JPH11228276A - Liquid fertilizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a liquid fertilizer, especially a liquid fertilizer for foliar application. SOLUTION: This liquid fertilizer contains, as active ingredient, a liquid obtained by separating diatomaceous earth after either one step of (1) a step for proliferating a large amount of yeast by using sugar as a raw material in sugar contained in saccarificated diatomaceous earth and adding an amino acid crystallized mother liquor thereto and treating the mother liquor with the yeast, (2) a step for autodigesting bacteria of bacterial cell-containing diatomaceous earth in the presence of diatomaceous earth and adding amino acid crystallized mother liquor thereto and treating the mother liquor with the yeast and (3) a step for mixing materials obtained in the steps (1) and (2).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid fertilizer using an amino acid crystallization mother liquor, and more particularly, to a mild amino acid crystallization mother liquor obtained by recovering an amino acid from an amino acid fermentation liquor by isoelectric crystallization. Related to liquid fertilizer. This liquid fertilizer is particularly suitable for foliar application.

[0002]

2. Description of the Related Art In order to separate amino acids produced from an amino acid fermentation solution such as phenylalanine, for example, first, fermentation cells are removed from the amino acid fermentation solution by using diatomaceous earth (eg, “Celite”) as a filter aid, The resulting filtrate is concentrated, the pH is adjusted to the isoelectric point of the generated amino acid to crystallize the amino acid, and finally the crystallized amino acid is subjected to solid-liquid separation to be separated from the mother crystallization liquid. (Isoelectric point crystallization method). Here, the isoelectric point in the case of adjusting to the isoelectric point of an amino acid does not always coincide with the isoelectric point of the amino acid in a pure system. For example, the isoelectric point of phenylalanine in a pure system is said to be 5.48, but when a phenylalanine fermentation solution is concentrated and its pH is adjusted to precipitate phenylalanine, the phenylalanine concentration in the mother liquor (crystallization mother liquor) is determined. Is usually about 4.5 (isoelectric point). This difference is, of course, due to co-existing impurities, and is similar for other amino acids.

[0003] The amino acid crystallization mother liquor by-produced in the method for separating amino acids from amino acid fermentation liquor is balanced with various organic components (proteins, various amino acids, polysaccharides, oils and fats) and ammonium sulfate. It is evaluated as a raw material for liquid fertilizers containing minerals. That is, when the crystallized mother liquor is diluted to an appropriate concentration and applied to the crops from the roots, there is no obstacle to the crops, and the fertilizing effect is assured. However, foliar application has been avoided for reasons such as a high content of inorganic compounds such as ammonium sulfate.

[0004] On the other hand, for example, in facility horticulture, liquid fertilizer is often sprayed on the leaves at important points in the seedling making stage and also in the main garden to recover the tree vigor. In particular, strawberries, eggplants, tomatoes, etc., which repeatedly harvest fruits, have a long cultivation period, and in some cases it is necessary to apply liquid fertilizer from the leaf surface that is effective immediately to maintain the growth of fruits and trees at the same time as flower bud formation. Many.

[0005] The following are commercially available liquid fertilizers for foliar spraying. In other words, minerals alone, sugars such as molasses and brown sugar that have been fermented for a long time and partially converted to organic acids, plant extracts containing elements such as Chinese herbal medicine, and special ingredients Those indicated include cytokinins and photosynthetic bacteria, as well as mixtures thereof. However, in many cases, their composition and origin are not perfect, and their effects are often not clear. Therefore, development of a foliar spraying agent (liquid fertilizer for foliar spraying), which has a known composition and origin and has little or no obstacle due to an increase in osmotic pressure due to concentration in crops, and has a clear effect, is greatly expected.

[0006]

SUMMARY OF THE INVENTION Under the background of the prior art described in the preceding paragraph, the present invention aims to develop and provide a liquid fertilizer suitable as a liquid fertilizer for foliar application described at the end of the same paragraph. .

[0007]

In order to achieve the above-mentioned object, the present inventor improved the above-mentioned amino acid crystallization mother liquor, which is practically used as a liquid fertilizer to be applied from the root, so as to be suitable for foliar spraying. As a result of diligent research (also referred to as mildening, the specific method will be described later), this amino acid crystallization mother liquor and the spent diatomaceous earth generated in connection with amino acid fermentation (the one used for purification of the saccharified liquid, It has been found that an excellent liquid fertilizer for foliar application can be obtained by skillfully combining and using the yeast used for removing the body) and yeast, and based on such findings, the present invention has been completed. . The liquid fertilizer for foliar application of the present invention can, of course, be used as a liquid fertilizer applied from the root.

That is, the present invention provides (1) a step of subjecting a sugar contained in saccharified diatomaceous earth to a large amount of yeast using the saccharified diatomaceous earth as a raw material and then adding an amino acid crystallization mother liquor; and (2) a step of diatomaceous earth containing bacterial cells. Any of the steps of: subjecting the bacterium to self-digestion in the presence of diatomaceous earth, and then adding an amino acid crystallization mother liquor; and (3) mixing the products obtained in (1) and (2) above. After that, the present invention relates to a liquid fertilizer characterized in that a liquid obtained by separating diatomaceous earth is used as an active ingredient, and a use of the liquid fertilizer for foliar application of such a liquid fertilizer.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

[0010] The present invention relates to a liquid fertilizer obtained by mildening an amino acid crystallization mother liquor which has already been put into practical use as a liquid fertilizer, particularly a liquid fertilizer for foliar spraying, as described above.
For this mildening, if possible, (a) it is necessary to contain minerals in a well-balanced manner, even if the concentration is low, and (b) it is necessary to lower the osmotic pressure. Ammonium, reducing the proportion of ammonium sulfate
(C) amino acids, which increase organic nitrogen such as proteins,
Sugars, fats and oils are low in the raw materials and are useful for plants. Organic acids are increased without being reduced. (D) Microorganisms such as yeasts used for mildening are used to prevent spoilage. Etc. are kept alive without sterilization, and (e)
The trial production was repeated based on the fact that the odor peculiar to the amino acid crystallization mother liquor was reduced in consideration of foliar spraying.

The diatomaceous earth used in the method of the present invention is not particularly limited, and for example, "Celite" can be used.

The amino acid of the mother liquor for crystallization of amino acids used in the method of the present invention is not particularly limited, and may be, for example, any of phenylalanine, tryptophan, tyrosine, leucine, isoleucine, threonine, serine, valine, histidine, lysine, and glutamic acid.

There is no particular limitation on the solid content of the mother liquor for amino acid crystallization, but it goes without saying that if the solid content of the amino acid or the like is below the saturated state, it is advantageous in the treatment operation. In addition, the amino acid crystallization mother liquor usually contains glucose as a solid component in addition to amino acids, such as polysaccharides, fats and oils, minerals, etc., in which glucose is connected several times.

Further, a concentrated solution obtained by directly concentrating the amino acid fermentation solution, a directly dried product of the amino acid fermentation solution, or the like can be added to the amino acid crystallization mother liquor, if necessary or desired.

There are two types of spent diatomaceous earth generated in connection with fermentation of amino acids such as phenylalanine.
One is saccharified diatomaceous earth. Generally, when glucose is required as a carbon source for amino acid fermentation, starch is hydrolyzed enzymatically or chemically using an acid or alkali to form a saccharified solution, and diatomaceous earth filtration is performed to convert the saccharified solution into a clarified glucose solution. The used diatomaceous earth used for such filtration is called saccharified diatomaceous earth. This includes 10
25% by weight, for example about 20% by weight of glucose and 25 to
35% by weight, for example about 30% by weight, of water remains. The other is diatomaceous earth containing bacterial cells. The amino acids (crude crystals) are separated from the amino acid fermentation solution by filtering out the fermentation cells using diatomaceous earth in advance, then crystallizing the amino acids by isoelectric point crystallization, etc., and subjecting them to solid-liquid separation. However, since the used diatomaceous earth used for such filtration naturally contains fermenting bacterial cells, it is called diatomaceous earth containing bacterial cells. The fermenting cells in the diatomaceous earth containing the bacterial cells are 10 to 30% by weight (as dry cells), for example, about 25% by weight, and the water content is 50%.
７０70% by weight, for example about 65% by weight.

The first method of mildening the amino acid crystallization mother liquor according to the present invention is by utilizing the glucose remaining in the saccharified diatomaceous earth. That is, the remaining glucose as a raw material in the presence of yeast, or if necessary, add yeast,
By growing these yeasts, the action of these bacteria makes the amino acid crystallization mother liquor mild, and the glucose is converted to an organic acid,
Change to alcohol etc. to eliminate the peculiar odor.

Specifically, saccharified diatomaceous earth is added to water to form a slurry (for example, a stirred mixture of 1 part by weight of wet saccharified diatomaceous earth and 1 part by weight of water). Then, as a starter, for example, sake lees is added, and the yeast is grown.
After the yeast has grown sufficiently (that is, until the alcohol smell is produced), the amino acid crystallization mother liquor is added continuously or intermittently to contact the yeast (addition treatment). This is mainly because the amino acid crystallization mother liquor is under a condition that the yeast can withstand the osmotic pressure since the inorganic salt is saturated. This process is carried out in an oxidizing system (ie, high temperature, low pH, with air entrained by a pump used to circulate the liquid in the step of isolating precipitated amino acids).
The intention is to expose the amino acid crystallization mother liquor that was in the air oxidation conditions under stirring to a reducing system (that is, a low-temperature oxygen-deficient system) to make it mild. By doing so, merits such as reduction can be obtained. As a matter of course, it is preferable that the growth of the yeast be carried out in a static condition without oxygen supply. As a pH range that suppresses the growth of various bacteria and actively activates yeast,
For example, it is conceivable to drop the pH to 4 or less,
Depending on the amino acid crystallization mother liquor (for example, phenylalanine crystallization mother liquor), it may be difficult to drop it due to its buffering action. In that case, if the harm caused by the proliferation of various bacteria is not significant, for example, the pH can be set to 4.5.

In addition, in the growth of yeast, a small amount of amino acid crystallization mother liquor is added as an N source at an early stage to obtain C / N.
It lowers the ratio (carbon to nitrogen ratio) and helps the growth of yeasts such as minerals, amino acids, and ammonium sulfate contained in the crystallization mother liquor. In particular, minerals are low in glucose in saccharified diatomaceous earth,
In this sense, minerals contained in the crystallization mother liquor are useful.
In addition, molasses (CM (potato molasses) and BM (sugar molasses))
Is also effective in promoting the initial growth, and the odor can be improved. The yeast culturing time depends on the culturing temperature and the initial amount of bacteria, but is set at a higher temperature of 25 to 40 for the purpose of increasing the yeast growth speed.
When the temperature is 40 ° C., for example, 40 ° C., it is preferable to take 4 to 5 days, for example, 4 days from the viewpoint of the amount of carbon dioxide generated according to the amount of bacteria. The amino acid crystallization mother liquor after yeast growth is preferably added intermittently (stepwise) from the viewpoint that the osmotic pressure does not increase rapidly.
Although it depends on the amount of yeast, for example, in the case of smooth growth, for example, the total amount may be the same as the amount of water used for the preparation of the saccharified diatomaceous earth slurry, which may be divided into 5 parts and added every 48 hours. The final pH is 3.5-5.5, depending on the type of mother liquor for amino acid crystallization.

The liquor obtained by such a treatment is used to remove diatomaceous earth therefrom to obtain an effective component of a liquid fertilizer for foliar application. The removal of diatomaceous earth is easy to filter and can be done without problems by centrifugation. At this time, a part of the viable yeast cells leaks to the filtrate side or remains in the supernatant side, so that the merit of rot prevention as described above can be obtained. It is not essential for the active ingredient of liquid fertilizer to leave live yeast cells on the filtrate side or the supernatant side.

[0020] The second method of making the amino acid crystallization mother liquor mild according to the present invention is by utilizing bacterial cells removed from the fermentation liquor along with diatomaceous earth. That is, the cytoplasm of bacteria used for amino acid fermentation, such as phenylalanine, is autolyzed into an extract, and then an amino acid crystallization mother liquor is added. The extract is transferred to the amino acid crystallization mother liquor. This is because various organic substances contained in the cytoplasm are extracted in a more natural state without severe acid decomposition or the like by a mineral acid and used for plant growth. In other words, the concept is that the bacterial portion of the diatomaceous earth containing the bacterial cells is autolyzed and the cytoplasm is taken out to form a liquid fertilizer. The idea of using cytoplasm as agricultural material without severe conditions is rare. Diluted and extracted with amino acid crystallization mother liquor, because autolysate alone is too thick as liquid fertilizer and there is a risk of spoilage during the treatment process.

More specifically, diatomaceous earth containing bacterial cells is added to water to form a slurry (eg, a stirred mixture of 1 part by weight of diatomaceous earth containing wet bacterial cells and 1 part by weight of water).

At this time, lysozyme and the protease papain can be used together if necessary for the purpose of promoting autolysis. As is well known, two enzymes are commonly used in the production of peptidoglycan and their working conditions can be applied. Therefore, the initial reaction pH is 6.
5 to 8.0, preferably 7.3 to 7.8, for example 7.5
And adjust it higher. The progress of self-digestion can be judged from the generation of slight gas, generation of extract odor, and improvement in the fluidity of the slurry. The autolysis time is usually 2 to 6 days, although it depends on the enzyme titer and the amount added.
For example, when 200 g of diatomaceous earth and 80 g of lysodium are used, the period can be set to, for example, 4 days.

After self-digestion, the mother liquor for amino acid crystallization is:
Do not add the whole amount at once, but add small amounts continuously,
Alternatively, it is preferable to add intermittently (in a stepwise manner) from the viewpoint that a sudden change in pH does not occur. Final p
H depends on the type of amino acid in the amino acid crystallization mother liquor,
3.5 to 5.5. The time interval and the amount added
For example, in the case of a standard design (a standard flow sheet determined by the present inventors), for example, the total amount of the amino acid crystallization mother liquor is set to the same weight part as the amount of water used for the slurry preparation, and divided into five parts, depending on the enzyme titer. And can be added every 48 hours. As the amino acid crystallization mother liquor is added, the pH gradually approaches the isoelectric point of the amino acid and stabilizes. For example,
When the amino acid crystallization mother liquor is a phenylalanine crystallization mother liquor, the pH gradually becomes close to 4.5 and stabilizes. It is considered that this is because the isoelectric point of phenylalanine is 4.5 and wild yeast contained in or flying in diatomaceous earth grows to produce organic acids.

The liquor obtained by such a treatment removes diatomaceous earth from the liquor to be used as an active ingredient of the liquid fertilizer for foliar application. Compared with saccharified diatomaceous earth, filterability is poor, and centrifugation is preferred, but that is not always easy. At this time, if the viable cells of the yeast are leaked to the filtrate side or left in the supernatant side, the merit of preventing decay of the product as described above is obtained, but the liquid fertilizer for foliar spray of the present invention is obtained. As an active ingredient of
It is not essential that live yeast cells remain on the filtrate or supernatant side. This is the same as for saccharified diatomaceous earth.

An important point in the autolysis of the fermented bacterial cells according to the present invention is that a phenomenon similar to the production of yeast extract from yeast cells from bacterial cells after fermentation is easily established. In an attempt, the same operation was compared using only squeezed bacterial cells without diatomaceous earth.
(That is, a state in which pH control accompanied by a bad odor is lost) is observed. Looking at the pH of the phenylalanine fermentation cell system, the difference between the two in pH is higher in the system without diatomaceous earth than in the system with diatomaceous earth, while the pH stably drops to around 4.5. In many cases, a value was shown (for example, pH 7.5 to 6.8). When diatomaceous earth is present, it is presumed that healthy bacteria such as yeast that prevent the transition to the "rot type" are living in the fine holes of the diatomaceous earth and suppress the germs which shift to the putrefaction.

Incidentally, few attempts have been made to effectively extract and utilize the cytoplasm from fermented bacteria after completion of amino acid fermentation.

The active ingredients of the two kinds of liquid fertilizers for foliar spray obtained as described above can be appropriately mixed. Such a mixed liquid fertilizer is obtained as described above.
Needless to say, it can also be prepared by mixing the addition treatment liquids of various kinds of amino acid crystallization mother liquors without removing diatomaceous earth, and then removing diatomaceous earth from the mixed liquid.

The liquid containing or not containing the viable yeast cells obtained by removing diatomaceous earth after the addition treatment of the mother liquor for amino acid crystallization can be used as it is as the liquid fertilizer for foliar application of the present invention. Further, the liquid fertilizer for foliar application of the present invention can be appropriately diluted to a concentration suitable for foliar application of crops. Considering the danger of decay, the former is preferably used in the former form. The liquid further comprises:
As explained earlier, it goes without saying that it can be applied from the root as a liquid fertilizer.

The liquid fertilizer for foliar spraying of the present invention is considered to be useful not only for the uses described in Examples below but also for the erect cultivation of strawberries.

That is, a nutrient (organic) suitable for the erect cultivation of strawberries (a cultivation method in which artificial cultivation is performed without using soil (peat moss, permiculite, zeolite, etc.) and raised to the waist level of a person). Since it has not been developed yet, the liquid fertilizer for foliar application of the present invention is expected to be the most suitable content as a comprehensive nutritional supplement focusing on the taste of fruit. Synthetic soil is less ion exchangeable than soil, and inorganic fertilizers are more prone to obstacles. It is expected that it is best to perform drip culture with the foliar spray of the present invention containing sugars, organic acids, minerals, amino acids and the like.

[0031]

The present invention will be further described with reference to the following examples.

Example 1 (Utilization of saccharified diatomaceous earth) 200 kg of saccharified diatomaceous earth containing 18% w / w of glucose
(Wet), 200 kg of water, 2 kg of phenylalanine crystallized mother liquor (pH 4.5 as described below) after isoelectric crystallization of phenylalanine from a phenylalanine fermentation solution as an N source, and a small amount of sake lees as a yeast seed (About 50
g) and a small amount of CM (about 100 g) were stirred and mixed (pH 5.5). This mixture was kept at a product temperature of 40 ° C. for 4 days to grow yeast. During this time, the pH was automatically set at around 4.5 (probably due to the production of organic acids by fermentation with yeast). When the growth started, a thick scum of about 0.5 cm floated on the surface layer.

Thereafter, 200 kg of the same phenylalanine crystallization mother liquor as described above was added every two days at the same temperature in five portions (40 kg / time). That is, the amount of water and the amount of phenylalanine crystallization mother liquor to be added were made equal. It was left for 2 days after the final addition, and diatomaceous earth was centrifuged under the condition that the bacterial cells were left in the supernatant to obtain almost 400 kg of a product of the active ingredient of the liquid fertilizer for foliar spray of the present invention (that is, the finished product amount was , Approximately the same as the total amount of water and amino acid crystallization mother liquor used). The pH of the obtained liquid manure was 4.5 and the concentration of phenylalanine was 0.3%. The odor of this liquid fertilizer was a mixed odor of an organic acid odor such as acetic acid, an alcohol odor such as ethanol, and an odor of the amino acid crystallization mother liquor. Was.

It should be noted that substantially the same results could be obtained by performing the operation under exactly the same conditions except that the temperature was changed from 40 ° C. to 27 ° C. (room temperature).

Incidentally, the phenylalanine crystallization mother liquor used above was prepared by removing the phenylalanine fermentation bacterial cells from the phenylalanine fermentation liquor with diatomaceous earth, then appropriately concentrating the phenylalanine fermentation liquor, adjusting the pH to 4.5 with sulfuric acid, and crystallizing phenylalanine. ,
This was obtained by subjecting it to a filtration method using a filter (the pH of the obtained crystallization mother liquor was 4.5, and the residual phenylalanine concentration was 0.7%).

Example 2 (Utilization of Bacterial Cell-Containing Diatomaceous Earth) Bacterial cells obtained by phenylalanine fermentation were treated for about 24 hours.
% Diatomaceous earth 200 kg (wet), water 200 kg,
Lysozyme enzyme preparation “Egg white lysozyme” (manufactured by Eisai Co., Ltd., titer: 0.8 mg lysozyme / mg)
Above) Enzyme preparation of 80 g and papain "Papain W-
4D "(manufactured by Amano Pharmaceutical Co., Ltd., titer: protein digestion 400)
While stirring 160 g of U / mg or more, a 6% aqueous KOH solution was added to adjust the pH to 7.5. This mixture was kept at a product temperature of 40 ° C. for 4 days to perform autolysis. During this time, a favorable odor similar to yeast extract came out. The color was slightly yellow and gray scum on the surface. Almost no gas was generated.

Thereafter, 200 kg of the same phenylalanine crystallization mother liquor (pH 4.5 as described above) as in Example 1 was added every two days, divided into five portions (40 kg / time). The odor similar to yeast extract did not disappear even when the phenylalanine crystallization mother liquor was added. When phenylalanine crystallization mother liquor was added, many fine bubbles appeared. It is considered to be dissolved carbon dioxide. As the phenylalanine crystallization mother liquor was added, the pH gradually became close to 4.5 and stabilized.

The phenylalanine crystallization mother liquor was allowed to stand for 2 days after the final addition, and was added (containing diatomaceous earth and / or
Or wild yeast was grown) and centrifuged. The product yield (centrifugation liquid volume) of the active ingredient of the liquid fertilizer for foliar spraying of the present invention by centrifugation is 340 at 85% of the total amount (400 kg) of the used water and phenylalanine crystallization mother liquor.
kg yield.

It should be noted that the operation performed under the same conditions except that the temperature was changed from 40 ° C. to 26 ° C. (room temperature) was slower and weaker than that at 40 ° C. It is preferable to perform the operation by heating to about 35 ° C., although the risk of migration is small.

Example 3 (mixed use example (leaf spraying)) The two types of the two types obtained in Examples 1 and 2 at the request of a farmer
1: 1 (weight ratio) of active ingredient of liquid fertilizer for foliar application of the present invention
The mixture was diluted appropriately and sprayed onto the crop. The target crops were strawberries, eggplants, mini tomatoes, cucumbers, and flowers (Larkspur). The odor was improved compared to the liquid fertilizer of phenylalanine crystallized mother liquor, and it was suitable for foliar spraying.

The strawberry, eggplant, mini tomato, cucumber and Larkspur were sprayed on the leaves at a dilution of 150-fold, 200-fold, 250-fold and 300-fold, respectively. Nothing was observed, and it was recognized that the application immediately contributed to growth.
In other words, in the case of strawberries, sprout came out, in the case of eggplant, fruit enlargement was recognized, in the case of mini tomatoes, the fruit shape became large, in the case of cucumber, the growth of sprout became strong,
Flower bud formation improved. And in the case of Larkspur, the height and the weight of each one increased. Also, in the case of mini tomatoes, it has been evaluated that the taste has improved.

It is presumed that the main factor which exerts the effect in such a short time is the mineral contained in the liquid fertilizer for foliar application of the present invention.

Example 4 (Example of Mixed Use (Application to Roots of Plants)) Plants in a decorative flowerpot placed in an office or the like generally do not grow because they only use water.

When the same mixture (ripened liquid manure) as in Example 3 was applied to the roots in such plants as diluted 150-fold, surprising growth was exhibited and sprout emerged vigorously.
In addition, no obstacle was seen.

Example 5 (mixed use example (use for radish roots in winter)) Aged liquid fertilizer similar to that in Example 4 was diluted 150-fold, and only one row of radish planted in two rows in the field (Experimental plots) and spread around roots. The radish in this ward has no toe standing,
The harvest was good.

The same phenylalanine crystallization mother liquor as in Example 1 was applied to the radish in the other row (control) so that the total nitrogen content was the same as the total nitrogen content of the fermented liquid fertilizer diluted 150 times in the test plot. It was diluted and fed to the test plots from the roots later in the same way, but due to the timing too late, the tow was violent and there was a problem eating.

[0047]

According to the present invention, glucose remaining in saccharified diatomaceous earth by-produced in connection with the fermentation of amino acids such as phenylalanine, the amino acid-fermenting bacterial cells contained in the filter aid, and the amino acid crystallization mother liquor are treated with organic acids. These can be used to regenerate useful liquid fertilizers, especially liquid fertilizers suitable for foliar application, by utilizing these factors, thereby protecting the environment from amino acid fermentation and reducing the cost of amino acid production. Can also contribute.

The liquid fertilizer of the present invention, including its raw materials, is assured of its safety, as is clear from its production method. In particular, it remains harmful to humans even if it is left on fruits by foliar application. Never.

Claims (2)

[Claims] (1) a step of adding yeast to a sugar contained in saccharified diatomaceous earth as a raw material and then adding an amino acid crystallization mother liquor; Diatomaceous earth is added after any of the steps of adding amino acid crystallization mother liquor after self-digestion in the presence and (3) mixing the above obtained (1) and (2). A liquid fertilizer characterized by comprising a liquid obtained by separating water as an active ingredient. 2. A step of (1) a step of subjecting the sugar contained in the saccharified diatomaceous earth to a process of adding yeast amino acid to the sugar as a raw material and then adding an amino acid crystallization mother liquor, and (2) diatomaceous earth-containing bacteria in the diatomaceous earth containing the bacterial cells. Diatomaceous earth is added after any of the steps of adding amino acid crystallization mother liquor after self-digestion in the presence and (3) mixing the above obtained (1) and (2). A liquid fertilizer for foliar spraying, characterized in that a liquid obtained by separating water is used as an active ingredient.