JPH06141680A - Method for removing salt from cultivated soil - Google Patents

Abstract

PURPOSE:To remove salts in cultivated soil according to the characteristics of the ground by regulating the depth of each rolled pulpy member, exposing the upper part, embedding the member in cultivated soil, absorbing water in the cultivated soil, evaporating the water, and thickening the dissolved salts into the pulpy member. CONSTITUTION:The upper parts of pulpy members such as paper rolls 21 are exposed and embedded in cultivated soil 22 at a prescribed interval and water rising from the lower part of the cultivated soil is mostly evaporated from the surface of the terrestrial exposed part of each pulpy member 21 to thicken salts in water in the pulpy member 21 and remove the salts in the cultivated soil 22. In the process, the length of the paper roll 21 in the water is increased from that in the aerial part of the paper roll 21 in the case of the cultivated soil good in water permeability. In the case of the cultivated soil poor in the water permeability, the length of the underground part of the paper roll 21 is longer than that of the aerial part. Thereby, the removal of the salts from the cultivated soil can efficiently and economically be performed by the length of the paper roll according to the characteristics of the ground.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing salt from cultivated soil, which is used for preventing salt damage when performing agriculture or greening business in dry agricultural land such as a desert.

[0002]

2. Description of the Related Art Conventional irrigation methods are shown in FIGS. 6 to 9 [Ayers.RS and Westcot.PW:Wate.
r Quality for Agriculture, Irrigation and Drainago
paper, 29, FAO, PP.15-63 (1985)].

FIG. 6 is an explanatory view of the sprinkler irrigation method, in which a sprinkler (not shown) pours water 1 onto the surface of the ground. Water penetrates into the cultivated soil from the surface,
Salts increase in the depth direction as shown by arrow 1a. That is,
The salinity increases in the order of 2d → 2c → 2b → 2a.

FIG. 7 is an explanatory view of the ridge irrigation method, in which water is sprinkled between the ridges 3 and 3, and water is accumulated as shown by a broken line.
The water between the ridges 3 and 3 permeates the cultivated soil from the surface of the ground, but in this case also, salt increases in the depth direction as shown by the arrow 3a as shown in FIG. That is, the salinity increases in the order of 4d → 4c → 4b → 4a. However, since the upper surfaces of the ridges 3 and 3 are exposed, water evaporates from the upper surfaces and concentrates as shown in the figure. Figure 6 above
In the case of the sprinkler irrigation method shown in Fig. 7 and the ridge irrigation method shown in Fig. 7, water is infiltrated at a constant depth over the entire farmland (cultivated soil).

Next, FIG. 8 is an explanatory view of the ridge irrigation method. Water is collected in the lowland between the ridges 5, 5 ... 5 as shown by the broken line, and the water permeates from the lowland in the direction of arrow 5a. As a result, the salt in the cultivated soil increases in the order of 6d → 6c → 6b → 6a and becomes concentrated.

Further, FIG. 9 is an explanatory diagram of the drip irrigation method. When the irrigation water is partially concentrated on the farmland as shown by arrows 7, 7, ... 7, Salt is supplied in the same manner as the furrow irrigation method of FIG. The rise of is not much different in the direction of depth. But,
In both of the ridge irrigation method of FIG. 8 and the drip irrigation method of FIG. 9, salt is concentrated in a portion not covered by water,
Salts form a spherical layer and concentrate.

By the way, the conventional irrigation method is
Instead of removing the salt in any way, by sprinkling the salt, the salt is simply driven downward or to the side, and when the sprinkling is stopped, these salts accompany the evaporation of water from the surface of the cultivated soil.
Remarkably concentrated on the surface layer. In other words, salt cannot be cut off from crops without constant water supply.

Further, since the salts are not fundamentally removed,
Salts slightly contained in irrigation water accumulate for a long time,
Salt is concentrated throughout the soil. If the salt removal is not carried out, the salt will be concentrated and the soil will not be usable due to salt damage. Therefore, the salt removal is indispensable for solving this problem.

[0009] Rinsing can be considered as a method of removing salts, but in a dry place, it is difficult to sufficiently rinse and to secure a large amount of water that can be drained into the river. On the other hand, in the process of irrigating farmland,
As shown in FIG. 10, the present invention provides a salt damage prevention method for dry farmland irrigation in which salt is collected in a specific portion and the portion is discarded.

This is because a pulp block 18 having an exposed upper portion and having a predetermined shape is embedded in a cultivated soil 19 of a dry farmland at a predetermined interval, and the ground surface of the pulp block 18 excluding the above-ground exposed portion is covered with straw. An evaporation preventing material 16 such as a branch is spread, and a permeable layer 13 and an impermeable layer 12 are provided below the cultivated soil 19, and the permeable layer 13 is a vertical permeable layer 13a.
Through the irrigation canal 14 through the irrigation canal 1
The water of No. 4 is raised from the lower part of the cultivated soil 19 through the water permeable layer 13, and most of the raised water is evaporated from the surface of the exposed surface of the pulp block 18, and the salt in the water is concentrated in the pulp block 18. Then, the pulp block 18 is replaced when the salt is concentrated above a predetermined concentration.

[0011]

However, such a conventional salt damage prevention method is disadvantageous in terms of cost because it is necessary to mold the pulp block 18 into a specific shape, and the difference in the characteristics of the ground, that is, the water permeability of the ground. The difference in the concentration distribution of salt due to the above is not taken into consideration, and there is a problem that the concentration efficiency is remarkably deteriorated depending on the usage of the pulp block. The present invention has been made in view of the above conventional problems, and provides a salt removal method for cultivated soil, which can economically realize efficient salt concentration removal suitable for the characteristics of the ground. The purpose is to do.

[0012]

According to the method for removing salt from cultivated soil according to the present invention, a pulp member is buried in the cultivated soil at a predetermined interval while exposing the upper part of the cultivated soil. Is evaporated from the above-ground exposed surface of the pulp member, in the salt removal method of cultivated soil to concentrate the salts in the water in the pulp member, the pulp member is a paper roll, in the cultivated soil good water permeability, The aerial part of the paper roll is longer than the aerial part, and in cultivated soil having poor water permeability, the aerial part of the paper roll is longer than the aerial part.

[0013]

The paper roll according to the present invention is used after being vertically inserted into the once submerged cultivated soil and then naturally dried, and when the cultivated soil has good water permeability such as sand ground, the aerial part is lengthened. By doing so, salt is concentrated at the upper end of this, and if the cultivated soil is soil with poor permeability such as clay, the underground portion is lengthened to add salt to the underground portion near the ground surface. Concentrate to efficiently remove salt according to the characteristics of the ground.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. First, sand A consisting of 100 (wt%) sand (flattery sand) and 0 (wt%) bentonite (Kunigel V1), mixed soil B consisting of 98 (wt%) sand and 2 (wt%) bentonite. , And 95 (wt%) sand and 5 (wt%) bentonite mixed soil C
Are prepared as test samples.

Next, as a sample container, an inner diameter of 5 cm,
Using a container of acrylic member having a height of 10 cm, prepare 200 g of a dry sample and a saline solution having a chlorine cl ⁻ concentration of 270 μg / g. And saturate. The amount of saline added depends on the type of specimen. In addition, the sample preparation condition is that the height of the specimen in the container is 6.2c for sand A.
m, the amount of saline solution required to saturate is 50 cc
(W = 25%), and 6.4 cm for mixed soil B,
48cc (W = 24%), 6.8 for mixed soil C
cm and 59 cc (w = 30%). Here, w represents a water content ratio.

Then, the specimens are dried in a constant temperature bath (35 ° C.), and in order to obtain sample data in several stages of dry state, a plurality of specimens are prepared, and the specimens taken out from the constant temperature bath are deeply removed. Slice in the vertical direction and measure the water content and the concentration of salinity cl ⁻ . In addition, the paper roll is 1 to 1 in the depth direction.
After cutting to a length of 2 cm and oven drying, the concentration (μg / cm) of water content cl ⁻ is measured.

Sand A and mixed soil B and C as samples now
The amount of cl ⁻ accumulated in the paper roll is about
As shown in, the cl ^- concentration of the salt solution is 270μ.
Assuming g / cc, for sand A, 10000μg / 270μ
g / cc = 37 cc, and the at one Kimwipe, the aerial part is 6 cm, cl of 37 cc is nine times the amount of water absorption of paper roll ^- can collect. The mixing soil B, and the C, cl from the top view ^- an integrated amount of it can be seen significantly lower.

Therefore, as shown in FIG. 1, in the case of the sand ground, the paper roll 21 is set so that the air part is sufficiently longer than the ground part with respect to the ground 22 having good water permeability such as sand A. When embedded in, cl as shown in FIG. 2 ^- the concentration distribution of, cl ^- is centrally can Enrichment the tip portion P of the paper roll 21, by increasing the length of the aerial parts, further cl ^- Can be increased.

On the other hand, from the characteristics shown in FIG. 5, as shown in FIG. 3, in the soil 23 having poor water permeability such as mixed soils B and C, the paper roll 21 is placed in the underground portion more than in the air portion. Lengthen. As a result, cl ⁻ concentrates in the underground portion Q near the surface of the ground 23 of the paper roll 21, and the concentration distribution of cl ⁻ becomes as shown in FIG. That is, depending on whether the ground is sand or mixed soil, the length of the air portion of the paper roll 21 with respect to the underground portion can be arbitrarily selected, so that cl ⁻ can be optimally accumulated.

[0020]

As described above, according to the present invention, the upper part is exposed in the cultivated soil and the pulp member is embedded at a predetermined interval, and most of the moisture rising from the lower part of the cultivated soil is stored in the pulp member. In the salt removal method of cultivated soil that is evaporated from the surface above the ground surface and concentrates the salt in the water in the pulp member, the pulp member is used as a paper roll, and in the cultivated soil with good water permeability, the vapor of the paper roll is used. In the cultivated soil where the middle part is longer than the underground part and the water permeability is not good, the underground part of the above paper roll is made longer than the aerial part, so the aerial length of the paper roll that matches the characteristics of the soil There is an effect that it is possible to efficiently remove salt in soil.

[Brief description of drawings]

FIG. 1 is a layout view of a paper roll showing a method for removing salt from cultivated soil according to an embodiment of the present invention.

[Figure 2] of the paper roll buried in sand ground length and cl ^-
It is a characteristic diagram showing the concentration distribution of.

FIG. 3 is a layout view of a paper roll showing a method for removing salt from cultivated soil according to another embodiment of the present invention.

[Fig. 4] Length and c of paper rolls embedded in mixed ground
l ^- is a characteristic diagram showing the concentration distribution of.

FIG. 5: c on paper roll for sand and mixed soil
l ^- is a characteristic diagram showing the accumulation amount of.

FIG. 6 is an explanatory view showing a conventional sprinkler irrigation method.

FIG. 7 is an explanatory view showing a conventional ridge irrigation method.

FIG. 8 is an explanatory view showing a conventional ridge irrigation method.

FIG. 9 is an explanatory diagram showing a conventional drip irrigation method.

FIG. 10 is an explanatory diagram showing a conventional salt damage prevention method.

[Explanation of symbols]

 1 paper roll

Claims (1)

[Claims] 1. A pulp member is buried in cultivated soil with its upper part exposed at a predetermined interval, and most of the moisture rising from the lower part of the cultivated soil is evaporated from the above-ground exposed surface of the pulp member. In the method for removing the salt content of cultivated soil in which the salts of the above are concentrated in the pulp member, the pulp member is a paper roll, and in the cultivated soil with good water permeability, the aerial part of the paper roll is made longer than the underground part, In the case of cultivated soil having poor water permeability, the method for removing salt from cultivated soil is characterized in that the underground part of the paper roll is made longer than the aerial part.