A method for quick fertilization and salt control of coastal heavy saline-alkali land by rain season sesbania flying sowing
Patent Information
- Application Number
- CN202611453537.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-09-18
- Publication Date
- 2026-10-30
AI Technical Summary
区域年降水量为520-600mm，但降水年内分配极不均衡，70%以上的降雨集中在夏季（7-9月），春季降雨量不足100mm，而同期蒸发量接近1000mm
[0020]本发明充分契合滨海重盐碱区土壤水盐周年动态规律，通过春季雨前深耕深松有效破除犁底层、提升土壤孔隙度与水分入渗性能，强化初夏集中降雨对土壤盐分的淋洗效果，在雨后土壤盐分处于低位的窗口期，采用无人机飞播种植抗涝耐盐的田菁品种，既破解了传统春播模式下春季土壤返盐严重、田菁出苗困难的核心痛点，又解决了雨后田间积水导致地面播种机械无法进地作业的实际问题，能够显著提高重盐碱地田菁的出苗率、出苗均匀度与地表植被覆盖度，大幅提升地上植株生物量。经实际应用验证，采用本方法田菁出苗率可达85%以上，地表植被覆盖度可达92%以上，收获期田菁鲜草生物量可达4.2t/亩，为重盐碱地开展秸秆还田、构建肥沃耕层提供了充足的物质基础。
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of soil improvement technology, specifically relating to a method for rapid fertilization and salt control in sesbania aerial seeding during the rainy season in coastal saline-alkali land. Background Technology
[0002] Saline-alkali land is an important reserve of arable land, and its efficient improvement and utilization play a vital role in expanding agricultural production space and ensuring the comprehensive productivity of arable land. The Bohai Rim region is one of the main distribution areas of coastal saline-alkali land. In this region, the groundwater is shallow and highly mineralized, resulting in high soil salinity and frequent salt migration. Coupled with the generally shallow topsoil and weak soil salt control and fertilizer retention capacity, this severely restricts the normal growth of crops. At the field scale, the region exhibits obvious soil salt patches in spring, with extremely uneven spatial distribution of salt, further contributing to low land productivity.
[0003] The core objective of saline-alkali land improvement is to reduce the salt content of the topsoil and improve the overall soil quality, thereby alleviating the stress of salt on plant growth and providing sufficient water and nutrients for plant growth. Due to the combined effects of the climate and hydrogeological characteristics of the Bohai Rim region, soil salinity in this area is persistent and recurring. Soil water and salt transport exhibits a clear seasonal pattern: summer rainfall is abundant and concentrated, resulting in a significant leaching and downward displacement effect on soil salts, marking the year-round salt leaching period; spring, autumn, and winter see high evaporation and low rainfall, causing soil salts to migrate to the surface with evaporating water, a period of salt return. Spring, with its intense evaporation and scarce rainfall, sees the most severe salt return.
[0004] From the perspective of water resource endowment, this region has almost no freshwater resources available for agricultural irrigation, apart from natural precipitation, and agricultural production is generally rainfed. The region's annual precipitation is 520-600 mm, but its distribution is extremely uneven throughout the year, with over 70% of rainfall concentrated in summer (July-September), and spring rainfall less than 100 mm, while evaporation during the same period approaches 1000 mm. Constrained by these combined hydrothermal and water resource conditions, agriculture in this region faces a prominent dual dilemma: spring drought coupled with soil salinization makes crop emergence difficult and survival rates low; concentrated summer rainfall easily leads to field flooding, inhibiting normal crop growth and development, ultimately resulting in low overall agricultural productivity. Especially in moderately to severely saline-alkali areas, high soil salinity in spring leads to low plant survival rates, resulting in very limited harvestable aboveground biomass, making it difficult to support the application of soil tillage, fertilization, and salt control techniques centered on straw return to the field.
[0005] Currently, the construction of a fertile topsoil layer in saline-alkali land has become an important direction for improvement and management. However, many shortcomings still exist in practice in coastal severely saline-alkali areas. On the one hand, existing agricultural planting patterns in these areas, such as the winter wheat-summer maize double cropping pattern and the single cropping pattern of spring maize, sweet sorghum, and sunflower, are highly dependent on natural rainfall. The annual dynamics of soil water and salt directly affect crop emergence and growth, resulting in large interannual fluctuations in crop yield and planting income, which cannot provide stable and continuous biomass support for the construction of a fertile topsoil layer and soil improvement and salt reduction. On the other hand, in severely saline-alkali areas, existing tillage and fertilization techniques are not fully matched to the annual transport patterns of soil water and salt, and there is a lack of supporting low-cost and high-efficiency cultivation models and deep tillage and fertilization measures, resulting in a generally weak capacity for fertilization and salt control in farmland topsoil.
[0006] Therefore, it is urgent to fully combine the climatic conditions and soil water and salt transport patterns of coastal areas, select suitable salt-tolerant and stress-resistant plant varieties, and implement corresponding efficient cultivation and fertilization management measures to systematically improve the salt control capacity of arable land, achieve optimized regulation of water and salt in the topsoil of saline-alkali land and rapid improvement of soil fertility. This is a technical problem that urgently needs to be solved in the field of coastal saline-alkali land improvement. Summary of the Invention
[0007] The purpose of this invention is to provide a method for rapid fertilization and salt control through aerial seeding of sesbania in coastal heavily saline-alkali land during the rainy season. This method can provide a reliable technical path for the tiered improvement of coastal heavily saline-alkali land from severely saline-alkali wasteland to lightly to moderately saline-alkali cultivated land, and has significant economic, social and ecological benefits, with broad prospects for promotion and application.
[0008] The objective of this invention is achieved through the following technical solution:
[0009] This invention provides a method for rapid fertilization and salt control in coastal saline-alkali land during the rainy season by aerial seeding of sesbania, including the steps of deep plowing and loosening of the soil before spring rain, aerial seeding of sesbania after rain, sesbania growth and cultivation management, and autumn sesbania plant straw crushing and returning to the field for fertilization.
[0010] Furthermore, it also includes the step of preparing the field plots before the deep plowing and loosening of the soil before the spring rains; the preparation of the field plots involves leveling the land and establishing plots and ridges.
[0011] Furthermore, in the field preparation, each plot is 250m long and 40m wide, with field ridges 0.4m wide and 0.3m high, and a laser leveling instrument is used to complete the land leveling operation.
[0012] Furthermore, the depth of deep tillage before spring rains should be no less than 20cm, the depth of deep loosening no less than 30cm, and the soil bulk density of the 0-20cm soil layer after deep tillage and loosening operations should not exceed 1.35g / cm³. 3 .
[0013] Furthermore, the specific method for post-rain sesame aerial seeding is as follows: after a single rainfall of more than 25mm in spring or early summer, sesame aerial seeding is carried out using a drone seeder, with a seeding rate of 2kg / mu.
[0014] Furthermore, before aerial seeding, the sesame seeds are pelleted and coated; during aerial seeding operations, the ambient wind speed is controlled to be no greater than 3m / s, the drone operating height is 2-5m, the flight path overlap rate is 10%-15%, the coefficient of variation (CV) of seed uniformity is no greater than 35%, and the relative error of the actual seed amount per unit area is controlled within ±10%.
[0015] Furthermore, in the cultivation and management of sesbania, urea is applied twice using drones during the branching and flowering stages of sesbania, with each application amount being 10 kg / mu.
[0016] Furthermore, in the cultivation and management of sesame, 70% imidacloprid is sprayed during the branching stage of sesame to control aphids; during the flowering stage of sesame, 3000 times high-efficiency cyhalothrin emulsion is sprayed twice using drones to control leaf rollers.
[0017] Furthermore, the operation time for crushing and returning the straw of the sesbania plants to the field for fertilization is during the autumn sesbania pod-setting and harvesting period; during the operation, a straw crusher is used to crush the sesbania plants and return them to the field, and the length of the crushed straw is no more than 5cm.
[0018] Furthermore, after the straw is crushed and returned to the field, a tiller is used to till the soil to a depth of not less than 20cm; then a rotary tiller is used to mix the sesame straw with the soil to a depth of not less than 20cm.
[0019] The beneficial effects of this invention are as follows:
[0020] This invention fully aligns with the annual dynamic patterns of soil water and salt in coastal saline-alkali areas. By deeply tilling and loosening the soil before spring rains, it effectively breaks up the plow pan, improves soil porosity and water infiltration, and enhances the leaching effect of concentrated early summer rainfall on soil salts. During the window of low soil salinity after rain, drones are used for aerial seeding of waterlogged and salt-tolerant sesbania varieties. This addresses the core pain points of traditional spring sowing methods, such as severe soil salinization and difficulty in sesbania germination, and solves the practical problem of ground-based seeding machinery being unable to operate due to post-rain waterlogging. It significantly improves the germination rate, uniformity, and surface vegetation coverage of sesbania in saline-alkali lands, greatly increasing aboveground plant biomass. Practical application verification shows that using this method, the sesbania germination rate can reach over 85%, the surface vegetation coverage can reach over 92%, and the fresh sesbania germination biomass at harvest can reach 4.2 t / mu, providing a sufficient material basis for straw return and the construction of a fertile topsoil layer in saline-alkali lands.
[0021] This invention utilizes straw crushing and returning to the field during the autumn sesbania pod-setting period, combined with deep plowing and rotary tillage. The crushed sesbania straw is evenly mixed into the 0-20cm topsoil layer. Through the humification process of the straw, the soil organic matter content is effectively increased, soil aggregate structure is improved, and soil bulk density is reduced. Simultaneously, it maintains low soil salinity in autumn, blocking the migration of salt from the lower soil layers and groundwater to the surface in spring, effectively weakening the intensity of spring salt return. This results in a steady annual decrease in soil salinity, a continuous reduction in the area of saline-alkali patches in the field, and a stable maintenance of suitable soil moisture content. Continuous application of this method can increase topsoil organic matter by 36.2%, reduce soil bulk density by 42%, gradually reduce the average soil salinity in spring from an initial 0.68% to 0.34%, reduce the proportion of saline-alkali patches in the field from 52% to below 9.8%, and maintain soil moisture content stably above 23%, achieving the dual goals of rapidly improving soil fertility and long-term salt control in coastal saline-alkali land.
[0022] This method utilizes existing general-purpose agricultural machinery and drone operation systems throughout the entire process, eliminating the need for additional specialized equipment development. The overall operation is simple and convenient, with no additional pollution during soil improvement, resulting in low overall costs. It is suitable for large-scale mechanized operations and can well match the production model of rain-fed agriculture in coastal areas with insufficient rainfall. It can provide a reliable technical path for the tiered improvement of severely saline-alkali land in coastal areas from severely saline-alkali wasteland to lightly to moderately saline-alkali arable land, with significant economic, social, and ecological benefits, and has broad prospects for promotion and application. Attached Figure Description
[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments 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.
[0024] Figure 1 This is a comparison of the growth of sesbania in a heavily saline-alkali area using the method described in this invention, as shown in Example 1. Detailed Implementation
[0025] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.
[0026] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.
[0027] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.
[0028] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.
[0029] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.
[0030] This invention fully utilizes the annual water and salt dynamics of coastal saline-alkali areas, characterized by strong evaporation and scarce rainfall in spring, leading to soil salt return, and concentrated rainfall in summer, resulting in soil salt leaching. Through a complete technical chain of "deep plowing before rain to promote salt leaching—aerial sowing after rain to ensure seedling survival—management during the growing season to increase biomass—returning to the field in autumn to improve fertility and control salt," it achieves rapid fertilization and salt control in saline-alkali land.
[0031] The specific implementation steps of the method are as follows:
[0032] (1) Field land consolidation
[0033] In late spring and early summer (early to mid-June), basic land preparation is carried out. The fields are divided according to the strip field construction model of the coastal area, with each field measuring 250m in length and 40m in width. Ridging machines are used to build field ridges around the fields, with a ridge width of 0.4m and a height of 0.3m. Laser leveling instruments are used to finely level the field surface to ensure uniform field elevation, providing the basic conditions for uniform salt leaching and uniform seeding after subsequent rainfall.
[0034] (2) Deep tillage and loosening of soil before spring rains
[0035] After land preparation is completed, deep tillage and subsoiling should be carried out immediately before the concentrated spring rainfall. A high-horsepower tractor equipped with a subsoiler should be used to loosen the deep soil to a depth of at least 30cm, breaking up the plow pan and increasing the porosity of the deeper soil layers. Simultaneously, a tiller should be used to till the soil to a depth of at least 20cm. After tillage, a rotary tiller should be used to mix and level the surface soil, ensuring that the soil bulk density of the 0-20cm layer does not exceed 1.35g / cm³. 3 This effectively increases the proportion of large pores in the soil and enhances the rapid leaching effect of subsequent concentrated rainfall on soil salinity.
[0036] (3) Post-rain drone seeding of sesame seeds
[0037] In early summer (late June to early July), when there is a concentrated rainfall event with a single rainfall of ≥25mm, and the soil salinity is fully leached, waterlogging in the fields prevents traditional ground seeding machinery from entering the fields. Therefore, multi-rotor drones equipped with seed broadcasters are used for aerial seeding of sesame. Before sowing, sesame seeds are pre-treated with pelleting and coating to improve their salt tolerance and germination ability; the sowing rate is 2kg per acre. During aerial seeding operations, the ambient wind speed is controlled to be no more than 3m / s, the drone's operating altitude is maintained at 2-5m, and the overlap rate of the flight path is controlled at 10%-15%. This ensures that the coefficient of variation (CV) of seed uniformity is no more than 35%, and the relative error of the actual seed amount per unit area is controlled within ±10%, achieving uniform emergence of sesame seedlings in heavily saline-alkali land after rain.
[0038] (4) Topdressing and pest and disease control during the growing season of sesame
[0039] During the sesame growing season, drones are used for topdressing and pest and disease control to ensure rapid growth and sufficient biomass accumulation in sesame fields.
[0040] Topdressing management: Apply urea twice using drones during the branching stage of sesbania (late July) and the flowering stage (mid-August), with 10 kg per acre each time, to supplement nitrogen nutrition and promote the growth of sesbania stems and leaves;
[0041] Pest and disease control: Spray 70% imidacloprid during the branching stage of sesame to control aphids; during the flowering stage of sesame, use drones to spray 3000 times high-efficiency cyhalothrin emulsion twice to control leaf roller damage and ensure the normal growth and development of sesame.
[0042] (5) Autumn management of returning sesbania straw to the field and deep plowing for fertilization
[0043] In autumn, after the sesbania plants enter the pod-setting stage (early to mid-October) and the soil conditions meet the requirements for ground-based agricultural machinery operations, straw crushing and returning to the field, along with deep plowing and fertilization, are carried out: First, large-scale straw crushing and returning machinery is used to crush the sesbania plants and return them to the field, ensuring that the length of the crushed straw is no more than 5cm; then, large-scale tillage machinery is used to till the soil to a depth of no less than 20cm, burying the crushed straw into the topsoil; finally, rotary tillage machinery is used to thoroughly mix the straw with the soil, simultaneously completing land leveling, with a tillage depth of no less than 20cm, so that the straw is evenly distributed in the 0-20cm topsoil layer. Through straw humification, soil fertility is improved, while soil structure is improved and the soil's salt control capacity is enhanced.
[0044] Example 1
[0045] This embodiment was carried out in a typical coastal heavily saline-alkali land plot in the Nandagang Industrial Park of Bohai New Area, Cangzhou City, Hebei Province, to verify the practical application effect of the method of the present invention.
[0046] 1. Overview of the test site
[0047] The experimental area has a warm temperate continental monsoon climate, with an average annual temperature of 11.9℃, a frost-free period of 215 days, and 2715 hours of sunshine annually. The average annual precipitation is 591 mm, with extremely uneven distribution throughout the year, with over 75% of the annual rainfall occurring from July to September. The area is a coastal low-lying plain, with a low-lying and flat terrain, ranging from 1.3 to 3.6 meters in elevation. The soil type is mainly coastal saline soil, with NaCl as the dominant salt ion. The average soil salinity is above 0.89%, with a salinity of approximately 0.3% during the summer leaching period and reaching up to 1.5% during the peak spring salt return period, making it a typical coastal heavily saline-alkali land. The groundwater level is shallow, averaging about 1 meter, with high mineralization and a salinity of 6–32 g / L.
[0048] This experiment has been conducted continuously since 2022. Typical saline-alkali land plots were selected. In the early stage, basic remediation was completed according to the strip field model, including repairing surrounding drainage ditches, completing land leveling and field ridge construction. Land leveling preparation was completed in advance in the spring. The specific implementation steps are as follows:
[0049] From June 12 to 17, 2022, land preparation was carried out: laser leveling instruments were used to finely level the field surface and field ridges were built, with a height of 30cm and a width of 40cm.
[0050] From June 17 to 20, 2022, a high-horsepower tractor with a subsoiler was used to carry out deep soil loosening to a depth of 30 cm.
[0051] From June 20 to 23, 2022, a high-horsepower tractor equipped with a three-furrow plow was used for deep plowing to a depth of 20cm; then a rotary tiller was used for rotary tilling to a depth of 20cm, and the land was ready for sowing.
[0052] From July 6th to 8th, 2022, the area experienced approximately 58mm of concentrated rainfall. After completing field drainage, drones were used for aerial seeding of sesbania. Seeds were coated before sowing, with a sowing rate of 2kg / mu. Sesbania seedlings emerged approximately 4 days after sowing, and subsequent concentrated rainfall was promptly drained.
[0053] From July 28 to 31, 2022, drones were used to spray pesticides to control aphids, and the first application of urea by drone was completed simultaneously.
[0054] From August 23 to 25, 2022, pesticides were sprayed using drones to control leaf rollers, and a second application of urea was completed simultaneously using drones.
[0055] From October 8th to 10th, 2022, a high-horsepower tractor equipped with a crusher and return machine was used to crush and return sesame straw to the field. Subsequently, the straw and soil were mixed by plowing and rotary tillage.
[0056] 2. Test Results
[0057] The results of three consecutive years of trials from 2022 to 2024 show that the sesame aerial seeding technology of this invention significantly improves indicators such as sesame seedling emergence rate, ground vegetation coverage, and fresh grass yield compared to the traditional spring sowing method.
[0058] The germination rate of sesbania seedlings reached over 85%, while the traditional spring sowing control group only achieved 22.6%.
[0059] The surface vegetation coverage reached over 92%, compared to only 39.5% for the traditional spring-sown control.
[0060] At harvest, the biomass of fresh sesbania grass reached 4.2 t / mu, compared to only 0.94 t / mu for traditional spring sowing control. This significant increase in aboveground biomass provides a sufficient material basis for straw return to the field in the fertile topsoil of saline-alkali land.
[0061] Through three consecutive years of technology application, the soil fertility and structural characteristics of the experimental plots were significantly improved, specifically as follows: Figure 1 As shown in the figure. Compared with the control, the organic matter in the topsoil increased by 36.2%, the soil bulk density decreased by 42%, and the soil salt control capacity was significantly enhanced: the average soil salt content in spring (March-May) was controlled between 0.35% and 0.54%, and showed a decreasing trend year by year, from 0.68% at the beginning of the experiment to 0.34% after 3 years; the soil moisture content was stably maintained above 23%, the soil salinization was rapidly alleviated, and the proportion of saline-alkali patches in the field decreased from the initial 52% to below 9.8%.
[0062] This invention provides a solid soil foundation for the tiered improvement of coastal saline-alkali land from severely saline-alkali wasteland to lightly to moderately saline-alkali arable land and subsequent crop planting, with significant economic, social and ecological benefits and broad application prospects.
[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.
Claims
1. A method for rapid fertilization and salt control through aerial seeding of sesbania in coastal saline-alkali land during the rainy season, characterized in that... The process includes deep tillage and loosening of the soil before spring rains, aerial sowing of sesame seeds after rains, cultivation and management of sesame seed growth, and autumn sesame seed stalk crushing and returning to the field for fertilization.
2. The method according to claim 1, characterized in that, It also includes the step of preparing the field plots before the deep plowing and loosening of the soil before the spring rains; the preparation of the field plots involves leveling the land and establishing plots and ridges.
3. The method according to claim 2, characterized in that, In the field preparation, each plot is 250m long and 40m wide, with field ridges 0.4m wide and 0.3m high. A laser leveling instrument is used to complete the land leveling operation.
4. The method according to claim 3, characterized in that, The depth of deep tillage before spring rains should be no less than 20cm, and the depth of deep loosening should be no less than 30cm. After deep tillage and loosening, the soil bulk density of the 0-20cm soil layer should not exceed 1.35g / cm³. 3 .
5. The method according to claim 4, characterized in that, The specific method for post-rain sesame aerial seeding is as follows: after a single rainfall of more than 25mm in spring or early summer, sesame seeds are spread by drone seeders at a seeding rate of 2kg / mu.
6. The method according to claim 5, characterized in that, Before aerial seeding, the sesame seeds are pelleted and coated; during aerial seeding, the ambient wind speed is controlled to be no more than 3m / s, the drone operating height is 2-5m, the flight path overlap rate is 10%-15%, the coefficient of variation (CV) of seed uniformity is no more than 35%, and the relative error of the actual seed amount per unit area is controlled within ±10%.
7. The method according to claim 6, characterized in that, In the cultivation and management of sesbania, urea was applied twice using drones during the branching and flowering stages of sesbania, with each application amount being 10 kg / mu.
8. The method according to claim 7, characterized in that, In the cultivation and management of sesbania, 70% imidacloprid was sprayed during the branching stage to control aphids; during the flowering stage of sesbania, 3000 times high-efficiency cyhalothrin emulsion was sprayed twice using drones to control leaf rollers.
9. The method according to claim 8, characterized in that, The operation time for crushing and returning the straw of the sesbania plants to the field for fertilization is during the autumn sesbania pod-setting and harvesting period; during the operation, a straw crusher is used to crush the sesbania plants and return them to the field, and the length of the crushed straw is no more than 5cm.
10. The method according to claim 9, characterized in that, After the straw is crushed and returned to the field, a tiller is used to till the soil to a depth of not less than 20cm; then a rotary tiller is used to mix the sesame straw with the soil to a depth of not less than 20cm.