Growth promoting supernatant

Abstract

A method of improving growth of a plant is disclosed The method comprises contacting a seed of the plant or a root of the plant with a calcium silicate supernatant in the form of water or an aqueous solution comprising calcium ions and silicate ions or adding the calcium silicate supernatant to a plant substrate and growing a seed or a root of the plant in the plant substrate. The calcium silicate supernatant has plant growth promoting effect and act as a plant fertilizer contributing to increased plant growth.

Description

[0001] GROWTH PROMOTING SUPERNATANT

[0002] TECHNICAL FIELD

[0003] The present invention relates to a supernatant from calcium silicate and its use in plant growth promotion.

[0004] BACKGROUND

[0005] Exogenous application of various nutrient fertilizers is a common way to improve general crop development and yield. Silicon (Si) is currently considered as a potential growth promoter. However, its role in growth and development or its effects on metabolism and physiological function in plants is not fully understood. Although Si has not been recognized as a necessary nutrient for plant growth, numerous studies have shown its positive impact on growth parameters of a variety of crops, including both monocots and dicots. Further, Si has shown potential in protecting plants against adverse impact of abiotic stressors, such as by regulating electrolytic leakage under stressful conditions. Si is traditionally added in the form of Si-supplemented fertilizer and then typically in the form of silicon dioxide (SiO2).

[0006] Attipoe et al., Evaluating the effectiveness of calcium silicate in enhancing soybean growth and yield, Plants 12: 2190 (2023) showed that the application of Si fertilizer had effects on most root and shoot parameters of soybean and exogenous Si application had a positive impact on the overall growth, morphological and physiological traits, and yield output of soybeans.

[0007] There is still a need for improved materials for promoting growth of plants.

[0008] SUMMARY

[0009] It is an objective to provide formulations that can be used in promoting growth of plants.

[0010] This and other objectives are met by embodiments disclosed herein.

[0011] The present invention is defined in the independent claims. Further embodiments of the invention are defined in the dependent claims.

[0012] An aspect of the invention relates to a method of improving growth of a plant. The method comprises contacting a seed of the plant or a root of the plant with a calcium silicate supernatant in the form of water or an aqueous solution comprising calcium ions and silicate ions. Another aspect of the invention relates to a method of improving growth of a plant. The method comprises adding a calcium silicate supernatant in the form of water or an aqueous solution comprising calcium ions and silicate ions to a plant substrate. The method also comprises growing a seed of the plant or a root of the plant in the plant substrate.

[0013] The calcium silicate supernatant has growth promoting effect and results in increased plant growth of the treated plant seeds or roots as compared to non-treated plant seeds or roots. The calcium silicate supernatant can thereby be used as a plant fertilizer to promote the growth and yield of plants and crops.

[0014] BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The embodiments, together with further objects and advantages thereof, may best be understood by making reference to the following description taken together with the accompanying drawings, in which:

[0016] Fig. 1 is a graph showing ion concentration as a function of time during manufacture of a calcium silicate supernatant according to an embodiment;

[0017] Fig. 2 is a graph showing ion concentration as a function of time during manufacture of a calcium silicate supernatant according to another embodiment;

[0018] Fig. 3 is a flow chart illustrating a method of improving growth of a plant according to an embodiment;

[0019] Fig. 4 is an illustration of plants grown from treated seeds (left) and plants grown from un-treated control seeds (right);

[0020] Fig. 5 is a flow chart illustrating a method of improving growth of a plant according to another embodiment; and

[0021] Fig. 6 is an illustration of plant grown in treated plant substrate (left) and plants grown in un-treated control plant substrate.

[0022] ABBREVATIONS AND DEFINITIONS

[0023] Monocalcium silicate - CaOSiO2, also expressed as Ca0-Si02 or CaSiOs and referred to as OS;

[0024] Dicalcium silicate - (CaO)2SiO2, also expressed as 2CaO-SiO2 or Ca2SiO4 and referred to as C2S; Tricalcium silicate - (CaO)3SiO2, also expressed as 3CaO-SiO2 or CasSiOs and referred to as C3S;

[0025] Bioglass - means bioglass 45S5, also referred to as calcium sodium phosphosilicate, which is a bioactive glass composed of 45 wt% SiC>2, 24.5 wt% CaO, 24.5 wt% Na2<3, and 6.0 wt% P2O5;

[0026] % by weight (wt%) - the weight fraction of a compound in relation to the total weight of a mixture or composition including the component, expressed in percent;

[0027] Calcium ion - Ca2+;

[0028] Silicate ion - wherein 0 < x < 2 and 1 < n < 2, and includes orthosilicate SiO^~(x = 0, n = 1), metasilicate SiOl~(x = 1 , n = 1), and pyrosilicate Si2O ~(x = 0.5, n = 2); and

[0029] Hydroxide - OH-.

[0030] DETAILED DESCRIPTION

[0031] The present invention relates to a supernatant from calcium silicate and its use in plant growth promotion.

[0032] Calcium silicate is a chemical compound comprising calcium and silicate, commonly in the form of a powder. It exists in different forms, such as monocalcium silicate (CaOSiO2), dicalcium silicate ((CaO)2SiO2), and tricalcium silicate ((CaO)3SiO2). It can also be referred to, and is often traded as, CS, C2S, C3S, meta-silicate or Cai-Sil or Calsil.

[0033] Calcium silicate is used in different pharmaceutical and food applications as an anti-caking agent, as an antiacid, but it can also be used in other applications, for example, in agriculture as a source of silicon.

[0034] The following calcium silicate phases are suitable for use according to the invention, monocalcium silicate (CaOSiO2), dicalcium silicate ((CaO)2SiO2), and tricalcium silicate ((CaO)3SiO2), preferably the monocalcium silicate phase. Such calcium silicate salts are soluble in water (or humid environment) and provide a source for forming a supernatant containing calcium ions (Ca2+), silicate ions and hydroxide. The pH of such formed supernatant is, prior to any pH adjustment, above 9 at room temperature in water. The present invention describes a method to form a supernatant from calcium silicate and the use of the supernatant as plant growth promotor agent.

[0035] The solubility of calcium silicates, which are a Ca-salts, increases with the amount of calcium in the calcium silicate. Without being bound by any theory, the present invention takes advantage of the solubility of the calcium silicate and release of different ions, such as hydroxide, calcium ions and silicate ions to promote growth of plants.

[0036] As another part of the invention described herein the calcium silicate can be replaced by a bioglass. Hence, herein ‘calcium silicate’ can be exchanged for ‘bioglass’ and, thus, in one aspect of the invention there is a bioglass powder material. The supernatant from a bioglass powder can be used as collagen promotor.

[0037] The parameters for the supernatant formation:

[0038] • Ratio: water to powder by weight: 1 :1 to 1000:1 ;

[0039] • Temperature: 10 degrees to 90 degrees Celsius; and

[0040] • Time: 1 minutes to 2 hours, even shorter time can be used for e.g., C3S at 90 degrees Celsius.

[0041] The remaining powder can be sieved or preferably centrifuged from the supernatant. pH of the calcium silicate supernatant > 9 when demineralized water is used.

[0042] An apparatus where the calcium silicate is in contact water-based liquid without the need of filtering or centrifuging is also included in the invention. The calcium silicate is in a “tea bag” of suitable material and porosity and dipped into water. Water can thereby also be in a continuous process.

[0043] An aspect of the invention relates to a method of improving growth of a plant. The method comprises contacting a seed of the plant or a root of the plant with a calcium silicate supernatant, also referred to as a calcium silicate solution, in the form of water or an aqueous solution comprising calcium ions and silicate ions.

[0044] The calcium silicate supernatant of the embodiments has plant growth promoting effect and acts as a plant fertilizer. This means that plant seeds or roots treated with the calcium silicate supernatant show increased growth as compared to non-treated control seeds or roots, which is shown in Fig. 4. The figure shows wheat at 15 days from seeding of seeds treated with a calcium silicate supernatant according to the invention (left) and corresponding un-treated control seeds (right). As is evident from the figure, the calcium silicate supernatant significantly promoted plant growth when used to treat the seeds.

[0045] Root of a plant as used herein include root of a plant in any stage of growth, such as root of a seedling or root of a plant at vegetating, budding, flowering or ripening stages.

[0046] In an embodiment, contacting the seed of the plant or the root of the plant comprises soaking the seed of the plant or the root of the plant in the calcium silicate supernatant. In such an embodiment, the seed of the pant or root of the plant is preferably soaked in the calcium silicate supernatant for at least 1 second, such as from 10 seconds to 60 min, preferably from 10 seconds to 15 min, and more preferably from 1 min to 10 min.

[0047] In another embodiment, contacting the seed of the plant or the root of the plant comprises spraying the calcium silicate supernatant onto the seed of the plant or the root of the plant. In this embodiment, the calcium silicate supernatant is preferably sprayed onto the seed of the plant or the root of the plant using a dispensing system or device comprising the calcium silicate supernatant. The dispensing system or device then preferably dispenses the calcium silicate supernatant as a spray, for instance an aerosol spray or aerosol mist.

[0048] In a further embodiment, contacting the seed of the plant or the root of the plant comprises watering the seed of the plant or the root of the plant with the calcium silicate supernatant.

[0049] According to an embodiment, the calcium silicate supernatant is diluted with water before being in contact with the seed or root of the plant. The calcium silicate supernatant can be diluted up to 1 : 1000, preferably up to 1 :500, more preferably up to 1 :100, such as up to 1 :50 or up to 1 :10, wherein 1 :X represents 1 volume of calcium silicate supernatant and X volumes of water.

[0050] In an embodiment, contacting the seed of the plant or the root of the plant comprises contacting the seed of a plant with the calcium silicate supernatant, such as using any of the above-presented embodiment. In a particular embodiment, the method also comprises drying the seed of the plant. The treated seed of the plant is preferably dried to form a thin coating comprising calcium silicate in the form of calcium ions and silicate ions. The drying can take place in ambient conditions, such as in room temperature (20- 25°C, such as about 23.5°C), or under reduced atmospheric pressure (<1 bar) and / or at elevated temperature (>25°C, preferably 26 to 75°C, more preferably 26 to 50°C) to speed-up the drying process.

[0051] The dried seed of the plant with the calcium and silicate ion coating can then be stored until seeding or planting.

[0052] Another aspect of the invention relates to a method of improving growth of a plant. The method comprises adding a calcium silicate supernatant in the form of water or an aqueous solution comprising calcium ions and silicate ions to a plant substrate. The method also comprises growing a seed of the plant or a root of the plant in the plant substrate.

[0053] In an embodiment, adding the calcium silicate supernatant comprises watering the plant substrate with the calcium silicate supernatant.

[0054] The addition of the calcium silicate supernatant to the plant substrate could be performed prior to and / or following to planting the seed of the plant or the plant in the plant substrate. In the former case, the plant substrate is pre-treated with the calcium silicate supernatant prior to growing the seed of the plant or the root of the plant in the pre-treated plant substrate. In the latter case, the seed of the plant or the plant is first planted in the plant substrate and then the plant substrate with the seed or the plant is treated with the calcium silicate supernatant. It is also possible to combine these two alternatives, i.e. , adding calcium silicate supernatant to the supernatant both prior to and following planting the seed or the plant in the plant substrate.

[0055] The seed or plant planted in the plant substrate in this aspect could have been pre-treated as described in the foregoing by contacting the seed of the plant or the root of the plant with calcium silicate supernatant. The various embodiments discussed in the foregoing regarding contacting the seed of the plant or the root of the plant with calcium silicate supernatant thereby also relate to the embodiments of adding the calcium silicate supernatant to the plant substrate.

[0056] The plant substrate, to which the calcium silicate supernatant is added, could be any substrate used for planting and growing plants. Illustrative, but non-limiting, examples of such plant substrates include soil, peat, compost, vermiculite, perlite, sand, clay, hemp and any combination thereof. The plant substrate could also be a liquid plant substrate in the case of hydroponic cultivation, optionally in combination with a solid support to anchor the plants, such as fiberglass, plastic, or porous rock material.

[0057] Fig. 3 schematically illustrates an embodiment of improving growth of a plant according to an embodiment. In a first step, the calcium silicate supernatant or solution is prepared by mixing water or an aqueous solution with the solid calcium silicate containing phase (mineral). A second step comprises treating the seeds with the prepared calcium silicate supernatant or solution, such as by soaking the seeds in the calcium silicate supernatant or solution. A third step comprises drying the treated seeds so that the seeds get a thin coating comprising calcium and silicate ions. The treated and dried seeds can then be stored until time for seeding or planting. Fig. 3 also shows growing plants from the treated and dried seeds in any suitable plant substrate, exemplified by a test growth in Petri dishes in the figure.

[0058] Fig. 4 illustrates growth of seeds in Petri dishes with seeds treated by the method shown in Fig. 3 to the left and untreated control seeds to the right. As is shown in the figure, the treatment of the seeds according to Fig. 3 led to a significant improved plant growth as compared to the untreated control seeds.

[0059] Fig. 5 schematically illustrates an embodiment of improving growth of a plant according to an embodiment. In a first step, the calcium silicate supernatant or solution is prepared by mixing water or an aqueous solution with the solid calcium silicate containing phase (mineral). A second step comprises adding the calcium silicate supernatant to the plant substrate. In the particular shown embodiment, a hemp mat is used as plant substrate and the hemp mat is dipped into the calcium silicate supernatant. In this particular embodiment, the treated hemp mat is then dried in room temperature or by application of hot air in a third step.

[0060] Seeds have been added to a hemp mat treated according to the method shown in Fig. 5 and to an untreated control hemp mat. Fig. 6 illustrates the growth of plants from the seeds planted in the treated hemp mat (left) and seeds planted in the untreated control hemp mat (right). As is shown in the figure, the treatment of the plant substrate (hemp mat) according to Fig. 5 led to a significant improved plant growth as compared to the untreated control plant substrate.

[0061] In an embodiment, the method further comprises contacting water or an aqueous solution with a solid calcium silicate containing phase at a mass weight of the water or the aqueous solution to the solid calcium silicate containing phase selected within an interval of from 1 :1 up to 1 ,000:1. The method also comprises removing any solid calcium silicate containing phase from the water or the aqueous solution to form the calcium silicate supernatant comprising calcium ions and silicate ions.

[0062] The solid calcium silicate containing phase is also referred to as a solid phase comprising calcium silicate herein. Thus, it is in the form of calcium silicate containing solids, such as powder, particles and / or granules comprising, or indeed made of, calcium silicate.

[0063] In an embodiment, contacting water or the aqueous solution comprises contacting the water or the aqueous solution with the solid calcium silicate containing phase at a temperature selected within an interval of from 10°C up to 90°C.

[0064] In a particular embodiment, the temperature is selected within an interval of from 20°C up to 80°C. In another particular embodiment, the temperature is selected within an interval of from 20°C up to 70°C.

[0065] In an embodiment, the mass ratio of the water or the aqueous solution to the solid calcium silicate containing phase is selected within an interval of from 1 :1 up to 100:1.

[0066] In a particular embodiment, the mass ratio of the water or the aqueous solution to the solid calcium silicate containing phase is selected within an interval of from 5:1 up to 100:1.

[0067] In an embodiment, contacting the water or the aqueous solution comprises contacting the water or the aqueous solution with the solid calcium silicate containing phase for a duration selected within an interval of from 1 minutes up to 2 hours.

[0068] In a particular embodiment, the duration is selected within an interval of from 2 minutes up to 2 hours. In another particular embodiment, the duration is selected within an interval of from 5 minutes up to 2 hours. In a further particular embodiment, the duration is selected within an interval of from 0.5 hours up to 1 .5 hours.

[0069] In an embodiment, the solid calcium silicate containing phase is selected from the group consisting of monocalcium silicate (CaOSiC ), dicalcium silicate ((CaO)2SiO2), tricalcium silicate ((CaO)3SiO2), calcium sodium phosphosilicate, and any combination thereof. In a particular embodiment, the solid calcium silicate containing phase is selected from the group consisting of monocalcium silicate (CaOSiC ), dicalcium silicate ((CaO)2SiO2), tricalcium silicate ((CaO)3SiC>2), and any combination thereof. In another particular embodiment, the solid calcium silicate containing phase is monocalcium silicate (CaOSiC>2).

[0070] In an embodiment, the solid calcium silicate containing phase is in the form of monocalcium silicate (CaOSiO2) powders or particles, dicalcium silicate ((CaO)2SiO2) powders or particles, tricalcium silicate ((CaO)3SiO2) powders or particles, or any combination thereof.

[0071] In an embodiment, the calcium silicate supernatant has, prior to any pH adjustment, a pH above 8.5, most often above 9 and higher when using water or a non-buffered aqueous solution.

[0072] In an embodiment, the method further comprises adjusting, if a pH of the calcium silicate supernatant exceeds 8.5, the pH of the calcium silicate supernatant by addition of an acid to a pH selected within an interval of from 4.5 up to 8.5.

[0073] In a particular embodiment, the calcium silicate supernatant has, prior to any pH adjustment, a pH selected within in interval of from 8.5 up to 12.5, wherein the pH of the calcium silicate supernatant is at least partly dependent on the calcium content of the solid calcium silicate containing phase. For instance, a calcium silicate supernatant produced using C3S as solid calcium silicate containing phase generally has a higher pH as compared to a calcium silicate supernatant produced using CS as solid calcium silicate containing phase.

[0074] In an embodiment, the method comprises measuring the pH of the calcium silicate supernatant. In such a case, if the measurement indicates that the pH of the calcium silicate supernatant exceeds 8.5 then the pH of the calcium silicate supernatant is preferably adjusted to a pH selected within an interval of from 4.5 up to 8.5.

[0075] However, if the pH does not exceed 8.5 and is thereby already within an interval of from 4.5 up to 8.5, then no pH adjustment is needed.

[0076] In an embodiment, adjusting the pH comprises adjusting, if the pH of the calcium silicate supernatant exceeds 8, the pH of the calcium silicate supernatant by addition of an acid to a pH selected within an interval of from 6 up to 8. The pH adjustment can be performed by addition of an acid, such as hydrogen chloride (HCI).

[0077] In some cases, no pH adjustment is needed and can thereby be omitted. For instance, if the aqueous solution used to produce the calcium silicate supernatant is an aqueous buffer or a buffered aqueous solution, the pH of the calcium silicate supernatant could be equal to or below pH 8.5. If the pH of the so- obtained calcium silicate supernatant is at or at least close to a desired or target pH for the calcium silicate supernatant then no pH adjustment is needed and could be omitted.

[0078] Illustrative, but non-limiting, examples of buffered aqueous solutions that could be used according to the embodiments include phosphate buffers, such as comprising dihydrogen phosphate (H2PO4 ) and hydrogen phosphate (HPO22), Tris buffers comprising tris(hydroxymethyl)aminomethane-HCI (Tris-HCI), and HEPES buffers comprising 4-(2-hydroxyethyl)-1 -piperazineethanesulfonic acid.

[0079] In an embodiment, the calcium silicate supernatant has a calcium concentration of at least 10 mg / L.

[0080] In a particular embodiment, the calcium silicate supernatant has a calcium concentration selected within an interval of from 10 up to 50 mg / L. In another particular embodiment, the calcium silicate supernatant has a calcium concentration selected within an interval of from 10 up to 30 mg / L.

[0081] The calcium silicate supernatant comprises the calcium in the form of calcium ions.

[0082] In an embodiment, the calcium silicate supernatant has a silicon concentration of at least 5 mg / L.

[0083] In a particular embodiment, the calcium silicate supernatant has a silicon concentration selected within an interval of from 5 up to 30 mg / L. In another particular embodiment, the calcium silicate supernatant has a silicon concentration selected within an interval of from 5 up to 20 mg / L.

[0084] The calcium silicate supernatant comprises the silicon in the form of silicate ions.

[0085] In an embodiment, contacting the water or the aqueous solution comprises contacting the water with the solid calcium silicate containing phase. In a particular embodiment, the water is deionized water. In another particular embodiment, the water is pure water or ultrapure water, preferably ultrapure water. Ultrapure water is referred to as type I water and is defined by the American Society for Testing and Materials (ASTM) as having a resistivity of >18 MQ-cm, a conductivity of <0.056 pS / cm and <50 ppb of Total Organic Carbons (TOC). An example of such ultrapure water is Milli-Q® water. Pure water is also referred to as type II water and is defined by ASTM as having a resistivity of >1 MQ-cm, a conductivity of <1 pS / cm and <50 ppb of TOCs. In a further particular embodiment, the water is tap water.

[0086] In an embodiment, removing any solid calcium silicate containing phase comprises centrifuging any solid calcium silicate containing phase and the water or the aqueous solution to form the calcium silicate supernatant comprising calcium ions and silicate ions.

[0087] In another embodiment, removing any solid calcium silicate containing phase comprises filtering any solid calcium silicate containing phase and the water or the aqueous solution to form the calcium silicate supernatant comprising calcium ions and silicate ions as a filtrate.

[0088] Contacting the solid calcium silicate containing phase with the water or the aqueous solution leads to release of calcium and silicon ions from the solid calcium silicate containing phase and into the liquid phase, i.e., into the water or the aqueous solution. Accordingly, the solid calcium silicate containing phase is at least partly dissolved. Generally, calcium silicate has a solubility in water of about 0.01 wt% at 20°C. Thus, if a comparatively small amount of the solid calcium silicate containing phase is contacted with the water or the aqueous solution and allowing sufficient incubation for the solid calcium silicate containing phase to almost completely dissolve then not removal of the solid calcium silicate containing phase is needed and could be omitted.

[0089] However, in a preferred embodiment, the method comprises removing the solid calcium silicate containing phase from the water or the aqueous solution to form the calcium silicate supernatant comprising calcium ions and silicate ions.

[0090] In an embodiment, contacting the water of the aqueous solution comprises contacting water or the aqueous solution with a semipermeable pouch or bag comprising the solid calcium silicate containing phase. In such an embodiment, removing the solid calcium silicate containing phase comprises removing the semipermeable pouch or bag from the water or the aqueous solution to form the calcium silicate supernatant comprising calcium ions and silicate ions. In this embodiment, the semipermeable pouch or bag has a porosity allowing water or the aqueous solution to penetrate into the semipermeable pouch or bag to contact the solid calcium silicate containing phase contained therein and allow calcium and silicate ions dissolved in the water or the aqueous solution to pass through the semipermeable pouch or bag. However, the pores of the semipermeable pouch or bag restrict the solid calcium silicate containing phase from passing through the semipermeable pouch or bag.

[0091] In an embodiment, the solid calcium silicate containing phase comprises solid calcium silicate containing powder or particles. In a preferred embodiment, the solid calcium silicate containing phase is in the form of calcium silicate powder, calcium silicate particles, or a mixture thereof.

[0092] In an embodiment, the solid calcium silicate solid calcium silicate containing powder or particles has or have a grain size of below 700 pm.

[0093] In a particular embodiment, the solid calcium silicate containing powder or particles has or have a grain size equal to or below 500 pm. In another particular embodiment, the solid calcium silicate containing phase comprises solid calcium silicate containing powder having a grain size equal to or below 300 pm.

[0094] The calcium silicate supernatant of the present invention can be used to treat any seeds, roots or plant substrates that would benefit from a growth promoting treatment and a silicon containing fertilizer. The plant could be a monocotyledon (monocot) or a dicotyledon (dicot). Illustrative, but non-limiting, examples of plants that can be treated with the calcium silicate supernatant of the present invention include sugarcane (Saccharum officinarum), rice (Oryza sativa), maize (Zea Mays L.), cucumber (Cucumis sativus L.), barley (Hordeum vulgare), soybean (Glycine max L.), wheat (Triticum aestivum), rye (Secale cereale), oat (Avena sativa), tomato (Solanum lycopersicum), pepper (Capsicum annuum), chili peppers (genus Capsicum), lettuce (genus Lactuca), and various herbs, such dill (Anethum graveolens).

[0095] The calcium silicate supernatant of the present invention has plant growth promoting effect when treating seeds, plants or a plant substrate. The plant growth promoting effect of the calcium silicate could be due to various reasons, such as addition of minerals, increase in pH, promoting phosphorus uptake, increased germination of treated seeds and inhibiting fungal pathogens.

[0096] A significant advantage of the calcium silicate supernatant of the embodiments when used as plant fertilizer is that the constituents of the calcium silicate supernatant can be precisely controlled by using the solid calcium silicate containing phase as the source of calcium and silicate ions. For instance, if using ultrapure water as liquid phase and mono-, di- and / or tricalcium silicate as solid phase, then the resulting calcium silicate supernatant substantially only consists of water comprising calcium and silicate ions.

[0097] Another advantageous effect of the calcium silicate supernatant of the embodiments is that it has antipathogenic properties and is capable of inactivation of pathogens. This means that the calcium silicate supernatant can be used as anti-pathogenic agent.

[0098] Pathogen as used herein is an organism causing disease to its host and is also referred to as infectious agent. Pathogen includes, for example, virus, bacteria and fungi. The term pathogen inactivating agent refers to an agent that has the ability to render a pathogen unable to infect a host. It can, or example, be by chemical alteration of lipids or proteins of the pathogen. In the present invention, a pathogen inactivating agent has the ability to inactivate 50% or more of the present pathogens.

[0099] All embodiments disclosed herein relate to all aspects of the present invention and all embodiments may be combined unless stated otherwise.

[0100] EXAMPLES

[0101] EXAMPLE 1

[0102] Monocalcium silicate powder (CaOSiCte) with a grain size of below 200 pm was mixed with deionized water for an hour at 60°C (ratio powder to water of 1 :10 by weight). The mixture was centrifuged, the supernatant separated. The supernatant was sterile filtered. Wheat seeds were soaked 5 minutes in the supernatant. Control group seeds were left untreated. The seeds were placed one by one on agar plates with 10 seeds on each agar plate and in total 100 seed in each group. After plating the dishes were placed in an incubator at 25 °C for 7 days. The difference in seed borne pathogens was by colony counting. The soaked seeds showed no colony formation whereas the untreated showed 12 seeds with colony formation.

[0103] EXAMPLE 2

[0104] Monocalcium silicate powder (CaOSiCte) with a grain size of below 100 pm was mixed with deionized water (ratio 1 :50 by weight) for an hour at 60°C. The mixture was centrifuged, the supernatant separated. The pH of the supernatant was 9 and was neutralized (pH 7) by addition of HCI. The supernatant was sprayed onto seeds at a temperature above about 50 °C. Growth tests were performed on untreated and treated seeds (wheat in a controlled cabinet). The treated seeds showed a significantly higher growth than untreated.

[0105] EXAMPLE 3

[0106] Tricalcium silicate powder ((CaO)3SiO2) with a grain size of below 200 pm was mixed with deionized water (ratio powder to water of 1 :10) for an hour at room temperature (about 23.5°C). Grain size of the powder was below 200 pm, sieved. The mixture was centrifuged, the supernatant separated. The pH of the supernatant was above 12. The supernatant was sterile filtered and then adenovirus was added to the supernatant and infected cells. The supernatant showed a virus inactivation of more than 95 %.

[0107] EXAMPLE 4

[0108] A pH study was conducted on a calcium silicate supernatant produced by soaking tablets of calcium silicate with a grain size below 700 pm in milli-Q water. All measurements were made at 23.5°C and with an initial pH at 7.7.

[0109] As is shown in Table 1 , the pH increased during the first 15 minutes before reaching an asymptote at about pH 10.7.

[0110] Table 1 - pH

[0111] EXAMPLE 5

[0112] Tablets of calcium silicate with a grain size below 200 pm was soaked in deionized water or Milli-Q® water. The concentrations of calcium and silicon were measured in the supernatant after soaking time using inductively coupled plasma (ICP) spectroscopy.

[0113] The results are presented in Fig. 1 for Milli-Q® water and in Fig. 2 for deionized water. As is seen in the figures, the concentration of Si increased rapidly during the 15 min of soaking and then reached a plateau concentration of about 25 mg / L for Milli-Q® water and 15 mg / L for deionized water. The corresponding plateau concentrations of Ca are slightly below 40 mg / L for Milli-Q® water and about 25 mg / L for deionized water.

[0114] EXAMPLE 6

[0115] Fig. 4 illustrates growth of wheat seeds in Petri dishes with seeds treated by the method shown in Fig. 3 to the left and untreated control seeds to the right. The seeds were soaked for a few minutes in a solution prepared by mixing 10 g calcium silicate with 100 g tap water. The seeds for the untreated control were soaked for the same time in water. The seeds were then placed on damp lint free nonwoven wipes in Petri dishes that were placed in a large Zip-lock bag. The picture shows the growth after 15 days in a bright north-west facing window.

[0116] As is shown in the figure, the treatment of the seeds according to Fig. 3 led to a significant improved plant growth as compared to the untreated control seeds.

[0117] EXAMPLE 7

[0118] A hemp mat was dipped in solution of 10 g calcium silicate to 100 g tap water and another hemp mat was dipped in water as shown in Fig. 5. The excess of liquid was removed before the moist mats were placed in Petri dishes and wheat seeds were added. The samples were placed in a Zip-lock bag and grown in a bright north-west facing window. Fig. 6 illustrates the growth of plants from the seeds planted in the treated hemp mat (left) and seeds planted in the untreated control hemp mat (right) after 7 days. As is shown in the figure, the treatment of the plant substrate (hemp mat) according to Fig. 5 led to a significant improved plant growth as compared to the untreated control plant substrate.

[0119] EXAMPLE 8

[0120] Monocalcium silicate powder (CaOSiO2) with a grain size of below 200 pm was mixed with tap water for 5 minutes at 20°C (ratio monocalcium silicate powder to tap water of 1 : 10 by weight). Grain size of the powder was sieved to be below 200 pm. The mixture was centrifuged, the supernatant separated and sterile filtered. The pH of the solution was 8.

[0121] The embodiments described above are to be understood as a few illustrative examples of the present invention. It will be understood by those skilled in the art that various modifications, combinations and changes may be made to the embodiments without departing from the scope of the present invention. In particular, different part solutions in the different embodiments can be combined in other configurations, where technically possible. The scope of the present invention is, however, defined by the appended claims.

Claims

CLAIMS1 . A method of improving growth of a plant comprising contacting a seed of the plant or a root of the plant with a calcium silicate supernatant in the form of water or an aqueous solution comprising calcium ions and silicate ions.

2. A method of improving growth of a plant comprising: adding a calcium silicate supernatant in the form of water or an aqueous solution comprising calcium ions and silicate ions to a plant substrate; and growing a seed of the plant or a root of the plant in the plant substrate.

3. The method according to claim 2, wherein adding the calcium silicate supernatant comprises watering the plant substrate with the calcium silicate supernatant.

4. The method according to claim 2 or 3, further comprising contacting the seed of the plant or the root of the plant with the calcium silicate supernatant.

5. The method according to claim 1 or 4, wherein contacting the seed of the plant or the root of the plant comprises soaking the seed of the plant or the root of the plant in the calcium silicate supernatant.

6. The method according to claim 1 or 4, wherein contacting the seed of the plant or the root of the plant comprises spraying the calcium silicate supernatant onto the seed of the plant or the root of the plant.

7. The method according to claim 1 or 4, wherein contacting the seed of the plant or the root of the plant comprises watering the seed of the plant or the root of the plant with the calcium silicate supernatant.

8. The method according to any one of claims 1 , 4 to 7, further comprising drying the seed.

9. The method according to any one of claims 1 to 8, further comprising: contacting water or an aqueous solution with a solid calcium silicate containing phase at a mass ratio of the water or the aqueous solution to the solid calcium silicate containing phase selected within an interval of from 1 :1 up to 1 ,000:1 ; and removing any solid calcium silicate containing phase from the water or the aqueous solution to form the calcium silicate supernatant.

10. The method according to claim 9, wherein contacting water or the aqueous solution comprises contacting the water or the aqueous solution with the solid calcium silicate containing phase at a temperature selected within an interval of from 10°C up to 90°C, preferably selected within an interval of from 20°C up to 80°C, and more preferably selected within an interval of from 20°C up to 70°C.11 . The method according to claim 9 or 10, wherein the mass ratio of water or the aqueous solution to the solid calcium silicate containing phase is selected within an interval of from 1 :1 up to 100:1 , preferably selected within an interval of from 5:1 up to 100:1.

12. The method according to any one of claims 9 to 11 , wherein contacting water or the aqueous solution comprises contacting the water or the aqueous solution with the solid calcium silicate containing phase for a duration selected within an interval of from 1 minutes up to 2 hours, preferably selected within an interval of from 2 minutes up to 2 hours, more preferably selected within an interval of from 5 minutes up to 2 hours and most preferably selected within an interval of from 0.5 hours up to 1 .5 hours.

13. The method according to any one of claims 9 to 12, wherein the solid calcium silicate containing phase is selected from the group consisting of monocalcium silicate (CaOSiC ), dicalcium silicate ((CaO)2SiO2), tricalcium silicate ((CaO)3SiO2), calcium sodium phosphosilicate, and any combination thereof, preferably selected from the group consisting of monocalcium silicate (CaOSiC>2), dicalcium silicate ((CaO)2SiO2), tricalcium silicate ((CaO)3SiO2), and any combination thereof, and more preferably monocalcium silicate (CaOSiC ).

14. The method according to claim 13, wherein the solid calcium silicate containing phase is in the form of monocalcium silicate (CaOSiC ) powders or particles, dicalcium silicate ((CaO)2SiO2) powders or particles, tricalcium silicate ((CaO)3SiO2) powders or particles, or any combination thereof.

15. The method according to any one of claims 9 to 14, further comprising adjusting, if a pH of the calcium silicate supernatant exceeds 8.5, the pH of the calcium silicate supernatant by addition of an acid to be equal to a pH selected within an interval of from 4.5 up to 8.5.

16. The method according to claim 15, wherein adjusting the pH comprises adjusting, if the pH of the calcium silicate supernatant exceeds 8, the pH of the calcium silicate supernatant by addition of an acid to be equal to a pH selected within an interval of from 6 up to 8.

17. The method according to claim 15 or 16, wherein adjusting the pH comprises adjusting, if the pH of the calcium silicate supernatant exceeds 8.5, the pH of the calcium silicate supernatant by addition of HCI to a pH selected within an interval of from 4.5 up to 8.5.

18. The method according to any one of claims 9 to 17, wherein the calcium silicate supernatant has a calcium concentration of at least 10 mg / L, preferably selected within an interval of from 10 up to 50 mg / L, and more preferably selected within an interval of from 10 up to 30 mg / L.

19. The method according to any one of claims 9 to 18, wherein the calcium silicate supernatant has a silicon concentration of at least 5 mg / L, preferably selected within an interval of from 5 up to 30 mg / L, and more preferably selected within an interval of from 5 up to 20 mg / L.

20. The method according to any one of claims 9 to 19, wherein contacting water or the aqueous solution comprises contacting water, preferably ultrapure water or tap water, with the solid calcium silicate containing phase.

21. The method according to any one of claims 9 to 20, wherein removing the solid calcium silicate containing phase comprises centrifuging the solid calcium silicate containing phase and the water or the aqueous solution to form the calcium silicate supernatant comprising calcium ions and silicate ions.

22. The method according to any one of claims 9 to 21 , wherein the solid calcium silicate containing phase comprises the solid calcium silicate containing powder or particles, optionally having a grain size of below 700 pm, preferably equal to or below 500 pm, and more preferably equal to or below 300 pm.

23. The method according to any one of claims 1 to 22, wherein the calcium silicate supernatant has a pH selected within an interval of from 4.5 up to 8.5, preferably selected within an interval of from 6 up to 8.

24. The method according to any one of claims 1 to 23, wherein the calcium silicate supernatant has a calcium concentration of at least 10 mg / L, preferably selected within an interval of from 10 up to 50 mg / L, and more preferably selected within an interval of from 10 up to 30 mg / L.

25. The calcium silicate supernatant according to any one of claims 1 to 24, wherein the calcium silicate supernatant has a silicon concentration of at least 5 mg / L, preferably selected within an interval of from 5 up to 30 mg / L, and preferably selected within an interval of from 5 up to 20 mg / L.

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