NZ547819A - Fertiliser compositions for reducing the progress of the production of nitrates in the soil - Google Patents

Abstract

A method of producing a particulate composition suitable to be applied to the soil and/or pasture, said method comprising or including: formulating an aqueous slurry of at least one particulate zeolite after, and/or prior to the inclusion of at least one nitrification inhibitor and after, and/or prior to the inclusion of at least one gum, and drying the slurry to result in an at least substantially dry particulate material with the zeolite carrying the nitrification inhibitor(s), wherein the at least one nitrification inhibitor is not a particulate.

Description

*7 8 19 NEW ZEALAND PATENTS ACT, 1953 Divided out of Application No: 531078 Date: 9 February 2004 COMPLETE SPECIFICATION FERTILIZER COMPOSITIONS We, BALLANCE AGRI-NUTRIENTS LIMITED, a company duly incorporated under the laws of New Zealand of Hewletts Road, Mount Maunganui, New Zealand, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to the treatment of the soil and/or pasture, compositions for application to the soil and/or pasture, procedures for preparing such compositions, compositions thus formed, fertiliser compositions and related uses.

Nitrification is the process of conversion of a relatively immobile form of nitrogen (N) from an ammonium (NH4+) form into the more mobile nitrate (N03") form. During nitrification the NH4+ is believed to be first oxidised to nitrite (N02~) and that this conversion is largely brought about by Nitrosomonas bacteria. Thereafter the N02" in turn, it is believed, is oxidised to N03" by Nitrobacter bacteria.

Nitrates, produced from the nitrification process, is subject to losses by leaching from soils and can potentially contaminate surface and ground water. Nitrates can also undergo denitrification in the absence of oxygen by a taxonomically diverse group of microorganisms to gaseous oxides of N (e.g. N20) and nitrogen gas (N2), which are commonly lost to the atmosphere. These losses of N account for inefficiencies in the use of applied N by plants, whether from N including fertilisers or urine, or both. N20 is one of the greenhouse gases and also has a catalytic effect on the destruction of stratospheric ozone.

An approach previously proposed to increase plant N use efficiency and minimise potential adverse environmental effects by nitrogeneous compounds is the use of nitrification inhibitors. Since NH4+ is less subject to loss from soils, delaying the microbial transformation (nitrification process) of NH4+ to N03" through the use of nitrification inhibitors can result in an increase in potential N availability for plant growth and a decrease in N03" and N20 production.

Nitrification inhibitors are compounds that delay the microbial oxidation of NH4+ to N02" (the first step of the nitrification process) for a certain period by depressing the activity of Nitrosomonas bacteria in soils. The second step of nitrification it is believed normally is not influenced.

An ideal nitrification inhibitor should have the following characteristics: Specificity. It should block the conversion of NH4+ to N03" and be nontoxic to other soil organisms, animals and humans.

Mobility. It should move with N fertilisers or nutrient solution. Persistence. It should stay in soils for an adequate period.

Economy. It should be cheap as it is frequently to be used as an additive to fertilisers.

Examples of compositions that hitherto have been considered for application to soils or pasture include those disclosed by Sumitomo Chemical Co Ltd in its New Zealand Patent Specification No. 161791 where they disclose a nitrophosphate fertiliser containing a nitrification inhibitor in the amount of from 1 to 20% by weight based on total nitrogen content and where the fertiliser contains nitrate nitrogen of from 20 to 80% by weight based on total nitrogen content. Examples of nitrification inhibitors given in New Zealand are as follows: N-2,5-dichlorophenyl succinamic acid 2-chloro-6-trichloromethyl pyridine ("Nitrapyrin") dicyandiamide ("DCD or "DCDIN"") which is HN=C(NH2)-NH-CN zinc ethylene-bis-dithiocarbamate 2,4,6-trichloroaniline pentachlorophenol thio-urea.

Other known nitrification inhibitors include ATS (ammonium thiosulphate) and water soluble DMPP (3,4-dimethypyrazole phosphate). Still other options are discussed in the prior art.

The term "nitrification inhibitor" or its plural refers to any suitable compound or compounds and is inclusive of those discussed above.

It is an object of the present invention to provide advantageous compositions inclusive of nitrification inhibitor(s) capable of agricultural use.

In one aspect the invention is a method of producing a particulate composition suitable to be applied to the soil and/or pasture, said method comprising or including formulating an aqueous slurry of at least one particulate zeolite after, and/or prior to the inclusion of at least one nitrification inhibitor therein, and/or prior to the inclusion of at least one gum, and drying the slurry to result in an at least substantially dry particulate material with the zeolite carrying the nitrification inhibitor(s) wherein the at least one nitrification inhibitor is not a particulate. Intellectual Property Office of N.Z. 27 NOV 2007 Dcrciucni The nitrification inhibitor(s) may be soluble to some extent in the liquid.

Preferred particle size ranges for the solid carrier or zeolite is from 1 to 3 mm (typically 100% passing a 3mm screen and < 1% a 1mm screen).

Chemically preferably the zeolite is 65 to 95% w/w mordenite and 5 to 20% smectite.

The nitrification inhibitor(s) prior to drying is supported in the liquid by a suspension agent (preferably a gum).

Preferably the slurry prior to drying (preferably to a dryness of less than 8 % w/w water/composition) includes as the suspension agent or otherwise a tackifier (e.g. a gum).

Examples of suitable gums for one or both purposes include microbial polysaccharides such as dextran, gellan, rhamsan, guar and xanthan gums; polysaccharide derivatives such as hydroxymethylcellulose, hydroxyethylcellulose, microcrystalline cellulose and modified starches; and synthetic polymers such as polyvinyl alcohols, polyvinyl acetates and cross-linked poly aery lates.

Preferably the composition produced by the process is any of the compositions hereinafter described.

In yet a further aspect the present invention consists in the aforementioned process(es) and the optional additional step of adding a flow enhancing agent such as a particulate agent such as talc to the dried product.

In still a further aspect the present invention consists in the aforementioned process(es) and the additional optional step (irrespective of whether or not a flow enhancing agent has been utilised) of admixing or otherwise associating the zeolite carried nitrification inhibitor(s) with a fertilising agent, compound or composition irrespective of whether or not it includes nitrogen. Preferably however it includes nitrogen and may be, by way of example, urea.

In a further aspect the present invention consists in a composition of any of the preceding kinds in admixture with a fertiliser.

Intellectual Property Office of N.z. 27 NOV 2007 Preferably said fertiliser is a nitrogen containing fertiliser. In other forms it is or can include trace elements or other fertilising elements.

Preferably the nitrification inhibitor is ATS.

Preferably said the composition is formed by any of the methods hereinbefore described and/or hereinafter described with or without reference to any example thereof and/or any of the accompanying drawings.

In still another aspect the invention is the use of any composition, fertiliser or product of the present invention on soil and/or pasture.

As used herein the term "zeolite" includes a zeolite of a kind (see attachment) As used herein the term "slurry" is not restrictive to water carried particle mixtures but preferably includes water in the liquid or has water as the sole liquid.

As used herein "nitrification inhibitor(s)" includes one or more inhibitor and preferably, but not only, one of those previously referred to. Examples include N-2,5-dichlorophenyl succinamic acid, pentachlorophenol, thio-urea, ATS (ammonium thiosulphate), and As used herein the term "and/or" means "and" and "or", or both.

As used herein the term "s" following a noun means the singular and plural forms of that noun.

Nothing herein precludes other agents in addition to the nitrification inhibitor(s) also being carried by the zeolite(s).

A preferred form of the present invention will now be described with reference to the accompanying drawings in which Figure 1 shows a flow diagram of one form of preparative method in accordance with the present invention leading either to a particulate form having a nitrification inhibitor or inhibitors carried by a particulate carrier or carriers or to a resultant mix thereof with a fertiliser, Figure 2 shows a more specific procedure of which the procedure of Figure 1 is generic, and Intellectual Property Office of N.Z. 27 NOV 2007 Figure 3 demonstrates efficacy as explained hereinafter.

In the preferred form of the present invention the zeolite is of a kind that is preferably with a substantially w/w Mordinite presence (preferably at least 20%, more preferably greater than 40% and most preferably at least 50% e.g. 55 to 95%).

Various aspects of the present invention will now be demonstrated by the following examples which are not limiting of the invention.

Example 1 shows one suitable zeolite form.

Example 1 Composition: Clinoptilolite Mordenite Smectite Opal C K Feldspar -65% 25-65% <5% -20% -20% Density Porosity Slurry pH CEC Internal surface area Colour Absorbencies Water Oil 1.2 g.cm 60% .6 80 meq/lOOg 35 m2/g Opaque 55% 45% Example 2 shows a more preferred higher mordenite containing zeolite form.

Example 2 Composition: Mordenite Smectite 65-95% 5-20% Intellectual Property Office of N.Z. 27 NOV 2007 Opal C <5% K Feldspar 5-20% Density Porosity Slurry pH CEC Internal surface area Pore size Colour Absorbencies Water Oil 0.89g.cm 60% to 6 for 20%w/v 120 meq/lOOg 48m2/g 7 Angstroms Off white 55% 45% Examples 3 and 4, which are outside the scope of the present invention show two composition forms where the nitrification inhibitor is DCD alone. Analogous examples can be formed with other nitrification inhibitors disclosed herein or blends of any such inhibitors disclosed herein. The more soluble nitrification inhibitors will be more adsorbed into the zeolite rather than to adhere to the zeolite as is the case with the less soluble nitrification inhibitors.

Example 3 - A PCD/Zeolite composition 250 gram DCD (ground until 100% passing 200jam screen) 250 gram Water Water and DCD were blended until a smooth slurry was formed. To this slurry 5 grams of xanthan gum was added and stirred until fully hydrated (approx 15 min).

Intellectual Property Office of N.z. 27 NOV 2007 The suspension was then added to 500 gram of zeolite (l-3mm) and mixed until the zeolite grains were evenly coated and the mix was the consistency of bread crumbs. 50 grams of talc was then added to form a free flowing, granular DCD product.

Final product contains 23.7% DCD and 0.47% xanthan gum.

The product of Example 3 is a heterogeneous mix of granules typically l-3mm particle size range. This material is relatively free flowing and is stable in blends with fertilisers.

Example 4 - A PCD/Zeolite composition 165 grams of DCD 300 grams of 55% w/w ATS solution DCD and ATS were mixed and blended for 5 minutes with a Silverstone type blender. 4.65 grams of xanthan gum was added and allowed to fully hydrate.

The above mix was added to 470 grams of zeolite (l-3mm) and stirred until bread crumb like granules were formed. The wet granules were dried to yield 800 grams of product.

The product of Example 4 is a heterogeneous mix of granules typically l-3mm particle size range. This material is relatively free flowing and is stable in blends with fertilisers.

These Example's 3 and 4 products are mixable in all proportions with urea which is a product for delivery to enhance the nitrogen use efficacy of the urea. intellectual Property Office of N.Z. 27 NOV 2007 D P O r i w r n Trial Performance The uniform placement of a fertiliser or nitrification inhibitor is most uniform and efficacious if applied as a liquid or suspension.

When applied as a DCD zeolite granule (e.g. a composition of Example 3), we have found the granule application surprisingly gave equal or superior efficacy to such liquid or suspension applications as either measured as nitrate or ammonia reduction or expressed as dry matter production. See Figure 3 in respect of nitrogen losses and Table 1.

This is illustrated from field trial data showing statistically the same efficacy in terms of soil N fractions but a statistically significant advantage in terms of dry matter production.

This may be due to a release characteristic from the zeolite core or an absorption property of the material. In any event, the association with the zeolite in such scenarios of application provide advantages.

Field trials show, almost without exception, at least equality of performance from the particulate (zeolite) application to that of a liquid vehicle application.

The following data presents some results from a range of field trials evaluating the DCD carried in/on zeolite particles when applied dry versus dissolved DCD formulations when applied as a spray, where high nitrogen application rates of order of 600 kg/ha of N have been applied to all treatments.

Pasture measurements were assessed by mowing cuts.

DCD N Care trial 1 Woodlands. The granule composition was as in Example 3 Table 1 Form Total yield (kg/ha) Control 1715 Liquid DCD (15 kg DCD/ha) 3194 Zeolite DCD granule (15 kg DCD/ha) 3957 Lsd 294 Intellectual Property Office of N.z. 27 NOV 2007 R E H F I \/ c n DCD N Care trial 2 Rotorua. The granule composition was as in Example 3 Table 2 Form Total yield (kg/ha) Control 4254 Zeolite DCD granule (30 kg/ha DCD) 5202 Lsd (5%) 493 DCD N Care trial 3 Ruakura. The granule composition was as in Example 3 Table 3 Form Total leaching (kg N/ha) Control (no urine) 11 Urine 210 Urine plus Zeolite DCD granule (12 kg DCD /ha) 145 Lsd Intellectual Property Office of N.Z. 27 NOV 2007 received 1 2 3 4 6 7 8 9 11 12 13 SED Cont sts 2 All with Table 4 is that table identified as Table 1 in our priority specification (the provisional specification of NZ Patent Application No. 531078). This table shows a range of DCD inhibitor rates and formulations including liquid (DCD L) and their impact on pasture production parameters. Urine was applied at 600 kg N/ha.

Table 4 Form Urine 15.12.03 15.01.04 Total Kg/ha Grass Clover Kg/ha Grass Clover Yield (kg/ha) DM % % DM % % Control 0 641 66.1 .1 392 52.0 40.3 1715 Urea 0 1099 63.3 31.1 508 52.5 38.8 2795 Urea + 1771 75.3 .8 503 67.4 22.3 3301 Super U 0 1243 66.8 28.3 384 53.6 39.2 2952 Super U + 2104 72.4 17.4 479 65.2 29.2 3852 Coated N 0 1168 67.2 29.4 394 58.6 .0 2877 Coated N + 1933 80.3 11.2 637 71.6 21.8 3565 DCD (L) 15 + 1827 77.4 18.5 443 73.2 19.7 3194 DCD (L) 30 + 1881 76.2 17.0 611 74.9 19.4 3636 Zeolite 15 + 2104 77.0 18.7 636 74.7 19.9 3957 Zeolite 30 + 2020 75.3 21.1 618 71.8 16.8 3792 Urea 0 988 67.9 27.9 380 54.7 33.9 2356 Urea + 2065 76.2 18.4 662 80.7 .0 3780 *** * *** ** * 182 6.9 .9 124 7.3 .7 294 + - Urine *** ** ** * # *** *** 4s** Urea v Super U NS NS N S NS N S t t Super U v Coated N NS N S N S NS N S N S NS Urea v Coated N NS NS N S NS N S NS NS Urine v Super U v Coated N NS NS NS N S NS NS N S Urea v Coated N & Super U NS NS NS NS NS N S NS Urea v DCD (all) NS NS NS NS NS NS N S Super U v Coated N NS NS NS NS N S N S NS Urea v DCD (Zeolite & Liq DCD) NS NS NS NS N S t N S 30kg/ha v 15 kg/ha NS NS NS NS NS NS N S Zeolite v Liquid DCD N S N S NS NS N S NS * Interaction NS NS N S NS N S NS N S Intellectual Property Office of N.Z. 27 NOV 2007 ■k mm_ ^ r~ i \ i C Pi

Claims (16)

WHAT WE CLAIM IS:

1. A method of producing a particulate composition suitable to be applied to the soil and/or pasture, said method comprising or including formulating an aqueous slurry of at least one particulate zeolite after, and/or prior to the inclusion of at least one nitrification inhibitor and after, and/or prior to the inclusion of at least one gum, and drying the slurry to result in an at least substantially dry particulate material with the zeolite carrying the nitrification inhibitor(s), wherein the at least one nitrification inhibitor is not a particulate.

2. A method of claim 1 wherein the aqueous slurry has water as a sole liquid.

3. A method of claim 1 or 2 wherein the nitrification inhibitor(s) is water soluble.

4. A method of any one of the preceding claims wherein particle size ranges for the particulate carrier or zeolite is from 1 to 3mm (typically 100% passing a 3mm screen and < 1% a 1mm screen).

5. A method of any one of the preceding claims wherein the zeolite is 65 to 95% w/w mordenite and 5 to 20% smectite.

6. A method of any one of the preceding claims wherein the drying is to a dryness of less than 8 % w/w water/composition.

7. A method of any one of the preceding claims wherein the gum(s) is (are) selected from microbial polysaccharides such as dextran, gellan, rhamsan, guar and xanthan gums; polysaccharide derivatives such as hydroxymethylcellulose, hydroxyethylcellulose, microcrystalline cellulose and modified starches; and synthetic polymers such as polyvinyl alcohols, polyvinyl acetates and cross-linked poly aery lates.

8. A method of any one of the preceding claims wherein the formation of said slurry is a stage wise process.

9. A method of any one of the preceding claims wherein the gum(s) is (are) added to water prior to the slurry being formed therewith.

10. A method of any one of the preceding claims wherein the nitrification inhibitor(s) is(are) selected from the range of nitrification inhibitors N-2,5-dichlorophenyl succinamic acid, Intellectual Property Office of N.Z. 27 NOV 2007 -13- pentachlorophenol, thio-urea, and ATS (ammonium thiosulphate).

11. A method of claim 10 wherein the nitrification inhibitor is ATS.

12. A method of any one of the preceding claims with the optional additional step of adding a flow enhancing agent such as a particulate agent to the dried product.

13. A method of claim 12 wherein the flow enhancing agent is talc.

14. A method of any one of the preceding claims with the additional optional step (irrespective of whether or not a flow enhancing agent has been utilised) of admixing or otherwise associating the zeolite carried nitrification inhibitor(s) with a fertilising agent, compound or composition.

15. A method of claim 14 wherein the fertilising compound is urea.

16. A composition produced by a method of any one of the preceding claims. END OF CLAIMS lnt«ll»ctu*l Property Office of N.z. 2 7 NOV 2007 received