WO2022087753A1

WO2022087753A1 - Soil additive composition and method of use

Info

Publication number: WO2022087753A1
Application number: PCT/CA2021/051545
Authority: WO
Inventors: Darren Sander
Original assignee: Crop Aid Nutrition Ltd
Current assignee: Crop Aid Nutrition Ltd
Priority date: 2020-11-02
Filing date: 2021-11-01
Publication date: 2022-05-05
Anticipated expiration: 2023-05-02

Abstract

A soil additive composition is described which includes lignin or a lignin derivative, plant micronutrients, and an algal extract.

Description

SOIL ADDITIVE COMPOSITION AND METHOD OF USE

FIELD OF THE INVENTION

[0001] This invention relates to a soil additive composition, and uses thereof.

BACKGROUND

[0002] Agricultural fertilizers comprise well-known macronutrients such as nitrogen, phosphorus and/or potassium, as well as sulphur in many cases. Nitrogen, phosphorus and potassium are typically provided as water soluble compounds such as ammonium nitrate, ammonium phosphate, urea, and potash. Direct application of a water soluble sulphate fertilizer such as ammonium sulphate is possible, but uptake suffers from immediate dissolution, resulting in uncontrolled release and leaching, thereby leading to poor returns on farm input investment. Particulate elemental sulphur may be used in fertilizer applications, but elemental sulphur is very slow in reaching the roots of plants. Sulphur in its elemental form is insoluble in water and hence cannot be absorbed by the roots of plants. It is converted by bacterial action into water soluble sulphate which is subsequently readily absorbed by plant roots.

[0003] Micronutrients may also be applied in a fertilizer, and may include essential plant nutrient elements such as boron (B), zinc (Zn), manganese (Mn), iron (Fe), copper (Cu), molybdenum (Mo), and chlorine (Cl).

[0004] Soil amendment products are known which are used to improve the physical properties of soil, such as water retention, permeability, water infiltration, aeration and structure. Many soil amendment products also include fertilizer macro- and micronutrients as well.

[0005] This background information is provided simply to facilitate understanding of the invention described herein, and is not an admission that any particular art is prior art or is relevant.

SUMMARY OF THE INVENTION

[0006] In one aspect, the invention relates to a soil additive product which may promote beneficial microorganisms in the soil, act as a fertilizer catalyst, reducing loss and soil tie- up of applied fertilizer, and/or may have other beneficial effects. Application of a composition described herein may enhance the production of crops suffering stress derived from cold or hot temperatures, unbalanced soil conditions, moisture availability, and disease.

[0007] The compositions comprise essential nutrients which are important to plants, particularly emerging plants, and may enhance root growth and nutrient uptake.

[0008] In one aspect, the invention comprises a composition, comprising"

(a) lignin or a lignin derivative;

(b) one or more of boron (B), zinc (Zn), manganese (Mn), iron (Fe), copper (Cu), molybdenum (Mo), and chlorine (Cl);

(c) a water soluble extract of algae, preferably a brown algae of the class Phaeophyceae, more preferably of the family Fucaceae, and most preferably of the genus

Ascophyllum. The composition is preferably water-soluble and/or may be in liquid form.

[0009] In another aspect, the invention comprise a method of preventing or ameliorating fungal crop diseases, such as clubroot, comprising the step of applying a soil additive composition of the present invention to soil either before or after seeding.

DESCRIPTION OF THE DRAWINGS

[0010] Figure 1. Clubroot DSIs of the canola hybrids ‘45H31’ and ‘CS2000’ with 1 x 10⁵ (a) and 1 x 10⁷ (b) resting spores/g in the soil. Bars with the same letter are not significantly different at P<0.05.

[0011] Figure 2. Average plant heights of the canola hybrids ‘45H31’ and ‘CS2000’ with

1 x 10⁵ (a) and 1 x 10⁷ (b) resting spores/g in the soil. Bars with the same letter are not significantly different at P<0.05.

[0012] Figure 3. Biomass per plant of the canola hybrids ‘45H31’ and ‘CS2000’ with 1 x 10⁵ (a) and 1 x 10⁷ (b) resting spores/g in the soil. Bars with the same letter are not significantly different at P<0.05.

[0013] Figure 4. Gall weight per plant of the canola hybrids ‘45H31’ and ‘CS2000’ with

DETAILED DESCRIPTION

[0014] One embodiment of a soil additive composition according to the present invention comprises:

(a) lignin or a lignin derivative, which is preferably water soluble; (b) at least one micronutrient comprising one or more of boron (B), zinc (Zn), manganese (Mn), iron (Fe), copper (Cu), molybdenum (Mo), and chlorine (Cl); and

(c) a water soluble extract of algae, preferably a brown algae of the class Phaeophyceae, more preferably of the family Fucaceae, and most preferably of the genus Ascophyllum.

The composition is preferably an aqueous solution or suspension of the components.

[0015] Lignin is a class of complex organic polymers that form key structural materials in the support tissues of vascular plants and some algae. It is not water-soluble but may be made so by derivitization, such as by sulphonation or carboxylation. As used herein, a "lignin derivative" is a material which comprises lignin that has been chemically modified to vary or improve a physical property of lignin. Therefore, in some embodiments, the lignin derivative is water soluble, and may comprise a sulphonated lignin or a carboxylated lignin. Preferred sulphonated lignin may include ammonium lignosulphonate. In other embodiments, the lignin or lignin derivative may comprise insoluble, finely divided particles.

[0016] The lignin derivative may be added in a proportion of about 1 to about 20% w/v of water, preferably between about 3 to about 10%, and more preferably between about 5 to about 8%.

[0017] The at least one micronutrient may comprise zinc, iron, manganese and boron, each in an amount between about 0.01% to about 1.0% w/v of water, preferably between about 0.05% to about 0.5%, and more preferably between about 0.08% to about 0.2%. In some embodiments, the at least one micronutrient is added in the amounts specified. Because the algal extract may include some amounts of micronutrients, the total content of a micronutrient in the composition may be higher than that added.

[0018] The algal extract comprises at least water-soluble components of a kelp plant, which may comprise known or unknown bioactive compounds, which may include carbohydrate compounds such as alginates and mannitol. In preferred embodiments, the extraction process may be a low-temperature, low pressure process to avoid altering the natural compounds in the kelp plant. Generally, extraction methods include steps such as In general, extraction procedures include maceration, digestion, decoction, infusion, percolation, solvent extraction, superficial extraction, ultrasound-assisted, and microwave- assisted extractions, known to those skilled in the art. However, the conditions may encourage mild glycosidic activity to increase the relative proportion of oligosaccharides (<12 monosaccharide units) compared to the polysaccharide (>12 monosaccharide units) component of the extract.

[0019] The algal extract may be derived from algae of the class Phaeophyceae, such as kelp which are large brown algae seaweeds that make up the order Laminariales. In preferred embodiments, the algal extract is derived from algae of the family Fucaceae, and most preferably of the genus Ascophyllum. One species of Ascophyllum, being A. nodosum, is a preferred source of the algal extract. In some examples, the extract is derived from freshly harvested algae, as opposed to processed or dehydrated algae. In some embodiments, the algal extract may comprise food grade preservatives, and preferably avoid industrial grade biocides. A. nodosum biomass is used to produce commercially available algal-based biostimulants (see Khan W et al. Seaweed extracts as biostimulants of plant growth and development. J Plant Growth Regul. 2009;28:386-99; Craigie JS. Seaweed extract stimuli in plant science and agriculture. J Appl Phy col.

2011;23:371-93; Mukherjee A et al. Seaweed extract: biostimulator of plant defense and plant productivity. Int J Environ Sci Technol. 2019:1-6, the entire contents of each which is incorporated herein by reference).

[0020] The extract may be produced using potassium based products, while avoiding sodium based products, as sodium is an undesirable element in agriculture.

[0021] The algal extract may be added in an amount between about 0.1% to about 5% w/v of water, preferably between about 0.5% to about 2%, and more preferably between about 0.8% to about 1.0%.

[0022] The composition may optionally include an organic carboxylic or sulfonic acid, preferably an organic polyvalent acid such as citric acid or oxalic acid. Some soils may benefit from a reduction in pH and/or some polyvalent acids are known to function as metal chelators, leading to phytoextraction of heavy metals and reducing phytoxi city of metals such as heavy metals, for example lead. The organic acid may be added in the same proportion as a micronutrient.

[0023] The composition may be blended by mixing with a suitable volume of water, which may be ordinary tap water, lake, river or spring sourced water, or distilled or deionized water. Any water which could be used for irrigation purposes may be suitable.

[0024] The aqueous product may be applied to a crop or field by any suitable method, such as by spraying or drip irrigation. [0025] In alternative embodiments, the product may be used in dried form, such as particulate form, and applied in like manner to solid fertilizers. Upon contact with water, some or all of the product will dissolve and infdtrate the soil.

[0026] The compositions described herein may have numerous beneficial impact on soil and crop growth. In some embodiments, the composition may help prevent or ameliorate fungal crop diseases such as clubroot. As the composition can be applied multiple times during the growing season, an additional spray of the product at different times before and after seeding may help with a better crop growth or yield.

EXAMPLES

[0027] The following examples are provided to illustrate embodiments of the invention and are not intended to limit the claimed invention in any way.

Example 1 - Composition

[0028] In one exemplary embodiment, the composition has the following elements:

which are dissolved in a suitable volume of water.

Example 2 - 10 liter Batch

[0029] A 10 liter batch of product was made with an initial volume of 7.5L water, to which was added 666.6 g of ammonium lignosulphonate, 50 g of boron, 166.6 g manganese, 166.6 g of zinc, 166.6 g of iron, 83.3 g of citric acid, 83.3 ml of liquid kelp extract (Ascophyllum nodosum), and topped up with additional water. This product may be applied at a rate of about 250 to about 500 ml/acre.

Example 3 - Anti-fungal Treatment

[0030] Applications of the composition of Example 2 have shown its capability of reducing clubroot severity on canola as well as maintaining plant growth under clubroot disease pressure. At a spore count (SC) of 1 x 10⁵ resting spores/g in soil, the treatment at 1 week before seeding (1WB) reduced the disease severity index (DSI) to less than 50% of the untreated control on a susceptible ‘45H31’ strain of canola, and to less than 40% on the moderately resistant ‘CS2000’ strain. There were no significant differences between treatment at 1 week after seeding (1 WA) and 1 WB, however the 1WA resulted in slightly higher average DSIs than 1WB, indicating that both these two application timings can efficiently control clubroot under low disease pressure.

[0031] Under a higher disease pressure of 1 x 10⁷ SC, all the composition treatments showed similar reductions of DSI on both cultivars, regardless of the application timings. DSIs of ~92% on the susceptible cultivar and over 62% on the moderately resistant cultivar were shown at the higher SC.

[0032] Three week after seeding (3WA) treatment delivered significantly higher biomass than the untreated control (UTC) on both cultivars and under both SCs.

[0033] Clubroot-free field soil and the greenhouse Sunshine Mix (Sungro Horticulture) were mixed in a 1 : 1 volume to volume ratio, then inoculated with the P. brassiccie resting spore suspension and used to fill plastic tubs (43 x 28 x 17.8 cm). Two canola hybrids

(‘45H3U and ‘CS2000’) were tested in two experiments to examine the treatment effects under two spore concentrations (SCs): 1 x 10⁵ and 1 x 10⁷ resting spores/g soil mixture, respectively. The treatments included an untreated control (UTC). The composition was applied at 250 mL/acre: one week before seeding (1WB), one week after seeding (1WA), or three weeks after seeding (3WA). Diluted fertilizer solution or distilled water was applied from the top of the tubs using a spray bottle. An additional application of the composition at 250 mL/acre was applied to all the tubs except for the UTC, which was treated with water. Two rows of twelve seeds were seeded in each tub with 2.5-cm seed intervals and a 10-cm row spacing. Each experiment was arranged in a completely randomized design with four replicates where one tub represented one experimental unit. After seven weeks, 10 plants were sampled from each tub for clubroot severity rating using a 0-3 scale previously described by Strelkov et al. (2006). Individual plant height, aboveground plant biomass and clubroot gall weight were measured. Each experiment was independently repeated once on separate benches in the greenhouse.

[0034] A disease severity index (DSI) for each experimental unit was calculated with the formula: where n = plant number in

each rating group and N = total plant number in an experimental unit (Horiuchi and Hoti 1980; Strelkov et al. 2006). Averages of plant height, aboveground biomass and clubroot gall weight per plant were also calculated and analyzed. Data comparison to designate significant differences at P < 0.05 were subject to Fisher’s LSD test using the ‘Agricolae’ package of R 3.6.1 (de Mendiburu 2019; R Core Team 2019).

[0035] Results - 1 x 10⁵ SC:

[0036] A significant reduction (p<0.05) in clubroot severity was observed in all the composition treatments compared with the UTC for both canola cultivars at the 1 x 10⁵ SC (Figure la). The treatment at 1WB reduced DSI by 31.3% on the susceptible ‘45H31' and by 25.7% on the moderately resistant ‘CS2000’. The application 1WA also lowered the DSI by -23% on both cultivars. No significant differences were observed on individual plant heights (Figure 2a). However, all of the composition treatments significantly increased the individual plant biomass, compared with the UTC, by 23.5% to 44.6% on ‘45H31’ and 21.8% to 34.5% on ‘CS2000’ (Figure 3a). A significant reduction in clubroot gall weight per plant was observed on ‘45H31’ but not on ‘CS2000’ (Figure 4a).

[0037] Results - 1 x 10⁷ SC:

[0038] Under 1 x 10⁷ SC, all the composition treatments significantly reduced clubroot severity on both canola cultivars (Figure lb). However, no significant differences were observed in regard to the application timing, the composition treatments reduced DSI by less than 8% on the susceptible ‘45H31', and up to 16.4% on ‘CS2000’. No significant differences were observed on individual plant heights for either cultivar, whereas ‘CS2000’ grew significantly higher than ‘45H31' (Figure 2b). The applications at 1WB and 3WA significantly increased individual plant biomass of ‘45H31' while the biomass growth on ‘CS2000’ was significantly enhanced by 1WA and 3WA (Figure

3b). Significantly higher clubroot gall weight was observed on ‘45H31' with the treatment 3WA (Figure 4b).

Interpretation

[0039] References in the specification to "one embodiment", "an embodiment", etc., indicate that the embodiment described may include a particular aspect, feature, structure, or characteristic, but not every embodiment necessarily includes that aspect, feature, structure, or characteristic. Moreover, such phrases may, but do not necessarily, refer to the same embodiment referred to in other portions of the specification. Further, when a particular aspect, feature, structure, or characteristic is described in connection with an embodiment, it is within the knowledge of one skilled in the art to affect or connect such module, aspect, feature, structure, or characteristic with other embodiments, whether or not explicitly described. In other words, any module, element or feature may be combined with any other element or feature in different embodiments, unless there is an obvious or inherent incompatibility, or it is specifically excluded.

[0040] It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for the use of exclusive terminology, such as "solely," "only," and the like, in connection with the recitation of claim elements or use of a "negative" limitation. The terms "preferably," "preferred," "prefer," "optionally," "may," and similar terms are used to indicate that an item, condition or step being referred to is an optional (not required) feature of the invention.

[0041] The singular forms "a," "an," and "the" include the plural reference unless the context clearly dictates otherwise. The term "and/or" means any one of the items, any combination of the items, or all of the items with which this term is associated. The phrase "one or more" is readily understood by one of skill in the art, particularly when read in context of its usage.

[0042] The term "about" can refer to a variation of ± 5%, ± 10%, ± 20%, or ± 25% of the value specified. For example, "about 50" percent can in some embodiments carry a variation from 45 to 55 percent. For integer ranges, the term "about" can include one or two integers greater than and/or less than a recited integer at each end of the range.

Unless indicated otherwise herein, the term "about" is intended to include values and ranges proximate to the recited value or range that are equivalent in terms of the functionality of the composition, or the embodiment.

[0043] [102] As will be understood by one skilled in the art, for any and all purposes, particularly in terms of providing a written description, all ranges recited herein also encompass any and all possible sub-ranges and combinations of sub-ranges thereof, as well as the individual values making up the range, particularly integer values. A recited range includes each specific value, integer, decimal, or identity within the range. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, or tenths. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc.

[0044] [103] As will also be understood by one skilled in the art, all language such as “between”, "up to", "at least", "greater than", "less than", "more than", "or more", and the like, include the number(s) recited and such terms refer to ranges that can be subsequently broken down into sub-ranges as discussed above. In the same manner, all ratios recited herein also include all sub-ratios falling within the broader ratio.

Claims

[0045] CLAIMS

1. A composition, comprising"

(a) lignin or a lignin derivative;

(b) at least one plant micronutrient;

(c) a water soluble extract of an algae.

2. The composition of claim 1 which is water-soluble and/or in liquid form.

3. The composition of claim 1 or 2, wherein the algae comprise a brown algae of the class Phaeophyceae.

4. The composition of claim 3 wherein the algae comprises a brown algae of the family Fucaceae.

5. The composition of claim 4, wherein the algae comprises a brown algae of the genus Ascophyllum.

6. The composition of any one of claims 1-5 wherein the at least one micronutrient comprises one or more of boron (B), zinc (Zn), manganese (Mn), iron (Fe), copper (Cu), molybdenum (Mo), and chlorine (Cl).

7. The composition of any one of claims 1-6 wherein the lignin derivative comprises ammonium lignosulphonate.

8. The composition of any one of claims 1-7 which is formulated in water, and wherein: (a) the lignin or lignin derivative is present in a amount of about 1 to about 20% w/v of water, preferably between about 3 to about 10%, and more preferably between about 5 to about 8%; and/or

(b) the at least one micronutrient is present in an amount of about 0.01% to about

1.0% w/v of water, preferably between about 0.05% to about 0.5%, and more preferably between about 0.08% to about 0.2%; and/or

(c) the algal extract is present in an amount between about 0.1% to about 5% w/v of water, preferably between about 0.5% to about 2%, and more preferably between about 0.8% to about 1.0%.

9. The composition of any one of claims 1-8, further comprising an organic carboxylic or sulfonic acid, preferably an organic polyvalent acid such as citric acid or oxalic acid.

10. The composition of any one of claims 1-9, wherein the algal extract is produced under conditions that encourage glycosidic activity.

11. The composition of claim 10 wherein the algal extract has an increased relative proportion of oligosaccharides (<12 monosaccharide units) compared to the polysaccharide (>12 monosaccharide units) components of the extract.

12. Use of a composition of any one of claims 1-11 for preventing or ameliorating a fungal crop disease, such as clubroot.

13. A method of preventing or ameliorating a fungal crop disease, comprising the step of applying a composition of any one of claims 1-11 to soil either before or after seeding.

14. The method of claim 13, wherein the composition is applied at a rate of about 250 to about 500 ml/acre.

15. The method of claim 13 or 14, wherein the fungal crop disease is clubroot.