Wheat-sesbania seeding method for dry farming saline-alkaline double cropping area

Abstract

The invention provides a sowing method for wheat-sesbania in a dry farming saline-alkaline double cropping area, and belongs to the technical field of agricultural sowing, and the sowing method comprises the following steps: S1, early-stage preparation; s2, shallow spinning and leveling; s3, sowing execution; s4, soil treatment; and S5, equipment resetting. The invention provides a wheat-sesbania seeding method for a dry farming saline-alkaline double cropping area. Through collaborative design of crop adaptation, soil improvement and equipment optimization, a multiple guarantee mechanism for yield stability is constructed. The yield reduction risk of unreasonable group structure of wheat is reduced through close planting optimization, biomass accumulation is improved through wide-distance planting of sesbania, and a green manure cycle of land use and land cultivation is formed; the rainwater collection ditch has the water collection and soil moisture conservation functions to buffer the influence of uneven rainfall and reduce the fluctuation impact of drought and flood on the yield. The method pertinently solves the core problems of insufficient adaptability, saline-alkali drought stress, low emergence rate and the like of the same seeder, and realizes double improvement of the emergence rate and the yield stability of the double-cropping product in the dry-farming saline-alkali area.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of agricultural seeding technology, and more particularly relates to a wheat-sesbania seeding method for dry farming in saline-alkali double-cropping areas. BACKGROUND

[0002] Dry farming in saline-alkali areas is generally faced with high degree of soil salinization, water resource scarcity, and poor plough layer structure.

[0003] Currently, crop planting in dry farming in saline-alkali areas is mainly single-cropping, and the land resource utilization rate is low. The double-cropping planting mode is greatly challenged due to the constraints of saline-alkali stress and seasonal drought. When the existing seeding technology of single-cropping crops is directly applied to the double-cropping planting mode, the use of the same seeding machine for double-cropping planting will result in low seedling emergence rate and poor yield stability of crops planted in dry farming in saline-alkali areas, which becomes a prominent bottleneck for sustainable agricultural development. SUMMARY

[0004] The purpose of the present application is to provide a wheat-sesbania seeding method for dry farming in saline-alkali double-cropping areas, aiming to solve the problems of low seedling emergence rate and poor yield stability of crops planted in dry farming in saline-alkali areas when the same seeding machine is used for double-cropping planting.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present application is to provide a wheat-sesbania seeding method for dry farming in saline-alkali double-cropping areas, comprising the following steps: S1. Preliminary preparation: check the integrity of the shallow rotary mechanism, the front and rear two staggered seeding discs, the seed separating device, and the roller parts of the seeding device, and preset the seeding density and row spacing parameters of wheat or sesbania according to the soil salt content of saline-alkali land and the type of crops; S2. Shallow rotary leveling: the tractor drags the seeding device at a uniform speed, starts the front shallow rotary mechanism to perform shallow rotary treatment on the ground surface, controls the rotary depth at 8-10 cm, and eliminates the tractor tire marks and breaks up the surface soil clods; S3. Seeding execution: if wheat is seeded, the double-disc driving mode of the seed separating device is enabled, the front and rear two staggered seeding discs are controlled to operate synchronously to form a double-row staggered seeding track; If sesbania is seeded, switch to the single-disc driving mode, and the single seeding disc operates independently to form a single-row wide-spacing seeding track, and the sesbania row spacing is twice that of the wheat row spacing; S4. Soil treatment: after seeding, the surface soil is straightened by the converging mechanism, low-intensity compaction is performed by the compaction roller, and high-intensity compaction with a depth of 4-5 cm is performed on the inter-seeding rows by the compaction roller to form continuous rain-collecting ditches; S5. Equipment reset: turn off all working mechanisms, clean the residual seeds in the seeding disc and seed separating device, check the wear of the parts, and record.

[0006] In a possible implementation, after step S2, the crushed corn stalks are laid on the ground surface in a grid of 30x30cm, the grid intersection points are compacted with soil, and the wheat is sown by penetrating the grid gaps with a sowing disc. After the wheat sprouts, the grid stalks are pressed into the surface soil by secondary compaction.

[0007] In a possible implementation, in step S3, before sowing the wheat, the two sowing discs are adjusted to a staggered mode, the front sowing disc is rotated clockwise, and the rear sowing disc is rotated counterclockwise, forming a vortex distribution of the wheat seeds in the soil, with adjacent wheat seeds staggered horizontally by 4.5-5.5cm and vertically forming a height difference of 2-3cm. When sowing the sesbania, the single sowing disc adopts an alternating mode of forward rotation and reverse rotation, and the rotation direction is switched every 1m of travel, forming a zigzag distribution of the sesbania seeds in the row.

[0008] In a possible implementation, in step S3, when sowing the wheat, the surface soil clump size is monitored in real time by a soil sensor. When the clump diameter is 1cm≤clump diameter≤3cm, the two sowing discs maintain an interlaced angle of 45°. When the clump diameter>3cm, the interlaced angle is increased from 45° to 60°. When the clump diameter<1cm, the interlaced angle is adjusted back to 30°. When sowing the sesbania, the angle of the single sowing disc is fixed at 60°, forming a wide scattering type seed dropping trajectory, and the sowing disc edge is provided with an elastic seed scraping piece that automatically adheres to the disc surface to remove residual seeds.

[0009] In a possible implementation, when sowing the wheat, the air pressure seed separation channel is opened, and the seeds are blown to the two sowing discs by high-pressure airflow, assisted by a mechanical eccentric seed picker. When sowing the sesbania, the air pressure seed separation channel is closed, and only the mechanical eccentric picker is used for seed separation. The mechanical eccentric picker speed is linked to the forward speed, and for every 1km / h increase in speed, the mechanical eccentric picker speed is increased by 50r / min.

[0010] In a possible implementation, when sowing the wheat, the sowing disc cam lifting mechanism is used to form a periodic change in depth along the travel direction of each row of seeds, with a cycle length of 30-50cm, and the depth peaks and valleys of adjacent rows are staggered, forming a three-dimensional water storage space. When sowing the sesbania, a linked deep tillage shovel is provided on the side of the trajectory of the single sowing disc. The deep tillage action of the deep tillage shovel is triggered every 3m of sowing distance. The deep tillage depth is 15-20cm, breaking the plough pan structure to form a ventilation channel. After deep tillage, the loosened soil is backfilled and compacted by a backfilling wheel.

[0011] In a possible implementation, in step S4, a wide rainwater collection ditch is arranged every 5 m on the land section with a slope < 3°, the width of the wide rainwater collection ditch is 12-15 cm, the depth is kept at 5 cm, and the intervals are smoothly connected through transition sections; the transverse rainwater collection ditch and the longitudinal rainwater collection ditch are arranged along the contour direction on the land section with a slope ≥ 3°, the distance between adjacent transverse rainwater collection ditches or adjacent longitudinal rainwater collection ditches is 8-10 m, and the transverse rainwater collection ditches and the longitudinal rainwater collection ditches are perpendicular to each other to form a grid-shaped rainwater collection system.

[0012] In a possible implementation, in step S4, a biochar injection channel is arranged on the inner side of the rolling wheel, 100 g of granular biochar is sprayed per meter between the wheat seeding rows, and the biochar is embedded in the topsoil with the rolling action; the biochar is mixed with the mature organic fertilizer at a ratio of 1:3, and is applied at a depth of 15 cm at a position 10 cm away from the seeding side through deep plowing to form a three-dimensional improved microenvironment of the seed, the biochar and the soil.

[0013] In a possible implementation, in step S4, the soil regulation range of the gathering mechanism is 10-15 cm on both sides of the seeding row, the pressure of the low-intensity rolling is controlled to be 0.2-0.3 MPa, the pressure of the high-intensity rolling is controlled to be 0.5-0.6 MPa, and the section of the continuous rainwater collection ditch is in the shape of an inverted trapezoid, and the ditch width is 8-10 cm.

[0014] In a possible implementation, in step S5, when the seeding disc and the seed distribution device are cleaned, a high-pressure airflow sweeping mode is adopted to ensure that the residual seed removal rate reaches more than 95%, and no visible seed residue is left in the tooth grooves of the cleaned seeding disc; when the wear condition of the components is checked, the wear amount of the seeding disc seed distribution hole is measured, the seeding disc is replaced when the wear amount exceeds 0.5 mm or a gap is formed, and the thickness of the rotating plow blade of the shallow rotating mechanism is recorded, and the rotating plow blade is replaced when the thickness is less than 70% of the initial value.

[0015] The wheat-vetch seeding method provided by the application has the beneficial effects that: compared with the prior art, the wheat adopts a double-disc driving and double-row staggered mode, the row spacing is reduced to increase the seeding density, and the double-row staggered layout reduces plant competition and ensures uniform distribution of light energy and nutrients; the vetch adopts a single-disc driving and single-row wide-spacing mode, the wide row spacing design provides sufficient space for branching and root expansion of the vetch, and the vetch row spacing is twice that of the wheat, which meets the growth needs of the leguminous green manure crop. The early parameter preset mechanism can adjust the seeding parameters according to the soil salt content and the crop type, avoids improper seeding caused by differences in saline-alkali land conditions, and significantly improves the seeding accuracy.

[0016] The shallow rotary leveling link passes through the rotary tillage depth of 8-10 cm, which can break the surface soil clods, eliminate the tractor tire marks, and avoid the upturning of the deep high-salt soil, so as to optimize the soil structure for seed germination from the source. The low-intensity compacting after sowing ensures the close contact between the seed and the soil, and meets the water demand in the germination period; the high-intensity compacting of 4-5 cm in the row constructs a continuous rain collection ditch, which realizes the efficient collection of rainwater in the dry farming area, and leaches the surface salt through water infiltration. The soil regulation of the gathering mechanism further reduces the water evaporation, and the multi-link cooperation solves the emergence obstacles caused by "dryness, salt and hardening" in the saline-alkali land, and significantly improves the seed germination rate and the seedling survival rate.

[0017] The early inspection component integrity and the later cleaning residual seeds and recording wear can effectively avoid the equipment failure problems such as missed sowing and repeated sowing. The double disc / single disc mode of the seed separating device can be quickly switched, the core components do not need to be replaced, the wheat and sesbania planting conversion can be completed, the adjustment time and labor cost are reduced, and the yield fluctuation caused by the delay of farm time is avoided.

[0018] The application provides a wheat-sesbania sowing method for dry saline-alkali double cropping area, which constructs a multiple guarantee mechanism for yield stability through the cooperative design of crop adaptation, soil improvement and equipment optimization. The wheat reduces the yield reduction risk caused by unreasonable population structure through dense planting optimization, the sesbania improves the biomass accumulation through wide spacing planting, and forms the green fertilizer circulation of land use and land maintenance; the water collection and soil conservation effect of the rainwater collection ditch buffers the influence of uneven precipitation, and reduces the fluctuation impact of drought and flood on yield. The method solves the core problems such as insufficient adaptability of the same sowing machine, saline-alkali drought stress and low emergence rate, and realizes the double improvement of emergence rate and yield stability of the double cropping crops in the dry saline-alkali area. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0020] Fig. 1 A step flow chart of a wheat-sesbania sowing method for dry saline-alkali double cropping area provided by the present application is provided. Fig. 2 A framework flow chart of a wheat-sesbania sowing method for dry saline-alkali double cropping area provided by the present application is provided. DETAILED DESCRIPTION

[0021] In order to make the technical problems, technical solutions and beneficial effects of the present application clearer, the present application will be further described in detail below in conjunction with the drawings and examples. It should be understood that the specific examples described herein are only intended to explain the present application and not to limit the present application.

[0022] Unless otherwise explicitly defined, the use of the terms "first", "second" or "third" etc. is merely intended to distinguish different objects, and is not intended to describe a particular order.

[0023] Unless otherwise explicitly defined, the use of terms such as "center", "transverse", "longitudinal", "horizontal", "vertical", "top", "bottom", "inner", "outer", "upper", "lower", "front", "back", "left", "right", "clockwise", "counterclockwise", "high", "low", etc. indicate the orientation or positional relationship based on the orientation and positional relationship shown in the drawings, and are only intended to facilitate the description of the present application and simplify the description, and therefore cannot be understood as limiting the specific protection scope of the present application.

[0024] Please refer to Figs. 1-2 , now a kind of for dry cultivation saline-alkali two-crop area wheat-sesbania sowing method provided by the present application will be described. The said one for dry cultivation saline-alkali two-crop area wheat-sesbania sowing method, including the following steps: S1. Preparation: check the shallow rotary mechanism of the sowing device, the front and rear two staggered sowing discs, the seed separating equipment and the compaction roller components for integrity, according to the salt content of the saline-alkali soil and the type of crops, preset the sowing density and row spacing parameters of wheat or sesbania; S2. Shallow rotary leveling: the tractor drags the sowing device at a uniform speed, starts the front shallow rotary mechanism to process the ground surface with shallow rotary, the rotary depth is controlled at 8-10cm, and the tractor tire marks are eliminated and the surface soil clods are broken; S3. Sowing execution: if sowing wheat, enable the double-disc driving mode of the seed separating equipment, control the front and rear staggered two sowing discs to operate synchronously to form a double-row staggered sowing track; If sowing sesbania, switch to single-disc driving mode, the single sowing disc operates independently to form a single-row wide-spacing sowing track, and the sesbania row spacing is twice that of wheat; S4. Soil treatment: after sowing, the surface soil is straightened by the gathering mechanism, low-intensity compaction is performed by the compaction roller, and high-intensity compaction is performed by the compaction roller on the sowing rows with a depth of 4-5cm to form continuous rain-collecting ditches; S5. Equipment reset: turn off all working mechanisms, clean up the residual seeds in the sowing disc and seed separating equipment, check the wear of the components and record.

[0025] The wheat-Sesbania planting method for dry farming and saline-alkali two-crop areas provided by the application, compared with the prior art, adopts double-disc driving and double-row staggered mode for wheat, reduces the row spacing to increase the planting density, and the double-row staggered layout reduces plant competition and ensures uniform distribution of light energy and nutrients; Sesbania is switched to single-disc driving and single-row wide spacing mode, the wide row spacing design provides sufficient space for branching and root expansion of Sesbania, and the row spacing of Sesbania is 2 times that of wheat, which adapts to the growth requirements of leguminous green manure crops. The early parameter preset mechanism can adjust the planting parameters according to the soil salt content and crop type, avoid improper planting problems caused by differences in saline-alkali conditions, and significantly improve the planting accuracy.

[0026] The shallow rotary leveling link breaks up the surface soil clods and eliminates the tractor tire marks through a rotary tillage depth of 8-10 cm, and avoids turning over the deep high-salt soil, thereby optimizing the soil structure for seed germination from the source. The low-intensity compaction after planting ensures that the seeds are in close contact with the soil, meeting the water requirement during the germination period; the high-intensity compaction of 4-5 cm between the rows constructs continuous rainwater collection ditches, which not only realizes efficient rainwater collection in dry farming areas, but also leaches the surface salt through water infiltration. The soil regulation of the gathering mechanism further reduces water evaporation, and the multiple links cooperatively solve the emergence obstacles caused by drought, salt and hardening in saline-alkali land, significantly improving the seed germination rate and seedling survival rate.

[0027] The early inspection component integrity and the later cleaning of residual seeds and recording of wear and tear can effectively avoid equipment failure problems such as missed planting and repeated planting. The double-disc / single-disc mode of the seed separating device can quickly switch between wheat and Sesbania planting without replacing the core components, reducing adjustment time and labor cost, and avoiding yield fluctuations caused by time delay.

[0028] The wheat-Sesbania planting method for dry farming and saline-alkali two-crop areas provided by the application, through the cooperative design of crop adaptation, soil improvement and equipment optimization, a multiple guarantee mechanism for yield stability is constructed. Wheat reduces the risk of yield reduction caused by unreasonable population structure through dense planting optimization, Sesbania improves biomass accumulation through wide spacing planting, forming a green fertilizer cycle of land use and land maintenance; the water collection and soil conservation effect of the rainwater collection ditch buffers the impact of uneven rainfall, reducing the fluctuation impact of drought and flood on yield. The method solves the core problems of insufficient adaptability of the same seeding machine, saline-alkali drought stress and low emergence rate, and realizes the dual improvement of emergence rate and yield stability of two-crop crops in dry farming and saline-alkali areas.

[0029] After step S2, first, the corn stalks are crushed into uniform segments of 5-8 cm to avoid long segments of more than 10 cm causing paving problems. After completing the shallow rotary leveling ground, mark the grid outline with a flag rope at an interval of 30x30 cm to ensure that the rows are neat. Then lay the crushed straw along the marked line to form a crisscross grid cover layer, with a thickness of 3-4 cm, ensuring that the lines are continuous and the intersection points are closely overlapped. At each grid intersection point, use a 10 cm diameter tool to take soil, and press the straw into the soil 2-3 cm with a pressure of 5-8 kg to prevent wind from blowing it away. Adjust the row spacing of the wheat seeding disc to match the grid gap, so that the seeding disc passes through the gap vertically into the soil, and the seeds are sown in the uncovered area, maintaining a consistent depth of 3-4 cm, forming a layout of a strip of seeds surrounded by straw. When the wheat emergence rate reaches 70% and the seedlings are 3-5 cm high, use an arc-shaped press blade roller to press along the grid lines, pressing the straw edges into the topsoil 2-3 cm, leaving 1-2 cm exposed on top, and the pressing pressure is set to 15-20 kPa to avoid compacting the root zone soil and affecting respiration.

[0030] The 30x30 cm straw grid cover can reduce surface water evaporation by more than 30%, and the grid structure intercepts runoff, allowing rainwater to converge towards the seed and root zone, improving precipitation utilization, especially providing stable moisture for seedlings during the spring drought period in dryland areas. The secondary pressing forms a composite cover layer of straw and soil, which can not only reduce water loss caused by air circulation, but also form a local humid microenvironment by absorbing water in the straw, reducing the risk of drought during the seedling stage. In terms of inhibiting salt and alkali hazards and optimizing the root zone environment, the straw grid blocks direct sunlight to reduce the surface soil temperature, reducing the phenomenon of salt return, reducing the salt content in the 0-5 cm surface soil by 20%-25%, and avoiding the high salt toxicity to seeds and seedlings. In addition, the straw releases organic acids during degradation in the topsoil, neutralizing alkalinity, increasing organic matter content, and improving the heavy and hard characteristics of saline-alkali soil, providing a loose and breathable environment for root systems.

[0031] In step S3, before sowing wheat, two seeding discs need to be adjusted to a front-back staggered mode, with the front disc rotating clockwise and the rear disc rotating counterclockwise, using the counter-rotating couple effect to give the seeds an initial horizontal velocity, and combining with the physical stagger to form a vortex-like distribution, with adjacent seeds staggered horizontally by 4.5-5.5 cm and vertically forming a height difference of 2-3 cm, forming a three-dimensional staggered spatial layout. This mode can optimize the spatial structure of the population, avoid competition in the same row by horizontal staggering, and adapt to uneven salt distribution in the surface layer of saline-alkali soil by vertical height difference, avoiding high salt stress to improve emergence rate; it also promotes the formation of an interlaced network of root systems, enhancing soil fixation and anti-lodging ability, and the three-dimensional distribution of the plant canopy slows down water evaporation, and the inter-row space is beneficial for rainwater infiltration and catchment, improving water use efficiency.

[0032] When sowing the field bean, a single sowing disc is enabled, and an alternating mode of forward rotation and reverse rotation is adopted, and the rotation direction is switched once every 1m of travel. When rotating forward, the seeds are sown to the left, and when rotating in reverse, the seeds are sown to the right, forming a zigzag distribution within the row, which cooperates with the wide row spacing to build a growth-adapted pattern. The zigzag distribution provides a loose and orderly growth space for the field bean, which can uniformly expand to both sides during the branching period, avoiding branch entanglement, improving ventilation and light transmittance and photosynthetic efficiency, and increasing biomass accumulation to lay the foundation for green manure. Its root system expands more widely horizontally, can uniformly utilize uneven nutrients and water in saline-alkali land, reduces growth problems, and staggered distribution of root system improves soil physical and chemical properties more comprehensively through nitrogen fixation and excretion; at the same time, the buffer space within the row enhances the stress resistance of the plant, and when drought and wind damage occur, it can block and support each other, reducing the risk of lodging or wilting, and ensuring the stability of field bean growth, providing good soil conditions for the following wheat.

[0033] Although the vortex distribution of wheat and the zigzag distribution of field bean are different in mode, they are both based on the characteristics of crops and the environment of saline-alkali land and are precisely designed to form a synergistic planting system. The vortex distribution solves the resource competition problem of dense planting of wheat and improves the stress resistance of the population; the zigzag distribution meets the growth space and functional requirements of field bean as green manure. Through optimizing the distribution of seed soil, the two modes make full use of limited resources and realize differentiated precision planting of two crops on the same seeding machine, effectively alleviating the problems of low emergence rate and poor yield stability caused by unreasonable sowing in the saline-alkali region of dry farming.

[0034] In step S3, when sowing wheat, the soil sensor is used to monitor the size of the surface soil clumps in real time, and the stagger angle of the two sowing discs is dynamically adjusted. When the soil clump diameter is in the suitable range of 1cm≤soil clump diameter≤3cm, the stagger angle of the two sowing discs is kept at 45° to ensure that the seeds form a reasonable distribution in the regular soil; when the soil clump diameter is >3cm, there are large soil clumps in the soil, and the stagger angle is increased from 45° to 60°, which widens the sowing coverage by increasing the angle to avoid large soil clumps hindering the uniformity of seed burial; when the soil clump diameter is <1cm, the soil is too fine, and the stagger angle is adjusted back to 30° to prevent the seeds from being distributed too scattered due to the large angle and to ensure the sowing density. This dynamic adjustment mode can always adapt the sowing disc to the surface soil conditions, so that the wheat seeds can be uniformly distributed in soil with different soil clump sizes, reducing the phenomenon of missed sowing and re-sowing caused by soil clumps, and laying the foundation for uniform emergence of wheat.

[0035] When sowing sesbania, the angle of a single sowing disc is fixed at 60°, forming a wide scattering seed drop trajectory, which meets the planting requirements of sesbania wide row spacing and provides sufficient space for its growth. At the same time, the elastic seed scraping piece set on the edge of the sowing disc can automatically adhere to the disc surface with angle adjustment, timely removing residual seeds to avoid seed adhesion on the disc surface affecting the accuracy of the next sowing amount. The wide scattering seed drop trajectory makes the sesbania seeds more evenly distributed within the row, avoiding local over-dense or over-sparse, which is beneficial to the full use of light, water and nutrients during the growth of sesbania seedlings; the setting of elastic seed scraping piece ensures the stability of sowing amount, reduces seed waste, ensures that the number of seeds sown each time meets the preset requirements, and improves the accuracy of sesbania sowing.

[0036] In summary, when sowing wheat, the sowing disc stagger angle is dynamically adjusted according to the size of the soil block, and when sowing sesbania, the angle is fixed and an elastic seed scraping piece is provided. These two targeted designs, respectively starting from adapting to soil changes and meeting crop characteristics, effectively solve the uneven sowing problem caused by complex soil conditions and different crop requirements in dry saline-alkali areas, further improving the emergence rate of the two crops and enhancing the yield stability.

[0037] In addition, when sowing wheat, a pneumatic seed separation mode combined with mechanical assistance is adopted. After opening the pneumatic seed separation channel, high-pressure airflow forms a stable conveying power to accurately blow wheat seeds to the two sowing discs, ensuring that the seeds are not easily blocked and are preliminarily evenly distributed during transmission; at the same time, the mechanical eccentric seed stirring wheel is started to assist in seed separation, and the number and spacing of seeds are further adjusted through the rotation of the stirring wheel to compensate for possible errors in single seed separation mode. Avoiding the problem of local over-dense or over-sparse caused by uneven seed separation, it ensures that the number of wheat seeds per unit area meets the preset density parameters, providing a basis for the rational construction of wheat population structure.

[0038] When sowing sesbania, the seed separation mode is switched to single mechanical eccentric stirring wheel seed separation, and the pneumatic seed separation channel is closed. This adjustment is compatible with the planting characteristics of sesbania wide row spacing and relatively low density planting, and does not require high-pressure airflow to meet the seed separation requirements, reducing energy consumption. More importantly, the speed of the mechanical eccentric stirring wheel is linked with the forward speed of the sowing device, and for every 1 km / h increase in speed, the stirring wheel speed increases by 50 r / min, ensuring the stability of the sowing amount of sesbania seeds per unit length through dynamic adjustment of the stirring wheel speed. The uniformity of sesbania seed distribution within the row is significantly improved, avoiding the situation of insufficient seed separation at high speed and excessive seed separation at low speed, providing protection for the uniform emergence of sesbania and the rational allocation of growth space in the later stage.

[0039] The switching between the two seed separation modes is convenient, and does not require large-scale modification of the equipment. It can be completed by using channel switches and adjusting parameters, which meets the needs of rapid conversion of crops in the double cropping system. For the double seed separation mode of wheat, it can reduce the loss and residue of seeds in the seed separation process and reduce the cost increase caused by seed waste. For the mechanical linkage seed separation mode of sesbania, it improves the seed separation efficiency and reduces manual intervention by precisely matching the speed and rotation speed.

[0040] When sowing wheat, the periodic operation of the sowing disc cam lifting mechanism causes the seeds in each row to form periodic changes in depth along the direction of travel, with the cycle length strictly controlled at 30-50 cm. The depth peaks and valleys of adjacent rows are staggered, i.e., when one row is at the depth peak, the adjacent row is at the depth valley. This layout creates a three-dimensional water storage space in the soil, with the deep-seeded area storing more deep soil water and the shallow-seeded area facilitating rapid seed absorption of surface precipitation. The staggered distribution of wave peaks and valleys forms interconnected micro-domain water circulation channels. In arid saline areas with scarce and unevenly distributed precipitation, the three-dimensional water storage space can improve the utilization efficiency of rainwater and soil water, reduce water loss caused by surface runoff, and provide a sustained and stable water supply for wheat seed germination and seedling growth, thereby alleviating the inhibitory effect of drought stress on emergence rate.

[0041] When sowing sesbania, in addition to the wide-distance sowing mode driven by a single disc, a linkage deep tillage shovel is also equipped on the side of the single sowing disc track. The deep tillage action is triggered every 3 m of sowing, with a depth of 15-20 cm. This depth can penetrate the soil surface and break the plough pan structure formed by long-term tillage, which is one of the important reasons for poor soil aeration and difficult water infiltration in saline soils. The aeration channels formed after deep tillage can significantly improve soil aeration, promote sesbania root expansion to deep layers, and accelerate the leaching and volatilization of saline components in the soil, reducing the root zone salt concentration. After the deep tillage action is completed, the loose soil is compacted in time by the backfill wheel to avoid rapid evaporation of water due to loose soil, while maintaining the structural stability of the aeration channels, so that the channels can not only play the role of aeration, but also guide water infiltration to deep layers during precipitation, reducing surface salt return.

[0042] In step S4, on gentle land with a slope < 3°, a segmented wide rainwater collection ditch design is adopted, with a wide rainwater collection ditch set every 5m, the width of a single segment controlled at 12-15cm, and the depth maintained at 5cm, to ensure efficient collection of surface runoff. Adjacent rainwater collection ditches are connected smoothly through transition sections to avoid water flow obstruction or erosion problems caused by abrupt connection of ditch bodies, allowing rainwater to flow smoothly along the preset path and into the rainwater collection ditch. This layout forms a linear water collection system evenly distributed on gentle land, which neither excessively divides farmland to affect seeding operations, nor maximizes interception of dispersed surface precipitation, concentrating rainwater in the ditch body to provide continuous moisture supply for the roots of surrounding wheat and sesbania, effectively alleviating surface soil drought problems, especially in the spring drought season.

[0043] For land with a slope ≥ 3°, a grid-shaped water collection system design is adopted. Transverse intercepting ditches are set along contour lines, and longitudinal rainwater collection ditches are set perpendicular to contour lines, with the distance between adjacent transverse intercepting ditches or longitudinal rainwater collection ditches controlled at 8-10m, allowing the transverse intercepting ditches and longitudinal rainwater collection ditches to intersect perpendicularly to form a regular grid structure. Transverse intercepting ditches can intercept surface runoff in the uphill direction, reducing the intensity of rainwater erosion down the slope and reducing the risk of water and soil loss; longitudinal rainwater collection ditches are responsible for transporting or storing rainwater collected by transverse intercepting ditches to low-lying areas, evenly distributing rainwater within the land through grid distribution to avoid local waterlogging or drought. This grid-shaped layout is particularly suitable for sloping land, enhancing water and soil conservation and improving the spatial utilization efficiency of precipitation.

[0044] In addition, the accumulated water in the rainwater collection ditch can leach salt from the soil beside the ditch through infiltration, reducing the salt content of the surface soil. The continuous rainwater collection ditches on gentle land form a strip-shaped salt leaching area, while the grid-shaped rainwater collection ditches on sloping land form a planar salt leaching network, accelerating the migration of saline-alkali components to deep soil or their discharge with runoff, gradually improving the soil environment of the crop root zone.

[0045] In step S4, when sowing wheat, granular biochar is sprayed at a dosage of 100g per meter, and the biochar is directly embedded in the surface soil with the compaction action of the compaction wheel. This allows the biochar to quickly combine with the surface soil, adsorbs the salt in the soil using the porous properties of biochar, reduces the salt concentration in the wheat seed germination zone, and reduces the inhibitory effect of saline-alkali stress on wheat emergence. At the same time, after the biochar is embedded in the surface soil, it can improve the structure of the surface soil, increase the soil porosity, and improve the water retention capacity of the soil, providing a more loose, breathable and moist growing environment for the wheat seedling root system, which is beneficial to the seedling root penetration and water and nutrient absorption, and improves the emergence rate and seedling growth of wheat.

[0046] When sowing sesbania, the biochar and mature organic fertilizer are mixed in a ratio of 1:3 and then applied. The mixed biochar and organic fertilizer are applied to a depth of 15 cm by deep plowing at a distance of 10 cm from the sowing side of the sesbania, forming a three-dimensional improved microenvironment for the interaction of seeds, biochar, and soil. The mature organic fertilizer provides abundant nutrients for the growth of sesbania, while the biochar can adsorb and release nutrients, prolong the supply time of nutrients, prevent nutrient loss, and improve nutrient utilization.

[0047] Specifically, the soil leveling range of the gathering mechanism is 10-15 cm on both sides of the sowing row, the pressure of low-intensity compaction is controlled at 0.2-0.3 MPa, the pressure of high-intensity compaction is controlled at 0.5-0.6 MPa, and the cross section of the continuous rain collection ditch is inverted trapezoidal with a width of 8-10 cm. The inverted trapezoidal structure is more conducive to the collection and storage of rainwater than other shapes, and the reasonable setting of the ditch width can ensure rapid rainwater collection during precipitation and reduce the waste of surface runoff.

[0048] In step S5, when cleaning the sowing disc and the seed distribution device, high-pressure airflow is used to ensure that the residual seed removal rate reaches more than 95%, and there is no visible seed residue in the tooth groove of the cleaned sowing disc. The high-pressure airflow can penetrate into the gaps, tooth grooves, and pipelines of the seed distribution device, thoroughly removing residual seed debris and impurities, and avoiding cross-residual of different crop seeds in the device. When checking the wear of the components, the wear amount of the sowing disc seed hole is measured, and the sowing disc is replaced when the wear amount exceeds 0.5 mm or a gap appears. The seed hole is the core component for controlling seed sowing amount and distribution, and excessive wear will lead to unstable seed sowing amount, uneven seed distribution, and even missed sowing. At the same time, the thickness of the blade edge of the shallow rotary mechanism is recorded, and the shallow rotary mechanism is replaced when the thickness is less than 70% of the initial value, which can ensure the effect of shallow rotary processing. Excessive wear of the rotary blade edge will result in insufficient shallow rotary depth and insufficient soil crushing, affecting the soil foundation for subsequent sowing, effectively eliminating tractor tire marks and crushing surface soil, and creating a loose soil environment for seed germination.

[0049] Example 1: Wheat-sesbania double cropping sowing in a mild saline-alkali gentle plot In the mild saline and alkaline gentle land with soil salt content of 0.1%-0.2% and slope of 2°, the following sowing process is adopted: in the early preparation stage, the integrity of the shallow rotary mechanism, double sowing disc, seed separating device and roller is checked, the row spacing of wheat is set to 15 cm, the sowing density is 350 grains / m2, the row spacing of sesbania is 30 cm, and the sowing density is 100 grains / m2. When shallow rotary leveling, the tractor drags the device at a speed of 5 km / h, the front shallow rotary mechanism rotates the surface 8 cm, and the tire marks are eliminated and the surface soil clods are broken. Then, 30x30 cm corn straw grid is laid, the intersection is compacted with soil, the wheat sowing disc penetrates the grid gap, the double disc driving mode is started, the front disc rotates clockwise and the rear disc rotates counterclockwise to form a vortex distribution, the adjacent seeds are laterally staggered by 5 cm and vertically staggered by 2 cm, and the soil sensor monitors that the soil clod diameter is 2 cm, the sowing disc is kept at an angle of 45°, the air pressure seed separating channel is started, and the mechanical eccentric wheel is used for seed separation. After sowing, the sowing row is straightened by 12 cm on both sides, the soil is compacted at a low intensity of 0.2 MPa, and the rain-collecting ditch with inverted trapezoidal cross section and 9 cm wide is formed in the row by compacting at a high intensity of 0.5 MPa every 5 m. The transition section is connected. The inside of the roller sprays 100 g of granular biochar embedded in the topsoil per meter. When the equipment is reset, the sowing disc and seed separating device are blown by high-pressure airflow to ensure that the residual removal rate is more than 95%, the wear of the seed hole is checked to be 0.3 mm, the thickness of the rotary tiller blade edge is 80% of the initial value, and the operation is completed after recording.

[0050] Example 2: Wheat-sesbania double cropping sowing in moderate saline and alkaline slope land For the moderate saline and alkaline slope land with soil salt content of 0.2%-0.3% and slope of 5°, the following operations are implemented: in the early preparation stage, the row spacing of wheat is set to 12 cm, the density is 400 grains / m2, the row spacing of sesbania is 24 cm, and the density is 80 grains / m2. When shallow rotary leveling, the rotary tiller depth is 10 cm, the tire marks are eliminated and the soil clods are broken. When sowing wheat, the double sowing disc is adjusted to an angle of 60° due to the soil sensor monitoring that the soil clod diameter is 4 cm, the cam lift mechanism makes each row of seeds form a deep-shallow-deep distribution with a period of 30 cm, and the adjacent rows are staggered; when sowing sesbania, the single disc driving is switched, the forward and reverse rotation is alternated to form a Z-shaped distribution every 1 m, the side linkage deep tiller is started synchronously, the plough pan is broken by 15 cm every 3 m, the biochar and decomposed organic fertilizer are mixed at a ratio of 1:3 and applied at a depth of 10 cm on the sowing side, and the backfill wheel is compacted and loosened. In the soil treatment stage, the transverse water interception ditch is set along the contour line, the longitudinal rain-collecting ditch is set in the vertical direction, the grid system is formed with a spacing of 8 m, the straightening range is 15 cm, the low-intensity compaction pressure is 0.3 MPa, and the high-intensity compaction is 0.6 MPa. The equipment cleaning adopts high-pressure airflow blowing, the seed hole with wear of 0.6 mm is replaced, and the rotary tiller blade edge is replaced when the thickness is 65% of the initial value.

[0051] Example 3: Wheat-sesbania double cropping sowing in severe saline and alkaline complex land In the severe saline-alkali land block with 0.3%-0.4% soil salt content, part of soil blocks with diameter more than 5 cm, and 4° slope, the sowing process is as follows: the pre-preparation sets the row spacing of wheat as 14 cm and the density as 450 particles / m2, and the row spacing of sesbania as 28 cm and the density as 90 particles / m2. When shallow rotary leveling, rotary tillage is 9 cm, and large soil blocks are broken to less than 3 cm in diameter. When sowing wheat, the soil sensor monitors that the diameter of part of soil blocks is 1 cm, the angle of the sowing disc is adjusted to 30°, the vortex distribution is formed by double-disc driving, the horizontal stagger is 4.5 cm, the vertical height difference is 3 cm, the air pressure seed distribution cooperates with the mechanical drag wheel to ensure the accurate seeding amount; the single-disc angle of sesbania sowing is fixed as 60°, the wide scattering seed is scattered, the elastic seed scraping piece removes the residual on the disc surface, and the deep tillage shovel is 20 cm deep every 3 m and applies the mixture of biochar and organic fertilizer. The rainwater collecting system adopts the horizontal+vertical grid layout with 8 m spacing, the folding mechanism processes the soil 10 cm away from the sowing row, the low-intensity compression is 0.25 MPa, the high-intensity compression is 0.55 MPa, and the 8 cm wide ditch is formed to collect rainwater. After the equipment is reset, the high-pressure airflow is used to blow and check the sowing disc tooth groove without residue, the sowing hole with notch and the rotary tillage blade with the thickness of 68% of the initial value are replaced to ensure the subsequent sowing accuracy. Through the above operation, the inhibition of severe saline-alkali and complex terrain on seedling emergence is effectively relieved.

[0052] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for dry saline two-crop area wheat-sesbania sowing, characterized in that, The method comprises the following steps: S1. Preparation: Check the shallow rotary mechanism, the front and rear two staggered seeders, the seed distribution device and the integrity of the roller parts, and preset the seeding density and row spacing parameters of wheat or sesbania according to the soil salt content of saline-alkali soil and the type of crops; S2. Shallow rotary leveling: The tractor drags the seeding device at a uniform speed, starts the front shallow rotary mechanism to process the ground surface, the rotary depth is controlled at 8-10 cm, and the tractor tire marks are eliminated and the surface soil clods are broken; S3. Seeding execution: If wheat is seeded, the double-disk driving mode of the seed distribution device is enabled, and the front and rear two seeders are controlled to operate synchronously to form a double-row staggered seeding track; If sesbania is seeded, switch to single-disk driving mode, and a single seeder operates independently to form a single-row wide-spacing seeding track, and the sesbania row spacing is twice that of wheat; S4. Soil treatment: After seeding, the surface soil is arranged by the arrangement mechanism, low-intensity rolling is performed by the rolling wheel, and high-intensity rolling with a depth of 4-5 cm is performed by the rolling wheel between the seeding rows to form continuous rain-collecting ditches; S5. Equipment reset: Turn off all working mechanisms, clean the residual seeds in the seeding disc and seed distribution device, check the wear of the parts and record them.

2. The method for dry farming of wheat and sesbania in a saline and alkaline double cropping area according to claim 1, characterized in that, After step S2, the crushed corn straw is laid on the ground in a grid of 30x30 cm, the grid intersection points are compacted with soil, the wheat seeding disc penetrates the grid gap to complete seeding, and the grid straw is pressed into the surface soil after the wheat emerges through secondary rolling.

3. The method for dry farming of wheat and sesbania in a double cropping saline area according to claim 1, wherein, In step S3, before seeding wheat, the two seeders are adjusted to the front and rear staggered mode, the front seeder rotates clockwise and the rear seeder rotates counterclockwise to form a vortex distribution of wheat seeds in the soil, the adjacent wheat seeds are staggered horizontally by 4.5-5.5 cm and vertically by 2-3 cm in height difference; When seeding sesbania, the single seeder adopts the mode of forward rotation and reverse rotation alternately, and the rotation direction is switched every 1m of travel to form a zigzag distribution of sesbania seeds in the row.

4. The method for dry farming of wheat and sesbania in a double cropping saline area according to claim 1, wherein, In step S3, when seeding wheat, the soil sensor is used to monitor the size of the surface soil clods in real time, when 1cm≤soil clod diameter≤3cm, the two seeders maintain an intersection angle of 45°; when the soil clod diameter is >3cm, the intersection angle is increased from 45° to 60°; when the soil clod diameter is <1cm, the intersection angle is adjusted back to 30°; When seeding sesbania, the angle of the single seeder is fixed at 60° to form a wide scattering type seed dropping track, and the edge of the seeder is provided with an elastic seed scraping piece which automatically adheres to the disc surface to remove residual seeds.

5. The method for dry farming of wheat and sesbania in a double cropping saline area according to claim 4, wherein, When seeding wheat, the air pressure seed distribution channel is opened, and the seeds are blown to the two seeders by high-pressure airflow, and the mechanical eccentric seed picker is used for auxiliary seed distribution; When seeding sesbania, the air pressure seed distribution channel is closed, and only the mechanical eccentric seed picker is used for seed distribution, and the speed of the mechanical eccentric seed picker is linked with the forward speed, and for every 1km / h increase in speed, the speed of the mechanical eccentric seed picker is increased by 50r / min.

6. The method for dry farming of wheat and sesbania in a double cropping saline area according to claim 5, wherein, When sowing wheat, the periodic deep-shallow changes of each row of seeds along the direction of travel are achieved by the sowing disc cam lifting mechanism, with the cycle length being 30-50 cm, and the deep-shallow peaks and valleys of adjacent two rows being staggered to form a three-dimensional water storage space; When sowing sesbania, a linkage deep ploughing shovel is arranged on the side of the trajectory of a single sowing disc, the deep ploughing action of the deep ploughing shovel is triggered every 3 m of sowing distance, the deep ploughing depth is 15-20 cm, the plough pan structure is broken to form a ventilation channel, and the loosened soil is backfilled and compacted by the backfilling wheel after deep ploughing.

7. The method for dry farming of wheat and sesbania in a double cropping saline area according to claim 1, wherein, In step S4, a wide rainwater collection ditch is arranged every 5 m on the land with a slope < 3°, the width of the wide rainwater collection ditch is 12-15 cm, the depth is kept at 5 cm, and the intervals are smoothly connected through transition sections; transverse rainwater collection ditches and longitudinal rainwater collection ditches are arranged along contour lines on the land with a slope ≥ 3°, the distance between adjacent transverse rainwater collection ditches or adjacent longitudinal rainwater collection ditches is 8-10 m, and the transverse rainwater collection ditches and the longitudinal rainwater collection ditches are perpendicular to each other to form a grid-shaped water collection system.

8. The method for dry farming of wheat and sesbania in a double cropping saline area according to claim 1, wherein, In step S4, a biochar injection channel is arranged on the inner side of the rolling wheel, 100 g of granular biochar is sprayed per meter between the sowing rows of wheat, and the biochar is embedded into the topsoil with the rolling action; the biochar and the matured organic fertilizer are mixed at a ratio of 1:3, and are applied at a depth of 15 cm at a position 10 cm away from the sowing side through the deep ploughing shovel to form a three-dimensional improved microenvironment of seeds, biochar and soil.

9. The method for dry farming of wheat and sesbania in a double cropping saline area according to claim 1, wherein, In step S4, the soil regulation range of the gathering mechanism is 10-15 cm on both sides of the sowing row, the pressure of low-intensity rolling is controlled at 0.2-0.3 MPa, the pressure of high-intensity rolling is controlled at 0.5-0.6 MPa, and the cross section of the continuous rainwater collection ditch is inverted trapezoidal with a ditch width of 8-10 cm.

10. The method for dry farming of wheat and sesbania in a double cropping saline area according to claim 1, wherein, In step S5, when cleaning the sowing disc and the seed distribution equipment, a high-pressure airflow sweeping method is adopted to ensure that the residual seed removal rate reaches more than 95%, and there is no visible seed residue in the tooth groove of the cleaned sowing disc; when checking the wear condition of the parts, the wear amount of the sowing disc seed distribution hole is measured, the sowing disc is replaced when the wear amount exceeds 0.5 mm or a notch appears, and the thickness of the cutting edge of the shallow rotary mechanism rotary ploughing knife is recorded, and the shallow rotary mechanism rotary ploughing knife is replaced when the thickness is less than 70% of the initial value.

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