A wheat-sesbania sowing method for dry saline-alkali two-crop area

Abstract

This invention provides a method for sowing wheat-sesbania in dryland saline-alkali double-cropping areas, belonging to the field of agricultural sowing technology. The method includes the following steps: S1. Pre-planting preparation; S2. Shallow tillage and leveling; S3. Sowing execution; S4. Soil treatment; and S5. Equipment reset. This invention provides a method for sowing wheat-sesbania in dryland saline-alkali double-cropping areas that constructs a multi-layered guarantee mechanism for yield stability through the synergistic design of crop adaptation, soil improvement, and equipment optimization. Wheat yield reduction risks due to unreasonable population structure are mitigated through optimized dense planting; sesbania biomass accumulation is enhanced through wide-spacing planting, forming a green manure cycle of land use and soil conservation; the water collection and moisture retention function of rainwater drainage ditches buffers the impact of uneven rainfall, reducing the impact of drought and flood on yield fluctuations. This method specifically addresses core issues such as insufficient adaptability of the same seeder, saline-alkali drought stress, and low emergence rate, achieving a dual improvement in emergence rate and yield stability for double-cropping crops in dryland saline-alkali areas.

Description

Technical Field

[0001] This invention belongs to the field of agricultural sowing technology, and more specifically, relates to a method for sowing wheat-sesbania in dryland saline-alkali double-cropping areas. Background Technology

[0002] Dryland saline-alkali areas generally face multiple constraints such as high soil salinization, water scarcity, and poor topsoil structure.

[0003] Currently, crop cultivation in dryland saline-alkali areas is mainly based on single-season crops, resulting in low land resource utilization. The double-cropping system faces significant challenges in its promotion and application due to saline-alkali stress and seasonal drought. When existing single-season crop sowing techniques are directly applied to the double-cropping system, using the same seeder for double-cropping will lead to low crop emergence rates and poor yield stability in dryland saline-alkali areas, becoming a prominent bottleneck for sustainable agricultural development. Summary of the Invention

[0004] The purpose of this invention is to provide a method for sowing wheat-sesbania in dryland saline-alkali double-cropping areas, aiming to solve the problems of low crop emergence rate and poor yield stability in dryland saline-alkali double-cropping when the same seeder is used for double-cropping.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: to provide a method for sowing wheat-sesbania in dryland saline-alkali double-cropping areas, comprising the following steps: S1. Preliminary preparation: Check the integrity of the shallow rotating mechanism of the sowing device, the two staggered sowing trays at the front and rear, the sowing equipment and the pressing roller components. Based on the salinity of the saline-alkali soil and the crop type, preset the sowing density and row spacing parameters for wheat or sesbania. S2. Shallow rotary tillage: The tractor pulls the seeding device forward at a constant speed, and the front shallow rotary mechanism is activated to perform shallow rotary treatment on the ground surface. The rotary tillage depth is controlled at 8-10cm, and the tractor tire tracks are removed and the surface soil clods are broken. S3. Sowing execution: If sowing wheat, activate the dual-disc drive mode of the sowing equipment to control the two staggered sowing discs to operate synchronously and form a double-row staggered sowing trajectory. If sowing sesame, switch to single-disc drive mode, where a single sowing disc operates independently to form a single-row wide-spacing sowing trajectory, and the row spacing of sesame is twice that of wheat. S4. Soil treatment: After sowing, the surface soil is leveled by a grading mechanism, and low-intensity compaction is carried out using a compaction wheel. Then, a high-intensity compaction with a depth of 4-5cm is carried out between the sowing rows using a compaction wheel to form continuous rainwater collection ditches. S5. Equipment Reset: Shut down all working mechanisms, clean the seeding tray and seeding equipment of any remaining seeds, check the wear of parts and record the findings.

[0006] In one possible implementation, after step S2, the crushed corn stalks are laid on the ground in 30×30cm grids to form a grid. The soil is compacted at the grid intersections. The wheat seeding tray penetrates the grid gaps to complete the sowing. After the wheat seedlings emerge, the grid stalks are pressed into the topsoil through a second compaction.

[0007] In one possible implementation, in step S3, before sowing wheat, the two sowing discs are adjusted to a staggered pattern, with the front sowing disc rotating clockwise and the rear sowing disc rotating counterclockwise, forming a vortex-like distribution of wheat seeds in the soil, with adjacent wheat seeds being staggered laterally by 4.5-5.5 cm and forming a height difference of 2-3 cm longitudinally. When sowing sesame seeds, each seeding tray uses an alternating clockwise and counterclockwise rotation pattern, switching the rotation direction every 1m of row movement, so that the sesame seeds are distributed in a zigzag pattern within the row.

[0008] In one possible implementation, in step S3, when sowing wheat, the size of the surface soil clods is monitored in real time by a soil sensor. When the soil clod diameter is 1cm ≤ 3cm, the two sowing discs maintain a 45° staggered angle; when the soil clod diameter is > 3cm, the staggered angle is increased from 45° to 60°; when the soil clod diameter is < 1cm, the staggered angle is reduced back to 30°. When sowing sesbania, the angle of a single sowing tray is fixed at 60°, forming a wide-range scattering seed trajectory. The edge of the sowing tray is equipped with an elastic seed scraper that automatically adheres to the tray surface to remove residual seeds as the angle is adjusted.

[0009] In one possible implementation, when sowing wheat, the pneumatic seeding channel is opened, and the seeds are blown to two seeding trays by high-pressure airflow, while a mechanical eccentric seed-distributing wheel assists in the sowing. When sowing sesbania, the air pressure sowing channel is closed, and sowing is carried out only by mechanical eccentric wheel. The speed of the mechanical eccentric wheel is linked to the forward speed. For every 1 km / h increase in speed, the speed of the mechanical eccentric wheel increases by 50 r / min.

[0010] In one possible implementation, when sowing wheat, the seeding disc is lifted by a cam lifting mechanism. Each row of seeds forms a periodic change in depth along the direction of travel, with a period length of 30-50cm. The peaks and troughs of the depth waves in adjacent rows are staggered to form a three-dimensional water storage space. When sowing sesbania, a linked deep tillage shovel is set on the side of the track of a single sowing disc. The deep tillage action of the deep tillage shovel is triggered every 3m distance of sowing, with a deep tillage depth of 15-20cm. This breaks up the plow bottom structure to form a breathable channel. After deep tillage, the loose soil is backfilled and compacted by the backfilling wheel.

[0011] In one possible implementation, in step S4, a wide rainwater collection ditch is set every 5m on plots with a slope of <3°. The width of the wide rainwater collection ditch is 12-15cm and the depth is kept at 5cm. The intervals are smoothly connected by transition sections. On plots with a slope of ≥3°, transverse rainwater collection ditches and longitudinal rainwater collection ditches are set along the contour line direction. The distance between adjacent transverse intercepting ditches or adjacent longitudinal rainwater collection ditches is 8-10m. The transverse intercepting ditches and longitudinal rainwater collection ditches intersect perpendicularly to form a grid-like water collection system.

[0012] In one possible implementation, in step S4, a biochar spraying channel is set inside the rolling wheel, and 100g of granular biochar is sprayed per meter between wheat sowing rows, embedding into the topsoil during the rolling action; the biochar is mixed with decomposed organic fertilizer in a 1:3 ratio, and applied to a depth of 15cm at a distance of 10cm to the side of the sowing using a deep tillage shovel, forming a three-dimensional improved microenvironment of seeds, biochar and soil.

[0013] In one possible implementation, in step S4, the soil leveling range of the leveling mechanism is 10-15cm on each side of the sowing row, the pressure of low-intensity compaction is controlled at 0.2-0.3MPa, the pressure of high-intensity compaction is controlled at 0.5-0.6MPa, the cross-section of the continuous rainwater collection ditch is an inverted trapezoid, and the ditch width is 8-10cm.

[0014] In one possible implementation, in step S5, when cleaning the seeding tray and seeding equipment, a high-pressure airflow is used to ensure that the residual seed removal rate reaches more than 95%, and that there are no visible seed residues in the tooth grooves of the seeding tray after cleaning. When checking the wear of the parts, the wear of the seed discharge hole of the seeding tray is measured. When the wear exceeds 0.5 mm or a gap appears, it is replaced. At the same time, the blade thickness of the rotary tillage blade of the shallow rotary mechanism is recorded. When the thickness is less than 70% of the initial value, it is replaced.

[0015] The beneficial effects of the wheat-sesbania sowing method provided by this invention for dryland saline-alkali double-cropping areas are as follows: Compared with existing technologies, the wheat adopts a double-disc driven and double-row staggered pattern, reducing row spacing to increase sowing density. The double-row staggered layout reduces plant competition and ensures uniform distribution of light and nutrients. Sesbania, on the other hand, switches to a single-disc driven and single-row wide-spacing pattern. The wide row spacing design provides ample space for branching and root expansion, and the sesbania row spacing is set to twice that of wheat, adapting to the growth needs of leguminous green manure crops. The pre-setting parameter mechanism can adjust sowing parameters according to soil salinity and crop type, avoiding improper sowing problems caused by differences in saline-alkali soil conditions, and significantly improving sowing accuracy.

[0016] The shallow rotary tillage stage, with a tillage depth of 8-10cm, breaks up surface clods and eliminates tractor tire tracks while preventing the uplift of deep, high-salt soil, thus optimizing the soil structure for seed germination from the outset. Low-intensity compaction after sowing ensures close contact between seeds and soil, meeting the water requirements during germination. High-intensity compaction between rows (4-5cm) creates continuous rainwater collection ditches, achieving efficient rainwater collection in dryland areas and leaching surface salts through water infiltration. Soil leveling by the compaction mechanism further reduces water evaporation. This multi-stage synergistic approach addresses the germination obstacles caused by drought, salinity, and soil compaction in saline-alkali land, significantly improving seed germination rate and seedling survival rate.

[0017] Pre-planting checks on component integrity and post-planting cleaning of residual seeds and recording of wear can effectively prevent equipment malfunctions such as missed sowing and re-sowing. The seeding equipment can quickly switch between dual-disc and single-disc modes, completing the conversion between wheat and sesbania planting without replacing core components, reducing adjustment time and labor costs, and avoiding yield fluctuations caused by agricultural delays.

[0018] This invention provides a wheat-sesbania sowing method for dryland saline-alkali double-cropping areas. Through the synergistic design of crop adaptation, soil improvement, and equipment optimization, a multi-layered mechanism for ensuring yield stability is constructed. Wheat yield reduction is mitigated by optimized dense planting to reduce the risk of yield loss due to unreasonable population structure; sesbania biomass accumulation is enhanced by wide-spacing planting, forming a green manure cycle that uses land to nourish the soil; and the water collection and moisture retention function of rainwater drainage ditches buffers the impact of uneven rainfall, reducing the fluctuations in yield caused by drought and flooding. This method specifically addresses core issues such as insufficient adaptability of the same seeder, saline-alkali drought stress, and low emergence rate, achieving a dual improvement in emergence rate and yield stability for double-cropping crops in dryland saline-alkali areas. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This invention provides a flowchart of the steps for a wheat-sesbania sowing method in dryland saline-alkali double-cropping areas; Figure 2 This invention provides a framework flowchart for a wheat-sesbania sowing method in dryland saline-alkali double-cropping areas. Detailed Implementation

[0021] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0022] Unless otherwise explicitly specified, the use of terms such as "first," "second," or "third" is intended to distinguish different objects, not to describe a specific order.

[0023] Unless otherwise expressly defined, the use of directional terms such as “center,” “lateral,” “longitudinal,” “horizontal,” “vertical,” “top,” “bottom,” “inner,” “outer,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “clockwise,” “counterclockwise,” “high,” and “low” to indicate orientation or positional relationships is based on the orientation and positional relationships shown in the accompanying drawings and is only for the convenience of describing the invention and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the specific scope of protection of the invention.

[0024] Please see Figures 1 to 2 The present invention will now describe a method for sowing wheat-sesbania in dryland saline-alkali double-cropping areas. The method includes the following steps: S1. Preliminary preparation: Check the integrity of the shallow rotating mechanism of the sowing device, the two staggered sowing trays at the front and rear, the sowing equipment and the pressing roller components. Based on the salinity of the saline-alkali soil and the crop type, preset the sowing density and row spacing parameters for wheat or sesbania. S2. Shallow rotary tillage: The tractor pulls the seeding device forward at a constant speed, and the front shallow rotary mechanism is activated to perform shallow rotary treatment on the ground surface. The rotary tillage depth is controlled at 8-10cm, and the tractor tire tracks are removed and the surface soil clods are broken. S3. Sowing execution: If sowing wheat, activate the dual-disc drive mode of the sowing equipment to control the two staggered sowing discs to operate synchronously and form a double-row staggered sowing trajectory. If sowing sesame, switch to single-disc drive mode, where a single sowing disc operates independently to form a single-row wide-spacing sowing trajectory, and the row spacing of sesame is twice that of wheat. S4. Soil treatment: After sowing, the surface soil is leveled by a grading mechanism, and low-intensity compaction is carried out using a compaction wheel. Then, a high-intensity compaction with a depth of 4-5cm is carried out between the sowing rows using a compaction wheel to form continuous rainwater collection ditches. S5. Equipment Reset: Shut down all working mechanisms, clean the seeding tray and seeding equipment of any remaining seeds, check the wear of parts and record the findings.

[0025] This invention provides a wheat-sesbania sowing method for dryland saline-alkali double-cropping areas. Compared with existing technologies, the wheat uses a double-disc driven and double-row staggered pattern, reducing row spacing to increase sowing density. The double-row staggered layout reduces plant competition and ensures even distribution of light and nutrients. The sesbania uses a single-disc driven and single-row wide-spacing pattern. The wide row spacing provides ample space for branching and root expansion, and the sesbania row spacing is set to twice that of wheat, adapting to the growth needs of leguminous green manure crops. The pre-setting parameter mechanism can adjust sowing parameters according to soil salinity and crop type, avoiding improper sowing problems caused by differences in saline-alkali soil conditions and significantly improving sowing accuracy.

[0026] The shallow rotary tillage stage, with a tillage depth of 8-10cm, breaks up surface clods and eliminates tractor tire tracks while preventing the uplift of deep, high-salt soil, thus optimizing the soil structure for seed germination from the outset. Low-intensity compaction after sowing ensures close contact between seeds and soil, meeting the water requirements during germination. High-intensity compaction between rows (4-5cm) creates continuous rainwater collection ditches, achieving efficient rainwater collection in dryland areas and leaching surface salts through water infiltration. Soil leveling by the compaction mechanism further reduces water evaporation. This multi-stage synergistic approach addresses the germination obstacles caused by drought, salinity, and soil compaction in saline-alkali land, significantly improving seed germination rate and seedling survival rate.

[0027] Pre-planting checks on component integrity and post-planting cleaning of residual seeds and recording of wear can effectively prevent equipment malfunctions such as missed sowing and re-sowing. The seeding equipment can quickly switch between dual-disc and single-disc modes, completing the conversion between wheat and sesbania planting without replacing core components, reducing adjustment time and labor costs, and avoiding yield fluctuations caused by agricultural delays.

[0028] This invention provides a wheat-sesbania sowing method for dryland saline-alkali double-cropping areas. Through the synergistic design of crop adaptation, soil improvement, and equipment optimization, a multi-layered mechanism for ensuring yield stability is constructed. Wheat yield reduction is mitigated by optimized dense planting to reduce the risk of yield loss due to unreasonable population structure; sesbania biomass accumulation is enhanced by wide-spacing planting, forming a green manure cycle that uses land to nourish the soil; and the water collection and moisture retention function of rainwater drainage ditches buffers the impact of uneven rainfall, reducing the fluctuations in yield caused by drought and flooding. This method specifically addresses core issues such as insufficient adaptability of the same seeder, saline-alkali drought stress, and low emergence rate, achieving a dual improvement in emergence rate and yield stability for double-cropping crops in dryland saline-alkali areas.

[0029] Following step S2, firstly, crush the corn stalks into uniform segments of 5-8cm, avoiding segments longer than 10cm which could cause laying problems. On the shallowly leveled surface, mark the grid outline with a marker rope at 30×30cm intervals, ensuring neat rows and columns. Then, lay the crushed stalks along the marked lines to form a crisscrossing grid covering layer, with a thickness controlled at 3-4cm, ensuring continuous lines and tight overlap at intersections. At each grid intersection, use a 10cm diameter tool to take soil and compact the stalks into the soil 2-3cm deep with 5-8kg of pressure to prevent them from being blown away by the wind. Adjust the row spacing of the wheat seeding trays to match the grid gaps, so that the seeding trays penetrate the soil vertically through the gaps, sowing the seeds in the uncovered areas at a consistent depth of 3-4cm, creating a layout where the stalks surround the seed strips. When the wheat germination rate reaches 70% and the seedling height is 3-5cm, use an arc-shaped pressing wheel to apply pressure along the grid lines, pressing the edges of the straw into the topsoil 2-3cm, leaving the top 1-2cm exposed. Set the pressing pressure to 15-20kPa to avoid compacting the soil in the root zone and affecting respiration.

[0030] A 30×30cm straw grid mulch can reduce surface water evaporation by more than 30%. The grid structure intercepts runoff, directing rainwater towards the seed root zone and improving water utilization, especially providing stable moisture for seedlings during the spring drought in dryland areas. The composite mulch layer of straw and soil formed by secondary compaction reduces water loss due to air circulation and creates a locally moist microenvironment by absorbing moisture through the straw, reducing the risk of drought during the seedling stage. In terms of suppressing salinity and optimizing the root zone environment, the straw grid blocks direct sunlight, lowers the surface soil temperature, reduces salt return, and reduces the salt content of the 0-5cm topsoil by 20%-25%, preventing seeds and seedlings from being poisoned by high salt. In addition, straw releases organic acids during topsoil degradation to neutralize alkalinity, increases organic matter content, improves the heavy and compacted properties of saline-alkali soil, and provides a loose and breathable environment for the root system.

[0031] In step S3, before sowing wheat, the two sowing trays need to be adjusted to a staggered arrangement. During operation, the front sowing tray rotates clockwise, and the rear sowing tray rotates counterclockwise. Utilizing the force couple effect of the counter-rotation, the seeds gain an initial lateral displacement velocity. Combined with the physical stagger, this creates a vortex-like distribution, with adjacent seeds staggered laterally by 4.5-5.5 cm and forming a 2-3 cm height difference longitudinally, constructing a three-dimensional, interwoven spatial layout. This mode optimizes the plant population's spatial structure. Lateral stagger avoids competition between rows, and the vertical height difference allows seeds to adapt to the uneven salinity of the surface layer in saline-alkali soil, avoiding high-salt stress and increasing germination rate. It also promotes the formation of an interwoven root network, enhancing soil stabilization and lodging resistance. The three-dimensional plant cover slows water evaporation, and the gaps between rows facilitate rainwater infiltration and drainage, improving water use efficiency.

[0032] When sowing sesbania, a single sowing tray is used, employing an alternating clockwise and counter-clockwise rotation pattern. The rotation direction is switched every 1 meter of row movement. When rotating clockwise, seeds are sown to the left, and when rotating counter-clockwise, seeds are sown to the right, forming a Z-shaped distribution within the row. This, combined with wide row spacing, creates a suitable growth pattern. The Z-shaped distribution provides sesbania with a spacious and orderly growth space, allowing it to expand evenly to both sides during the branching period, avoiding branch entanglement, improving ventilation and light penetration, and increasing photosynthetic efficiency. This increases biomass accumulation, laying the foundation for green manure return to the field. Its root system extends laterally over a wider range, enabling it to evenly utilize the uneven distribution of nutrients and water in saline-alkali soil, reducing growth problems. Furthermore, the interwoven root system comprehensively improves soil physical and chemical properties through nitrogen fixation and exudates. Simultaneously, the buffer space within the rows enhances the plant's resistance to adverse conditions. In the event of drought or wind damage, the plants provide mutual shading and support, reducing the risk of lodging or wilting, ensuring the stability of sesbania growth, and providing favorable soil conditions for the subsequent wheat crop.

[0033] Although the vortex-like distribution of wheat and the zigzag distribution of sesbania differ in pattern, both are precisely designed based on crop characteristics and the saline-alkali soil environment, forming a synergistic and efficient planting system. The vortex-like distribution solves the resource competition problem of dense wheat planting and improves the plant's stress resistance; the zigzag distribution meets the growth space and functional needs of sesbania as green manure. By optimizing seed-soil distribution, both models make full use of limited resources and achieve differentiated and precise planting of two crops on the same seeder, effectively alleviating the problems of low germination rate and poor yield stability caused by unreasonable sowing in dryland saline-alkali areas.

[0034] In step S3, during wheat sowing, soil sensors monitor the size of surface soil clods in real time, dynamically adjusting the staggered angle of the two sowing trays accordingly. When the soil clod diameter is within the suitable range of 1cm ≤ soil clod diameter ≤ 3cm, the two sowing trays maintain a 45° staggered angle to ensure a reasonable distribution of seeds in well-organized soil. When the soil clod diameter is > 3cm, indicating the presence of large soil clods, the staggered angle is increased from 45° to 60° to widen the sowing coverage area and prevent large soil clods from hindering even seed distribution. Conversely, when the soil clod diameter is < 1cm, indicating fine and fragmented soil, the staggered angle is adjusted back to 30° to prevent excessively scattered seed distribution and ensure sowing density. This dynamic adjustment mode allows the sowing trays to adapt to the soil surface conditions, ensuring even distribution of wheat seeds in soil with different clod sizes, reducing missed sowing and double sowing caused by soil clod issues, and laying the foundation for uniform wheat emergence.

[0035] When sowing sesbania, the angle of each sowing tray is fixed at 60°, forming a wide-range, scattering seed trajectory that meets the wide row spacing requirements of sesbania and provides ample space for growth. Simultaneously, the elastic seed scraper at the edge of the sowing tray automatically adjusts to fit the tray surface, promptly removing residual seeds and preventing them from sticking to the tray surface and affecting the accuracy of subsequent sowing. The wide-range, scattering seed trajectory ensures more even distribution of sesbania seeds within the rows, avoiding areas of excessive density or sparseness, which is beneficial for sesbania seedlings to fully utilize light, water, and nutrients during growth. The elastic seed scraper ensures stable sowing rates, reduces seed waste, and ensures that the number of seeds sown each time meets the preset requirements, improving the accuracy of sesbania sowing.

[0036] In summary, the staggered angle of the sowing trays is dynamically adjusted according to the size of the soil clods when sowing wheat, while the angle is fixed and a flexible seed scraper is provided when sowing sesame. These two targeted designs, which are based on adapting to soil changes and meeting crop characteristics respectively, effectively solve the problem of uneven sowing caused by complex soil conditions and different crop needs in dryland saline-alkali areas, further improving the emergence rate of the two crops and enhancing yield stability.

[0037] In addition, a combination of pneumatic sowing and mechanical assistance is used when sowing wheat. After the pneumatic sowing channel is opened, the high-pressure airflow creates a stable conveying force, precisely delivering wheat seeds to two sowing trays, ensuring that the seeds are not easily blocked during transport and are initially evenly distributed. Simultaneously, a mechanical eccentric seed-distributing wheel is activated to assist in sowing. The rotation of the wheel further adjusts the number and spacing of seeds, compensating for potential errors from a single sowing method. This avoids localized over-density or under-density issues caused by uneven sowing, ensuring that the number of wheat seeds per unit area meets the preset density parameters, thus providing a foundation for the rational construction of the wheat population structure.

[0038] When sowing sesbania, the sowing method is switched to a single mechanical eccentric wheel, and the pneumatic sowing channel is closed. This adjustment is adapted to the wide row spacing and relatively low planting density of sesbania, meeting the sowing needs without the need for high-pressure airflow, thus reducing energy consumption. More importantly, the rotation speed of the mechanical eccentric wheel is linked to the forward speed of the sowing device; for every 1 km / h increase in speed, the wheel speed increases by 50 r / min. This dynamic adjustment of the rotation speed ensures a stable sowing rate of sesbania seeds per unit length. The uniformity of sesbania seed distribution within the row is significantly improved, avoiding insufficient sowing at high speeds and excessive sowing at low speeds, thus ensuring uniform germination and reasonable allocation of space for later growth.

[0039] Switching between the two sorting methods is convenient and requires no large-scale modification to the equipment; it can be accomplished simply by switching channels and adjusting parameters, adapting to the agricultural time requirements for rapid crop switching in double-cropping systems. For wheat, the dual sorting mode reduces seed loss and residue during the sorting process, lowering costs caused by seed waste. Meanwhile, the mechanical linkage sorting mode for sesbania improves sorting efficiency and reduces manual intervention through precise matching of rotation speed and rotational speed.

[0040] When sowing wheat, the periodic operation of the sowing disc cam lifting mechanism creates a cyclical variation in seed depth along the sowing direction, with the period length strictly controlled between 30-50 cm. The peaks and troughs of the depth variations between adjacent rows are staggered; that is, when one row is at its peak depth, the adjacent row is at its trough. This arrangement constructs a three-dimensional water storage space in the soil. Deeply sown areas can store more deep soil moisture, while shallowly sown areas facilitate rapid absorption of surface rainfall by the seeds. The staggered peaks and troughs form interconnected micro-water circulation channels. In arid and saline-alkali areas where rainfall is scarce and unevenly distributed, this three-dimensional water storage space improves the efficiency of rainwater and soil moisture utilization, reduces water loss due to surface runoff, provides a continuous and stable water supply for wheat seed germination and seedling growth, and alleviates the inhibitory effect of drought stress on emergence rate.

[0041] When sowing sesbania, in addition to the single-disc driven wide-spacing sowing mode, a linked deep-tillage shovel is also equipped on the side of the track of each sowing disc. A deep-tillage action is triggered every 3 meters of sowing, reaching a depth of 15-20 cm. This depth penetrates the soil surface, breaking up the plow pan structure formed by long-term cultivation. The existence of the plow pan is one of the important reasons for the poor aeration and difficulty in water infiltration in saline-alkali soils. The aeration channels formed after deep tillage significantly improve soil aeration, promote the expansion of sesbania roots into deeper layers, and accelerate the leaching and volatilization of salt and alkali components in the soil, reducing the salt and alkali concentration in the root zone. After deep tillage, the loosened soil is promptly backfilled and compacted using a backfilling wheel to prevent rapid water evaporation due to loose soil, while maintaining the structural stability of the aeration channels. This ensures that the channels not only provide aeration but also guide water to deeper layers during rainfall, reducing surface salt return.

[0042] In step S4, on gently sloping plots with a gradient of less than 3°, a segmented wide-width rainwater harvesting ditch design is adopted. A wide rainwater harvesting ditch is installed every 5 meters, with the width of each ditch controlled at 12-15 cm and the depth maintained at 5 cm to ensure efficient collection of surface runoff. Adjacent rainwater harvesting ditches are smoothly connected via transition sections to avoid water flow obstruction or erosion caused by abrupt ditch joints, allowing rainwater to flow smoothly along the predetermined path and converge into the harvesting ditches. This layout forms a uniformly distributed linear water collection system on gently sloping plots, avoiding excessive division of farmland that could affect sowing operations, while maximizing the interception of scattered surface rainfall and concentrating rainwater within the ditches. This provides a continuous water supply to the roots of surrounding wheat and sesbania roots, effectively alleviating surface soil drought, especially during the spring drought season.

[0043] For plots with a slope of ≥3°, a grid-like water collection system design combining horizontal and vertical elements is adopted. Horizontal intercepting ditches are installed along contour lines, while vertical collecting ditches are installed perpendicular to these contour lines. The spacing between adjacent horizontal or vertical intercepting ditches is controlled at 8-10 meters, creating a regular grid structure through the perpendicular intersections of the horizontal and vertical ditches. The horizontal intercepting ditches intercept surface runoff from the uphill direction, reducing the scouring force of rainwater down the slope and mitigating the risk of soil erosion. The vertical collecting ditches transport or store the rainwater collected by the horizontal intercepting ditches to low-lying areas. The grid distribution ensures even distribution of rainwater within the plot, preventing localized waterlogging or drought. This grid-like layout is particularly suitable for sloping terrain, enhancing both soil and water conservation capabilities and improving the spatial utilization efficiency of precipitation.

[0044] In addition, the water collected in the drainage ditches can leach salts from the soil along the ditches through infiltration, reducing the salinity of the topsoil. Continuous drainage ditches on flat land form strip-shaped salt leaching areas, while grid-like drainage ditches on slopes form a surface salt leaching network. Combined with previous shallow rolling and compaction measures, this accelerates the migration of saline-alkali components into deeper soil layers or their discharge with runoff, gradually improving the soil environment in the crop root zone.

[0045] In step S4, when sowing wheat, granular biochar is sprayed at a rate of 100g per meter, and the biochar is directly embedded into the topsoil during the compaction action of the roller. This allows the biochar to quickly combine with the topsoil, utilizing its porous nature to adsorb salts in the soil, reducing the salt concentration in the wheat seed germination zone, and mitigating the inhibitory effect of salt-alkali stress on wheat emergence. Simultaneously, the biochar embedded in the topsoil improves the structure of the topsoil, increases soil porosity, and enhances the soil's water retention capacity, providing a looser, more aerated, and moist growing environment for wheat seedling roots. This promotes root development and the absorption of water and nutrients, thereby increasing the wheat emergence rate and seedling growth.

[0046] When sowing sesbania, apply a mixture of biochar and well-rotted organic fertilizer in a 1:3 ratio. Using a deep tillage shovel, apply the mixed biochar and organic fertilizer to a depth of 15cm, 10cm to the side of the sesbania seed, creating a three-dimensional microenvironment where seeds, biochar, and soil interact. The well-rotted organic fertilizer provides abundant nutrients for sesbania growth, while the biochar adsorbs and slowly releases nutrients, extending the nutrient supply time, preventing nutrient loss, and improving nutrient utilization.

[0047] Specifically, the soil compaction radius of the compaction mechanism is 10-15cm on each side of the sowing row. The pressure for low-intensity compaction is controlled at 0.2-0.3MPa, and the pressure for high-intensity compaction is controlled at 0.5-0.6MPa. The cross-section of the continuous rainwater collection ditch is an inverted trapezoid, with a width of 8-10cm. Compared with other shapes, the inverted trapezoidal structure is more conducive to rainwater collection and storage. The reasonable setting of the ditch width can ensure rapid collection of rainwater during rainfall and reduce the waste of surface runoff.

[0048] In step S5, when cleaning the seeding tray and the seeding equipment, a high-pressure airflow is used to ensure that the residual seed removal rate reaches over 95%, and that there are no visible seed residues in the grooves of the seeding tray after cleaning. The high-pressure airflow can penetrate deep into the gaps and grooves of the seeding tray and the fine structures such as the pipes of the seeding equipment, thoroughly removing residual seed debris and impurities, and preventing cross-contamination of different crop seeds within the equipment. When checking the wear of components, the wear of the seed dispensing holes of the seeding tray is measured. When the wear exceeds 0.5mm or a gap appears, the holes are replaced. The seed dispensing holes are the core components controlling the seeding rate and distribution. Excessive wear can lead to unstable seed dispensing, uneven seed distribution, and even missed seeding. At the same time, the blade thickness of the rotary tiller of the shallow rotary mechanism is recorded. When the thickness is less than 70% of the initial value, the blade is replaced to ensure the effectiveness of the shallow rotary treatment. Excessive wear of the rotary tiller blade will result in insufficient shallow rotary depth and inadequate soil breaking, affecting the soil foundation for subsequent sowing. The dry tiller effectively eliminates tractor tire marks and breaks up surface soil clods, creating a loose soil environment for seed germination.

[0049] Example 1: Wheat-Senecio double cropping in mildly saline-alkali and gently fertile land In gently sloping, slightly saline-alkali soil with a salinity of 0.1%-0.2% and a slope of 2°, the following sowing process was adopted: In the preliminary preparation stage, the integrity of the shallow rotary tillage mechanism, double seeding trays, seeding equipment, and press wheels was checked. The preset row spacing for wheat was 15cm, with a sowing density of 350 seeds / m², and the row spacing for sesbania was 30cm, with a sowing density of 100 seeds / m². During shallow rotary tillage, the tractor towed the device forward at a speed of 5km / h. The front shallow rotary tillage mechanism tilled the surface to a depth of 8cm, eliminating tire marks and breaking up surface clods. Then, a 30×30cm corn stalk grid was laid, and the intersections were compacted with soil. The wheat seeding tray penetrated the grid gaps, and the dual-disc drive mode was activated. The front disc rotated clockwise, and the rear disc rotated counterclockwise to form a vortex-like distribution. Adjacent seeds were offset laterally by 5cm and vertically by 2cm. Simultaneously, soil sensors monitored soil clods with a diameter of 2cm. The seeding trays were maintained at a 45° staggered angle, and the pneumatic seeding channel was activated in conjunction with the mechanical eccentric wheel for seeding. After sowing, the soil leveling mechanism tampers the soil to a depth of 12cm on both sides of the sowing row, compacting it with a low intensity of 0.2MPa, and then compacting it between the rows with an intensity of 0.5MPa to form rainwater collection ditches with an inverted trapezoidal cross-section and a width of 9cm. Wide rainwater collection ditches are set every 5m and connected by transition sections. 100g of granular biochar is sprayed per meter on the inside of the compaction wheel and embedded in the topsoil. When the equipment is reset, a high-pressure airflow blows through the sowing tray and seed distribution equipment to ensure a residue removal rate of over 95%. The wear of the seed discharge hole is checked to be 0.3mm and the thickness of the rotary tillage blade is checked to be 80% of the initial value. The operation is completed after recording the results.

[0050] Example 2: Wheat-Senecio double cropping on moderately saline-alkali slopes For moderately saline-alkali slopes with a soil salinity of 0.2%-0.3% and a slope of 5°, the following operations were implemented: Pre-planning: wheat row spacing was preset at 12cm, density at 400 seeds / m²; sesbania row spacing was preset at 24cm, density at 80 seeds / m². Shallow rotary tillage was performed at a depth of 10cm to remove tire marks and break up soil clods. When sowing wheat, because the soil sensor detected soil clods with a diameter of 4cm, the double sowing discs were adjusted to a staggered angle of 60°. The cam lifting mechanism ensured that each row of seeds formed a deep-shallow-deep distribution with a 30cm cycle, and the peaks and troughs of adjacent rows were staggered. When sowing sesbania, the single-disc drive was switched, and the forward and reverse rotations alternated every 1m to form a zigzag distribution. Simultaneously, the side-linked deep tillage shovel was activated, tilling 15cm every 3m to break the plow pan. Biochar and well-rotted organic fertilizer were mixed at a 1:3 ratio and applied to a depth of 10cm to the side of the sowing. The backfill wheel was then used to compact and loosen the soil. During the soil treatment stage, transverse intercepting ditches are set along contour lines, and longitudinal rainwater collection ditches are set vertically, forming a grid system with a spacing of 8m and a convergence width of 15cm. The compaction pressure is 0.3MPa for low-intensity compaction and 0.6MPa for high-intensity compaction. The equipment is cleaned by high-pressure airflow purging. Seed discharge holes with a wear of 0.6mm are replaced, and rotary tillage blades are replaced promptly when the blade thickness reaches 65% of the initial value.

[0051] Example 3: Wheat-Senecio double cropping in severely saline-alkali complex plots For severely saline-alkali land with a soil salinity of 0.3%-0.4%, containing some soil clods larger than 5cm in diameter, and a slope of 4°, the sowing process is as follows: Pre-preparation: Pre-set wheat row spacing of 14cm and density of 450 seeds / m², and sesbania row spacing of 28cm and density of 90 seeds / m². Shallow rotary tillage: Rotary tillage to 9cm to break up large soil clods to less than 3cm in diameter. When sowing wheat, if soil sensors detect soil clods with a diameter of 1cm in some areas, adjust the sowing disc angle to 30°, and use a dual-disc drive to form a vortex-like distribution with a lateral offset of 4.5cm and a longitudinal height difference of 3cm. Air pressure sowing combined with a mechanical guide wheel ensures accurate seeding. For sesbania sowing, a single disc is fixed at 60° for wide-area scattering of seeds. An elastic seed scraper removes residue from the disc surface. A deep tillage shovel tills 20cm every 3m and applies a biochar-organic fertilizer mixture. The rainwater harvesting system employs a horizontal and vertical grid layout with an 8m spacing. A soil collection mechanism treats the 10cm soil layer on both sides of the sowing row, using low-intensity compaction (0.25MPa) and high-intensity compaction (0.55MPa) to create 8cm wide rainwater collection trenches. Upon equipment reset, a high-pressure airflow is used to purge the sowing disc grooves to ensure no residue remains. The notched seed discharge holes and rotary tillers with a blade thickness of 68% of the initial value are then replaced to ensure subsequent sowing accuracy. These operations effectively mitigate the inhibitory effects of severe salinity and complex terrain on seedling emergence.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for dry saline two-crop area wheat-sesbania sowing, characterized by, Includes the following steps: S1. Preliminary preparation: Check the integrity of the shallow rotating mechanism of the sowing device, the two staggered sowing trays at the front and rear, the sowing equipment and the pressing roller components. Based on the salinity of the saline-alkali soil and the crop type, preset the sowing density and row spacing parameters for wheat or sesbania. S2. Shallow rotary tillage: The tractor pulls the seeding device forward at a constant speed, and the front shallow rotary mechanism is activated to perform shallow rotary treatment on the ground surface. The rotary tillage depth is controlled at 8-10cm, and the tractor tire tracks are removed and the surface soil clods are broken. S3. Sowing execution: If sowing wheat, activate the dual-disc drive mode of the sowing equipment to control the two staggered sowing discs to operate synchronously and form a double-row staggered sowing trajectory. If sowing sesame, switch to single-disc drive mode, where a single sowing disc operates independently to form a single-row wide-spacing sowing trajectory, and the row spacing of sesame is twice that of wheat. S4. Soil treatment: After sowing, the surface soil is leveled by a grading mechanism, and low-intensity compaction is carried out using a compaction wheel. Then, a high-intensity compaction with a depth of 4-5cm is carried out between the sowing rows using a compaction wheel to form continuous rainwater collection ditches. S5. Equipment Reset: Shut down all working mechanisms, clean the seeding tray and seeding equipment of any remaining seeds, check the wear of parts and record the condition; In step S3, when sowing wheat, the size of the surface soil clods is monitored in real time by a soil sensor. When the soil clod diameter is 1cm ≤ 3cm, the two sowing discs maintain a 45° staggered angle; when the soil clod diameter is > 3cm, the staggered angle is increased from 45° to 60°; when the soil clod diameter is < 1cm, the staggered angle is reduced back to 30°. When sowing sesbania, the angle of a single sowing tray is fixed at 60°, forming a wide-range scattering seed trajectory. The edge of the sowing tray is equipped with an elastic seed scraper that automatically adheres to the tray surface to remove residual seeds as the angle is adjusted.

2. The method for sowing wheat-sesbania in dryland saline-alkali double-cropping areas as described in claim 1, characterized in that, After step S2, the crushed corn stalks are laid on the ground in a 30×30cm grid to form a grid. The soil is compacted at the intersection of the grid. The wheat seeding tray penetrates the grid gaps to complete the sowing. After the wheat seedlings emerge, the grid stalks are pressed into the topsoil through a second compaction.

3. The method for sowing wheat-sesbania in dryland saline-alkali double-cropping areas as described in claim 1, characterized in that, In step S3, before sowing wheat, the two sowing discs are adjusted to be staggered, with the front sowing disc rotating clockwise and the rear sowing disc rotating counterclockwise, forming a vortex-like distribution of wheat seeds in the soil. Adjacent wheat seeds are staggered laterally by 4.5-5.5 cm and have a height difference of 2-3 cm in the longitudinal direction. When sowing sesame seeds, each seeding tray uses an alternating clockwise and counterclockwise rotation pattern, switching the rotation direction every 1m of row movement, so that the sesame seeds are distributed in a zigzag pattern within the row.

4. The method for sowing wheat-sesbania in dryland saline-alkali double-cropping areas as described in claim 3, characterized in that, When sowing wheat, the air pressure seeding channel is opened, and the seeds are blown to two seeding trays by high-pressure airflow, while the mechanical eccentric seed-distributing wheel assists in seeding. When sowing sesbania, the air pressure sowing channel is closed, and sowing is carried out only by mechanical eccentric wheel. The speed of the mechanical eccentric wheel is linked to the forward speed. For every 1 km / h increase in speed, the speed of the mechanical eccentric wheel increases by 50 r / min.

5. A method for sowing wheat-sesbania in dryland saline-alkali double-cropping areas as described in claim 4, characterized in that, When sowing wheat, the seeding tray cam lifting mechanism is used to create a periodic change in the depth of each row of seeds along the direction of travel. The period length is 30-50cm. The peaks and troughs of the depth waves of adjacent rows are staggered to form a three-dimensional water storage space. When sowing sesbania, a linked deep tillage shovel is set on the side of the track of a single sowing disc. The deep tillage action of the deep tillage shovel is triggered every 3m distance of sowing, with a deep tillage depth of 15-20cm. This breaks up the plow bottom structure to form a breathable channel. After deep tillage, the loose soil is backfilled and compacted by the backfilling wheel.

6. The method for sowing wheat-sesbania in dryland saline-alkali double-cropping areas as described in claim 1, characterized in that, In step S4, a wide rainwater collection ditch is set every 5m on plots with a slope of <3°. The width of the wide rainwater collection ditch is 12-15cm and the depth is kept at 5cm. The intervals are smoothly connected by transition sections. On plots with a slope of ≥3°, transverse rainwater collection ditches and longitudinal rainwater collection ditches are set along the contour line. The distance between adjacent transverse intercepting ditches or adjacent longitudinal rainwater collection ditches is 8-10m. The transverse intercepting ditches and longitudinal rainwater collection ditches intersect perpendicularly to form a grid-like water collection system.

7. The method for sowing wheat-sesbania in dryland saline-alkali double-cropping areas as described in claim 1, characterized in that, In step S4, a biochar spraying channel is set inside the rolling wheel. 100g of granular biochar is sprayed per meter between wheat sowing rows and embedded into the topsoil during rolling. The biochar is mixed with decomposed organic fertilizer in a 1:3 ratio and applied to a depth of 15cm at a distance of 10cm to the side of the sowing using a deep tillage shovel, forming a three-dimensional improved microenvironment of seeds, biochar and soil.

8. A method for sowing wheat-sesbania in dryland saline-alkali double-cropping areas as described in claim 1, characterized in that, In step S4, the soil leveling range of the leveling mechanism is 10-15cm on each side of the sowing row, the pressure of low-intensity compaction is controlled at 0.2-0.3MPa, the pressure of high-intensity compaction is controlled at 0.5-0.6MPa, the cross-section of the continuous rainwater collection ditch is an inverted trapezoid, and the ditch width is 8-10cm.

9. A method for sowing wheat-sesbania in dryland saline-alkali double-cropping areas as described in claim 1, characterized in that, In step S5, when cleaning the seeding tray and seeding equipment, a high-pressure airflow is used to ensure that the residual seed removal rate reaches more than 95%, and that there are no visible seed residues in the tooth grooves of the seeding tray after cleaning. When checking the wear of the parts, the wear of the seed dispensing holes of the seeding tray is measured. When the wear exceeds 0.5 mm or a gap appears, it is replaced. At the same time, the blade thickness of the rotary tillage blade of the shallow rotary mechanism is recorded. When the thickness is less than 70% of the initial value, it is replaced.

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