Liquid fertilizer containing silica and iron

Abstract

To provide a liquid fertilizer containing silica and iron, which has excellent stability while suppressing a decrease in pH. [Solution] A liquid fertilizer containing acidic silica sol, supernatant of fermentation and distillation residue from distilled spirits, and water-soluble iron.

Description

Technical Field

[0001] The present invention relates to a liquid fertilizer used for cultivating plants in foliar spraying liquid, soil irrigation liquid, and hydroponics.

Background Art

[0002] Silicon is an important element for gramineous plants such as rice, wheat, and turf grass. By accumulating on the cell surface of stems and leaves, silicified cells are formed, which is known to prevent the invasion and damage of pathogenic bacteria and pests by improving mechanical strength and contribute to reducing damage. In addition, silicon suppresses lodging, thereby allowing the leaves to expand well, increasing the light reception efficiency, and promoting photosynthesis. Furthermore, effects such as enhancing drought tolerance, improving water use efficiency, and improving root growth are also known. In particular, in recent years, it has been reported that damage caused by abnormal weather such as high temperatures in summer, low temperatures in winter, and the return of cold in spring can be reduced. Therefore, the application of silicon is not only widespread in rice and turf grass with high silicon requirements but also in other plants.

[0003] Iron functions as a cofactor for various enzymes and is known to contribute to the formation of chlorophyll and enhance photosynthesis efficiency. Therefore, in turf grass that emphasizes appearance, it has a great impact on the color and gloss of the leaves. In rice, when the amount of iron decreases, root rot is likely to occur, and the so-called "autumn decline" phenomenon inhibits ripening, leading to a decrease in quality and yield. Thus, it is an important element similar to silicon.

[0004] In addition, it has been suggested that silicon and iron not only function independently in plants but also bring a synergistic effect. That is, silicon improves the leaf thickness and structure, and the synergistic effect with iron improves chlorophyll synthesis and electron transfer efficiency, strengthening the photosynthetic ability. Furthermore, silicon helps plants absorb iron, and there are examples where supplying silicon to rice and tomatoes has alleviated chlorosis (yellowing symptoms) caused by iron deficiency. It is also known to reduce various oxidative stresses and mitigate the toxins of harmful elements to plants, such as cadmium and aluminum, as a countermeasure against salt damage and heavy metal stress.

[0005] Currently, fertilizers that allow for the simultaneous application of silicon and iron are granular solids, such as wollastonite fertilizer, slag silicate fertilizer (calcium silicate), lightweight aerated concrete powder fertilizer, silica gel fertilizer, and silica hydrogel fertilizer. However, these fertilizers require considerable effort to apply, and after application, silica, iron, and other components gradually dissolve according to their solubility, resulting in problems such as the inability to expect immediate effects or synergistic effects between silica and other components. In particular, for rice and turf, there is a strong demand for fast-acting liquid fertilizers that contain high concentrations of both silicon and iron.

[0006] Typically, potassium silicate is used in liquid fertilizers containing silicon. However, its pH is quite high, around 10-11, so even diluting it 100-1000 times does not prevent adverse effects on plants. Therefore, it must be used after sufficient dilution, which presents the problem of not being able to supply plants with a sufficient amount of silicon. Furthermore, it is known that when the pH shifts towards neutral, the silica easily condenses, causing gelation or precipitation. In addition, since metal salts such as iron, zinc, manganese, and copper do not dissolve, it is not only impossible to incorporate these mineral components, but actually applying it can cause so-called trace metal elements such as iron ions, zinc ions, and copper ions contained in the soil or other liquid fertilizers to become insoluble, leading to deficiency disorders. Furthermore, in order to cope with extreme weather conditions, it is desirable to ensure the stability of liquid fertilizers in the maximum temperature range of around 30-40°C and the minimum temperature range of around 1-4°C, for use in barns, open fields, or greenhouses in the fields.

[0007] Patent Document 1 discloses a potassium silicate liquid fertilizer prepared by adding potassium silicate to a heated citric acid aqueous solution and stirring. This fertilizer has a pH adjusted to 8.5 and 9.5, resulting in a slightly lower burden on plants. Furthermore, minerals are added by incorporating EDTA, EDTA-Fe, EDTA-Mn, etc. Furthermore, Patent Document 2 discloses that by adding salts such as gluconic acid or sodium gluconate to potassium silicate, the chelating effect results in higher stability of silicic acid and metal ions compared to cases where metal salts such as iron, copper, zinc, and molybdenum are incorporated, and citric acid or EDTA is added. However, it is known that silicic acid precipitates during long-term storage, and gelation occurs relatively quickly, especially under low-temperature conditions in winter and high-temperature conditions in summer.

[0008] Furthermore, Patent Document 3 discloses an aqueous silicate solution containing one or more solubilizers selected from ethylene glycol, glycerin, diethylene glycol, dipropylene glycol, casein, gelatin, arginine, histidine, L-glutamic acid, soy protein-binding amino acids, and urea, with a pH of 5 to 7, and containing a complex of iron, zinc, calcium, and magnesium.

[0009] Furthermore, Patent Document 4 discloses a liquid fertilizer using colloidal silica, which is obtained by dispersing colloidal silica in water. This is an acidic silica sol obtained by dealkalizing an alkaline silica aqueous solution by ion exchange with a cation exchange resin, and then strengthening the siloxane bonds by maturing it with acid or alkali, and it contains iron and manganese. However, this liquid fertilizer may gel under low or high temperature conditions.

[0010] Furthermore, Patent Document 5 discloses a liquid silica fertilizer in which citric acid is added to an alkaline silica sol to lower the pH to 4 or below, and the silicon dioxide content is up to 19.7%, with iron, calcium, magnesium, boric acid, manganese, zinc, copper, and molybdenum stably blended in. However, the conditions under which silicon dioxide and iron are blended result in a strongly acidic pH of 1 or lower. This could potentially have adverse effects on plants when applied. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] Japanese Patent Application Publication No. 02-2837 [Patent Document 2] Japanese Patent Application Publication No. 07-101792 [Patent Document 3] Japanese Patent Application Publication No. 04-59514 [Patent Document 4] Japanese Patent Application Publication No. 09-268092 [Patent Document 5] Japanese Patent Publication No. 2014-009152 [Overview of the project] [Problems that the invention aims to solve]

[0012] The objective of the present invention is to provide a liquid fertilizer containing silicic acid and iron, which has excellent stability while suppressing a decrease in pH. [Means for solving the problem]

[0013] The inventors of this invention conducted extensive research to solve the above problems and, as a result, discovered that the above problems can be solved by using acidic silica sol and the supernatant of the fermentation distillation residue of distilled spirits, thus completing the present invention.

[0014] In other words, the present invention includes the following embodiments. (1) A liquid fertilizer containing acidic silica sol, supernatant of fermentation distillation residue of distilled spirits, and water-soluble iron. (2) Furthermore, the liquid fertilizer according to (1), which contains one or more selected from the group consisting of water-soluble magnesium, water-soluble calcium, water-soluble manganese, water-soluble boron, water-soluble zinc, water-soluble copper, and water-soluble molybdenum. (3) Furthermore, the liquid fertilizer according to (1) or (2), which contains citric acid. (4) The liquid fertilizer according to any one of (1) to (3), which contains 1 to 20% by mass of acidic silica sol as silicon dioxide and 0.1 to 3% by mass of water-soluble iron as iron ions. (5) The liquid fertilizer according to any one of (1) to (4), which is for gramineous plants.

Advantages of the Invention

[0015] The liquid fertilizer of the present invention can suppress quality deterioration due to long-term gelation, separation and precipitation not only at normal temperature around 20 °C, but also at high temperature of 30 to 40 °C and low temperature of 1 to 4 °C. In addition, silicic acid and iron can be blended at relatively high concentrations respectively. In that case, it is possible to obtain the strengthening of the plant body, the improvement of photosynthesis efficiency, the improvement of stress resistance to high temperature, low temperature, drying, etc., and the pest prevention effect, which were difficult with conventional liquid silicic acid fertilizers.

Modes for Carrying Out the Invention

[0016] The acidic silica sol used in the present invention can use liquid raw materials such as sodium silicate and potassium silicate, for example, and is formed by removing sodium ions and potassium ions using a cation exchange resin or the like until the pH of the liquid raw material becomes 2 to 4, and is a silica sol in which Na on the surface is removed and becomes an OH group. The particle size of the acidic silica sol is not particularly limited, but is preferably 3 to 60 nm, more preferably 5 to 40 nm, still more preferably 8 to 30 nm, and particularly preferably 10 to 20 nm. As the acidic silica sol, synthetic products or commercially available products may be used. Examples of commercially available products include Snowtex (registered trademark) ST-O, OXS, OS, O-40, OL, OYL, etc. manufactured by Nissan Chemical Industries, Ltd.

[0017] The content of the acidic silica sol in the liquid fertilizer of the present invention is not particularly limited, but from the viewpoint of the plant growth promoting effect and the like, it is preferably 1 to 40% by mass as silicon dioxide, more preferably 1 to 20% by mass, still more preferably 5 to 20% by mass, and particularly preferably 10 to 15% by mass.

[0018] In addition, the supernatant of the fermented distillation residue of distilled liquor used in the present invention is the supernatant obtained by solid-liquid separation of the fermented distillation residue generated in the production process of distilled liquor such as shochu or awamori, and it is also drunk as a food as "moromi vinegar". That is, it is a fraction obtained by further solid-liquid separation of the residue after distilling alcohol from the moromi fermented with shochu or awamori raw materials and koji mold using a filter press or the like.

[0019] The content of the supernatant of the fermented distillation residue of distilled liquor in the liquid fertilizer of the present invention is not particularly limited, but from the viewpoint of stability and the like, 1 to 40% by mass is preferable, 5 to 45% by mass is more preferable, and 10 to 35% by mass is still more preferable.

[0020] Iron contributes to the electron transport system in photosynthesis and the redox reactions necessary for respiration, and is related to the formation of chlorophyll. Therefore, when lacking, the color of the leaves changes from yellow to white, and growth inhibition occurs. Although the required amount of plants is large and it exists in a relatively high concentration in the cultivation environment such as soil, it is easily oxidized and has low solubility under alkaline conditions, so it needs to be supplied in a state of ions that plants can easily absorb. Examples of the water-soluble iron used in the present invention include ferrous sulfate, ferrous nitrate, ferrous chloride, ferrous phosphate, ferrous acetate, ferrous citrate, ferrous gluconate, ferrous ascorbate, and the like.

[0021] Magnesium is a component of chlorophyll and is involved in the metabolism of carbohydrates and phosphoric acid. When lacking, chlorosis between leaf veins occurs. Examples of water-soluble magnesium compounds include magnesium nitrate, magnesium chloride, magnesium acetate, etc., and they can be used alone or in combination.

[0022] Calcium, in combination with pectic acid, contributes to the formation and strengthening of plant cell membranes. Deficiency inhibits the development of apical buds and root hairs. Water-soluble calcium compounds include calcium nitrate, calcium chloride, calcium acetate, calcium lactate, calcium gluconate, and calcium ligninsulfonate, which can be used individually or in combination.

[0023] Manganese is involved in chlorophyll production, photosynthesis, and vitamin C synthesis. Deficiency can cause yellowing between leaf veins. Water-soluble manganese compounds include manganese sulfate, manganese nitrate, manganese chloride, and manganese acetate, which can be used individually or in combination.

[0024] Boron is involved in calcium absorption and transport, and contributes to maintaining cell wall structure by binding with pectin polysaccharides. Deficiency leads to the cessation of new leaf growth and inhibits the elongation of root hair cells. Water-soluble boron compounds include boric acid and sodium borate, which can be used individually or in combination.

[0025] Zinc is a component of enzymes in the body and is involved in glycolysis and the citric acid cycle. Deficiency can cause malformations in new leaves and yellowing of the intervenea. Water-soluble zinc compounds include zinc sulfate, zinc nitrate, zinc chloride, and zinc acetate, which can be used individually or in combination.

[0026] Copper is a component of enzymes in plants and is involved in oxidation-reduction reactions. Deficiency inhibits the growth of new leaves and causes yellowing of the leaves. Water-soluble copper compounds include copper sulfate, copper nitrate, copper chloride, and copper acetate, which can be used individually or in combination.

[0027] Molybdenum is a component of enzymes in plants and is involved in nitrogen fixation and nitrate reduction by rhizobia. Deficiency can lead to leaf deformities and wilting. Water-soluble molybdenum compounds include sodium molybdate and ammonium molybdate, which can be used alone or in combination.

[0028] The content of water-soluble iron raw material in the liquid fertilizer of the present invention is not particularly limited, but from the viewpoint of plant growth promoting effect and stability, it is preferably 0.1 to 3% by mass as iron, more preferably 0.5 to 3% by mass, and even more preferably 1 to 2% by mass.

[0029] The liquid fertilizer of the present invention may further contain 0.01 to 8% by mass of magnesium as magnesium oxide (MgO), 0.01 to 15% by mass of calcium as calcium oxide (CaO), 0.01 to 2% by mass of manganese as manganese oxide (MnO), 0.01 to 2% by mass of boron as diboron trioxide (B2O3), 0.001 to 1% by mass of zinc, 0.0005 to 1% by mass of copper, and 0.0001 to 0.1% by mass of molybdenum, with one or more of these being commonly used as water-soluble raw materials in liquid fertilizers, blended according to the plant's requirements.

[0030] Furthermore, in order to fully exhibit the synergistic effect of silicon and iron, it is preferable that the acidic silica gel contains 1 to 20% by mass as silicon dioxide and 0.1 to 3.0% by mass as water-soluble iron ions, and more preferably that it contains 10% by mass or more as silicon dioxide and 1% by mass or more as iron ions. It is hypothesized that the synergistic effects of silicon's cell wall strengthening and stress-resilience-enhancing properties, and iron's photosynthesis and respiration-promoting effects, occur when silicon and iron are present in sufficiently stable conditions.

[0031] The liquid fertilizer of the present invention may contain other fertilizer components as needed, as long as they do not impair the effects of the present invention.

[0032] The liquid fertilizer of the present invention can be prepared by mixing the above components according to conventional methods. The pH of the liquid fertilizer of the present invention is not particularly limited, but from the viewpoint of its effect on plants, it is preferably greater than 1.8 and less than or equal to 5, and more preferably greater than 2 and less than or equal to 4.

[0033] The liquid fertilizer of the present invention is not particularly limited in terms of the plants to which it can be applied. For example, it can be applied to a wide range of plants such as cucumbers, strawberries, leeks, and tomatoes. However, because a synergistic effect between silicon and iron is easily obtained, it is particularly suitable for grasses such as rice, wheat, and turf. Grasses have the highest silicon requirements and silicon is easily accumulated as silicified cells in their leaves and stems, so it is thought that the synergistic effect between silicon and iron is easily exerted in them. In particular, recent extreme weather events such as high summer temperatures and low winter temperatures significantly reduce the quality and yield of rice, and improving stress tolerance can help maintain or improve the quality of the rice. Furthermore, since rice is known to absorb cadmium particularly easily, the accumulation of harmful heavy metals can be suppressed. Also, turf is constantly exposed to threats such as lodging due to being trampled, breakage of leaves and stems, friction from clubs and putters on golf courses, and root breakage. To mitigate this damage and stress, and because its aesthetic appeal is important throughout the year, there is a great demand for liquid fertilizers that contain high concentrations of silicon and iron in a stable state.

[0034] The liquid silica fertilizer of the present invention can be diluted with water 100 to 2000 times and used as a foliar spray, soil drenching solution, and nutrient solution for hydroponics. It can also be easily mixed with other liquid fertilizers and pesticides when diluted. For foliar application, a manual or electric sprinkler can be used. For soil drenching and hydroponics, the diluted solution can be placed in a tank and used with irrigation tubes, drip tubes, etc. [Examples]

[0035] The liquid fertilizer of the present invention (hereinafter referred to as "the present invention fertilizer") will be described in more detail below with reference to examples, but the present invention is not limited in any way to these examples.

[0036] Examples 1-5, Comparative Examples 1-4 The presence or absence of gelation or precipitation, color, and pH of liquid silicate fertilizers with various formulations shown in Table 1 below were evaluated at various temperatures.

[0037] (1) Preparation of liquid fertilizer Liquid fertilizer was prepared according to the formula in Table 1. As the supernatant of the distilled spirits fermentation distillation residue, moromi vinegar pressed liquid (manufactured by Masahiro Shuzo Co., Ltd.), obtained by solid-liquid separation of awamori distillation residue, was used. To this, iron (ferrous sulfate heptahydrate, manufactured by Shinyo Co., Ltd.), magnesium (magnesium sulfate heptahydrate TPC fertilizer, manufactured by Mai Kasei Kogyo Co., Ltd.), calcium (calcium chloride, 70% purity calcium chloride, for snow removal), boron (boric acid, manufactured by USBorax Inc.), manganese (manganese sulfate monohydrate, manufactured by Shinyo Co., Ltd.), zinc (zinc sulfate heptahydrate, manufactured by Shinyo Co., Ltd.), and copper (copper sulfate, manufactured by Sumitomo Metal Mining Co., Ltd.) were added and stirred well after each addition to dissolve. To this solution, Snowtex® ST-O (containing 20% ​​silicon dioxide, manufactured by Nissan Chemical Corporation) was added as an acidic silica sol, and the mixture was thoroughly stirred to prepare the liquid fertilizer of the present invention. Furthermore, liquid fertilizers were prepared and tested in the same manner using citric acid (anhydrous, manufactured by RZBC (JUXIAN) CO. LTD) instead of or in addition to the moromi vinegar extract, and using Surfloid (containing 30% silicon dioxide, manufactured by Aichi Keiso Kogyo Co., Ltd.) as an alkaline silica sol instead of the acidic silica sol. The values ​​in the table represent mass percent.

[0038] (2)pH measurement The liquid fertilizer prepared in (1) was collected and its pH was measured using a pH meter (LAQUA twin, manufactured by Horiba, Ltd.). (3) Storage stability test at 40°C, room temperature, and 1°C The liquid fertilizer prepared in (1) was placed in a constant temperature chamber set to 40°C, a refrigerated chamber set to 1°C, and its color, presence or absence of gelation, etc., under room temperature conditions (20-25°C), and observed visually every day.

[0039] [Table 1]

[0040] As shown in Table 1, when 0.1% citric acid and 1.4% iron were added to the alkaline silica sol, gelation occurred immediately after preparation, as shown in Comparative Example 1. Also, as shown in Comparative Examples 2 and 3, when 50% and 47% of moromi vinegar extract and 1.4% and 2.8% of iron were added to the alkaline silica sol, gelation occurred immediately after preparation. When citric acid was used instead of moromi vinegar extract, the pH was a low value of 1.5. On the other hand, in the fertilizers of the present invention shown in Examples 1 to 5, under conditions in which mash extract and iron were added to acidic silica sol, no gelation or precipitation occurred for more than three months in any of the cases.

[0041] The effects on plants were evaluated under various conditions shown in Table 2 below. (1) Tomato cultivation experiment Tomato seedlings (Momotaro variety) were transplanted into 10.5cm PP pots using commercially available potting soil, and 18 such pots were prepared. These were grown under normal conditions, and the fertilizer of the present invention was applied under conditions A and B. The growth rate was then compared with that of normal cultivation. Six pots were used for each condition. Furthermore, 28 days later, the above-ground portion was cut at the base, its weight was measured, and the average weight was calculated. After washing the soil from the roots, they were dried at 60°C for 4 hours, and then their weight was measured and the average weight was calculated. (conditions) Under condition A, a 1000-fold dilution of the fertilizer of the present invention from Example 3 was applied as a foliar spray at a frequency of 30 ml per pot once a week. Under condition B, a 1000-fold dilution of the fertilizer of the present invention from Example 3 was applied as a drenching at the base of each pot at a frequency of 30 ml per pot once a week. [Table 2]

[0042] (2) Turf cultivation experiment Korean grass mats were placed on topsoil, and 500-fold and 1000-fold dilutions of the fertilizer of the present invention from Example 5 were uniformly applied as a foliar spray at a rate of 200 ml / m² once a week. As a result, compared to areas where foliar spraying was not performed, the grass became stronger and tended to be slightly darker green. This is thought to be due to the synergistic fertilizer effect of the iron contained in the fertilizer, along with the fertilizer effect of silica on the grass.

Claims

1. A liquid fertilizer containing acidic silica sol, supernatant of fermentation and distillation residue from distilled spirits, and water-soluble iron.

2. Furthermore, the liquid fertilizer according to claim 1 contains one or more selected from the group consisting of water-soluble magnesium, water-soluble calcium, water-soluble manganese, water-soluble boron, water-soluble zinc, water-soluble copper, and water-soluble molybdenum.

3. The liquid fertilizer according to claim 1 or 2, further containing citric acid.

4. The liquid fertilizer according to claim 1 or 2, comprising 1 to 20% by mass of acidic silica sol as silicon dioxide and 0.1 to 3% by mass of water-soluble iron as iron ions.

5. The liquid fertilizer according to claim 1 or 2, which is for use on grasses.

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