JPH1066443A - Sulfur-containing culture soil for raising seedling, and raising seedling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain sulfur-containing culture soil capable of preventing poor growth, damping-off and occurrence of steamed seedling, suitable for growing an acidophilic plant such as rice plant, by adding sulfur to natural soil, thermally insulating the soil and acidifying. SOLUTION: Sulfur is added to natural soil, which is kept or heated to 20-35 deg.C and acidified to pH 4. 5-5.5. Preferably, the natural soil containing sulfur is adjusted to <=20%, preferably <=10%. Seeds are sowed in sulfur- containing culture soil for raising seedling, which is watered and germination is promoted to preferably raise seedlings.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cultivation method and a method for raising acidophilic plants, especially rice seedlings.

[0002]

2. Description of the Related Art Rice seedlings will be described below. Today, rice seedlings are raised in a nursery box (30 cm x 60 cm).
x 3 cm) was filled with approximately 4.0 L of cultivated soil (floor soil) adjusted to pH 4.5 to 5.5, and the germinated paddy was 100
g to 200 g, irrigated, covered with soil, and maintained or warmed at an average of about 20 ° C. to 35 ° C., which is the highest and lowest temperature of the day, for about 1 to 5 days to promote budding, and almost every day as needed. The seedlings are irrigated and raised for about 20 days after sowing, and the middle seedlings are raised for about 30 to 40 days.

[0003] When 100g of paddy is sowed, the number of paddy is approximately 3,500.
It is about 7,000 grains in 200g seeding. Therefore,
The cultivation soil per seedling is approximately 1.0 to 0.5 g. Compared to the nursery were seeded 1 m ² per rice about 100g provided nursery one corner of the previous field or fields, is unimaginable overcrowding nursery. Thus, in box raising seedlings, when raising seedlings using rice field or field soil, diseases and physiological disorders such as damping-off and stuffy seedlings that have not been experienced with the conventional seedling raising seedlings occur. The pH of the soil is about 6.0, and the pH of the field is about 7.0.
There are many. During the nursery season from March to April, the climate is still unstable,
Particularly in cold years, damping-off and stuffy seedlings occur frequently, causing serious problems in rice planting. However, the pH of the seedling culture
However, if it is maintained at 4.5 to 5.5 in the seedlings, the seedlings grow well and grow well, and the seedling failure as described above is greatly reduced. Therefore, today, the pH of the seedling cultivation soil is 4.5 to 4.5.
It is publicly instructed to adjust to 5.5. ("About the quality of artificial floor soil", Ministry of Agriculture and Forestry,
"Seedling of paddy rice" by Kiyochika Hoshikawa, pages 28-29)

In order to adjust natural soil such as mountain soil, rice field, and field soil having a pH of 6 to 7 to pH 4.5 to 5.5, sulfuric acid or sulfur is generally used. Sulfuric acid is a strong acid and dangerous,
The pH is adjusted quickly and quickly. Although sulfur is safe, it takes approximately one month after mixing to mix with the soil and adjust the pH to the desired 4.5-5.5. It is useless immediately after mixing (Kiyoshi Hoshikawa, "Physiology and Technology of Young Seedlings and Nakanae", pages 165 to 166).

The seedlings are sown and germinated using the seedling cultivation medium in which the pH of the natural soil is adjusted to 4.5 to 5.5 as described above. The seedlings are raised every day. During this period, the pH of the cultivated soil adjusted to pH 4.5 to 5.5 by irrigation or rainfall gradually increases, and has the property of returning to the original soil pH of 6 to 7. After sowing,
The pH is about 6.0 on the 15th, and the pH may even be 6.5 to 7.0 near the 20th day when the seedling raising is completed. That is, in the middle seedling raising, the effect of pH adjustment is almost eliminated in the middle of the seedling raising. In addition, the seedling raising season is a sign of instability in the early spring, and depending on the region, the temperature may rise by one at night.
The temperature may drop to 0 ° C or lower, and even 5 ° C or lower, and there is late frost. Overgrown rice seedlings are more susceptible to physiological disorders at 10 ° C or lower when the soil culture is higher than pH 5.5, and are more strongly impaired at 5 ° C or lower, causing wilt disease and stuffiness more frequently.

[0006] Therefore, various fungicides are used for pesticide pickling, and efforts are made to control them. However, they are difficult to control with pesticides because of poor growth due to an increase in the pH of the cultivated soil, and a complex disorder of physiological disorders and fungal disorders. . It is the fate of box raising seedlings by conventional cultivation. (Refer to Kiyochika Hoshikawa, "Physiology and Technology of Seedlings and Nakanae," pp. 191 to 201)

[0007]

As described above, the important problems in the conventional box raising of rice seedlings are poor growth due to cold during the raising of seedlings and an increase in the pH of the cultivation soil, and complex damage due to the occurrence of damping-off and stuffy seedlings. It is. An object of the present invention is to solve the problem relating to the pH of the inner soil. As described above, in the prior art, sulfur cannot be used immediately after mixing it with the soil,
After approximately one month, the pH of the soil must be adjusted to the desired value. It is easiest to adjust the pH with sulfuric acid, but sulfuric acid is a strong acid and is extremely dangerous in handling. In addition, even if the pH of the soil is adjusted as described above, the pH gradually increases due to frequent irrigation and rainfall during the seedling raising, and the p of the original soil is raised in the latter half of the seedling raising for the young seedling and half of the seedling raising for the middle seedling.
It has the property of returning to H6 to H7, and when it is cold, the growth of the seedlings is poor and the wilt disease and stuffy seedlings occur frequently. The present invention solves the above problems.

[0008]

In the present invention, as a means for solving the above-mentioned problems, sulfur is added to natural soil, and the temperature is maintained or warmed to an average of about 20 ° C. to 35 ° C. on the average of the maximum and minimum temperatures per day. Then, seeds are sown on a sulfur-added seedling cultivation soil prepared by acidifying the natural soil, and seeds are sown on the sulfur-added natural soil, and the natural soil is covered with soil. Keep or warm to an average of about 20 ° C to 35 ° C,
A method for raising seedlings that promotes seed germination and simultaneously acidifies the natural soil is provided.

In the present invention, sulfur or a sulfur compound is used as a soil acidification regulator. Practically, sulfur flower or sulfur powder is used. (1) Mountains, fields, fields and the like of general natural soils used as the original soil for cultivation generally contain about 35% or more of water. Sulfur is added to the dry soil, sulfur is added to the natural soil, and the temperature is maintained or warmed to an average of about 20 ° C. to 35 ° C., which is the highest and lowest temperature of the day. (2) Seeds are seeded and irrigated on natural soil such as mountain soil, field soil, and field soil to which sulfur is added, and the natural soil is covered with soil. Keep warm or warm. (3) The present invention also includes soil cultivation in which the moisture is adjusted so that the moisture of the natural soil to which sulfur is added is approximately 20% or less, preferably 10% or less. (4) As a seedbed for raising seedlings, seeds are sown with an organic or inorganic molding medium as a seedbed, irrigated, and covered with natural soil to which sulfur has been added.
Keep or warm to 35 ° C.

[0010]

[Action]

(1) When the natural soil to which sulfur is added is kept or warmed to an average of about 20 ° C. to 35 ° C., which is the highest and lowest temperature of the day, the pH of the natural soil becomes about one month at the natural temperature as in the prior art. It drops quickly in a few days without need. For example, when 25 g of sulfur powder is added to 4 L of mountain soil pH 6.5 for one public nursery box and the temperature is kept at an average temperature of 25 ° C. for 4 days per day, the pH of the mountain soil becomes 4.5 to 5.5. It is adjusted to. 32 ° C
And the pH is adjusted in the same manner as described above.

(2) 4 L of field soil pH for one nursery box for public use
7 was added with 30 g of sulfur powder to obtain a seedling cultivation soil.
L into a nursery box as sowing seeds
２００200 g was sown and watered, 0.7 L of the seedling cultivation soil was covered, and the seedling was cultivated at a public germination temperature of 32 ° C. for 2 days.
It is adjusted to 4.5 to 5.5. Thereafter, 20 days for seedlings, 35 to 40 days for middle seedlings, approximately 1L daily except rainy days
The seedlings are raised by irrigating 1.5 L of water.
Maintains the pH of 4.5 to 5.5 without returning to pH 7 of the original soil and the soil during the seedling raising period as in the conventional cultivation.

(3) When the water content of natural soil such as mountain soil, rice field, and field soil to which sulfur is added is made approximately 20% or less, preferably 10% or less, sulfur is not oxidized for a long time,
The pH of the natural soil exists as it is in the original soil.

(4) 150 g of germinated rice seeds are sown on a rock wool molding medium having a pH of 8 and covered with a seedling culture medium obtained by adding 25 g of sulfur to 0.8 L of a paddy soil having a pH of 6, and irrigated with 2 L of water. When kept at the lowest average temperature of 25 ° C. for 4 days, the seedlings of the rock wool and cover soil are acidified to a pH of 4.5 to 5.5 at the same time as the seedlings emerge and the seedlings are acidified to pH 4.5 to 5.5. The seedlings are raised by irrigating with water 1.0 L to 1.5 L almost every day except for the rainy day for 35 to 40 days.
Keep 5.5.

Sulfur bacteria widely exist in natural soil and water in Japan, and the sulfur bacteria live by oxidation of sulfur (Tokyo Kagaku Dojin, edited by "Biochemical Dictionary", p. 111, "Sulfur Bacteria"). In the prior art, utilizing the above-mentioned effects, sulfur is added to natural soil such as mountain soil, rice field, and field soil, and is stored at natural temperature for approximately one month to obtain a desired pH of 4.5 to 5.5. A seedling culture was obtained. Incidentally, natural soil generally contains moisture, and sulfur bacteria live there. Sulfur bacteria also exist in water.

However, in the present invention, when sulfur is added to natural soil to form a seedling cultivation medium, and the temperature is maintained or heated in the same manner as in the official technology for promoting germination of rice seedlings, the sulfur is rapidly oxidized and the natural soil is oxidized. Found that it acidified to the desired pH in a short period of time. It has also been found that when the moisture content of the sulfur-added natural soil is dried to about 20% or less, preferably about 10% or less, the soil can be stored without being oxidized for a long time. Further, the dried sulfur-added natural soil,
If necessary, the soil is acidified in a short period of time by irrigating it and keeping it warm or warm as described above.

[0016] In order to keep warm, the official technology of rice seedlings is:
In general, put the soil in the glass room or greenhouse,
The seedling boxes sown with rice and irrigated are stacked in several layers and covered with a heat insulating sheet, or the same seedling raising box is laid flat and covered with a heat insulating sheet to keep it warm. Then, on a sunny day in the seedling raising period, it is about 30 to 40 ° C in the daytime and 15 ° C in the nighttime.
It can be kept warm, and the maximum and minimum average temperature is about 23 ℃ ～ 2
It becomes 8 ° C, and germination is uniform around 5 days ago. The soil cultivation of the sulfur-added natural soil of the present invention is oxidized to a desired pH simultaneously with the emergence of seeds. In addition, for heating, 32
The seedling raising boxes sowed are stacked in layers in a warmer heated to ° C. and heated. Then, the sown paddy emerges uniformly in 2 days, but the soil added with sulfur also has the desired pH in 2 days.
Acidified to

Further, as for the cultivated soil obtained from the natural soil to which sulfur is added according to the present invention as a raw material, the pH is adjusted to a desired value of 4.5 to 4.5 as soon as the seedlings germinate by keeping or warming as described above.
Adjusted to 5.5. Thereafter, the seedlings are irrigated almost every day for 20 days for the seedlings and 30 to 40 days for the middle seedlings. In the present invention, the pH of the soil during the seedling raising period returns to the pH of the original soil in the middle of the seedling raising as in the conventional technique. And maintain the desired pH of 4.5 to 5.5 unchanged during the seedling raising period.

[0018]

Example 1 120 g of sulfur flower was added to and mixed with 20 L of field soil having a pH of 7.0 for 5 rice nursery boxes, and 5 L of water was irrigated, deposited in a greenhouse, and covered with a heat insulating sheet. The temperature was kept at an average of about 25 ° C., which is the highest and lowest temperature for one day, for 5 days to obtain a sulfur-added seedling cultivation soil of the present invention adjusted to pH 5.0. In addition, similarly to the above, a field soil 2 having a pH of 7.0 to which 120 g of sulfur flower was added and mixed.
0 L was put into 5 seedling boxes in 4 L aliquots, and each box was irrigated with 1.5 L of water, stacked in a warmer heated to 32 ° C., and heated for 2 days to obtain a pH of 5.0. To obtain a sulfur-added seedling cultivation soil of the present invention, which was adjusted to a concentration of 1%.

Example 2 Twenty liters of soil at pH 6.5 was collected, dried with hot air, and 100 g of sulfur powder was added and mixed to obtain a sulfur-added seedling culture soil of the present invention having a water content of 10%. The seedling cultivation soil was packed in a plastic bag, stored for 6 months, and the pH was measured. In addition, the sulfur-added seedling culture soil 20
L was put into 5 public rice nursery boxes in 4 L increments, and each nursery box was irrigated with 1.5 L of water, stacked in a warmer heated to 32 ° C., and heated for 2 days. When the pH of the soil was measured, it was 5.0.

Example 3 Five seedlings of rice seedlings were raised in a public nursery box on the 35th day. 150 g of sulfur flower is added to and mixed with 20 L of field soil having a pH of 7.0 to form cultivation soil, and the cultivation soil is 3.5 L per box for raising seedlings.
100 g of paddy inserted as a sowing bed and germinated as officially used below
Was seeded, 0.5 L of the soil was covered, 1.5 L of water was irrigated, and the mixture was heated at 32 ° C. for 2 days to obtain a seedling box with uniform emergence. As a fertilizer, 1.5 g of NPK was applied per box as an original manure. After emergence, seedlings were raised for 33 days. In the meantime, 30 times of 1.3 L of irrigation were performed per box. PH of soil during this period
Is 5.5 days on the second day after seeding (when budding is uniform)
5.0 on days 2, 10, 5.0, 5.0 on day 15, and 5.
4.9 on day 0, 25, 4.8 on day 30, 4.7 on day 35
Met. The leaf color was dark green and the roots were pure white and strongly intertwined. In the seedling raising, 5 ° C night is 2 days, 4 ° C night is 1 day.
Although there were days, there were no physiological disorders or diseases, and the seedlings were very strong and resistant to seedlings. No pesticides were used. As for the fertilizer, 1.5 g each of the original manure NPK and 1.0 g each of the top fertilizer NPK were applied twice per box.

Example 4 100 g of sulfur powder was added to 20 L of mountain soil having a pH of 6.0, mixed and dried with warm air to obtain a sulfur-added seedling cultivation soil containing 10% of water according to the present invention, and stored for 6 months. Using the cultivated soil, 5 boxes of middle seedlings for raising seedlings were raised for 40 days. The pH of the soil immediately before raising the seedling was 6.5, which was the same as the pH of the original soil and was unchanged. The seedling cultivation soil was used in an amount of 4 L per box including floor soil and cover soil. As a sowing bed, 3.3 L was inserted into a seedling raising box, 120 g of germinated paddy was sown, 1.5 L of water was irrigated, and 0.7 L of the cultivated soil was covered. Then, at 32 ° C., 2
The seedlings were heated for 30 days to promote budding, and then seedlings were raised for 38 days. In the meantime, the water was irrigated 1.3 times per box once a day for 34 times. Fertilizer is 1.5g for each NPK as the original manure and N as the top fertilizer
Each gram of PK was applied twice. There were three nights at 5 ° C. during the seedling raising period, but there were no physiological disorders or diseases such as stuffy seedlings and damping-off disease, and very good seedlings could be raised. Agrochemicals such as Tachigaren and Homai were not used at all. The pH change of the seedling cultivation soil during the seedling raising was 5.8 one day after heating, 5.5 at the same time of emergence on the second day, and maintained 4.5 to 5.0 during the seedling raising period. Was 4.8. Incidentally, the seedlings were further raised for another 10 days for reference. The pH on day 45 was 5.5 and the pH on day 50 was 6.0. According to this, the proper pH period of the main soil is approximately 45 days for raising seedlings.

Example 5 A commercially available mountain soil was used as the original soil, and a granular soil for rice seedlings whose pH was adjusted to 4.5 to 5.5 was purchased, and 20 g of sulfur powder was added to 4 L of the granular soil per box. Then, 120 g of germinated rice seeds were sown, and 5 boxes were raised for 40 days. During this time, there were three nights below 5 ° C., but the seedlings were dark green on the top and pure white on the underground, and were extremely entangled with each other. During the seedling raising period, sowing, watering,
It was 4.9 when the seeds emerged uniformly after heating at 32 ° C for 2 days. Thereafter, sowing on the 5th day 4.8, the 10th day 4.8, the 15th day 4.7, the 20th day 4.7, the 25th day 4.7, the 30th day 5.0, the 35th day 5. It was 5.0 on the 0th and 40th days. By the way, the original manure N1.5g, P2.0g, K2.0g,
The fertilizer was contained in the commercial medium, and topdressing was performed three times with 1 g each of NPK.

Example 6: Acidification treatment to pH 4.5 to 5.5 using a commercially available conventional technique,
Using five rock wool mats to which 1.5 g each of NPK was added, seeded 120 g of germinated paddy on each mat, and adjusted the pH.
6.5 g of field soil 1 L each 25 g of sulfur powder and 1 g of original manure NPK
Was added and mixed to cover the soil.
Was heated for 2 days to obtain a seedling mat with uniform emergence. The seedling mats with uniform budding were top-fertilized with 1 g each of NPK four times, irrigated with 1.3 L to 1.5 L of water 26 times, and sown for 30 days after sowing. During the germination, the pH during this period was 5.
0) Sowing 5th day 5.0, 10th day 4.5, 15th day 5.
0, 20 days 5.0, 25 days 5.0, 30 days 5.0
Met. The leaves of the seedlings were dark green, the roots were pure white, and a very intertwined medium seedling mat was obtained. During the seedling raising period, there was one night when the late frost became 4 ° C. or less for two nights.

Example 7 At the same time as Example 6, seedlings were grown in the same manner as in Example 6 except that 35 g of sulfur was used, using a commercially available rock wool mat without acidification treatment. The pH at the time of emergence uniformity by heating for 2 days at the beginning of the seedling raising was 4.5, the fifth day of sowing was 4.5,
4.5 on the 10th day, 4.5 on the 15th day, 4.8 on the 20th day, 2
The results were 4.8 on day 5 and 5.0 on day 30. Seedlings were extremely healthy seedlings as in Example 6, and neither sapling nor damping-off occurred.

Comparative Example 1 Concentrated sulfuric acid was added to 20 L of field soil having the same pH of 7.0 as in Example 3.
2,000 cc diluted with 8 times water was added and mixed well to obtain a seedling cultivation soil having a pH of 5.0. Using the seedling cultivation soil acidified with the concentrated sulfuric acid, five boxes of middle seedlings were raised for 35 days at the same time as in Example 3. The seedling raising method is exactly the same as in Example 3. Changes in seedling raising results and changes in soil pH are as follows. The pH at the time when the seeds were heated and germinated at 32 ° C. for 2 days after sowing and irrigation was 5.0. Thereafter, on the fifth day, the pH was 5.0, 10
At day 5.5, day 15, 5.8, day 20, 6.5, and day 25, it remained at 7.0 until day 35. Until the 15th day of the seedling raising, the leaf color was good, the root color was pure white and well entangled, and it grew well. As for the seedlings on the 20th day at the end of the seedling raising, one box of stuffy seedlings came out, but it was a marginal seedling that could be transplanted. The seedlings after the middle seedling stage were weak seedlings with extremely poor leaf color and root color, and four boxes of damping-off and stuffy seedlings occurred, and were not seedlings that could withstand rice planting.

Comparative Example 2 50 g of sulfur flower was added to 20 L of field soil having the same pH of 7.0 as in Example 3.
, And stored at natural temperature for 30 days.
A seedling cultivation soil of 5.2 was obtained. Using the cultivated soil, seedlings were raised in the same manner as in Example 3 by the same method of raising seedlings. Seedling performance and soil cultivation
The transition of H is as follows. The pH when the seeds were uniformly germinated by heating at 32 ° C. for 2 days was 5.0, and 5.0 on the 5th day after seeding,
It was 5.5 days on the 10th day, 5.5 days on the 15th day, and 5.8 days on the 20th day. The seedlings were dark green, the roots were pure white, and the seedlings were excellent and well-tangled. Thereafter, the pH of the cultivated soil after the middle seedling stage
Are 6.0 at 25 days, 6.5 at 30 days, 7.0 at 35 days
The leaf color became light green and the root color became brown.
In the seedling stage, the seedlings were dark green and healthy, but after entering the middle seedlings, the seedlings became light green and soft seedlings, and two boxes of take-all disease occurred. Incidentally, as described in Example 4, the appropriate pH period of the seedling cultivation soil of the present invention is about 45 days from the start of the seedling raising, but in this comparative example, sulfur was added to the field soil 30 days before the seedling raising according to the conventional technique. Since the oxidation of sulfur has already progressed, the appropriate pH period was about 25 days after the start of the seedling raising. After that, the pH of the soil increased day by day.

COMPARATIVE EXAMPLE 3 Using the commercially available granular soil for rice seedlings used in Example 5,
At the same time as in Example 5, five boxes were raised by the same seedling raising method. The pH on the day when the germination was warmed at 32 ° C. for 2 days was 5.0, and after that, 5.0 days on the 5th day, 5.5 days on the 10th day, 5.8 days on the 15th day, and
6.1 on day 0, 6.5 on day 25, 6.7, 35 on day 30
Day 6.7 and day 40 6.7. Up to the 15th day, the seedlings were dark green in the aerial part and pure white in the underground part.
From around the day, the leaf color began to fade, and on the 20th day, the root color became slightly brown, and on the 25th day, the leaf color did not recover even after topdressing, and the root color became darker brown. Especially after 30 days, this tendency became stronger. Thus, the seedling stage is
Although it was a seedling that could withstand use even if it could not be said to be a healthy seedling, the growth gradually weakened after the seeding and reached the middle seedling stage after 20 days, and after 30 days the leaf color recovered even if further fertilization was applied Without this, the leaves became pale and soft seedlings. As a result, two out of the five boxes had stuffy seedlings and one box had damping-off.

COMPARATIVE EXAMPLE 4 Acidification treatment with a commercially available mineral acid and a mineral acid salt was carried out.
A rock wool mat for raising seedlings containing 5 g was used as a sowing bed, and commercially available mountain soil was used as the original soil to obtain a pH of 4.5 to 5.5 by a conventional technique.
Example 6 except that a granular soil containing 1.5 g of NPK per box was used as a 1 L cover soil after acidification treatment.
Seedlings were raised in the same manner as described above. As a result, the pH at the time of uniform germination of warmed seeds at 32 ° C. for 2 days was 5.0, 5.0, 10 days 5.5, 15 days 5.8, 20 days 6.5 and 25 after sowing. The results were 6.5 on day, 7.0 on day 30, and 7.0 on day 35. Up to about 15 days after sowing, the seedlings were dark green in leaf color, pure white in root color, and had good rooting. On the 17th day, the leaf color became slightly lighter and the root color became slightly dusty. Was. From the 25th day onward, around the 30th day, the leaf color became pale, the root color became brown, and the seedlings became clearly poorly grown soft seedlings. Two boxes of stuffy seedlings and two cases of damping-off occurred.

[0029]

Since the present invention is configured as described above, the following excellent effects can be obtained. Rice seedling cultivation soil, when the pH is 4.5 to 5.5 as described above,
Seedlings grow best and grow well, and are extremely resistant to physiological disorders and diseases even in the cold season. Therefore, it is also publicly instructed. That is, pH 4.5-5.5 is an absolute condition of the cultivation soil for rice seedlings. However, the pH of natural soil used for rice seedlings, such as mountain soil, field soil, and rice field, is approximately 6.0 to 7.0. These are compared with 4.5 to
Even when the pH is adjusted to 5.5, the pH tends to increase every day due to irrigation and rainfall during seedling raising, and tends to return to the pH of the original soil in the middle of seedling raising. Thus, the growth is inferior, and in cold weather, rice is susceptible to damping-off and stuffiness.

However, the sulfur-added seedling cultivation soil of the present invention can be used for 30 days to 4 days for middle seedlings as well as for 20 days for seedlings.
Maintain the initially adjusted pH of 4.5 to 5.5 for a long period of 0 days. Seedlings grow extremely healthy and have extremely remarkable effects against cold and cold even in cold weather.

The applicant of the present invention conducted a seedling raising test of several hundred seedling raising boxes during the seedling raising period from March to May for several years, but did not experience any damping-off disease or stuffy seedlings at all. So why do we have such an excellent effect? The scientific basis is not clear, but it is that the pH of the cultivation soil is completely 4 during the seedling raising period.
Of course, by keeping it at 5 to 5.5,
However, it is supposed that such a remarkable effect not only depends on the pH but also contributes to the bactericidal action of sulfur itself and also to the action of any action other than the oxidation of sulfur bacteria.

Claims (4)

[Claims] 1. A sulfur-added seedling culture medium prepared by adding sulfur to natural soil, keeping it warm or warming it, and acidifying the natural soil. 2. A sulfur-added seedling cultivation soil in which the sulfur-added natural soil is adjusted to contain about 20% or less, preferably about 10% or less of water. 3. Seeding a seed on a natural soil to which sulfur has been added,
A method for raising seedlings comprising irrigating, covering the natural soil, and keeping or warming the seeds to promote seed emergence and acidify the natural soil. 4. An artificial molding medium in which seeds are sown, irrigated, covered with sulfur-added natural soil, kept warm or heated to promote seed germination, and at the same time, the molding medium and the natural soil are combined. A method of raising seedlings that acidifies.