CN110692304A

CN110692304A - Saline-alkali soil reconstruction structure and closed-loop control method thereof

Info

Publication number: CN110692304A
Application number: CN201910970469.0A
Authority: CN
Inventors: 尤学一; 刘磊
Original assignee: Tianjin University
Current assignee: Tianjin University
Priority date: 2019-10-13
Filing date: 2019-10-13
Publication date: 2020-01-17

Abstract

The invention discloses a saline-alkali soil reconstruction structure and a closed-loop control method thereof, wherein the saline-alkali soil reconstruction structure mainly comprises a soil layer, a permeable membrane, a ceramsite layer and a gravel layer, a water supply pipe is laid below the gravel layer, and a salinity sensor and a water level sensor are arranged at the middle upper part of the soil layer; under the condition of maintaining the normal growth of the planted crops, the excessive irrigation is prevented, so that the automatic closed-loop control of saline and alkaline land is realized. Compared with the prior art, the saline-alkali land reconstruction structure can avoid the phenomenon of excessive waste of water resources in a salt pressing method, overcome the defect that the nutrient composition of soil is changed due to the application of acidic substances in a direct reconstruction method, effectively improve the growth condition of saline-alkali land crops, avoid excessive waste of water resources and promote the improvement and protection of ecological environment.

Description

Saline-alkali soil reconstruction structure and closed-loop control method thereof

Technical Field

The invention relates to the technical field of saline-alkali soil reformation and ecological environment protection, in particular to a saline-alkali soil reformation method.

Background

The salinization of soil has become an urgent problem to be solved nationwide or even worldwide. The salinization of soil is more serious due to factors such as drought in climate, high underground water level, unreasonable irrigation, imperfect drainage and the like, the salinization of soil has a series of hazards, the salinization of soil can reduce the yield of crops, and the development of agricultural economy is restricted. In addition, plants planted in the saline-alkali soil are not easy to grow, so that earth surface vegetation is gradually damaged, the phenomenon of water and soil loss is aggravated, even the soil is desertified, and finally the ecological environment is damaged.

At the present stage, the saline-alkali soil is treated mainly by a salt pressing method, a salt avoiding method, a direct improvement method and the like. The salt pressing method is to irrigate a large amount of water to enable salt to seep into deep soil to maintain normal growth of crops, but when the evaporation capacity is increased, the deep salt rises to the ground surface along with the water to influence the normal growth of the crops, and the method needs a large amount of exogenous water and is not beneficial to saving and utilizing water resources. The salt-avoiding method is to reform the land into one-way furrows, when water is evaporated, salt is mainly concentrated on the ridge backs, so that the salt in the furrows is not too high, and the normal growth of crops in the furrows is protected. The direct improvement method is to apply organic fertilizer with high acidity to the soil to reduce the alkalinity of the soil, but the method is easy to destroy the original structure of the soil nutrient components, and the organic fertilizer with high acidity is applied for a long time, so that the soil can not be utilized.

Disclosure of Invention

The invention provides a saline-alkali land reconstruction structure for improving the saline-alkali of land, and the designed novel saline-alkali land reconstruction structure avoids excessive waste of water resources, does not change the original nutrient composition in the land and is beneficial to the protection of ecological environment.

The invention relates to a saline-alkali soil reconstruction structure, which at least comprises a soil layer, and a water permeable membrane 5, a ceramsite layer 6 and a gravel layer 7 which are respectively paved below the soil layer from top to bottom, wherein:

the water permeable membrane 5 prevents soil from running off to the ceramsite layer 6 and the gravel layer 7,

and the water supply pipe 8 vertical to the water permeable hole 9 is laid below the gravel layer 7, the other end of the water supply pipe 8 is connected with a reservoir 12, one end of the reservoir is connected with a drain pipe 14, and the other end of the reservoir is connected with a water pump on the ground. A salinity sensor 13 is arranged in the middle of the ceramsite layer 6, a first water level sensor 10 is arranged in the water supply pipe 8, a second water level sensor is arranged at the middle lower part of the reservoir 12, and the change conditions of salinity and water level are monitored in real time.

The invention discloses a closed-loop control method of a saline-alkali soil reconstruction structure, which specifically comprises the following steps:

when the salinity of the soil layer is higher than the tolerance salinity of the planted crops, starting the water suction pump 15 to pump out high salinity water to prevent the high salinity water of the soil layer from influencing the growth of the ground crops, and simultaneously starting the sprinkling pump 3 and the sprinkling head 1 to irrigate the planted crops; when the second water level sensor 11 in the reservoir 12 senses that the water level is low, the water pump 15 is turned off, and irrigation is continued; when the first water level sensor 10 in the feed pipe 8 senses that the water level is high, the sprinkling pump 3 is turned off. The salinity inductor 13 and the changes of the salinity and the water level of the first water level inductor and the second water level inductor can be monitored in real time, and under the condition of maintaining the normal growth of the planted crops, the excessive irrigation is prevented, so that the automatic closed-loop control of the saline and alkaline land is realized.

Compared with the prior art, the saline-alkali land reconstruction structure can avoid the phenomenon of excessive waste of water resources in a salt pressing method, overcome the defect that the nutrient composition of soil is changed due to the application of acidic substances in a direct reconstruction method, effectively improve the growth condition of saline-alkali land crops, avoid excessive waste of water resources and promote the improvement and protection of ecological environment.

Drawings

FIG. 1 is a schematic diagram of a saline-alkali soil reclamation structure;

reference numerals:

1. sprinkling irrigation sprinkler, 2, plant the crop, 3, the sprinkling irrigation pump, 4, soil, 5, the membrane of permeating water, 6, the haydite layer, 7, the gravel layer, 8, the feed pipe, 9, the hole of permeating water, 10, first water level inductor, 11, second water level inductor, 12, cistern, 13, salinity inductor, 14, the drain pipe, 15, the suction pump.

Detailed Description

The invention is further illustrated by the following figures and examples, which are not to be construed as limiting the invention.

FIG. 1 is a schematic structural view of the reclamation of saline-alkali soil. The structure mainly comprises a soil layer, and a water permeable membrane 5, a ceramsite layer 6 and a gravel layer 7 are paved below the soil layer from top to bottom respectively, wherein the water permeable membrane 5 can prevent soil from losing to the ceramsite layer 6 and the gravel layer 7, a water supply pipe 8 with a vertical water permeable hole 9 is paved below the gravel layer 7, the other end of the water supply pipe 8 is connected with a reservoir 12, one end of a drain pipe is connected with the reservoir, and the other end of the drain pipe is connected with an above-ground water suction pump. A salinity sensor 13 is arranged in the middle of the ceramsite layer 6, a first water level sensor 10 is arranged in the water supply pipe 8, a second water level sensor is arranged at the middle lower part of the reservoir 12, and the change conditions of salinity and water level are monitored in real time.

The invention discloses an overall process of a closed-loop control method of a saline-alkali soil reconstruction structure, which specifically comprises the following steps:

when the salinity of soil horizon is higher than the tolerant salinity value of planting the crop, start suction pump 15, take out high salinity water, prevent that the high salinity water of soil horizon from influencing the growth of earth's surface crop, start irrigation pump 3 and sprinkling irrigation sprinkler head 1 simultaneously, water and plant the crop. When the second water level sensor 11 in the reservoir 12 senses that the water level is low, the water pump 15 is turned off, and irrigation is continued; when the first water level sensor 10 in the feed pipe 8 senses that the water level is high, the sprinkling pump 3 is turned off. The salinity inductor 13 and the changes of the salinity and the water level of the first water level inductor and the second water level inductor can be monitored in real time, under the condition of maintaining the normal growth of the planted crops, the excessive irrigation can be prevented, the waste of water resources is caused, and therefore the automatic closed-loop control of the saline-alkali soil is realized.

The transformation process of the salinized land is illustrated by taking the transformation of landscape land with high salinization degree in Tianjin city as an example, and the specific implementation mode is described as follows:

1. firstly, the soil structure is improved, the soil is changed into a three-layer structure which comprises a soil layer 4, a ceramsite layer 6 and a gravel layer 7, wherein the soil layer 4 is positioned at the top, a water permeable membrane 5 (preventing soil particles from blocking holes between the ceramsite layer 6), the ceramsite layer 6 and the gravel layer 7 are respectively paved below the soil layer 4 from top to bottom, a water supply pipe 8 is paved below the gravel layer 7, a vertical water permeable hole 9 is arranged on the water supply pipe 8, one end of the water supply pipe 8 is connected with a reservoir 12, one end of a drain pipe 14 is connected with the reservoir 12, and the other end of the drain pipe is connected with a water suction pump 15. The sprinkling pump 3 supplies water, and the sprinkling head 1 realizes even sprinkling and watering. The solar panel is used for generating electricity, the storage battery is used for storing electricity, and solar energy is converted into electric energy. The water pumps 3 and 15 are driven by solar energy, so that the power supply system line is saved, and renewable energy sources are utilized.

2. The water level sensor 10 and the water level sensor 11 are arranged, and the salinity sensor 13 is arranged to monitor the salinity and the water level change in real time. A salinity sensor 13 is arranged in the middle of the ceramsite layer 6, a water level sensor 10 is arranged in the water supply pipe 8, and a water level sensor 11 is arranged at the middle lower part of the reservoir 12.

3. When the salinity and alkalinity in the soil is higher than the tolerance of the planted crops, the water suction pump 15 is started to pump out the high salinity and the sprinkling irrigation water pump 3 is started to supply water, the sprinkling head 1 sprays water evenly to irrigate the ground, the salinity and alkalinity in the soil is reduced in time, and the high salinity and alkalinity in the soil layer is prevented from influencing the growth of the surface crops 2. The extracted high salinity water can be desalted and then reused.

4. When the water level sensor 11 senses that the water level is low, the water pump 15 is turned off, but the water pump 3 continues to irrigate the crops. When the water level sensor 10 senses the water level, the sprinkling irrigation pump 3 is closed, and irrigation is stopped, so that the normal growth of crops can be maintained, and excessive irrigation can be prevented, and the waste of water resources is caused.

Claims

1. The utility model provides a salinized soil reforms transform structure which characterized in that, this structure includes the soil horizon at least and has spread respectively in the below top-down of soil horizon permeable membrane (5), haydite layer (6) and gravel layer (7), wherein:

the water permeable membrane (5) prevents soil loss to the ceramsite layer (6) and the gravel layer (7);

a water supply pipe (8) vertical to the water permeable hole (9) is laid below the gravel layer (7), the other end of the water supply pipe (8) is connected with a reservoir (12), one end of the reservoir is connected with a drain pipe (14), and the other end of the reservoir is connected with a water pump on the ground; a salinity sensor (13) is arranged in the middle of the ceramsite layer (6), a first water level sensor (10) is arranged in the water supply pipe (8), a second water level sensor is arranged at the middle lower part of the reservoir (12), and the change conditions of salinity and water level are monitored in real time.

2. The closed-loop control method for the saline-alkali soil reclamation structure as recited in claim 1, which comprises the following steps:

when the salinity of the soil layer is higher than the tolerance salinity of the planted crops, a water suction pump (15) is started to pump high salinity water out to prevent the high salinity water of the soil layer from affecting the growth of the surface crops, a sprinkling pump (3) and a sprinkling irrigation sprinkler head (1) are started to irrigate the planted crops, when a second water level sensor (11) in a reservoir (12) senses that the water level is low, the water suction pump (15) is closed to continue irrigation, when a first water level sensor (10) in a water supply pipe (8) senses that the water level is high, the sprinkling pump (3) is closed, a salinity sensor (13) and the first and second water level sensors monitor the changes of salinity and the water level in real time, under the condition that the normal growth of the planted crops is maintained, excessive irrigation is prevented, and therefore the automatic closed-loop control of the salinized soil is realized.