in soil consists of the following four reagents and the method of preparation of each reagent is mentioned below. Apart from these reagents activated charcoal is required is also required for decolourization.

Phosphorus Reagent 1: It is the extracting reagent for phosphorus. It is 0.5 M sodium bicarbonate (NaHC03 Molecular weight 84.01 g) (pH 8.5). It is prepared by dissolving 42.0 g of NaHC03 (laboratory reagent) in distilled water to give one litre of the solution. The pH is adjusted to 8.5 with small quantities of 10 per cent NaOH.

Activated Charcoal: Activated Charcoal is a decolourizing powder, which is commercially available. It should be free from phosphorus. A4% aqueous suspension of activated charcoal should have a pH of 5 to 7.0.

Note: The activated carbon (even if marked phosphorus- free) is likely, to contain traces of P which have to be removed by repeated washings should test free of phosphorus when extracted with 0.5 M Sodium hydrogen carbonate extracting reagent. The sodium bicarbonate should also be free from any, phosphate contamination.

Phosphorus Reagent II (5N Sulphuric acid): It is prepared by dissolving 141 ml of concentrated sulphuric acid in one litre of distilled water.

Phosphorus Reagent III: It is a mixer of ammonium molybdate, antimony potassium tartarate and sulphuric acid. It is prepared by dissolving 12.0 g of ammonium molybdate (AR) in 250 ml of distilled water and 0.291 g of antimony potassium tartarate in 100 ml distilled water separately. Add these two solutions to 1000 ml of approx. 5 N H2S04 (141 ml conc. H2S04 in one litre), mix them thoroughly and makeup to two liters with distilled water.

Phosphorus Reagent IV: It is L- Ascorbic acid (C6H806) having a molecular weight of 176.13 g. It is commercially available in chemically pure form either as crystalline form or powder. This L-Ascorbic acid powder is filled and stored in dry scintillation vials and shall be used in very little quantity as a reducing agent for each sample estimation of phosphorus.

Method of testing: Take 2 g of soil using big spatula in to soil shaking bottle. Add a pinch of charcoal and add 20 ml Phosphorus reagent I using measuring cylinder. Close the bottle with inner and outer lids and shake the contents of the bottle for 10 minutes and filter in to a test tube using filter paper. To a 5 ml of clear filtrate add 6-8 drops of Phosphorus reagent II and shake well. Add 4 ml of Phosphorus reagent III using measuring cylinder followed by a pinch of Phosphorus reagent IV (powder) and mix well. Match the developed colour with the phosphorus colour chart.

Observation chart (Available phosphorus colour chart)

Range
Colour

Low
Light Sky Blue

Low
Medium Sky Blue

Medium
Dark Sky blue

High
Medium Navy Blue

High
Very Dark Navy Blue

V. DETERMINATION OF AVAILABLE POTASSIUM

Preparation of Reagents: Estimation of available potassium in soil consists of two reagents. The method of preparation of these reagents is as follows.

Potassium Reagent I: (neutral normal Ammonium Acetate, CH3COO.NH4)
This Neutral normal ammonium acetate is prepared by dissolving 154 g of ammonium acetate in 500 ml distilled water and makeup to two litre. Adjust the pH of this solution to 7.0 with acetic acid or ammonia solution.

Potassium Reagent II (0.05N Silver Nitrate): It is 0.05N Silver Nitrate (AgN03 Molecular weight 169.87 g) solution, It .is prepared by dissolving 8.494 g Silver Nitrate (AgN03) in distilled water and make up the volume up to one litre.

Method of testing: Take 2 g of soil using big spatula in to shaking bottle and add 10 ml of potassium reagent I using measuring cylinder. Close the bottle with inner and outer lids and shake for 5 min. filter the contents in to a test tube. To a clear filtrate of 5ml add 3-4 drops of potassium reagent II and shake well. Match the white turbidity so formed with the Potassium colour chart.

Observation Chart (Available Potassium colour chart):

RANGE
COLOUR

Low
Transparent colourless solution

Medium
Translucent Solution

High
Opaque solution with complete milky white turbidity

VI. DETERMINATION OF AVAILABLE SULPHUR
Preparation of Reagents: Estimation of available sulphur in soil consists of two reagents. The method of preparation of these reagents is as follows.

Sulphur Reagent I (0.15% Calcium Chloride dehydrate) : It is prepared by dissolving 1.5 g of Calcium Chloride dihydrate (CaCI2.2H20) in about 700 ML of distilled water and make up to one litre with distilled water.

Sulphur Reagent II (0.25% Barium Chloride) : It is prepared by dissolving 2.5 g of Barium Chloride (BaCI2.2H20) in about 700 ML of distilled water and make up to one litre with distilled water

Method of testing: Take 2 g of soil using big spatula in a test tube and add 10ml of Sulphur reagent I using measuring cylinder. Close the test tube with rubber cork and shake for 5 minuets. Filter the contents in to another test tube. To a clear filtrate of 5 ml add 4-5 drops of Sulphur reagent II and mix well. Match the white turbidity so formed with the Sulphur colour chart.

Observation Chart (Available Sulphur colour chart):

RANGE
COLOUR

Low
Transparent colourless solution

Medium
Translucent Solution

High
Opaque solution with complete milky white turbidity

VII. DETERMINATION OF CALCAREOUSNESS OF A SOIL
Preparation of Reagents: Qualitative estimation of calcareousness of a soil consists of one reagent. The method of preparation of this reagent is as follows.

Reagent I (3N Hydrochloric acid, Specific Gravity-1.18) : It is prepared by dissolving 250 ml of concentrated Hydrochloric acid to about 700 ml of distilled water and make up to one litre with distilled water.

Method of testing: A qualitative test for free calcium carbonate is made by observing the intensity of effervescence when a suitable reagent is added to the soil. Take 5 g of soil using tea spoon on to a plastic paper and add 3-4 drops of Calcium reagent provided in a dropper bottle or watch glass on this soil and observe any effervescence comes out of the soil.
Observation chart: The amount of calcium carbonate present in the soil can be broadly categorized on the basis of the amount of effervescence produced.

AMOUNT OF EFFERVESCENCE
RANGE

No effervescence Nil or Traces

Low effervescence
Low

Moderate effervescence
Medium

Severe effervescence
High

Very severe effervescence
Very High

VIII. DETERMINATION OF AVAILABLE ZINC IN SOIL

Estimation of available Zinc in soil consists of three reagents. The method of preparation of these reagents is as follows.

Zinc Reagent I : It is prepared by dissolving 1.67 ml of concentrated Hydrochloric acid (HCI 12N) in 1 litre of double distilled water.

Zinc Reagent II : It is commercially available as ammonium sulphide solution extra pure. It can be directly used and each sample require about 1 ml of ammonium sulphide solution.

Zinc Reagent III : It is Ammonium Purpurate (Muroxide indicator powder). It is commercially available in the market. A pinch of ammonium purpurate (Muroxide indicator powder) is required for analysis of each sample.

Available Zinc colour chart

RANGE
COLOUR

Below critical limit or deficient range <0.70 PPM
colourless solution

Above critical limit or sufficient level
Light pink colour >0.70 PPM

IX. DETERMINATION OF AVAILABLE IRON IN SOIL

Estimation of available iron in soil consists of four reagents. The methods of preparation of these reagents are as follows:

Iron Reagent I : It is Neutral normal ammonium acetate (CH3 COO NH4 Molecular weight 77.0 g). This Neutral normal ammonium acetate is prepared by dissolving 154 g of ammonium acetate in 500 ml distilled water and make up to two liters. Adjust the pH of this solution to 7.0 with acetic acid or ammonia solution.

Iron Reagent II : It is Hydroxylamine hydrochloride (NH2OH.HCI), 10%: This Hydroxyl amine hydrochloride 10% is prepared by dissolving 10 g of Hydroxylamine hydrochloride in 90ml of distilled water.

Iron Reagent III : It is 1-10 ortho-Phenanthroline 0.30% reagent: It is prepared by dissolving 0.30 g of 1-10 Ortho Phenanthroline monohydrate reagent powder in 60 ml of distilled water by heating the mixture of 80 C. Cool the solution, and add water to make a volume of 100 ml.

Iron Reagent IV: It is 6N Hydrochloric acid (HCI 6.0 N). It is prepared by dissolving 50 ml of concentrated Hydrochloric acid (12N) in 100 ml of distilled water.
Available Iron colour chart

RANGE
COLOUR

Below critical limit or deficient level <5.0 PPM.
Very light red in colour or colourless solution

Above critical limit Sufficient level Ranging from 5.0 to 20.0 PPM.
Light red in colour

20.0 PPM
Red in colour

X. DETERMINATION OF AVAILABLE BORON IN SOIL
Estimation of available Boron in soil consists in four reagents. The methods of preparation of these reagents are as follows:

Boron Reagent I : It is distilled water stored in a clean plastic container.

Boron Reagent II : It is a buffer solution made of ammonium acetate (NH4OAC) ethylene diamine tetra acetic acid di-sodium salt (EDTA disodium) and glacial acetic acid mixture: It can be prepared by dissolving 250 g of ammonium acetate (NH4OAC) and 15 g of ethylene diamine tetra acetic acid disodiuim salt (EDTA disodium) in 400 ml of distilled water. Slowly and add 125 ml of glacial acetic acid, and mix well and stored in a clean plastic container.

Boron Reagent III : It is Azomethine - H reagent: It is Azomethine - H Monosodium salt, monohydrate C17H12N Nao8S2H20. It is prepared by dissolving 0.450 g of azomethine - H (Pierce chemical co. Rockford III) in 100 ml of distilled water and stored in a clean plastic container.

Boron Reagent IV : It is L-Ascorbic acid (CeHgOe) having a molecular weight of 176.13 g. It is commercially available in chemically pure form either as crystalline form or powder. This L-Ascorbic acid powder is filled and stored in dry scintillation vials and shall be used in very little quantity as a reducing agent for each sample estimation of Boron.
Available Boron colour chart

RANGE
COLOUR

Below critical limit or deficient level <0.50 PPM.
Very light yellow in colour or colorless solution

Above critical limit Sufficient level Ranging from 0.50 to 2.0 PPM.
Yellow color solution 2.00 PPM. Dark yellow in colour

Interpretation of the soil test values and fertilizer recommendation: The interpretation of the soil test values for the above nutrients depending upon their colour shades Low, Medium or High is judged and the fertilizer recommendations can be seen in the Tables 1 and 2 in terms of nutrients and fertilizers and may be recommended in each case study.

FERTILIZER RECOMMENDATION IN KG/ACRE

Rainfed/Irrigated Kharif/ Rabi Sr. no Crops N Phosphorus Potassium Organic Manure t/ha Low Medium High Low Medium High

1 Paddy (irrigated) 32-48 31 24 17 21 16 11 2/1.2

2 Sorghum and millets 12-20 16 12 8 2/1.2

3 Castor (rainfed) 12-20 12 8 4 2/1.2

4 Chilli (irrigated) 45-65 28 24 18 25 20 15 2/1.2

5 Chilli (rainfed) 18-30 14 12 9 15 12 8

6 Cotton (irrigated) 42-54 25 20 15 26 20 15 2/1.2

7 Cotton (rainfed) 14-22 15 12 9

8 Pulses 6-10 25 20 15 " 2/1.2

9 Groundnuts 8-12 21 16 11 26 20 14 2/1.2

10 Sunflower (irrigated) 24-35 40 36 30 16 12 14 2/1.2

11 Sunflower (rainfed) 12-31 30 24 18 16 12 8

12 Maize (irrigated) 48 36 24 18 15 12 9 2/1.2

RECOMMENDATION OF DIFFERENT KINDS OF FERTILIZERS AND COMPLEXES (kg /acre)

Crops Urea Super Phosphate Muriate of Potash Urea DAP Potash Urea 17:17:17

Potash

Pulses 13-22 156 (L) - - 54(L) - - - -

125(M) - - 44(M) - - - - 94 (H) - - 33(H) - - - -

Groundnut 18-26 132(L) 43(L) - 45(L) 43(L) - 123(L) 8(L)

Loo (M) 34(M) 8(M) 35(M) 34(M) - 94(M) 6(M)

70(H) 24(H) - 24(H) 24(H) - 66(H) 5(H)

Sunflower 52-76 250(L) 27(L) 27- 87(L) 27(L) - - -

(irrigated) 225(M) 20(M) 42 78(M) 20(M) - - -

188(H) 13(H) 65(H) 13(H) - - -

Sunflower 46-67 188(L) 27(L) 31- 65(L) 27(L) - - -

(rainfed) 150(M) 20(M) 42 52(M) 20(M) - - -

113(H) 13(H) 39(H) 13(H) - - -

Maize 90 225(L) 25(L) 76- 78(L) 25(L) - - -

150(M) 10(M) 83 50(M) 20(M) - - -

112(H) 15(H) 38(H) 15(H) - - -

L-Low, M- Medium, H- High

SCOPE OF THE INVENTION

1. The primary advantage of this invention is that it can be used for testing

a. pH (Soil Reaction)
b. Organic Carbon
c. Available Nitrogen
d. Available Phosphorus
e. Available Potassium
f. Available Sulphur
g. Calcareousness of Soil
h. Available Zinc
i. Available Iron
j. Available Boron

2. Another advantage of this invention is that it is easy to handle and is portable thus can be carried easily from one place to another.

3. A further advantage of this invention is that the soil kit is very simple to use and thus can be efficiently used by an ordinary person. Thus a skilled hand is not required for the administration of the kit.

4. Another advantage of this invention is that it can be used to assess the fertility of the soil.

5. One more advantage of this invention is that since it gives an assessment of the fertility of the soil, it enables one to judge the amount of fertilizers required for the soil, thus will help in avoiding wastage of fertilizers and provide balanced nutrition to the crops.

6. Another advantage is that since the kit helps in ensuring that the right amount of fertilizers are provided to the soil, it will certainly help in enhancing the quality and quantity of the crop produced.

7. A further advantage of this invention is that it is easy to use as it does not contain any mechanical or electrical device and does not need electricity either AC or DC since the results are purely based on the colour shade development.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternate embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. It is therefore contemplated that such modifications can be made without departing from the spirit or scope of the present invention as defined.

Senthil Kumar B
Agent for the applicant
IN/PA-1549

,CLAIMS:CLAIMS
I Claim:

1. A method for qualitative assessment of soil fertility, comprising the steps of :

a) providing a portable soil testing kit for detection of various parameters such as pH (soil Reaction), Organic Carbon, Available Nitrogen, Available Phosphorus, Available Potassium, Available Sulphur, Calcareousness of Soil, Available Zinc, Available Iron, Available Boron;

b) taking a sample quantity of soil to be tested and introducing a few drops of relevant reagent / reagents

c) shaking the test tube for a few minutes;

d) observing the colour change in the liquid;

e) comparing the colour of liquid in test tube with that of the colour chart provided; and

f) recording the value of the parameter.

2. A portable soil testing kit for qualitative assessment of soil fertility, such kit comprising a set of instruments for performing tests, such instruments generally including:

a) Reagent bottles containing;

i) pH Reagent I comprising 0.01N Calcium Chloride Solution, for estimating the soil pH,

ii) pH Reagent II comprising pure Chemical Universal Indicator Solution for estimating the soil pH,

iii) Organic Carbon Reagent I comprising 1N Potassium Dichromate for testing the organic carbon in soil

iv) Organic Carbon Reagent II comprising concentrated sulphuric acid having a molecular weight of 98.0g and specific gravity of 1.84 and 1.25g of silver sulphate per litre of sulphuric acid for testing the organic carbon in soil,
v) Nitrogen Reagent I, comprising 0.01N Calcium Chloride Solution for estimation of available nitrogen in soil,

vi) Nitrogen Reagent II comprising 500g of magnesium oxide, 100g of phenolphthalein and 10 ml of 5% phenolphthalein indicator for estimation of available nitrogen in soil,

vii) Phosphorus Reagent I comprising 0.5M Sodium bicarbonate dissolved in distilled water with its pH adjusted to 8.5 for estimation of available phosphorus in soil

viii) Phosphorus Reagent II comprising 5N Sulphuric Acid, for estimation of available phosphorus in soil

ix) Phosphorus reagent III comprising a mixture of ammonium molybdate, antimony potassium tartarate and 5N sulphuric acid, for estimation of available phosphorus in soil

x) Phosphorus Reagent IV, comprising L-Ascorbic acid, for estimation of available phosphorus in soil

xi) Potassium Reagent I comprising neutral normal Ammonium acetate, for estimation of available potassium in soil,

xii) Potassium Reagent II, comprising 0.05N Silver Nitrate solution for estimation of available potassium in soil,

xiii) Sulphur Reagent I, comprising 0.15% Calcium Chloride dehydrate in one litre of distilled water, for estimation of available sulphur in soil,

xiv) Sulphur Reagent II, comprising 0.25% Barium Chloride in one litre of distilled water, for estimation of available sulphur in soil,

xv) 3N Hydrochloric acid having a specific gravity of 1.18, which is the reagent for qualitative estimation of calcareousness of the soil
xvi) Zinc Reagent I, comprising 1.67 ml of concentrated Hydrochloric acid in 1 litre of distilled water, for estimation of available zinc in the soil

xvii) Zinc Reagent II, comprising commercially available ammonium sulphide solution, for estimation of available zinc in the soil
xviii) Zinc Reagent III, comprising Ammonium Purpurate, for estimation of available zinc in the soil

xix) Iron Reagent I, comprising 154g of ammonium acetate dissolved in 2 litres of distilled water such that the pH of the solution is adjusted to 7, for estimation of available Iron in the soil

xx) Iron Reagent II, comprising 10% of Hydroxylamine hydrochloride, for estimation of available Iron in the soil

xxi) Iron Reagent III, comprising 0.3% of 1-10 ortho Phenanthroline solution, for estimation of available Iron in the soil

xxii) Iron Reagent IV, comprising 6N Hydrochloric acid, for estimation of available Iron in the soil

xxiii) Boron Reagent I, comprising distilled water, for estimation of available Boron in the soil,

xxiv) Boron Reagent II, comprising buffer solution made up of 250g ammonium acetate, 15g EDTA di sodium in 400 ml water and 125ml Glacial acetic acid, for estimation of available Boron in the soil,

xxv) Boron Reagent III, comprising Azomethine-H Monosodium salt dissolved in 100 ml distilled water, for estimation of available Boron in the soil,

xxvi) Boron Reagent IV comprising L-Ascorbic Acid, for estimation of available Boron in the soil,

b) relevant standard colour charts for comparison of test results based on the parameter to be checked;

c) preferably 6 number of Test tubes, Test tube stand, preferably 2 measuring cylinders of varied capacity, filter paper, glass rod, stirrer, preferably 3 numbers of spatulas of varied measures, beaker, cleaning brush, rubber corks, wash bottles, dropper, mixing bottle, activated charcoal powder, calcium carbonate powder, user manual, relevant colour charts, distilled water, Cone shaped test tubes for Zinc analysis, watch glass, hand gloves, preferably 2 funnels;

3. The invention as claimed in claim 2, wherein the portable soil testing kit can be used on site to check the suitability and quality of soil.

4. The invention as claimed in claim 2, wherein the portable soil testing kit provides for an inexpensive method of testing the soil quality by checking for many important parameters and prevents the need to send the soil sample to a laboratory to verify the quality.

5. The invention as claimed in claim 2, wherein the portable soil testing kit does not require electricity as it is based on studying the colour shade developed, thereby ensuring immediate results to check the suitability of soil for cultivation purposes at the farm level.

6. The invention as claimed in claim 2, wherein the portable soil testing kit can be also be used by any ordinary person including a farmer, who is not skilled in the art to check the soil quality with the help of colour charts provided in the kit.

7. The invention as claimed in claim 4, wherein the portable soil testing kit can assess the fertility of the soil and thus will enable optimum administration of fertilizers and result in balanced nutrition to the crops.

Senthil Kumar B
Agent for the applicant
IN/PA-1549