JP6820710B2 - Three-element liquid fertilizer containing humic acid - Google Patents

Description

The present invention relates to a three-element liquid fertilizer containing humic acid and a method for producing the same.

It is said that humic acid has an effect of promoting growth on plants (Non-Patent Documents 1 and 2), and it has been proposed to use humic acid as a fertilizer. Further, a technique for extracting and liquefying this humic acid has also been proposed (Patent Documents 1 and 2).

Here, humic acid is a natural high molecular weight organic substance existing in soil and terrestrial water, and includes those contained in lignite and peat, metabolites of bacterial groups, and natural humic acid derived from animals and plants. In addition, industrially, there are many such as oxidatively decomposed young charcoal such as brown charcoal (Patent Document 3) or a compound such as an alkali metal salt or an alkaline earth metal salt of the oxidative decomposition product (Patent Document 3). 4, 5).

When these humic acids are used as fertilizers, it is desirable to use them in combination with fertilizer components such as nitrogen, phosphoric acid and potassium. This is because humic acid has effects such as promoting rooting and promoting absorption of fertilizer components, but the ability to supply the above fertilizer components is low or almost nonexistent.

In recent years, hydroponic cultivation in which liquid fertilizer is applied to soil has become widespread in garden crops such as tomatoes, and the use of liquid fertilizer is expanding. In addition, hydroponics in plant factories is becoming widespread. Therefore, since humic acid is used as a liquid fertilizer, an effective extraction method thereof has been proposed (Patent Document 6).

JP-A-2007-196172 Japanese Unexamined Patent Publication No. 2005-89615 Special Publication No. 40-14122 Japanese Unexamined Patent Publication No. 60-18565 Japanese Unexamined Patent Publication No. 51-72987 Japanese Patent Application No. 2015-198501

Akashi et al., Journal of Japanese Society of Soil Science and Technology, Vol. 46, No. 5, P175-179 Yamada et al., Journal of Japanese Society of Soil Science and Technology, Vol. 73, No. 6, P777-781

In general, humic acid has good solubility on the alkaline side, so extraction is often carried out at a pH of 7.0 or higher, and the pH of commercially available products is often around 12, which is strongly alkaline. Therefore, when it is used as a fertilizer, it may be different from the optimum pH of the crop and the solubility of the fertilizer component may be deteriorated. There is also a handling risk.

In order to reduce transportation costs, liquid fertilizers are often shipped in a concentrated state at the time of supply and diluted 300 to 1,000 times with water at the time of use.

As described above, humic acid needs to be used in combination with an appropriate fertilizer component, but if the fertilizer component is mixed in a concentrated state, there is a problem that humic acid precipitates due to salting out or co-precipitation. One of the advantages of liquid fertilizer is that it dissolves quickly and becomes uniform when diluted, but liquid fertilizer that has settled requires time and effort such as stirring and dissolving. Further, the precipitation of humic acid generated by salting out or the like is difficult to redissolve and causes non-uniformity of components, and there is a concern that the liquid feeding line may be clogged due to the precipitation.

The humic acid-containing three-element liquid fertilizer according to the present invention is a liquid containing three-element fertilizer components of nitrogen, phosphoric acid, and potassium, whose pH is near neutral, which is suitable for plant growth, and which does not easily form a precipitate even in a concentrated state. It is fertilizer.

The pH fluctuates depending on the dissolution of the fertilizer component, but if the pH of the humic acid extract is in the range of 5.0 to 7.0, the target pH range can be obtained. The above problems can be solved by limiting the extraction pH of humic acid and defining the types of fertilizer components to be dissolved.

According to the present invention, it is possible to provide a concentrated liquid fertilizer containing humic acid and a three-element fertilizer component of nitrogen, phosphoric acid and potassium. These humic acid-containing three-element liquid fertilizers have a pH suitable for plant growth, are less likely to precipitate, dissolve quickly when diluted, homogenize the components, and prevent problems such as clogging of the liquid feeder. It is possible to do. This provides a composition of a humic acid-containing three-element liquid fertilizer suitable for growing crops, which is a combination of humic acid and fertilizer components.

Hereinafter, embodiments of the humic acid-containing three-element liquid fertilizer according to the present invention will be described.

[Measurement of pH]
The pH of the humic acid-containing three-element liquid fertilizer was measured by the glass electrode method. When the concentrated liquid fertilizer is diluted with water, the pH changes due to the dilution effect. Here, the pH was measured in a concentrated state, and if it was in the target pH range, the pH approached 7.0 and remained within the target range, so the measurement was performed in a concentrated state.

[Total organic carbon concentration]
The method for measuring the total organic carbon (TOC) concentration of the extract is a value measured by a combustion catalytic oxidation method using a total organic carbon meter (TOC-L manufactured by Shimadzu Corporation). TOC is not a direct quantitative value of humic acid. In the present invention, a TOC that can be easily quantified is used as an index as compared with a complicated method for quantifying humic acid (such as the International Humus Society Method). There is a strong correlation between these values, and although it depends on the type of lignite used as a raw material, the amount of humic acid can be estimated to be 1.4 to 1.8 times that of TOC.

[Verification of precipitation amount]
35 g of a humic acid-containing three-element liquid fertilizer at 20 ° C. was placed in a 50 ml centrifuge tube and centrifuged at 3,500 × g for 5 minutes. The supernatant was removed, the precipitate was dried at 105 ° C. to a constant weight, and the precipitate was weighed to determine the mass of the precipitate. The amount of precipitation of the humic acid-containing three-element liquid fertilizer was expressed as the precipitation rate (precipitation mass ÷ liquid fertilizer mass × 100 (mass%)).

[Content and notation of fertilizer component]
The fertilizer component is expressed as the content of that component, but the nitrogen component is expressed as nitrogen (N). Phosphoric acid, potassium is denoted in the form of traditionally oxide, phosphorus pentoxide (P2 O5), expressed in terms of the content of the potassium oxide (K ₂ O). Hereinafter, the content and notation of fertilizer components are as described above.

As the humic acid according to the present embodiment, a solution obtained by oxidizing young charcoal such as lignite with nitric acid is extracted from a crude product of humic acid using an aqueous potassium hydroxide solution at pH 5.0 to 7.0 and centrifuged. (Patent Document 6). The fertilizer component is dissolved in this humic acid extract.

As the fertilizer component, the raw materials shown in Table 1 can be selected.

As a result of examination, it was found that these raw materials are water-soluble, can be mixed with a humic acid extract, and that precipitation is unlikely to occur by appropriately selecting a combination in consideration of pH and target component values.

It is desirable to change the mixing ratio of humic acid and the three-element fertilizer component depending on the type of crop such as leaf vegetables (for example, komatsuna) and fruit vegetables (for example, tomato) and the fertilizer application application.

It is necessary to adjust appropriately according to the number of applications, but when applying the three-element component and humic acid in a well-balanced manner like leafy vegetables, it is possible to design with the same proportion of fertilizer component and humic acid. Further, in the case of using humic acid as a supplement mainly for humic acid such as fruits and vegetables, it is possible to design to increase the ratio of humic acid and reduce the amount of humic acid compounded. Hereinafter, a V-shaped design (design in which the component value is nitrogen = potassium> phosphoric acid), which is common in top dressing applications, will be described as a representative.

<Action effect>
Hereinafter, the action and effect of the humic acid-containing three-element liquid fertilizer according to the above embodiment will be described.

The humic acid-containing three-element liquid fertilizer according to the above embodiment is a concentrated solution extracted from the nitrate oxide of juvenile charcoal, which is obtained by adding a fertilizer component to the humic acid extract and having a pH of 6.5 to 7.5, which is less likely to cause precipitation. It is characterized by being. The pH of the liquid fertilizer prepared by dissolving the fertilizer component fluctuates, but by using a humic acid extract with a pH of 5.0 to 7.0 and appropriately selecting the fertilizer component to be dissolved, the pH is near neutral and precipitates. It is possible to prepare a three-element liquid fertilizer containing humic acid, which is less likely to cause humic acid.

The humic acid-containing three-element liquid fertilizer can be produced by selecting the type and content of humic acid and fertilizer raw materials from the above raw materials depending on the intended use and the target crop.

Since the pH of these humic acid-containing three-element liquid fertilizers is near neutral, which is suitable for growing crops, and precipitation is unlikely to occur, it is easy to prepare a uniform diluted solution, and hydroponic cultivation, hydroponics, etc. It can be used as a liquid fertilizer.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples.

[Example 1]
[Humic acid extract]
500 g of lignite was placed in a 2 liter beaker and 630 g of nitric acid having a concentration of 48% by mass was added. After an oxidation reaction was carried out in a water bath at 70 ° C. for about 1 hour, it was dried at 105 ° C. to obtain a crude humic acid product.
Approximately 900 mL of a 0.5 mol / L potassium hydroxide aqueous solution was added to 100 g of this crude humic acid product, and a 1.0 mol / L potassium hydroxide aqueous solution was appropriately added while monitoring with a pH meter to adjust the pH to 6.5. Water was added to make up to 1 liter, and the mixture was extracted at 80 ° C. for 1 hour. This extract was centrifuged at 3,000 × g for 10 minutes to obtain a humic acid extract containing 3.7% by mass of humic acid as TOC and 1.8% by mass of potassium oxide in terms of potassium oxide. 50 g of water was added to 820 g of this humic acid extract, 92 g of urea and 38 g of dipotassium hydrogen phosphate were sequentially added and dissolved by stirring to prepare 1,000 g of a humic acid-containing three-element liquid fertilizer. The pH and precipitation rate of this liquid fertilizer were measured as described above.

[Example 2]
About 900 mL of a 0.4 mol / L potassium hydroxide aqueous solution was added to 100 g of the crude humic acid product, and the pH was adjusted to 5.5 while monitoring with a pH meter. Further, it was carried out in the same manner as in Example 1 except that 450 g of the obtained humic acid extract for pH 5.5 extraction, 408 g of water and 50 g of dipotassium hydrogen phosphate were used. The humic acid extract of Example 2 had a humic acid TOC of 3.0% by mass, and the potassium component had a potassium oxide equivalent of 1.4% by mass.

[Comparative Example 1]
About 900 mL of a 0.6 mol / L potassium hydroxide aqueous solution was added to 100 g of the crude humic acid product, and the pH was adjusted to 8.0 while monitoring with a pH meter. Further, it was carried out in the same manner as in Example 1 except that the obtained humic acid extract for pH 8 extraction was 740 g, water was 138 g, and dipotassium hydrogen phosphate was 30 g. The humic acid extract of Comparative Example 1 had a humic acid TOC of 4.1% by mass, and the potassium component had a potassium oxide equivalent of 2.5% by mass.

[Comparative Example 2]
About 900 mL of a 0.6 mol / L potassium hydroxide aqueous solution was added to 100 g of the crude humic acid product, and the pH was adjusted to 8.0 while monitoring with a pH meter. Further, it was carried out in the same manner as in Example 1 except that 350 g of the obtained humic acid extract for pH 8 extraction, 516 g of water and 42 g of dipotassium hydrogen phosphate were used.

As shown in the results of Table 2, the humic acid-containing three-element liquid fertilizers of Examples 1 and 2 according to the present invention have a pH in the range of 6.5 to 7.5 and a precipitation rate of 1% or less. The amounts of nitrogen, phosphoric acid, and potassium are also within the target range. In Comparative Examples 1 and 2, the pH exceeded the target values while the precipitation rate and the amount of components were also within the target ranges. In addition to the high pH of the humic acid extract, it is considered that the pH increased because the fertilizer component to be dissolved was alkaline. As in Comparative Example 2, in a design in which the amount of humic acid added is small, the pH buffering capacity is assumed to be low, which may lead to a further increase in pH. By appropriately selecting the pH and the amount of the humic acid extract to be added, a humic acid-containing three-element liquid fertilizer in a target range can be obtained.

[Selection of fertilizer components]
Subsequent examples and comparative examples used a humic acid extract having a pH of 6.5.

[Example 3]
The same procedure as in Example 1 was carried out except that 36 g of water was added to 820 g of the humic acid extract having a pH of 6.5, and 92 g of urea, 28 g of an 85 mass% phosphoric acid solution and 24 g of potassium hydroxide were sequentially added.

[Example 4]
The same procedure as in Example 1 was carried out except that 130 g of ammonium nitrate and 38 g of dipotassium hydrogen phosphate were sequentially added to 820 g of the humic acid extract having a pH of 6.5.

[Example 5]
The same procedure as in Example 1 was carried out except that 15 g of water was added to 820 g of the humic acid extract having a pH of 6.5, and 130 g of ammonium nitrate, 30 g of dipotassium hydrogen phosphate and 5 g of potassium chloride were added in that order.

[Example 6]
The same procedure as in Example 1 was carried out except that 15 g of water was added to 820 g of the humic acid extract having a pH of 6.5, and 130 g of ammonium nitrate, 30 g of dipotassium hydrogen phosphate and 5 g of potassium sulfate were added in that order.

[Comparative Example 3]
The same procedure as in Example 1 was carried out except that 38 g of water was added to 820 g of the humic acid extract, and 92 g of urea and 50 g of potassium dihydrogen phosphate were sequentially added.

[Comparative Example 4]
The same procedure as in Example 1 was carried out except that 128 g of 70% nitric acid, 28 g of 85 mass% phosphoric acid solution and 24 g of potassium hydroxide were sequentially added to 820 g of the humic acid extract.

[Comparative Example 5]
The same procedure as in Example 1 was carried out except that 128 g of 20% ammonia water, 28 g of 85% by mass phosphoric acid solution and 24 g of potassium hydroxide were sequentially added to 820 g of the humic acid extract.

As shown in the results of Table 3, the humic acid-containing three-element liquid fertilizers of Examples 3 to 6 according to the present invention have achieved the targets in terms of pH, precipitation rate, and component rate. On the other hand, in Comparative Examples 3 and 4, the humic acid extract gelled, and neither the pH nor the precipitation rate could be measured, so that the target humic acid-containing three-element liquid fertilizer could not be obtained. In Comparative Example 5, the precipitation rate was good, but the pH was significantly increased, and the amount of the components did not reach the target value. Acidic or alkaline fertilizer components have a large pH fluctuation at the time of mixing, and contribute to precipitation formation especially on the acidic side. In addition, the target amount of components cannot be achieved with a raw material having a low component ratio.

[Selection of fertilizer components 2]

[Example 7]
The same procedure as in Example 1 was carried out except that 430 g of water was added to 275 g of the humic acid extract having a pH of 6.5, and 220 g of urea, 75 g of an 85 mass% phosphoric acid solution and 70 g of potassium hydroxide were sequentially added.

[Comparative Example 6]
The same procedure as in Example 1 was carried out except that 395 g of water was added to 275 g of the humic acid extract having a pH of 6.5, 220 g of urea and 110 g of dipotassium hydrogen phosphate were sequentially added.

As shown in the results of Table 4, the humic acid-containing three-element liquid fertilizer according to Example 7 according to the present invention has an increased fertilizer component for top dressing of fruits and vegetables, but the pH, precipitation rate, and component rate are all increased. You have achieved your goal. On the other hand, the humic acid-containing three-element liquid fertilizer of Comparative Example 6 has a high pH and a high precipitation rate. The target value of the fertilizer component is sufficient, but the increase in pH is high due to the large amount of addition. Furthermore, the solubility is low and the precipitation rate is deteriorated.

[Cultivation test]
Below, a cultivation test was conducted to verify the effect of the humic acid-containing three-element liquid fertilizer, which was prototyped for leafy vegetables. Komatsuna (variety: Rakuten, Takii & Co., Ltd.) was used as a prototype, and a cultivation test of a humic acid-containing three-element liquid fertilizer was conducted by pot cultivation. Put 1 L of Akadama soil in a 1.2 liter poly pot (manufactured by Fujiwara Seisakusho Co., Ltd.), and add 1.0 g of calcium carbonate, 0.33 g of ammonium sulfate, 0.29 g of superphosphate, and 0.08 g of potassium chloride as basal fertilizer. It was applied. It should be noted that this is the same amount of fertilizer application as the application of 7 kg of nitrogen component, 5 kg of phosphoric acid component and 5 kg of potassium component per 10a.

The three-leaf stage seedlings germinated and raised in the cell tray in advance were transplanted to pots and cultivated for 35 days. Irrigation was carried out as appropriate by observing the condition of the crop. After cultivation, the above-ground part (stem and leaf part) was cut, and the mass of each was measured and used as the yield. The test was carried out at n = 5 and represented by an average value.

[Example 8] The humic acid-containing three-element liquid fertilizer obtained in Example 1 was diluted with water so as to be 1,000 times, and 50 ml per pot was applied every 7 days. It was applied 4 times during the cultivation period.

[Comparative Example 7] Instead of the added humic acid-containing three-element liquid fertilizer, a control liquid fertilizer containing nitrogen, phosphoric acid, and potassium components equivalent to those of the humic acid-containing three-element liquid fertilizer was prepared, and the same as in Example 8. Carried out.

Below, a cultivation test was conducted to verify the effect of the humic acid-containing three-element liquid fertilizer, which was prototyped for fruit and vegetable use. Tomatoes (variety: CF Momotaro York, seedlings purchased at a seedling shop) were used as prototypes, and cultivation tests were conducted in a heated greenhouse at the Denka Omi Plant. The number of strains in one test group was 16. As the basal fertilizer, 10.8 g of nitrogen component, 10.2 g of phosphoric acid component, and 10.8 g of potassium component were applied per strain. This is the same amount of fertilizer application as the application of 16 kg of nitrogen component, 15 kg of phosphoric acid component and 16 kg of potassium component per 10a.

Seedlings were planted on October 27, 2015, and the first top dressing was carried out on December 21, 2015, which is the flowering period of the first inflorescence, and the second top dressing was carried out on January 29, 2016. Harvesting of tomato fruits started around the end of January, and the initial yield for about one month was measured.

[Example 9] The humic acid-containing three-element liquid fertilizer obtained in Example 7 was diluted with water so as to be 50 times, and 1,000 ml per strain was applied. As mentioned above, it was applied twice during the cultivation period.

[Comparative Example 8] Instead of the humic acid-containing three-element liquid fertilizer added in Example 9, a control liquid fertilizer containing the same nitrogen, phosphoric acid, and potassium components as in Example 9 was prepared, and the same as in Example 9. Carried out.

As shown in the results of Table 5, the humic acid-containing three-element liquid fertilizer of Example 1 according to the present invention worked effectively on the growth of Komatsuna and increased the growth amount of the above-ground part. In addition to the effect of the fertilizer component, it is considered that the effect of promoting the growth of humic acid contributed to the growth of the above-ground part.

In addition, as shown in the results in Table 6, the humic acid-containing three-element liquid fertilizer of Example 9 according to the present invention significantly improved the yield of tomatoes. This example is short-term data for about one month from the start of harvesting. It can be considered that the improvement in the initial yield is a result of the effect of promoting the growth of crops and the early harvesting.

From the above two cultivation test results, it was found that liquid fertilizers with different component concentrations, target crops and three-element fertilizers containing humic acid have different effects, and are effective materials for agricultural production. It was.

Huhumic acid has agricultural advantages such as promoting the growth of crops when used in combination with fertilizer components such as nitrogen, phosphoric acid, and potassium. The humic acid liquid fertilizer according to the present invention contains humic acid-containing three-element fertilizer components of nitrogen, phosphoric acid, and potassium, has a pH near neutrality suitable for crop growth, and is less likely to form a precipitate even in a concentrated state. It is a liquid fertilizer. These humic acid-containing three-element liquid fertilizers are easily homogenized at the time of dilution, and when used in hydroponic cultivation or the like, precipitation does not occur, so that troubles such as clogging of the liquid feeding line can be avoided.

Claims (3)

A humic acid-containing three-element liquid fertilizer containing the following components (1) to (4), having a pH of 6.5 to 7.5 and a precipitation content of 1.0% by mass or less at a liquid temperature of 20 ° C.
(1) Humic acid is 1.0 to 3.0% by mass as TOC
(2) Nitrogen component is 4.0 to 10.5% by mass in terms of nitrogen
(3) Phosphoric acid component is 1.0 to 4.5% by mass in terms of phosphorus pentoxide
(4) Potassium component is 3.0 to 6.5% by mass in terms of potassium oxide The humic acid-containing three-element liquid fertilizer according to claim 1, wherein the nitrogen component, the phosphoric acid component and the potassium component are the following (1) to (3).
(1) At least one nitrogen component of urea and ammonium nitrate (2) At least one or more phosphoric acid component of phosphoric acid and dipotassium hydrogen phosphate (3) Potassium component is potassium hydroxide, potassium chloride, potassium sulfate and At least one or more of dipotassium hydrogen phosphate The method for producing a humic acid-containing three-element liquid fertilizer according to claim 1 or 2, wherein the fertilizer component is dissolved using a humic acid extract having a pH of 5.0 to 7.0.