GB2411896A

GB2411896A - Plant feed solutions comprising nutritive metals

Info

Publication number: GB2411896A
Application number: GB0405446A
Authority: GB
Inventors: Yoram Tsivion
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-03-11
Filing date: 2004-03-11
Publication date: 2005-09-14
Also published as: GB0405446D0; WO2005086579A3; WO2005086579A2

Abstract

A plant feed composition contains water, nutritive metal ions and at least one organic compound having at least one anionic functional group. The nutritive metals include iron, copper, manganese, zinc, calcium and potassium. Preferably the organic compound is a chelating agent such as citric acid, lactic acid, malic acid or EDTA. Alternatively, the organic compound may be a maleic / acrylic acid copolymer. The solution is prepared by reacting at least one water insoluble metal source with the a least one organic compound. The composition may be devoid of inorganic anions. Stock solution can be made in accordance with the invention, into which additional nutrients or beneficial factors, such as pesticides and hormones, can be added.

Description

241 1 896

NUTRITIVE COMPOSITIONS CONTAINING METALS

FIELD OF THE INVENTION

The present invention relates generally to solutions of metal ions used for feeding purposes. A more specific use of such solutions is in the fertilization of agricultural crops.

to BACKGROUND OF THE INVENTION

Fertilising crops is perfommed by applying nutritive elements or compounds to the soil or to the foliage to be subsequently taken up by the plants for further consumption by the various organs. Iron, calcium, manganese, zinc, copper and molybdenum are nutritive metals of which iron, zinc, copper, manganese and to lesser extent calcium ions tend to form coordinative bonds with certain active groups of organic materials. This is sometimes referred to as _. . _ _ _. . complexing of the metals with ligands. Such complexation is used as practical means for keeping metal ions in a non precipitated form which they would otherwise tend to fall into if no specific measures are taken. When a molecule forms more than one coordinative bond with a metal ion, a chelate is formed. A large variety of commercial products in the market exist which use chelated metal ions for applying such metals to crops for supplying the chelated metals to the crop.

In US patent 4,265,653 sources for the preparation of a citric acid metal ion combination is disclosed. Citric acid is a naturally occurring chelating agent (ligand) containing anionic (acidic) groups, but the preferable source for the ferrous ion in this publication is either iron sulfate or ferrous chloride, and for manganous ion is any of manganese nitrate, manganese sulfate, manganese JO chloride or manganous oxide.

Preparing the nutritive compositions of the above metals solutions is achieved usually using soluble metal salts such as sulfates, nitrates, chlorides.

Insoluble compounds of the nutritive metal are used, for example US patent 4,265,653 mentioned above discloses the use manganese oxide as component of the nutritive preparation. In WO 9716395A1 publication, two non soluble species of nutritive metals are made to react, namely zinc metal and manganese dioxide are made to interact. The interaction is made in a solution of sulfuric acid, which introduces sulfate to the preparation. However, especially nitrates and chlorides are considered as potentially phytotoxic, or having a negative effect on JO the crop, respectively.

In a co - pending GB patent application 0321771.8 by the same inventor, the solubilising of copper is disclosed, in which polyanion is used as a solubilising agent.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

In accordance with the present invention, preparations for applying metal nutrients to crops are made using sources for metal ions which are water insoluble or sparingly water soluble forms of the respective metal. Such fomms are typically metals in the metal form, carbonate of metal ions, oxides of metal ions, hydroxides or silicates. The metal ion source is converted to a more available form by a method as will be described below.

Oxides of metals, typically oxides of zinc, calcium, copper and manganese are available in the market to provide the metal ion required.

to Carbonates of metals such as manganese carbonate, calcium carbonate are available metal in the market. Metals in zero oxidation state are also available in the market, typically iron, copper, manganese and zinc.

Converting the metal ion sources In general, suspensions of one or more species of the desired metal sources are prepared by reacting in a solution or a suspension of one acidic reactant species or a plurality of such reactants. Stirring and optionally heating for a long enough period of time to turn the entire amount of insoluble metal source to a soluble metal form. Heating the suspension of the metal source expedites the conversion process. Typically, one or more organic acid species are used, to acidify the suspension, containing at least one anionic functional group respectively.

Further are described exemplary conversion schemes, exemplifying the metal sources reacted upon and reactants.

Example 1: 1 gram of iron powder was stirred with 10 mis of poly(acrylic acid) co polymerized with maleic acid (50% in water of poly(acrylic acidco-maleic acid) by Sigma Aldrich. After a few days a clear solution formed.

Example 2: 3 gram of iron powder were stirred in 30 mis water and 10 grams malic acid. After a few days all the iron powder dissolved and a whitish paste formed. This white precipitate could be dissolved by raising the pH gently with bicarbonate and increasing the amount of water.

Example 3: 2 grams of manganese oxide were mixed and stirred with 5.6 grams of citric acid and 10 mis water. Without wamming after a few days ail lo the oxide dissolved forming a white - gray paste. This paste could be dissolved by raising the pH gently with bicarbonate and increasing the amount of water.

Example 4: 1.5 grams of calcium oxide were mixed and stirred with 10 mis of poly(acrylic acid) co polymerised with maleic acid (50% in water of poly(acrylic acid-co-maleic acid) by Sigma Aldrich and 5 mis water. After a few Is days of stirring a stable solution formed.

Example 5: To the solution of example 4, 0.5 grams of MnO were added and also 1 mi of 85% lactic acid. After a few days of stirring a clear solution formed.

Example 6. To 15 mis of poly(acrylic acid) co polymerised with maleic to acid (50% in water of poly(acrylic acid-co-maleic acid) by Sigma Aldrich mixed with 5 mis (millilitres) of water were added 0.7 grams of CuO. Constant stirring and heating to about 80 C dissolved all the oxide and a green solution formed.

To this solution 1.0 grams of CaO were introduced under constant stirring. After a few hours the CaO dissolved as well.

Example 7. To 20 mis of water were added 4 grams of ethylene diamine tetra acetic acid EDTA (Sigma Aldrich) and 0.5 grams of metallic manganese. After a few hours of stirring and heating to about 60 C, the metal dissolved completely and a white precipitate formed. Adding 1.5 grams KOH while stirring cleared the solution, forming a reddish brown transparent solution.

To this, 10 mis of the solution of example 6 were added, forming a green solution.

Example 8. Two grams of manganous carbonate were dispersed in 11 mis of water to which were added 3.2 grams of citric acid and 1 ml of 85 % lactic to acid. The suspension was stirred for several days until a whitish paste formed, eventually completely replacing the brown carbonate powder suspension. Three grams of KOH were added while stirring, turning the pase into a clear, transparent brownish liquid.

Example 9. To 10 grams of poly acrylic acid (35% in water by Sigma Aldrich) were added 1.1 gram ZnO. The mixture was stirred and temperature raised to about 90 C. The reaction was very slow and water was added to keep an overall volume of about 15 ml mixture. After a few days, 1.5 mis of lactic acid was added to finish the conversion process, i.e. solubilise the entire oxide left.

Some benefits of compositions of the invention Metal ion solutions or suspensions prepared in accordance with the invention provide potentially a wealth of combinations varying in qualitative and quantities aspects. Thus, the presence of sulfates, nitrates, chlorides, can be eliminated altogether or largely, while the neutralizing charges for the metal ions (cations) are provided by organic anions of mono-anions, poly-anions or anionic polymers. In accordance with the present invention it is possible to prepare virtually any combination of nutritive metals in one suspension or solution.

Using a polyanion as an acidifying agent for the conversion process, promotes a reduction in the amount of dissolved molecules in the spraying solutions as compared to the use of soluble metal species as metal source.

Using as a nutritive preparation a combination including less molecules altogether potentially decreasing the osmotic effect of the spraying solution. The use of polymers as charge neutralizers decreases potentially the number of molecules in a nutritive preparation even further.

to Malic acid, citric acid, lactic acid and EDTA are all chelating agents being able to bind the metallic ion specified above. In accordance with the present invention, chelated metal solutions can be prepared without using a metal salt source, thereby diversifying the combinations available. Some of the anionic compounds useful in a conversion process of the invention are natural products (e.g. malic acid, lactic acid) which may be appealing to customers insisting on the use of natural products in the agricultural practice implemented for raising their food.

Iron oxides are rather difficult to extract the metal ion from. In the method of the present invention, extracting the metal ion from iron powder is very so convenient and may be quite fast if temperature is applied. This way, the inclusion of chloride, nitrate, sulfate which are the most abundant component of commercially available iron salts can be avoided altogether.

In another embodiment of the invention, stock preparations are used for preparing nutritive products, in which metal solutions or dispersions are prepared using the conversion process described above generally and in the examples. To such stock preparations additional beneficial factors may be added, such as nutrients, for example urea, phosphoric acid, phosphoric acid, ammonia, nitrate. Other factors are non nutrients, such as pesticides and hormones.

To raise the pH after the conversion process has terminated, potassium hydroxide is typically used as an agent for providing hydroxyl ions.

Ammonia, which is also nutritive, can be used. Sodium may be less desirable in this respect because it is usually not considered as a nutritive element, although lo for some crops it may be nutritive. The hydroxide, is a component of water and is produced when the ammonia, potassium hydroxide and CaO is introduced to aqueous systems.

Claims

1. A nutritive composition comprising in total: at least one species of nutritive metal ion; at least one organic compound species having at least an anionic functional group for neutralizing the charges of said at least one species of nutritive ions, and To water and water components.

2. A nutritive composition as in claim 1, containing at least one organic chelating agent.

3. A nutritive composition as in claim 1, wherein nitrate, chloride and sulphate are not present.

4. A nutritive composition as in claim 1 and wherein said at least one organic compound species is a natural product.

5. A nutritive composition as in claim 1 and wherein said at least one organic compound species is an ionic polymer.

6. A nutritive composition as in claim 1 containing iron ions.

7. A nutritive composition as in claim 1 containing two metal ion species.

8. A nutritive composition as in claim 1 containing three metal ion species.

9. A nutritive composition as in claim 7 wherein one metal ion species is potassium ion.

10. A nutritive composition comprising at least one metal ion dissolved in water and water components, wherein any other ions present are anionic functional groups of organic molecules.

11. A method for preparing nutritive compositions comprising reacting at least one water insoluble source of nutritive metal species with at least one organic compound containing at least one anionic functional group, go

12. A method for preparing nutritive composition as in claim 10, comprising reacting two water insoluble source of nutritive metal species.

13. A method for preparing nutritive composition as in claim 10, and wherein one nutritive metal species is calcium.

14. A method for preparing nutritive composition as in claim 10, and wherein one metal species is potassium.

15. A method for preparing nutritive composition as in claim 10, and wherein said composition is a stock preparation.