阅读说明：本技术 一种用于盐田的洗盐处理系统及方法 (Salt washing treatment system and method for salt pan ) 是由 秦龙 朱秀鑫 岑艳妮 冯波 于 2020-05-30 设计创作，主要内容包括：本发明涉及一种用于盐田的洗盐处理系统,包括排盐田块以及连通到排盐田块内的进水渠和排水沟；所述排盐田块包括中间耕作区、设置在中间耕作区外侧的排盐沟以及设置在中间耕作区内的排盐毛沟,所述中间耕作区上部设置有耕作层,所述耕作层下方设置有碎石滤层,所述碎石滤层与排盐沟和排盐毛沟连通；所述进水渠和排水沟与排盐沟连通；所述耕作层与碎石滤层之间设置有第一隔层,所述第一隔层包括铺设在碎石滤层上的垫土层以及铺设在垫土层上的第一土工布层。通过本发明的系统和方法,能够有效地改善盐田的土质,降低盐田含盐量,达到复垦农田的要求。(The invention relates to a salt washing treatment system for a salt field, which comprises a salt discharge field block, and a water inlet channel and a water drainage channel communicated with the salt discharge field block; the salt discharge field block comprises a middle cultivation area, a salt discharge ditch arranged on the outer side of the middle cultivation area and a salt discharge rough ditch arranged in the middle cultivation area, a cultivation layer is arranged on the upper part of the middle cultivation area, a gravel filter layer is arranged below the cultivation layer, and the gravel filter layer is communicated with the salt discharge ditch and the salt discharge rough ditch; the water inlet channel and the water drainage channel are communicated with the salt drainage channel; be provided with first interlayer between plough layer and the rubble filter bed, first interlayer is including laying the first geotechnological cloth layer on the soil cushion layer and laying on the soil cushion layer on the rubble filter bed. The system and the method can effectively improve the soil quality of the salt pan, reduce the salt content of the salt pan and meet the requirement of land reclamation.)

1. A salt washing processing system for salt pan, its characterized in that: comprises a salt discharge field block, and a water inlet channel (100) and a water drainage channel (200) communicated with the salt discharge field block;

the salt removing field comprises a middle cultivation area (1), a salt removing ditch (2) arranged on the outer side of the middle cultivation area (1) and a salt removing hair ditch (3) arranged in the middle cultivation area (1), wherein a cultivation layer (11) is arranged on the upper part of the middle cultivation area (1), a gravel filter layer (12) is arranged below the cultivation layer (11), and the gravel filter layer (12) is communicated with the salt removing ditch (2) and the salt removing hair ditch (3);

the water inlet channel (100) and the drainage channel (200) are communicated with the salt drainage channel (2).

2. The salt washing treatment system for the salt pan as claimed in claim 1, wherein: be provided with first interlayer between plough layer (11) and rubble filter layer (12), first interlayer is including laying in bedding layer (13) on rubble filter layer (12) and laying in first geotechnological cloth layer (14) on bedding layer (13).

3. The salt washing treatment system for the salt pan as claimed in claim 1, wherein: the soil layer (4) is arranged below the gravel filter layer (12), and a second geotextile layer (15) is laid between the gravel filter layer (12) and the original soil layer (4).

4. The salt washing treatment system for the salt pan as claimed in claim 1, wherein: an original soil interlayer (41) is arranged between the middle cultivation area (1) and the salt and hair removing ditch (2) and the salt and hair removing ditch (3), and the height of the original soil interlayer (41) is greater than the surface height of the middle cultivation area (1).

5. A salt washing treatment system for salt pan according to claim 4, characterized in that: and a diversion pipe (5) is laid below the original soil interlayer (41), and the diversion pipe (5) is communicated with the gravel filter layer (12) and the salt discharge ditch (2) and the salt discharge rough ditch (3).

6. A salt washing treatment system for salt pan according to claim 5, characterized in that: arrange salt ditch (2) including equal width groove (21) and flaring groove (22) on upper portion of lower part, honeycomb duct (5) intercommunication is between equal width groove (21) and rubble filtering layer (12), the bottom surface height that the bottom surface height of equal width groove (21) is less than rubble filtering layer (12), equal width groove (21) and flaring groove (22) both sides set up the banket and tamp.

7. A salt washing treatment system for salt pan according to claim 5, characterized in that: the salt-removing hair ditch (3) comprises a narrow groove (31) at the lower part and a wide groove (32) at the upper part, the draft tube (5) is communicated between the narrow groove (31) and the gravel filtering layer (12), the bottom surface of the narrow groove (31) is as high as the bottom surface of the gravel filtering layer (12), and the two sides of the narrow groove (31) and the wide groove (32) are filled with soil and tamped.

8. The salt washing treatment system for the salt pan as claimed in claim 1, wherein: the water inlet channel (100) is parallel to the salt discharge channel (2), the bottom height of the water inlet channel is higher than that of the salt discharge channel (2), a water conduit (6) is obliquely arranged at the bottom of the water inlet channel (100), and the water conduit (6) is communicated to the bottom of the salt discharge channel (2).

9. The salt washing treatment system for the salt pan as claimed in claim 1, wherein: the drainage ditch (200) is perpendicular to the salt discharge ditch (2) and is arranged, the bottom height of the drainage ditch is lower than that of the salt discharge ditch (2), and the end parts of the salt discharge ditch (2) and the salt discharge rough ditch (3) are communicated into the drainage ditch (200).

10. A salt washing treatment method for a salt pan is characterized by comprising the following steps:

step 1: land leveling, namely, concentrating connected pieces, forming a check field block by taking a ditch and a road as a reference, wherein the height difference of the land leveling surface of the field soil is within +/-10 cm, the thickness of a plowing layer is not less than 30cm, the design length of the check field is 100-250 m, and the design width is 40-60 m;

step 2: drainage ditches (200) are built outside two short edges of the farmland, salt discharge ditches (2) are built outside two long edges, the salt discharge ditches (2) are communicated to the drainage ditches (200), and drainage pump stations are built in the drainage ditches (200);

and step 3: salt-removing hair ditches (3) are built between the salt-removing ditches (2) at two sides every 4-6 m, and two ends of the salt-removing hair ditches (3) are communicated into the drainage ditches (200);

and 4, step 4: digging and stacking one side of the surface soil of the field, continuously digging to the depth of 70-100 cm, stacking the dug soil and the surface soil in a distinguishing way, laying geotextile at the bottom of a pit, paving broken stones with the particle size of 2-4 cm to 20-30 cm, laying geotextile after covering with 5-10 cm of thin soil, backfilling the dug soil to a designed height, and loading and transporting the surplus soil to other places;

and 5: transversely punching holes at the bottom of the side walls of the salt discharge ditch (2) and the salt discharge rough ditch (3) at intervals of 50-100 cm, penetrating the holes into the gravel filter layer (12), and inserting a guide pipe (5) into the holes;

step 6: constructing a field road and a tractor-ploughing road in a field block, and constructing a water inlet channel (100) along the field road;

and 7: fresh water is introduced into a field area through a water inlet channel (100) to clean a salt field, the middle cultivation area (1) is irrigated, salt enters a gravel filtering layer (12) along with water flow, and is discharged to a salt discharge ditch (2) and a salt discharge rough ditch (3), converged into a drainage ditch (200), and pumped away by a drainage pump station;

and 8: planting halophilic and alkaline plants in the field block to absorb salt and salt in the soil, and planting leguminous green manure or multi-application farmyard manure after the salinity and the alkaline meet the requirements.

Technical Field

The invention relates to the technical field of soil improvement, in particular to a salt washing treatment system and method for a salt pan.

Background

In recent years, salt farm production enters a difficult-to-walk stage, a plurality of salt fields become waste fields, the waste fields are soaked by seawater for many years, the granular structure of soil is damaged, the loss of nutrient components such as organic matters is serious, the soil adaptability is extremely poor, the soil is hardened, the soil volume is large, the permeability is reduced, particularly, the salt content of the soil is extremely high and is higher by more than 1.5%, and crops cannot grow normally. In order to improve the land utilization rate and increase the cultivated land area, the salt pan needs to be transformed to meet the cultivated land requirement.

At present, the abandoned salt pan is reclaimed into a farmland, great breakthroughs are not made in the technology at home and abroad, the efficiency of the reclaimed farmland of the salt pan is low, the difficulty of the salt washing and transformation project of the salt pan is high, the capital cost is high, and the effect is not obvious.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a salt washing treatment system and method for a salt pan, which can effectively improve the soil property of the salt pan, reduce the salt content of the salt pan and meet the requirement of farmland reclamation.

The above object of the present invention is achieved by the following technical solutions:

a salt washing treatment system for a salt pan comprises a salt pan block, and a water inlet channel and a water drainage channel communicated with the salt pan block;

the salt discharge field block comprises a middle cultivation area, a salt discharge ditch arranged on the outer side of the middle cultivation area and a salt discharge rough ditch arranged in the middle cultivation area, a cultivation layer is arranged on the upper part of the middle cultivation area, a gravel filter layer is arranged below the cultivation layer, and the gravel filter layer is communicated with the salt discharge ditch and the salt discharge rough ditch;

the water inlet channel and the drainage channel are communicated with the salt discharge channel.

Through adopting above-mentioned technical scheme, when carrying out salt washing in the salt pan, earlier irrigate fresh water to row salt field piece through the inlet channel, fresh water gets into by middle farming district and row salt ditch, through the infiltration of plough layer downwards, dissolve the salinity in the plough layer and take away, enter into the rubble filter bed, the filtration through rubble filter bed flows into row salt ditch and row salt hair ditch, flow into the escape canal by row salt ditch and row salt hair ditch again, flow away along with the escape canal, wash the salt through irrigating many times, the salinity in the salt pan soil layer reduces gradually, reach the requirement that satisfies the farming.

The present invention in a preferred example may be further configured to: be provided with first interlayer between plough layer and the rubble filter bed, first interlayer is including laying the first geotechnological cloth layer on the soil cushion layer and laying on the soil cushion layer on the rubble filter bed.

Through adopting above-mentioned technical scheme, bedding layer and first geotechnological cloth layer are spread on the rubble filtering layer, separate rubble filtering layer and plough layer, can prevent promptly that the soil of plough layer from infiltrating down and block up the rubble filtering layer, can guarantee again that the plough layer has sufficient thickness to keep soil and water and satisfy vegetation, and bedding layer then can protect first geotechnological cloth layer not damaged by the rubble.

The present invention in a preferred example may be further configured to: and an original soil layer is arranged below the gravel filter layer, and a second geotextile layer is laid between the original soil layer and the gravel filter layer.

Through adopting above-mentioned technical scheme, the second geotechnological cloth layer separates former soil layer and rubble filtering layer, has guaranteed permeability and drainage ability of rubble filtering layer bottom.

The present invention in a preferred example may be further configured to: and an original soil interlayer is arranged between the middle cultivation area and the salt and hair removing ditches, and the height of the original soil interlayer is greater than the surface height of the middle cultivation area.

Through adopting above-mentioned technical scheme, separate through the original soil interlayer between middle farming district and salt discharge ditch and the salt discharge hair ditch, guaranteed the firmness of structure and the compactedness of soil nature between middle farming district and salt discharge ditch and the salt discharge hair ditch, avoid the condition that the lateral wall of salt discharge ditch and salt discharge hair ditch appears collapsing, also can avoid irrigating the interior fresh water of middle farming district directly to flow into in salt discharge ditch and the salt discharge hair ditch simultaneously.

The present invention in a preferred example may be further configured to: and a diversion pipe is laid below the original soil interlayer and is communicated with the gravel filtering layer, the salt discharge ditch and the salt discharge rough ditch.

Through adopting above-mentioned technical scheme, the honeycomb duct can guide the flow of rivers, and the salt solution that permeates in the rubble stratum filtrate can flow to the salt drain ditch and arrange the salt hair ditch through the honeycomb duct in, the discharge of the salt of being convenient for.

The present invention in a preferred example may be further configured to: the salt discharge ditch comprises an equal-width groove at the lower part and an expanding groove at the upper part, the guide pipe is communicated between the equal-width groove and the gravel filter layer, the bottom surface height of the equal-width groove is lower than that of the gravel filter layer, and the equal-width groove and the expanding groove are filled with soil and tamped.

Through adopting above-mentioned technical scheme, the setting of salt discharging ditch can reduce the earth that falls to the ditch bottom, prevents that salt discharging ditch from blockking up and can not play the effect of salt discharging, and the bottom surface height that highly is less than the bottom surface height of rubble filtering layer of constant width groove is convenient for introduce the water in the rubble filtering layer to constant width inslot, discharges through constant width groove, avoids containing salt moisture backward flow to in the rubble filtering layer.

The present invention in a preferred example may be further configured to: the salt-removing hair ditch comprises a narrow groove at the lower part and a wide groove at the upper part, the guide pipe is communicated between the narrow groove and the gravel filter layer, the bottom surface of the narrow groove is as high as the bottom surface of the gravel filter layer, and the two sides of the narrow groove and the wide groove are filled with soil and tamped.

Through adopting above-mentioned technical scheme, the setting of salt discharge hair ditch can reduce the earth that falls to the ditch bottom, prevents that the salt discharge ditch from blockking up and can not play the effect of arranging the salt, and the bottom surface of narrow groove and the bottom surface of rubble filtering layer are equal height, are convenient for contain salt moisture and flow between narrow groove and rubble filtering layer to the guide is advanced to arrange in the salt ditch.

The present invention in a preferred example may be further configured to: the water inlet channel is arranged in parallel to the salt discharge ditch, the bottom height of the water inlet channel is higher than that of the salt discharge ditch, a water conduit is obliquely arranged at the bottom of the water inlet channel downwards, and the water conduit is communicated to the bottom of the salt discharge ditch.

Through adopting above-mentioned technical scheme, be convenient for irrigation water enters into the salt elimination ditch through the inlet channel, can enough irrigate the plough layer, can take away the salinity in plough layer and the rubble filtering layer again with the salinity scouring.

The present invention in a preferred example may be further configured to: the drainage ditch is perpendicular to the salt discharge ditch, the bottom height of the drainage ditch is lower than that of the salt discharge ditch, and the end parts of the salt discharge ditch and the salt discharge rough ditch are communicated into the drainage ditch.

Through adopting above-mentioned technical scheme, the ditch bottom height in escape canal is less, conveniently guides to contain salt moisture and enters into the escape canal, avoids the salinity to flow back to the plough layer along with rivers, guarantees the salt washing salt desalination effect of this system.

The invention discloses a salt washing treatment method for a salt pan, which comprises the following steps:

step 1: land leveling, namely, concentrating connected pieces, forming a check field block by taking a ditch and a road as a reference, wherein the height difference of the land leveling surface of the field soil is within +/-10 cm, the thickness of a plowing layer is not less than 30cm, the design length of the check field is 100-250 m, and the design width is 40-60 m;

step 2: drainage ditches are built outside two short edges of the farmland, salt discharge ditches are built outside two long edges, the salt discharge ditches are communicated to the drainage ditches, and a drainage pump station is built in the drainage ditches;

and step 3: salt-removing rough ditches are built every 4-6 m between the salt-removing ditches at the two sides, and the two ends of the salt-removing rough ditches are communicated into drainage ditches;

and 4, step 4: digging and stacking one side of the surface soil of the field, continuously digging to the depth of 70-100 cm, stacking the dug soil and the surface soil in a distinguishing way, laying geotextile at the bottom of a pit, paving broken stones with the particle size of 2-4 cm to 20-30 cm, laying geotextile after covering with 5-10 cm of thin soil, backfilling the dug soil to a designed height, and loading and transporting the surplus soil to other places;

and 5: transversely punching holes at the bottom of the side walls of the salt discharge ditch and the salt discharge rough ditch at intervals of 50-100 cm, penetrating the holes into the gravel filter layer, and inserting a guide pipe into the holes;

step 6: constructing a field road and a tractor-ploughing road in a field block, and constructing a water inlet channel along the field road;

and 7: fresh water is introduced into a field area through the water inlet channel to clean the salt field, the middle cultivation area is irrigated, salt enters the gravel filter layer along with water flow, and is discharged to the salt discharge ditch and the salt discharge rough ditch, converged into the drainage ditch and pumped away by the drainage pump station;

and 8: planting halophilic and alkaline plants in the field block to absorb salt and salt in the soil, and planting leguminous green manure or multi-application farmyard manure after the salinity and the alkaline meet the requirements.

By adopting the technical scheme, the salinity in the salt pan can be quickly reduced, the soil quality is effectively improved, the soil fertility is enhanced, and the requirements of planting and farming are met.

In summary, the invention includes at least one of the following beneficial technical effects:

1. according to the system, the salt discharge ditch is arranged in the salt field, the gravel filter layer is arranged under the soil layer of the salt field, the irrigation water is used instead, salt in the plough layer is dissolved by fresh water, then flows into the salt discharge ditch and the salt discharge rough ditch through the gravel filter layer, and the salt water is discharged into the drainage ditch through the salt discharge ditch and the salt discharge rough ditch, so that the salt water is discharged by the drainage pump station, the salt content in the salt field can be quickly and effectively reduced through multiple times of irrigation, the purpose of salt washing and restoration of the salt field is achieved, and the requirement of cultivated land planting is met.

2. Through the implementation of the land reclamation project, firstly, the farmland water conservancy facility of salt pan is perfected, the water inlet channel, the salt discharge channel, the drainage channel, the pump station and the like are newly built, the peripheral saline water system of the project area is isolated, the water circulation mainly depends on the pump station, fresh water is introduced into the salt pan to drip the salt pan, and then the water is discharged through the drainage pump station.

3. A salt separation filter layer is prepared, broken stones and geotextile are used, the pores of the bottom layer of the field are enlarged, and the phenomenon that the salt of the bottom layer of the soil is returned to the ground surface by the capillary phenomenon is avoided; reducing alkali and providing organic matter content of soil by applying a meta-acid fertility and an organic fertilizer; traffic facilities in the salt field are perfected, field roads and tractor-ploughing roads are newly built, and mechanical energy can reach all fields conveniently.

Drawings

Fig. 1 is a schematic view of the overall structure of the present invention.

FIG. 2 is a schematic structural diagram of a salt-removing field fault according to the present invention.

FIG. 3 is a schematic structural view of a salt discharge section of a field of the present invention.

FIG. 4 is a schematic diagram of the structure of the salt discharge channel of the present invention.

FIG. 5 is a schematic view of the structure of the salt elimination furrows in the present invention.

FIG. 6 is a connecting structure diagram of the salt drain ditch and the water inlet ditch in the present invention.

In the figure, 1, a middle cultivation area, 100, a water inlet channel, 11, a cultivation layer, 12, a gravel filter layer, 13, a soil bedding layer, 14, a first geotextile layer, 15, a second geotextile layer, 2, a salt discharge ditch, 200, a drainage ditch, 21, equal-width grooves, 22, flaring grooves, 3, a salt discharge capillary ditch, 31, a narrow groove, 32, a wide groove, 4, an original soil layer, 41, an original soil interlayer, 5, a flow guide pipe, 6 and a water guide pipe.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Referring to fig. 1 and 2, the salt washing treatment system for the salt pan disclosed by the invention comprises a salt pan block, and an inlet channel 100 and a drainage channel 200 communicated with the salt pan block, wherein the salt pan block is divided into rectangular pan blocks, the inlet channel 100 is arranged at two sides and in the pan block along the length direction of the salt pan block, and the drainage channel 200 is arranged at two ends along the width direction of the salt pan block.

The salt removing field block comprises a middle cultivation area 1, a salt removing ditch 2 arranged on the outer side of the middle cultivation area 1 and a salt removing hair ditch 3 arranged in the middle cultivation area 1, the salt removing ditch 2 and the salt removing hair ditch 3 divide the field block into a plurality of independent middle cultivation areas 1, and a field channel and a mechanical cultivation channel are built in the field block, so that the field can pass conveniently.

Referring to fig. 2 and 3, the middle cultivation area 1 is arranged to be of a layered structure, the cultivation layer 11 is arranged on the upper portion, the gravel filter layer 12 is arranged below the cultivation layer 11, the original soil layer 4 is arranged below the gravel filter layer 12, irrigation water enters the middle cultivation area 1 through the water inlet channel 100 and is infiltrated by the cultivation layer 11 to take salt in the cultivation layer 11 away, the salt flows into the gravel filter layer 12, the gravel filter layer 12 is communicated with the salt discharge ditch 2 or the salt discharge capillary ditch 3, salt-containing water is discharged into the salt discharge ditch 2 or the salt discharge capillary ditch 3 and then is gathered into the drainage ditch 200 through the salt discharge ditch 2 or the salt discharge capillary ditch 3, and the salt-containing water is pumped away by the drainage pump.

A first interlayer is arranged between the gravel filter layers 12 below the plough layer 11, the first interlayer comprises a soil bedding layer 13 laid on the gravel filter layer 12 and a first geotextile layer 14 laid on the soil bedding layer 13, the thickness of the soil bedding layer 13 is smaller than that of the gravel filter layer 12, and the thickness of the gravel filter layer 12 is smaller than that of the plough layer 11; the original soil layer 4 is positioned below the gravel filter layer 12, and a second geotextile layer 15 is laid between the original soil layer 4 and the gravel filter layer 12 for separation, so that the permeability and the water filtering capacity of the bottom of the gravel filter layer 12 are ensured.

An original soil interlayer 41 is arranged between the middle cultivation area 11 and the salt and hair removing ditches 2 and 3, the original soil interlayer 41 and the original soil layer 4 are both in original soil structure, the width of the original soil interlayer 41 is smaller than the opening width of the salt and hair removing ditches 2 and 3, and the height is larger than the surface height of the middle cultivation area 11; therefore, the firmness of the structure and the compactness of soil between the middle cultivation area 11 and the salt discharge ditch 2 and the salt discharge hair ditch 3 are ensured, the condition that the side walls of the salt discharge ditch 2 and the salt discharge hair ditch 3 collapse is avoided, and meanwhile, the condition that fresh water irrigated into the middle cultivation area 11 directly flows into the salt discharge ditch 2 and the salt discharge hair ditch 3 can be avoided, so that the salt washing effect is ensured.

Honeycomb duct 5 has been laid to the below of former soil interlayer 41, and honeycomb duct 5 transverse arrangement communicates rubble filtering layer 12 and arranges salt ditch 2 and arrange salt mao ditch 3, and honeycomb duct 5 can guide the flow of rivers, and the salt water that permeates among the rubble filtering layer 12 can flow to arrange salt ditch 2 and arrange salt mao ditch 3 in through honeycomb duct 5, the discharge of the salt of being convenient for. In order to collect the salt-containing water into the salt discharge ditch 2, the gravel filter layers 12 and the salt discharge rough ditch 3 have the same height and are all higher than the height of the bottom of the salt discharge ditch 2, and the height of the bottom of the salt discharge ditch 2 is smaller than that of the bottom of the drainage ditch 200.

Referring to fig. 2 and 4, the salt discharge ditch 2 comprises a constant width groove 21 at the lower part and an expanded groove 22 at the upper part, the bottom of the constant width groove 21 is a plane, two walls of the constant width groove are vertical surfaces, the expanded groove 22 is a slope surface with two sides inclined outwards, a guide pipe 5 is communicated between the middle part of the constant width groove 21 and the bottom of the gravel filter layer 12, the bottom height of the constant width groove 21 is lower than that of the gravel filter layer 12, and after the salt discharge ditch 2 is excavated, backfill soil is arranged on two side walls of the constant width groove 21 and the expanded groove 22 and is tamped, so that the drainage effect and the structural strength of the salt discharge ditch 2 are ensured.

Referring to fig. 2 and 5, the salt elimination ditch 3 comprises a narrow groove 31 at the lower part and a wide groove 32 at the upper part, the groove bottom of the narrow groove 31 is a plane, two walls are vertical surfaces, the wide groove 32 is a slope surface with two sides inclined outwards, the guide pipe 5 is communicated between the narrow groove 31 and the gravel filter layer 12, the bottom surface of the narrow groove 31 is as high as the bottom surface of the gravel filter layer 12, and after the salt elimination ditch 3 is excavated, the two side walls of the narrow groove 31 and the wide groove 32 are filled with soil and tamped. Set up like this, can reduce the earth that falls to the ditch bottom, prevent that the salt discharge hair ditch from blockking up and not playing the effect of arranging the salt, the bottom surface of narrow groove 31 and rubble filter bed 12's bottom surface are equal height, are convenient for contain salt moisture and flow between narrow groove 31 and rubble filter bed 12 to the guide is advanced and is arranged in salt hair ditch 3.

Referring to fig. 6, the water inlet channel 100 is parallel to the salt discharge ditch 2, the bottom height of the water inlet channel 100 is higher than the bottom height of the salt discharge ditch 2, the water conduit 6 is obliquely arranged at the bottom of the water inlet channel 100, and the water conduit 6 is communicated to the bottom of the salt discharge ditch 3 so as to be convenient for introducing fresh water into the salt discharge ditch 3. The lateral wall and the bottom of the water inlet channel 100 are backfilled with soil and tamped, then a layer of concrete inner channel is poured, the water conduit 6 is also set to be a concrete pipe, one is distributed at intervals of ten meters between the water inlet channel 100 and the salt discharge channel 2, so that the irrigation water can enter the salt discharge channel 2 through the water inlet channel 100, the plough layer 11 can be irrigated, and the salt in the plough layer 11 and the gravel filter layer 12 can be washed away.

The invention discloses a salt washing treatment method for a salt pan, which comprises the following steps:

step 1: land leveling, namely, concentrating connected pieces, forming a gridding field block by taking a ditch and a road as references, wherein the height difference of the land leveling surface of the field soil is within +/-10 cm, the thickness of a plowing layer is not less than 30cm, the thickness of the plowing layer is designed to be 50cm in the embodiment, the design length of the gridding field is 100-250 m, and the design width is 40-60 m;

step 2: a drainage ditch 200 is built on the outer sides of two short edges of the farmland, salt discharge ditches 2 with the depth of 100cm are built on the outer sides of two long edges, the salt discharge ditches 2 are communicated to the drainage ditch 200, and a drainage pump station is built in the drainage ditch 200;

and step 3: salt-removing hair ditches 3 with the depth of 80cm are built between the salt-removing ditches 2 at the two sides every 5m, and the two ends of each salt-removing hair ditch 3 are communicated into a drainage ditch 200;

and 4, step 4: digging and stacking one side of the surface soil of the field, continuously digging to the depth of 70cm, stacking the dug soil and the surface soil in a distinguishing way, laying geotextile at the bottom of a pit, paving crushed stone with the particle size of 2-4 cm to 20cm, laying geotextile after covering 5cm of thin soil, backfilling the dug soil to a designed height, and loading and transporting the surplus soil to other places;

and 5: transversely punching holes at the bottom of the side walls of the salt discharge ditch 2 and the salt discharge rough ditch 3 at intervals of 50cm, penetrating the holes into the gravel filter layer 12, inserting a flow guide pipe 5 into the holes, and setting the flow guide pipe 5 as a UPVC pipe with the pipe diameter of 50 cm;

step 6: constructing a field road and a tractor-ploughing road in the field block, and constructing an inlet channel 100 along the field road and the outer side of the field block;

and 7: fresh water is introduced into a field area through the water inlet channel 100 to clean a salt field, the middle cultivation area 1 is irrigated, salt enters the gravel filter layer 12 along with water flow, is discharged to the salt discharge ditch 2 and the salt discharge rough ditch 3, converges to the drainage ditch 200, and is pumped away by the drainage pump station;

and 8: planting halophilic and alkaline plants in the field block to absorb salt and salt in the soil, and planting leguminous green manure or multi-application farmyard manure after the salinity and the alkaline meet the requirements.

The embodiments of the present invention are preferred embodiments of the present invention, and the scope of the present invention is not limited by these embodiments, so: all equivalent changes made according to the structure, shape and principle of the invention are covered by the protection scope of the invention.