Method for planting rain-fed dry-farming early-spring sesbania in coastal moderate-severe saline-alkali soil

Abstract

The invention belongs to the technical field of saline-alkali soil improvement, and relates to a coastal moderate-severe saline-alkali soil rain-fed dry-farming early-spring sesbania planting method which comprises the following steps: S1, deep rotation is performed on saline-alkali soil; s2, ridging, wherein ditching and ridging are conducted on the saline-alkali soil subjected to deep rotation; s3, punching holes in the ridge sides and forming water gathering pits arranged in a duckbilled shape, and then paving a mulching film on the water gathering pits; s4, holes are drilled in the side face of the water gathering pit in the vertical direction, a seeding channel is formed, then the sesbania seeds are sown into the seeding channel, the peripheries of the holes of the mulching film are covered with soil, a duckbilled structure is formed, and rainwater is guided by means of the mulching film to flow into the water gathering pit to be gathered; s5, forming a straw interlayer after the whole sesbania is returned to the field. Rainwater is gathered to the seeding channel through the mulching film, the amount of water capable of being absorbed by the sesbania seeds is increased, in addition, the mulching film can also achieve the effects of improving the soil temperature and preserving soil moisture, so that the sesbania can be planted in a rain-fed dry farming mode at the end of March, and the saline-alkali soil improvement period is shortened.

Description

Technical Field

[0001] The invention belongs to the technical field of saline-alkali land improvement, and particularly relates to a method for planting sesbania in rain-fed dryland early spring in coastal medium-to-severe saline-alkali land. Background Art

[0002] Coastal moderately and heavily saline-alkali areas are formed under the influence of seawater, many of which are land reserve resources with a salt content of more than 10‰. Their rational development and utilization can alleviate the pressure of insufficient land resources, improve the ecological environment, and enhance the stability of the ecosystem.

[0003] Sesbania is an annual sub-shrubby herb of the Leguminosae family and the genus Sesbania. It is an excellent summer green manure crop with a well-developed root system, many nodules, strong nitrogen fixation ability, rich plant nutrient content and strong salt tolerance. Sesbania is a pioneer plant for the management of saline-alkali land, providing high-quality plant-derived organic matter for severely saline-alkali land and barren wasteland. The supporting technology of full-scale turning and returning the plants to the fields forms a straw barrier, achieving the purpose of salt discharge and salt inhibition in summer and improving soil structure.

[0004] At present, some saline-alkali areas adopt the model of rain-fed dryland farming. However, due to the drought in spring and the scarcity of fresh water resources in coastal medium and severe saline-alkali areas, artificial watering is impossible, resulting in a delay in the planting time of Sesbania campestris. It needs to be delayed from March to June and can only be planted after sufficient rain, which affects the improvement cycle of the saline-alkali land. Summary of the invention

[0005] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a method for planting sesbania in early spring in coastal medium to severe saline-alkali land by rain-fed dry farming. Rainwater is gathered at the seeding channel through the ground film, thereby increasing the amount of water that can be absorbed by sesbania seeds. In addition, the ground film can also play a role in raising temperature and retaining moisture, so that sesbania can be planted in a rain-fed dry farming mode at the end of March, shortening the cycle of saline-alkali land improvement.

[0006] The specific technical solution adopted by the present invention is:

[0007] S1. Land preparation: Deep swamping of saline-alkali land to a depth of 25-35cm;

[0008] S2, Ridge making: Ditch and ridge the deep-turned saline-alkali land;

[0009] S3, Film covering: Lay the film along the top of the ridge, with the edge of the film 5-10cm higher than the ridge furrow;

[0010] S4, hole sowing: vertical holes are drilled on the ridge side between the mulch film and the ridge furrow to form a seeding channel, and then the sesbania seeds are sown in the seeding channel, and the rainwater is guided to flow into the seeding channel and collected by the mulch film;

[0011] S5. Return the whole plant to the field and cover it with soil: When the Sesbania sesbania is in bloom, return the whole plant to the field and cover it with soil to form a straw layer.

[0012] The width of the ridges is 40-50 cm, the height of the ridges is 25-35 cm, and the width of the furrows between ridges is 35-45 cm.

[0013] The ground film is a fully biodegradable ground film.

[0014] In step S4, the sowing amount of the sesbania seeds is 2.5-3.5 kg / mu, the sowing spacing is 10-15 cm, 4-7 sesbania seeds are sown in each sowing channel, and the sowing depth is 1.5-2 cm.

[0015] The method for planting Sesbania sesbania also includes the following steps:

[0016] S1. Land preparation: Deep swamping of saline-alkali land to a depth of 25-35cm;

[0017] S2, Ridge making: Ditch and ridge the deep-turned saline-alkali land;

[0018] S3, Film covering: Drill holes on the side of the ridge to form multiple water collection pits arranged in a "duckbill" shape, then spread the film on the surface of the water collection pits, with the edge of the film 5-10cm higher than the ridge furrow;

[0019] S4, hole sowing: vertical holes are drilled at the water collection pit to form a seeding channel, and then the sesbania seeds are sown in the seeding channel. The holes of the mulch are covered with soil to form a "duckbill" structure, and the mulch is used to guide rainwater into the water collection pit for collection;

[0020] S5. Return the whole plant to the field and cover it with soil: When the Sesbania sesbania is in bloom, return the whole plant to the field and cover it with soil to form a straw layer.

[0021] The mulching and hole sowing adopt rain-fed dryland sesbania planting equipment, which includes a frame and a traction machine that drives the frame forward. The frame is provided with a pit digging device, a mulching roll and a drilling and sowing mechanism in sequence along the forward direction. A water collecting pit is formed on the side of the ridge with the help of the pit digging device, and the ground film is covered to the surface of the water collecting pit with the help of the mulching roll. The drilling and sowing mechanism includes a seed box, a drop pipe, a lifting seat and an auger rod. The auger rod is a hollow structure. The auger rod is driven to rotate with the help of a motor fixedly connected to the lifting seat. The output end of the drop pipe is sleeved into the hollow chamber of the auger rod. The auger rod has the freedom to slide back and forth along the drop pipe with the help of the lifting seat. The auger rod passes through the ground film with the help of the lifting seat and drills through the bottom of the water collecting pit to form a seeding channel. The seeds in the seed box fall into the seeding channel along the drop pipe and the hollow chamber of the auger rod.

[0022] The digging device includes a digging shaft and multiple groups of earth-moving plates arranged in a ring shape on the digging shaft. The digging shaft forms a transmission connection with the driving device of the tractor. The rotation direction of the digging shaft is opposite to the forward direction of the tractor. The surface of the ridge top is formed into a water collection pit with an arc-shaped bottom by the moving of the earth-moving plates.

[0023] The lifting seat is an inverted dome structure, and includes a fixing plate and a fixing ring arranged up and down, and multiple groups of arc-shaped frames are arranged between the fixing plate and the fixing ring. A through hole is arranged on the fixing plate, and the through hole and the fixing ring together form a channel for the spiral drill rod to pass through. The lifting seat is lifted and lowered by means of a telescopic cylinder fixedly connected to the frame and presses the ground film to form a concave funnel-shaped structure.

[0024] The fixed end of the motor is fixed to the fixed plate, the output end of the motor is provided with a first gear, the auger rod is provided with a second gear meshing with the first gear, a fixing frame is also provided on the fixed plate, and the fixing frame and the fixed plate are respectively rotatably connected with the auger rod by means of bearings.

[0025] A seeding mechanism is also provided between the seed box and the drop tube, and the seeding mechanism includes a seeding chamber and a seeding wheel located in the seeding chamber, the input end of the seeding chamber is connected to the seed box, and the output end of the seeding chamber is connected to the drop tube by means of a connecting pipe, and a plurality of groups of seeding grooves are provided on the surface of the seeding wheel in a circular array, and the seeding wheel has the freedom to rotate along the seeding chamber, and the seeds enter the seeding grooves and fall into the drop tube in batches by means of the rotation of the seeding wheel.

[0026] The drilling and sowing mechanism also includes a water tank and a high-pressure water pump. The water tank is connected to the drop pipe by means of the high-pressure water pump. The water in the water tank passes through the output end of the spiral drill rod through the drop pipe by means of the high-pressure water pump to form a dredging system.

[0027] The beneficial effects of the present invention are:

[0028] 1. The present invention forms a straw barrier through the matching fully biodegradable mulch film covering and the whole-plant turning and returning technology of sesbania to the field, which not only effectively improves the ground temperature and soil moisture content in early spring, creates a good soil microenvironment for germination and emergence of sesbania seeds, but also achieves the purpose of salt removal and salt inhibition in summer and improves soil structure.

[0029] In coastal rain-fed dryland areas, spring is dry, freshwater resources are scarce, and soil salt content is high. The seasonal changes of soil "re-salting" and "de-salting" are very obvious. Therefore, in the coastal medium-to-severe saline-alkali areas, the planting time of Sesbania sesbania is concentrated at the end of May. Advancing the planting time of Sesbania sesbania to the end of March can effectively utilize idle saline-alkali land, increase one season's biomass, and shorten the saline-alkali land improvement cycle.

[0030] 2. To ensure the survival rate of Sesbania sesbania, the planting of Sesbania sesbania is usually carried out at the end of May. However, in the present invention, through the provision of film covering and water collection pits, Sesbania sesbania can be planted in a rain-fed dry farming mode at the end of March, thus shortening the period of improvement of saline-alkali land.

[0031] In early spring in coastal saline-alkali areas, the temperature is not only low, but also there is little rain. In the case of a small amount of rainfall, not only can it not provide enough water for plants, but it can also cause soil caking, and seeds wrapped in soil blocks are difficult to germinate. Therefore, the present invention is provided with a water collection pit and a film is applied. The film not only increases the soil temperature, but also introduces a small amount of rainwater into the water collection pit for concentration, thereby increasing the water content of the soil near the seeds and the local "rainfall", avoiding the problem of soil caking, and promoting the germination of seeds. At the same time, the film itself also has a moisture retention effect. In addition, the rainwater that does not enter the water collection pit will be concentrated at the ridge ditch, and then infiltrate the soil and moisten the soil around the seeds, avoiding the seeds being directly soaked by a large amount of rainwater, and achieving the effect of slow release of water.

[0032] 3. In order to realize mechanical mulching and hole sowing, the present invention also provides a rain-fed dryland sesbania planting equipment. When in use, the spiral drill rod will pass through the ground film and drill through the bottom center of the water collection pit to form a seeding channel. At this time, the seeds in the seed box will fall into the seeding channel along the drop pipe and the hollow chamber of the spiral drill rod with the help of the seed discharge mechanism. In the process of the spiral drill rod drilling through the seeding channel, the soil at the seeding channel will rise along the thread of the spiral drill rod and pass through the drill holes in the ground film and scatter to the surface of the ground film. The soil on the surface of the ground film presses the ground film into a funnel shape with its own weight. When the sowing is completed, the spiral drill rod is pulled out with the help of the lifting seat, and the soil around the drill holes in the ground film will slide back into the seeding channel along the drill holes and cover the seeds, thereby completing the mechanization of mulching and hole sowing. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of ridge film covering of Sesbania in specific embodiment 1;

[0034] Figure 2 This is a schematic diagram of ridge-covered film in Specific Example 2;

[0035] Figure 3 It is a schematic diagram of the structure of the rain-fed dryland sesbania planting equipment of the present invention;

[0036] Figure 4 It is a structural schematic diagram of the drilling and sowing mechanism;

[0037] Figure 5 It is a structural schematic diagram of the lifting seat;

[0038] Figure 6 for Figure 5 Schematic diagram of the cross-sectional structure in the aa direction;

[0039] Figure 7 This is the soil and plant growth conditions of experimental group 1;

[0040] Figure 8 This is the soil and plant growth conditions of experimental group 2;

[0041] Fig. 9 This is the soil and plant growth conditions of the control group 1;

[0042] Fig.10 This is the soil and plant growth conditions of the control group 2;

[0043] In the attached drawings, 1, water collection pit, 2, ground film, 3, frame, 4, covering film roll, 5, seed box, 6, drop pipe, 7, lifting seat, 8, spiral drill rod, 9, motor, 10, digging shaft, 11, earth-moving plate, 12, fixed plate, 13, fixed ring, 14, frame, 15, telescopic cylinder, 16, first gear, 17, second gear, 18, fixed frame, 19, seed wheel, 20, seed trough, 21, water tank, 22, high-pressure water pump, 23, seeding channel. DETAILED DESCRIPTION

[0044] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments: 1. Specific embodiments

[0046] Specific embodiment 1, as Figure 1 As shown, the present invention provides a method for planting early spring sesbania in rain-fed dryland on coastal medium-to-severe saline-alkali land, comprising the following steps:

[0047] S1. Land preparation: Deep swamping of saline-alkali land to a depth of 25-35cm;

[0048] S2, Ridge making: Ditch and ridge the deep-turned saline-alkali land;

[0049] S3, film covering: lay the ground film 2 along the ridge top direction, and the edge of the ground film 2 is 5-10cm higher than the ridge furrow;

[0050] S4, hole sowing: vertically drill holes on the ridge side between the ground film 2 and the ridge furrow to form a seeding channel 23, and then sow the sesbania seeds into the seeding channel 23, and guide the rainwater to flow into the seeding channel 23 with the help of the ground film 2 to gather;

[0051] S5. Return the whole plant to the field and cover it with soil: When the Sesbania sesbania is in bloom, return the whole plant to the field and cover it with soil to form a straw layer.

[0052] At present, some saline-alkali areas adopt the rain-fed dryland farming model for planting. However, due to the drought in spring and the scarcity of fresh water resources in the coastal medium and severe saline-alkali areas, artificial watering is impossible, resulting in a delay in the planting time of Sesbania, which needs to be delayed from March to June. Planting can be carried out after sufficient rain, affecting the improvement cycle of saline-alkali land. In addition, due to the small amount of precipitation in spring, soil caking is easily generated, affecting the emergence rate of Sesbania.

[0053] In the present invention, the ridge is covered with a film, and holes are punched on the side of the ridge slightly higher than the furrow to form a seeding channel 23. The film covering not only increases the soil temperature, but also introduces a small amount of rainwater into the seeding channel 23 for concentration, thereby increasing the water content of the soil near the seeds and the local "rainfall", avoiding the problem of soil caking, and promoting the germination of seeds. At the same time, the film 2 itself also has a moisture conservation effect. In addition, the rainwater that does not enter the seeding channel 23 will be concentrated at the furrow. Since the furrow and the seed position are basically flush, the water gathered in the furrow will penetrate into the soil and moisten the soil around the seed, which can avoid the seeds being directly soaked by a large amount of rainwater, and achieve the effect of slow release of water. Using the planting method of the present invention, the field sesbania can be planted in the rain-fed dry farming mode at the end of March, shortening the cycle of improving saline-alkali land.

[0054] In June, returning the whole field sebaceous plant to the field can provide plant-derived organic matter to the soil, increase the soil organic matter content, and form a straw barrier to improve the soil structure, which is conducive to summer salting, reducing surface salt and avoiding salt accumulation on the surface.

[0055] The width of the ridges is 40-50 cm, the height of the ridges is 25-35 cm, and the width of the furrows between ridges is 35-45 cm.

[0056] The mulch film 2 is a fully biodegradable mulch film 2. After the dry season, the mulch film 2 has been degraded. When the whole sesbania plant is returned to the field, there is no need to clean the mulch film 2. At the same time, the degradable mulch film 2 can prevent the accumulation of mulch film and pollution of the field environment.

[0057] In step S4, the sowing amount of the sesbania seeds is 2.5-3.5 kg / mu, the sowing spacing is 10-15 cm, 4-7 sesbania seeds are sown in each sowing channel 23, and the sowing depth is 1.5-2 cm. Specific embodiment 2

[0059] The only difference between the specific embodiment 2 and the specific embodiment 1 is that the specific embodiment 2 is further provided with a water collecting pit 1. Figure 2 As shown, the method for planting Sesbania sesbania in specific embodiment 2 comprises the following steps:

[0060] S1. Land preparation: Deep swamping of saline-alkali land to a depth of 25-35cm;

[0061] S2, Ridge making: Ditch and ridge the deep-turned saline-alkali land;

[0062] S3, mulching: holes are made on the side of the ridge to form multiple groups of water collecting pits 1 arranged in a "duckbill" shape, and then the mulch film 2 is spread on the surface of the water collecting pits 1, and the edge of the mulch film 2 is 5-10 cm higher than the ridge furrow;

[0063] S4, hole sowing: vertically drill holes at the water collecting pit 1 to form a seeding channel 23, and then sow the sesbania seeds into the seeding channel 23. The holes of the ground film 2 are covered with soil to form a "duckbill" structure, and the ground film 2 is used to guide rainwater into the water collecting pit 1 for collection;

[0064] S5. Return the whole plant to the field and cover it with soil: When the Sesbania sesbania is in bloom, return the whole plant to the field and cover it with soil to form a straw layer.

[0065] Since the aperture of the seeding channel 23 is relatively narrow, in order to ensure that rainwater can flow smoothly into the seeding channel 23, the specific embodiment 2 is provided with a large-diameter water collection pit 1 to make the ground film 2 form a funnel shape, thereby guiding the rainwater.

[0066] like Figure 3-6 As shown, specific embodiment 2 also provides a rain-fed dryland sesbania planting equipment, which includes a frame 3 and a tractor that drives the frame 3 forward. The frame 3 is provided with a pit digging device, a covering film roll 4 and a drilling and sowing mechanism in sequence along the forward direction. A water collecting pit 1 is formed on the ridge side with the help of the pit digging device, and the ground film 2 is covered to the surface of the water collecting pit 1 with the help of the covering film roll 4. The drilling and sowing mechanism includes a seed box 5, a drop pipe 6, a lifting seat 7 and an auger rod 8. The auger rod 8 is a hollow structure, and the auger rod 8 is driven to rotate with the help of a motor 9 fixedly connected to the lifting seat 7. The output end of the drop pipe 6 is sleeved into the hollow chamber of the auger rod 8. The auger rod 8 has the freedom to slide back and forth along the drop pipe 6 with the help of the lifting seat 7. The auger rod 8 passes through the ground film 2 with the help of the lifting seat 7 and drills through the bottom of the water collecting pit 1 to form a seeding channel 23. The seeds in the seed box 5 fall into the seeding channel 23 along the drop pipe 6 and the hollow chamber of the auger rod 8.

[0067] In order to realize mechanical mulching and hole sowing, the present invention also provides a rain-fed dryland sesbania planting equipment. When in use, the spiral drill rod 8 will pass through the ground film 2 and drill through the bottom center of the water collection pit 1 to form a seeding channel 23. At this time, the seeds in the seed box 5 will fall into the seeding channel 23 along the hollow chamber of the drop pipe 6 and the spiral drill rod 8 with the help of the seed discharge mechanism. During the process of the spiral drill rod 8 drilling through the seeding channel 23, the soil at the seeding channel 23 will rise along the thread of the spiral drill rod 8 and pass through the drill holes of the ground film 2 and scatter to the surface of the ground film 2. The soil on the surface of the ground film 2 presses the ground film 2 to form an arc with its own weight. When the sowing is completed, the spiral drill rod 8 is pulled out with the help of the lifting seat 7, and the soil around the drill holes of the ground film 2 will slide back into the seeding channel 23 along the drill holes and cover the seeds, thereby completing the mechanization of mulching and hole sowing.

[0068] In addition, a plurality of drilling and sowing mechanisms are arranged at intervals along the forward direction of the tractor on the rain-fed dryland Sesbania planting equipment of the present invention. The tractor stops moving forward every 2-3 m. At this time, a plurality of water collection pits 1 covered with ground film 2 have been formed at the rear. Then, a plurality of drilling and sowing mechanisms are aligned with the plurality of water collection pits 1 one by one and hole sowing is carried out.

[0069] The digging device includes a digging shaft 10 and a plurality of groups of earth-moving plates 11 arranged in a ring shape on the digging shaft 10. The digging shaft 10 forms a transmission connection with the driving device of the tractor. The rotation direction of the digging shaft 10 is opposite to the forward direction of the tractor. The ridge side is formed with the help of the earth-moving plates 11 to form a water collection pit 1 with an arc-shaped bottom. The rotation direction of the digging shaft 10 in the present invention is opposite to the forward direction of the tractor, so as to prevent the excess soil generated by digging the water collection pit 1 from falling into the already formed water collection pit 1.

[0070] The lifting seat 7 is an inverted vault structure, and the lifting seat 7 includes a fixing plate 12 and a fixing ring 13 which are arranged up and down. A plurality of arc-shaped skeletons 14 are arranged between the fixing plate 12 and the fixing ring 13. A through hole is arranged on the fixing plate 12, and the through hole and the fixing ring 13 together form a channel for the spiral drill rod 8 to pass through. The lifting seat 7 is lifted and lowered by means of a telescopic cylinder 15 fixedly connected to the frame 3 and presses the ground film 2 to form a concave funnel-shaped structure. Since the ground film 2 is in a tight state after being covered to the surface of the water collection pit 1 by means of the covering film roll 4, it cannot play the role of collecting rainwater. Therefore, the lifting seat 7 in the present invention is an inverted vault structure, and the ground film 2 is pressed by the lifting seat 7 itself to form a funnel-shaped structure, and the funnel-shaped structure is maintained by means of the soil on the surface of the ground film 2, thereby playing the role of collecting rainwater. In addition, the skeleton 14 of the lifting seat 7 forms a cage-like structure, which can ensure that the soil at the seeding channel 23 rises to the top of the ground film 2 and falls to the surface of the ground film 2 through the gap between the skeletons 14.

[0071] The fixed end of the motor 9 is fixed on the fixed plate 12, and a first gear 16 is provided at the output end of the motor 9. A second gear 17 meshing with the first gear 16 is mounted on the auger rod 8. A fixing frame 18 is also provided on the fixed plate 12. The fixing frame 18 and the fixed plate 12 are respectively rotatably connected with the auger rod 8 by means of bearings. In the present invention, two groups of upper and lower bearings located on the same vertical plane are provided. The auger rod 8 is limited by these two groups of bearings, thereby preventing the auger rod 8 from deflecting during rotation.

[0072] A seeding mechanism is also provided between the seed box 5 and the drop tube 6, and the seeding mechanism includes a seeding chamber and a seeding wheel 19 located in the seeding chamber. The input end of the seeding chamber is connected to the seed box 5, and the output end of the seeding chamber is connected to the drop tube 6 by means of a connecting pipe. The surface of the seeding wheel 19 is provided with a plurality of groups of seeding grooves 20 in a circular array, and the seeding wheel 19 has the freedom to rotate along the seeding chamber. Seeds enter the seeding grooves 20 and fall into the drop tube 6 in batches by means of the rotation of the seeding wheel 19. In the present invention, the seeds in the seed box 5 are sown in batches by the seeding wheel 19, each seeding groove 20 can hold about 4-7 seeds, and 4-7 seeds are sown in each seeding channel 23.

[0073] The drilling and sowing mechanism also includes a water tank 21 and a high-pressure water pump 22. The water tank 21 is connected to the drop pipe 6 by means of the high-pressure water pump 22. The water in the water tank 21 passes through the output end of the auger rod 8 through the drop pipe 6 by means of the high-pressure water pump 22 and forms a dredging. Since the auger rod 8 is a hollow structure, during the drilling process of the auger rod 8, the soil or ground film 2 can easily block the discharge end of the hollow chamber of the auger rod 8. Therefore, a water tank 21 and a high-pressure water pump 22 are provided. Each time sowing is performed, the discharge end of the hollow chamber is dredged by high-pressure water flow, while providing a small amount of moisture for the seeds and increasing the combination between the fallen soil and the soil under the seeds.

[0074] 2. Comparative Experiment

[0075] An experimental group and a control group were set up, wherein the experimental group 1 was planted using the Sesbania planting method in specific embodiment 1, and the experimental group 2 was planted using the Sesbania planting method in specific embodiment 2. The control group 1 only used the flat sowing method to plant Sesbania, and the control group 2 was covered with film on the basis of the flat sowing method. The sowing time was March 25, and the soil and Sesbania related parameters were measured on May 25. No watering was performed during the period, and the total rainfall was about 16 mm. The measurement results are shown in Table 1 and Figure 7-10 .

[0076] Table 1

[0077] Soil moisture content (%) Plant height (cm) EC(ms / cm) Control group 1 15.5 10.8 44.44 Control group 2 16.1 12.9 50.4 Experimental Group 1 16.5 27.9 35.0 Experimental Group 2 16.4 27.8 38.4

[0078] From Table 1 and Figure 7-10 It can be seen that when the planting method of the present invention is used to plant Sesbania, the Sesbania emergence rate is high, the plant growth is higher, and the salt-alkali improvement effect on the soil is better within the same period of time.

[0079] First, the experimental group can increase the spring soil temperature through film covering, which plays a role in moisture conservation and salt suppression, thus facilitating the emergence of field sesbania seedlings. At the same time, the film covering in the present invention will also introduce a small amount of rainwater into the water collection pit, thereby increasing the moisture content of the soil near the seeds and the local "rainfall", avoiding the problem of soil caking and promoting seed germination.

Claims

1. A method for planting early spring sesbania in rain-fed dryland on coastal medium to severe saline-alkali land, characterized in that: The following steps are involved: S1. Land preparation: Deep swamping of saline-alkali land to a depth of 25-35cm; S2, Ridge making: Ditch and ridge the deep-turned saline-alkali land; S3, covering: laying the ground film (2) along the top of the ridge, with the edge of the ground film 5-10 cm higher than the ridge furrow; S4, hole sowing: vertically drilling holes on the ridge side between the ground film (2) and the ridge furrow to form a sowing channel (23), and then sowing the sesbania seeds into the sowing channel (23), and guiding rainwater to flow into the sowing channel and gather with the help of the ground film (2); S5. Return the whole plant to the field and cover it with soil: When the Sesbania sesbania is in bloom, return the whole plant to the field and cover it with soil to form a straw layer.

2. The method for planting early spring sesbania in rain-fed dryland coastal medium-to-severe saline-alkali land according to claim 1, characterized in that: The width of the ridges is 40-50 cm, the height of the ridges is 25-35 cm, and the width of the furrows between ridges is 35-45 cm.

3. The method for planting early spring sesbania in rain-fed dryland coastal medium-to-severe saline-alkali land according to claim 1, characterized in that: The ground film (2) is a fully biodegradable ground film (2).

4. The method for planting early spring sesbania in rain-fed dryland coastal medium-to-severe saline-alkali land according to claim 1, characterized in that: In step S4, the sowing amount of the sesbania seeds is 2.5-3.5 kg / mu, the sowing spacing is 10-15 cm, 4-7 sesbania seeds are sown in each sowing channel, and the sowing depth is 1.5-2 cm.

5. The method for planting early spring sesbania in rain-fed dryland coastal medium-to-severe saline-alkali land according to claim 1, characterized in that: The method for planting Sesbania sesbania also includes the following steps: S1. Land preparation: Deep swamping of saline-alkali land to a depth of 25-35cm; S2, Ridge making: Ditch and ridge the deep-turned saline-alkali land; S3, mulching: holes are made on the side of the ridge to form a plurality of water collecting pits (1) arranged in a "duckbill" shape, and then the ground film (2) is spread on the surface of the water collecting pits (1), with the edge of the ground film (2) being 5-10 cm higher than the ridge furrow; S4, hole sowing: vertical holes are drilled at the water collecting pit (1) to form a seeding channel (23), and then the sesbania seeds are sown into the seeding channel (23). The holes of the ground film (2) are covered with soil to form a "duckbill" structure, and the ground film (2) is used to guide rainwater into the water collecting pit (1) and collect it; S5. Return the whole plant to the field and cover it with soil: When the Sesbania sesbania is in bloom, return the whole plant to the field and cover it with soil to form a straw layer.

6. The method for planting early spring sesbania in rain-fed dryland coastal medium-to-severe saline-alkali land according to claim 5, characterized in that: The film covering and hole sowing adopt rain-fed dryland sesbania planting equipment, and the rain-fed dryland sesbania planting equipment comprises a frame (3) and a tractor driving the frame (3) forward, and a pit digging device, a film covering roll (4) and a drilling sowing mechanism are sequentially arranged on the frame (3) along the forward direction, and a water collecting pit (1) is formed on the side of the ridge by means of the pit digging device, and the ground film (2) is covered on the surface of the water collecting pit (1) by means of the film covering roll (4), and the drilling sowing mechanism comprises a seed box (5), a drop pipe (6), a lifting seat (7) and a spiral drill rod (8), and the spiral drill rod (8) is The hollow structure is characterized in that the auger rod (8) is driven to rotate by means of a motor (9) fixedly connected to a lifting seat (7); the output end of the drop tube (6) is sleeved into the hollow chamber of the auger rod (8); the auger rod (8) has the freedom to slide back and forth along the drop tube (6) by means of the lifting seat (7); the auger rod (8) passes through the ground film (2) and drills through the bottom of the water collection pit (1) by means of the lifting seat (7) to form a seeding channel (23); the seeds in the seed box (5) fall into the seeding channel (23) along the drop tube (6) and the hollow chamber of the auger rod (8).

7. The method for planting early spring sesbania in rain-fed dryland coastal medium-to-severe saline-alkali land according to claim 6, characterized in that: The lifting seat (7) is an inverted dome structure. The lifting seat (7) comprises a fixing plate (12) and a fixing ring (13) which are arranged in an upper and lower manner. A plurality of groups of arc-shaped skeletons (14) are arranged between the fixing plate (12) and the fixing ring (13). A through hole is arranged on the fixing plate (12). The through hole and the fixing ring (13) together form a passage for the spiral drill rod (8) to pass through. The lifting seat (7) is lifted and lowered by means of a telescopic cylinder (15) which is fixedly connected to the frame (3) and presses the ground film (2) to form a concave funnel-shaped structure.

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