JPH047646B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a soil improvement method, and more particularly to a method for soil improvement by adjusting the ecosystem in the soil. [Prior Art] Conventionally, it has been generally said that it is preferable for the soil of agricultural land to be neutral to weakly acidic, and from this viewpoint, soil conditions have been maintained appropriately. For example, in order to prevent imbalances in soil PH values caused by the use of ammonium sulfate as fertilizer, calcium carbonate is sprayed to neutralize the soil. On the other hand, the quality of soil is said to be greatly influenced by the ecosystem within the soil, and it is said that soil is in good condition especially when the ratio of actinomycetes to filamentous fungi living in the soil is approximately 7:3. has been done. [Problems to be solved by the invention] However, in the conventional soil improvement based on the above-mentioned PH value, even if the PH value is adjusted to a preferable range,
There are many times when things don't lead to the desired results. In other words, although the pH value of the soil is neutral or slightly acidic, which is considered to be appropriate, this results in poor growth and reduced yields. Furthermore, the survival ratio of actinomycetes and filamentous fungi in soil is hardly adjusted at present because there is no specific adjustment method. [Means for solving the problem] By the way, as a result of the present inventor collecting soil from various places and culturing it, it was found that good results were not obtained even though the PH value was adjusted to an appropriate range. It was found that filamentous fungi were abnormally more abundant than actinomycetes in areas where there were no. The present invention is based on the above-mentioned fact discovered by the present inventor, and aims to solve the above-mentioned problems by making it possible to appropriately adjust the ratio of actinomycetes and filamentous fungi. The method is to spray an alkalizing agent and leave it for a period of time so that the pH of the soil is between 9 and 13. The alkalizing agent used in the present invention may be any agent that can alkalinize soil without adversely affecting crops, but calcium hydroxide, calcium oxide, etc. are preferred for reasons of availability and harmlessness. preferable. These alkalizing agents are usually sprayed as they are in the form of powder, but they may also be sprayed as an aqueous suspension. The above alkalizing agent is sprayed so that the pH value of the soil immediately after spraying is 9 to 13.
The pH value is preferably 10-12. Alkalizing the soil with an alkalizing agent promotes the growth of actinomycetes by suppressing the growth of filamentous fungi.If the PH value of the soil immediately after application is too low, the growth of filamentous fungi cannot be sufficiently suppressed. , it becomes impossible to effectively promote the proliferation of actinomycetes. On the other hand, if the pH of the soil is raised too high, it tends to inhibit the reproduction of actinomycetes. In the present invention, the PH of soil is the value measured with a PH meter after collecting 30 g of soil in a container such as a beaker, adding 100 c.c. of purified water, and stirring well. The leaving period after spraying the alkalizing agent is
It is 5 to 10 days, preferably 7 to 10 days. During this standing period, actinomycetes multiply and increase in the soil, and the balance between actinomycetes and filamentous fungi is properly adjusted. In addition, the soil may have a high
During this period, the pH value is naturally neutralized by carbon dioxide in the soil and gradually decreases, reaching a value that does not pose a problem for crop planting. Therefore, crop planting is
This can be done after this period has elapsed. [Effect] The reason why the balance between actinomycetes and filamentous fungi is restored by temporarily exposing the soil to a high PH value is not necessarily clear, but the inventor speculates as follows. There is. That is, it is thought that many actinomycetes are relatively resistant to alkali, whereas many filamentous fungi are relatively weak to alkali. this is,
This can be seen from the fact that although cultured actinomycetes are rarely killed when immersed in alkaline solution, many of the cultured filamentous fungi are killed when immersed in alkaline solution. Therefore, when the soil is exposed to a certain high pH value, some of the filamentous fungi will die and some of their activity will be suppressed, and until then the activity of the filamentous fungi has been suppressed by the active proliferation of the filamentous fungi. It is thought that the reproduction of actinomycetes, which had previously been present, will become more active, and the balance between the two will be restored. [Example] Soils A, B, and C shown in Table 1 were cultured on an agar medium, and the proportions of actinomycetes and filamentous fungi contained in each were measured. The measurement standard is to calculate the area of the area where actinomycetes are seen to the naked eye and the area where filamentous fungi are seen to grow, and then calculate the area ratio as the approximate ratio of the two. did. Furthermore, for each soil, 10 points were randomly selected, a vinyl pipe with a diameter of 5 cm and a length of 20 cm was driven into the pipe, the soil contained therein was sampled, and the pH was measured using the method described above. The results are shown in Table 1.

[Table] Calcium hydroxide was sprayed at 10g/ ^m2 for soils A and B, respectively, calcium oxide was sprayed at 5g/m2 for soil C, and soil A was ^sprayed at 5g/m2.
PH12.2, PH11.5 for soil B, and PH10.1 for soil C. After leaving these soils A, B, and C for 10 days, the PH value of each was measured.
The PH value of soil A is 7, the PH value of soil B is 6.8, and the soil C
The pH value was 7.3. In addition, each soil was cultured in the same manner as above, and the proportions of actinomycetes and filamentous fungi contained in each soil were measured. The results are shown in Table 2.

[Table] [Effects of the Invention] As described above, according to the present invention, it is possible to adjust the ratio of actinomycetes and filamentous fungi in soil to an appropriate balance, thereby reducing the adverse effects on crops caused by disturbance of this ecosystem. Since it is possible to prevent this, it is possible to increase the yield of crops.

Claims (1)

[Claims] 1. A soil improvement method characterized by spraying an alkalizing agent on the soil so that the pH of the soil becomes 9 to 13 immediately after spraying and allowing a period of standing.