Comprehensive treatment system for saline-alkali soil

Abstract

The embodiment of the invention provides a comprehensive treatment system for saline-alkali soil, and relates to the technical field of agriculture, and the comprehensive treatment system comprises a water source collection system for collecting rainwater and shallow brackish water; the water source treatment and storage system is used for carrying out purification and desalination treatment on the rainwater and the shallow brackish water collected by the water source collection system, and storing the treated fresh water in a storage pool; the intelligent irrigation system is used for irrigating the saline-alkali soil by using the fresh water stored in the storage pool when detecting that the pore water conductivity of the saline-alkali soil exceeds a preset threshold value, and washing salt accumulated on the surface layer of the saline-alkali soil by using salt washing mixed water; the salt washing mixed water is mixed water of rainwater collected by the water source collecting system and shallow brackish water. By applying the embodiment of the invention, the vicious circle problem of'water shortage-salt accumulation-low yield 'in the saline-alkali soil can be overcome, and the ecology of the saline-alkali soil is improved.

Description

Comprehensive management system for saline-alkali land Technical Field

[0001] This application relates to the field of agricultural technology, and in particular to integrated management systems for saline-alkali land. Background Technology

[0002] Saline-alkali land is a soil type widely distributed in arid and semi-arid regions. Specifically, the water-scarce environment of these areas, characterized by low rainfall and high evaporation, easily leads to the accumulation of salts from deep soil layers and groundwater on the soil surface, resulting in salt accumulation. This stresses the growth of surface crops, leading to low yields. Furthermore, poor crop growth and low vegetation cover, resulting in bare soil, further exacerbate the ineffective evaporation of soil moisture, accelerating the upward accumulation of salts on the soil surface, creating a vicious cycle of "water scarcity-salt accumulation-low yield," which becomes a key bottleneck restricting sustainable agricultural development.

[0003] Therefore, how to improve the vicious cycle of "water shortage-salt accumulation-low yield" in saline-alkali land is a key issue to be addressed in order to achieve sustainable agricultural development. Summary of the Invention

[0004] The purpose of this application is to provide a comprehensive management system for saline-alkali land to overcome the vicious cycle of "water shortage-salt accumulation-low yield" in saline-alkali land and improve the ecology of saline-alkali land. The specific technical solution is as follows: This application provides a comprehensive management system for saline-alkali land, including: a water source collection system for collecting rainwater and shallow brackish water; a water source treatment and storage system for purifying and desalinating the rainwater and shallow brackish water collected by the water source collection system, and storing the treated freshwater in a storage tank; and an intelligent irrigation system for irrigating the saline-alkali land with the freshwater stored in the storage tank when the pore water conductivity of the saline-alkali land is detected to exceed a preset threshold, and for flushing the salt accumulated on the surface of the saline-alkali land with a salt-flushing mixture, which is a mixture of rainwater collected by the water source collection system and shallow brackish water.

[0005] Optionally, the salt concentration of the brine mixture is controlled between 1 g / L and 3.5 g / L.

[0006] Optionally, the integrated management system for saline-alkali land also includes: a land improvement system for applying a pre-prepared land conditioner to the saline-alkali land to form an improved layer on the land; wherein the land conditioner is made by mixing and reacting coal gangue, straw ash and desulfurized gypsum as raw materials.

[0007] Optionally, the land conditioner is obtained as follows: Coal gangue, straw ash, and desulfurized gypsum are placed in a sealed mixing tank according to a mass ratio of coal gangue: straw ash: desulfurized gypsum of 1.5-2.5:0.8-1.2:1.5-2.5, water is added until the moisture content of the mixture is 15%-25%, and sodium humate and sodium silicate are added as adjuvants; the coal gangue, straw ash, and desulfurized gypsum are then reacted at room temperature in the sealed mixing tank for 20-28 hours to obtain the land conditioner.

[0008] Optional, a land improvement system is used to mix a land conditioner into the soil layer at a depth of 0-20cm in saline-alkali land, then rake and compact it to form a land improvement layer; wherein, the amount of land conditioner mixed into the saline-alkali land is 3-5 tons per acre.

[0009] Optionally, the comprehensive management system for saline-alkali land also includes: an energy supply system, including wind-solar hybrid energy supply modules and diesel generators, wherein the wind-solar hybrid energy supply modules include wind power generation systems and photovoltaic power generation systems; an energy storage and distribution system, used to power the comprehensive management system with the electricity generated by the wind-solar hybrid energy supply modules and to store redundant electricity in batteries; and to start the diesel generator to power the comprehensive management system when the electricity provided by the wind-solar hybrid energy supply modules and batteries is insufficient.

[0010] Optionally, the saline-alkali land includes multiple work zones, and each work zone is rotated according to a rotation cycle as a first-class work zone, a second-class work zone, and a third-class work zone. The comprehensive management system for saline-alkali land also includes: a crop rotation system, used to sow salt-tolerant forage grass in the first-class work zone of the saline-alkali land, sow salt-tolerant grain in the second-class work zone of the saline-alkali land, and sow sorghum or peas in the third-class work zone of the saline-alkali land and apply microbial agents; wherein, the microbial agents adopt a mixed formula of nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and root-promoting bacteria.

[0011] Optionally, the microbial agent is a mixture of *Arthrobacter pastoris* and *Rhizobium*, and the concentration of the microbial agent is not less than... CFU / g.

[0012] Optionally, the water treatment and storage system includes a sedimentation zone, a filtration zone, an ion exchange desalination device, and a storage tank arranged sequentially. After the rainwater and shallow brackish water collected by the water collection system enter the water treatment and storage system, they are first purified by passing through the sedimentation zone and the filtration zone, and then enter the ion exchange desalination device for desalination treatment. After being treated by the ion exchange desalination device to meet the target conditions, they are placed into the storage tank. The target conditions are: conductivity less than 1.5 mS / cm and sodium ion concentration less than 35 mg / L.

[0013] Optionally, the intelligent irrigation system includes a drip irrigation network deployed on saline-alkali land, which includes multiple rotating irrigation zones. The drip irrigation network is independently controlled for irrigation of each rotating irrigation zone. Specifically, when the pore water conductivity of a rotating irrigation zone is detected to exceed a preset value, the intelligent irrigation system uses fresh water stored in a storage tank to irrigate that rotating irrigation zone through the drip irrigation network, and uses salt flushing mixed water to flush away the salt accumulated on the surface of that rotating irrigation zone.

[0014] The beneficial effects of this application's embodiments: The comprehensive management system for saline-alkali land provided in this application embodiment, when detecting that the pore water conductivity of saline-alkali land exceeds a preset threshold, uses a mixture of rainwater and shallow brackish water to flush away the salt on the surface of the saline-alkali land. This actively regulates the salinity of the surface soil by utilizing the salt buffering capacity of the brackish water and the dilution effect of rainwater, preventing the accumulation of surface salt from harming crop growth. Furthermore, while flushing away the surface salt with the mixed water, this application embodiment also uses fresh water to irrigate the saline-alkali land to supplement the water needed by crops, avoiding soil moisture deficiency caused by excessive salt flushing. Therefore, this application embodiment can break the vicious cycle of "water shortage-salt accumulation-low yield" in saline-alkali land and ensure that the water needs of crops are met, thereby contributing to the improvement of the saline-alkali land ecosystem.

[0015] Furthermore, the embodiments of this application collect rainwater and shallow brackish water, and treat the rainwater and shallow brackish water into freshwater that can be used for irrigation, thereby alleviating the pressure on freshwater resources and having good ecological benefits.

[0016] Of course, implementing any product or method of this application does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, 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 this application. For those skilled in the art, other embodiments can be obtained based on these drawings.

[0018] Figure 1 is a schematic diagram of one embodiment of the comprehensive management system for saline-alkali land provided in this application; Figure 2 is another schematic diagram of the comprehensive management system for saline-alkali land provided in this application. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art based on this application are within the scope of protection of this application.

[0020] To overcome the vicious cycle of "water shortage-salt accumulation-low yield" in saline-alkali land, this application provides a comprehensive management system for saline-alkali land. Referring to Figure 1, the system includes a water collection system, a water treatment and storage system, and an irrigation system, which are described in detail below: Among the components of the above comprehensive management system, the water collection system is used to collect rainwater and shallow brackish water.

[0021] In one example, the rainwater collected by the water collection system can be the rainy season surface runoff that falls on saline-alkali land; shallow brackish water can be groundwater with a groundwater level of 5 to 8 meters and a salt content of 2 to 5 grams per liter.

[0022] The water treatment and storage system is used to purify and desalinate rainwater and shallow brackish water collected by the water collection system, and store the treated freshwater in a storage tank.

[0023] In other words, the water treatment and storage system is used to treat rainwater and shallow brackish water collected by the water collection system into fresh water and store this fresh water in a storage tank.

[0024] The intelligent irrigation system is used to irrigate saline-alkali land with fresh water stored in a storage tank when the pore water conductivity of the saline-alkali land exceeds a preset threshold, and to flush away the salt accumulated on the surface of the saline-alkali land with salt-flushing mixed water.

[0025] Specifically, the brine mixed water is a mixture of rainwater collected by the water source collection system and shallow brackish water, which is a mixture of rainwater and shallow brackish water that has not been desalinated by the water source treatment and storage system.

[0026] As can be easily understood from the background section of this application, salt accumulation on the surface of saline-alkali land promotes a vicious cycle of "water shortage-salt accumulation-low yield". The role of the intelligent irrigation system in this application is to detect and regulate the salinity of the surface layer of saline-alkali land, prevent salt accumulation on the soil surface, and thus break the vicious cycle of "water shortage-salt accumulation-low yield".

[0027] In practical applications, intelligent irrigation systems can continuously monitor the pore water conductivity of the surface layer of saline-alkali soil at predetermined intervals. Since pore water conductivity directly reflects the dynamics of salt content in the root zone, intelligent irrigation systems can determine whether salt accumulation has occurred in the soil surface layer by detecting the pore water conductivity. For example, an intelligent irrigation system can specifically monitor the pore water conductivity of the top 20 cm layer of soil.

[0028] In this embodiment, when the detected pore water conductivity exceeds a preset threshold, it can be considered that salt accumulation has occurred in the root zone. In this case, the intelligent irrigation system irrigates the saline-alkali land with fresh water stored in the storage tank to replenish the soil with fresh water and maintain the normal physiological needs of the crops. On the other hand, it flushes the saline-alkali land extensively with salt-water mixture to leach the salt accumulated in the surface soil to the deeper soil or discharge it outside the cultivated land system, thereby breaking the salt accumulation in the soil surface.

[0029] The preset threshold value can be set according to actual needs. In one example, the preset threshold can be set to 6 dS / m (in Siemens units per meter).

[0030] Specifically, by using rainwater and shallow brackish water to flush the land with large volumes, the salt buffering capacity of the brackish water and the dilution effect of rainwater can be utilized to reduce the harmful effects of salt on crops. Replenishing saline-alkali land with fresh water can avoid soil moisture deficiency caused by excessive salt flushing.

[0031] In addition, shallow brackish water usually contains substances such as NaCl (sodium chloride) and Ca. 2+ Minerals such as calcium ions can partially replace chemical fertilizers. Rainwater typically contains minerals such as potassium (K). + (Potassium ions), Mg 2+ Micronutrients such as magnesium ions can improve the soil nutrient balance. Therefore, flushing saline-alkali land with salt-water mixture can not only prevent the accumulation of salt on the soil surface, but also improve soil nutrients.

[0032] In practical applications, the amount of flushing water required for salt removal (the process of flushing saline-alkali land with a salt-water mixture) can be determined based on the extent to which the pore conductivity exceeds the standard, ensuring that the salt content of the soil surface drops to a safe threshold after flushing (e.g., the pore water conductivity drops to no more than 6 dS / m). The amount of freshwater replenishment can be dynamically adjusted according to the crop's water requirements, and is usually much lower than the amount of flushing water used.

[0033] In one possible implementation of this application, the salt-flushing mixture can be prepared in a ratio of 50% rainwater and 50% shallow brackish water. Specifically, the salt content of the shallow brackish water is generally between 2 g / L and 5 g / L, while the conductivity of the rainwater is generally between 0.5 mS / cm and 2 mS / cm. By mixing the shallow brackish water with the rainwater, the salt concentration of the mixed salt-flushing mixture can be reduced to 1 g / L to 3.5 g / L, which can effectively leach salt while avoiding direct damage to the root system from high salt content. Compared to directly using fresh water to flush away surface soil salts, using a mixture of rainwater and shallow brackish water to flush away surface soil salts can achieve the same dilution effect with less water, thereby avoiding water waste.

[0034] As can be seen from the above description, the comprehensive management system for saline-alkali land provided in this application embodiment, when detecting that the pore water conductivity of the saline-alkali land exceeds a preset threshold, uses a mixture of rainwater and shallow brackish water to flush away the salt on the surface of the saline-alkali land. This actively regulates the salinity of the surface soil by utilizing the salt buffering capacity of the brackish water and the dilution effect of rainwater, preventing the accumulation of surface salt from harming crop growth. Furthermore, while flushing away the surface salt with the mixed water, this application embodiment also uses fresh water to irrigate the saline-alkali land to supplement the water needed by crops, avoiding soil moisture deficiency caused by excessive salt flushing. Therefore, this application embodiment can break the vicious cycle of "water shortage-salt accumulation-low yield" in saline-alkali land and ensure that the water needs of crops are met, thereby contributing to the improvement of the saline-alkali land ecosystem.

[0035] Furthermore, the embodiments of this application collect rainwater and shallow brackish water, and treat the rainwater and shallow brackish water into freshwater that can be used for irrigation, thereby alleviating the pressure on freshwater resources and having good ecological benefits.

[0036] In one embodiment of this application, a drip irrigation network can be deployed in saline-alkali land to irrigate the land with fresh water and flush away salt.

[0037] This application does not limit the specific form of the drip irrigation network. In one example, a drip irrigation network can be formed by PE (Polyethylene) film drip irrigation tape, specifically with specifications of INT-H 16 mm × 0.6 mm × 30 cm spacing, a flow rate of 2 liters / hour per hole, and drippers arranged in a 30 cm × 30 cm grid to ensure root zone moisture.

[0038] In practical applications, saline-alkali land can be further subdivided into multiple rotational irrigation zones, allowing the drip irrigation network to independently control irrigation for each zone. In this scenario, the intelligent irrigation system can detect the pore water conductivity of the topsoil within each rotational irrigation zone. When the pore water conductivity of a zone exceeds a preset value, the system uses fresh water stored in a storage tank to irrigate that zone via the drip irrigation network, and also uses a salt-flushing mixture to flush away the accumulated salt on the surface of that zone.

[0039] In one example, at least three salt flushings can be carried out during the entire growing season of crops in saline-alkali land, using a dry-water rotation irrigation method.

[0040] In one possible implementation of this application, the intelligent irrigation system can also detect the soil conductivity of the surface layer of saline-alkali land at a certain set cycle to help determine the salt accumulation in the surface layer of saline-alkali land.

[0041] In one example, the detected soil conductivity can be used to help verify the accuracy of the pore water conductivity measured by the pore water conductivity sensor, avoiding false alarms caused by problems such as sensor malfunction.

[0042] In another example, the detection of soil electrical conductivity can be used to determine whether the current salt accumulation in the soil surface layer requires human intervention. For instance, if the detected soil electrical conductivity is abnormally high (e.g., exceeding a preset threshold), but the detected pore water electrical conductivity is normal (e.g., not exceeding a preset threshold), it may mean that human intervention is needed to address the salt accumulation in the soil surface layer, such as loosening the soil surface. In this case, the integrated management system can use the reminder module to alert the relevant personnel to perform the corresponding operations.

[0043] In one embodiment of this application, the integrated management system further includes a land improvement system for applying a pre-prepared land conditioner to saline-alkali land to form a land improvement layer on the saline-alkali land.

[0044] The soil conditioner is prepared by mixing and reacting coal gangue, straw ash, and desulfurized gypsum as raw materials. In one example, the soil conditioner can be prepared through the following steps a1-a2: Step a1: Coal gangue, straw ash, and desulfurized gypsum are placed in a sealed mixing tank according to the mass ratio of coal gangue: straw ash: desulfurized gypsum of 1.5-2.5:0.8-1.2:1.5-2.5, water is added until the moisture content of the mixture is 15%-25%, and sodium humate and sodium silicate are added as auxiliary agents.

[0045] Among them, coal gangue is mainly used to regulate Ca. 2+The release rate of alkaline substances is controlled by straw ash, while desulfurized gypsum is used to balance the soil pH. Adding sodium humate and trace amounts of sodium silicate as adjuvants helps to enhance the formation of soil aggregates.

[0046] In one example, the carbon content of the coal gangue in the raw material is less than 15%, and the coal gangue can be crushed to a particle size of less than 10 mm before being put into a sealed mixing tank; the alkali content of the straw ash solid is 10%-15%, the particle size is less than 5 mm, and it can be dried to a moisture content of less than 5% before being put into a sealed mixing tank; the desulfurization gypsum is powdered CaSO4·2H2O with a particle size of less than 2 mm.

[0047] In a preferred embodiment, the mass ratio of coal gangue:straw ash:desulfurized gypsum can be controlled at 2:1:2, and water is added to the mixture until the moisture content of the mixture is 20% after the coal gangue, straw ash and desulfurized gypsum are placed in a sealed mixing tank. However, in practical applications, the ratio can be adjusted within the range listed in step a1 above according to specific needs.

[0048] In one possible implementation, the composition of the raw materials can be adjusted based on the initial pH of the saline-alkali soil, the salt tolerance threshold of the crops to be grown in the saline-alkali soil, and the activity of the coal gangue used as raw material. For example, when the initial pH of the soil is greater than 9, or when the salt tolerance threshold of the crops is low (e.g., rice requires a lower salinity environment), the proportion of desulfurized gypsum can be increased to reduce the alkalinity of the soil; and when the carbon content of the coal gangue is low, the amount of coal gangue added can be appropriately increased.

[0049] Step a2: Coal gangue, straw ash and desulfurized gypsum are reacted at room temperature in a sealed mixing tank for 20-28 hours to obtain a land conditioner.

[0050] Specifically, a soil conditioner can be prepared by reacting coal gangue, straw ash, and desulfurized gypsum at room temperature in a closed mixing tank to promote the release of calcium ions.

[0051] In a preferred embodiment, when the mass ratio of coal gangue:straw ash:desulfurized gypsum in the raw materials is controlled at 2:1:2, the coal gangue, straw ash and desulfurized gypsum can be reacted at room temperature in a closed mixing tank for 24 hours to obtain a land conditioner.

[0052] In one possible implementation of this application, when applying a soil conditioner to saline-alkali land, the soil conditioner can be mixed into the soil layer at a depth of 0-20cm, then raked and compacted to form a uniform soil conditioner layer of 0-20cm.

[0053] The application rate of soil conditioner can be 3 to 5 tons per acre. For a soil layer of 0-20cm, the mixing volume per acre is approximately 200 square meters of soil.

[0054] In one example, when mixing soil conditioner into saline-alkali land, a rotary tiller with a power of no less than 75 kilowatts can be used to mechanically mix the soil conditioner and soil layer. The working depth of the deep tillage plow can be set to 20 centimeters, and the rotation speed can be set to 200 revolutions per minute.

[0055] In this embodiment, the land conditioner prepared based on steps a1-a2 can be used to reduce the salinity of the topsoil in saline-alkali land and increase the proportion of available calcium ions and aggregates in the soil, thereby increasing crop yields in saline-alkali land. In practical applications, after improving saline-alkali land by mixing in the land conditioner, the improvement effect can be evaluated by periodically testing (e.g., monthly during the first crop growing season) the soil's pH, electrical conductivity, and the proportion of available calcium ions and aggregates. The inventors of this application have verified that within one year of improving saline-alkali land, the soil pH decreased from 8.5 to 7.8-8.0, electrical conductivity decreased by 20%-30%, and field water holding capacity increased by 15%. After three years of continuous improvement, the yield of salt-tolerant grains can be increased by 30%-50% per mu, and significant regional carbon sequestration benefits can be generated.

[0056] In one embodiment of this application, salt-tolerant crops and microorganisms can be co-cultivated in saline-alkali land. Specifically, the saline-alkali land can be divided into multiple operational zones, and these zones can be rotated according to a cycle to become a first-class, second-class, and third-class operational zone, with different types of crops planted in each zone. The following is a detailed description: In this embodiment, the integrated management system also includes a crop rotation system, which is used to sow salt-tolerant forage grasses in the first-class operational zone, sow salt-tolerant grains in the second-class operational zone, and sow sorghum or peas in the third-class operational zone, while applying microbial agents.

[0057] The microbial inoculant uses a mixture of nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and root-promoting bacteria. This application does not limit the specific formulation of the microbial inoculant; it can be selected according to actual needs. In one example, the microbial inoculant can be a mixture of *Arthrobacter pastoris* and *Rhizobium*, and the concentration of the mixture is not less than... CFU / g (colony forming units per gram).

[0058] In one example, the application of microbial agents within the third-category work zone can be achieved through seed treatment and rhizosphere spraying. One possible implementation involves mixing 2 kg of microbial agent with 10 kg of seeds per acre during seed treatment, and then applying it three times during the growing season, with 3 liters of microbial agent applied per acre each time. In practical applications, the effectiveness of the microbial agent can be evaluated by comparing it with conventional controls based on monitoring indicators such as crop chlorophyll content, root content, and biomass.

[0059] In one example, when applying microbial inoculants to the roots during the crop's growing season, the timing of application can be determined based on the soil's microbial activity, such as the density of nitrogen-fixing bacteria in the soil. Supplement spraying when CFU / g is reached. Furthermore, the timing of spraying can be adjusted according to weather conditions; for example, spraying can be suspended before rainfall to prevent the loss of microbial agents.

[0060] Of course, in practical applications, microbial agents can also be sprayed on both the first and second types of work zones. However, the spraying process can be controlled by zones to ensure precise application as needed. For example, the spraying frequency for the third type of work zone can be set to be higher than the spraying efficiency for the first and second types of work zones.

[0061] The specific types of salt-tolerant forage and salt-tolerant grains can be selected according to actual needs. For example, salt-tolerant forage can include Suaeda salsa and sweet sorghum, while salt-tolerant grains can include salt-tolerant rice and salt-tolerant millet.

[0062] To illustrate this, a specific example can be provided: A 2-hectare salt-tolerant crop-microorganism co-cultivation zone can be established in saline-alkali land. This zone can be divided into three parallel strips, each 15 meters wide, with a 5-mu (approximately 0.33 hectares) wide access road between adjacent strips. In actual cultivation, these three strips are rotated as the first, second, and third type of operational strips. Salt-tolerant forage grasses are planted in the first type of operational strip at a seeding rate of 4 kg / mu (approximately 0.067 hectares). Salt-tolerant grains are planted in the second type of operational strip at a seeding rate of 10 kg / mu (approximately 0.067 hectares). The third type of operational strip serves as a nitrogen-fixing microorganism rotation zone, inoculated with microbial agents and planted with sorghum or peas.

[0063] In this embodiment of the application, by dividing the saline-alkali land into multiple work zones and rotating each work zone as a salt-tolerant forage planting area, a salt-tolerant grain planting area, and a microbial inoculation area, it is possible to improve the yield and diversity of crops in the saline-alkali land while ensuring soil fertility.

[0064] In one embodiment of this application, in order to provide power to the integrated management system, the integrated management system may further include an energy supply system and an energy storage and distribution system.

[0065] The energy supply system includes wind-solar hybrid power supply modules and diesel generators. The wind-solar hybrid power supply modules consist of wind power generation systems and photovoltaic power generation systems. The energy storage and distribution system is used to power the integrated governance system with the electricity generated by the wind-solar hybrid power supply modules and to store excess electricity in batteries. When the electricity provided by the wind-solar hybrid power supply modules and batteries is insufficient, the diesel generator is started to power the integrated governance system.

[0066] In one example, when using a wind-solar hybrid power generation module, the photovoltaic power generation system (with a power generation efficiency of up to 19%) can be used first on sunny days, and the wind power generation system can be switched on during windy weather to generate electricity in a complementary manner, thus ensuring a stable and continuous power supply.

[0067] In practical applications, while using the electricity generated by the wind-solar hybrid power supply modules to power the integrated governance system, the redundant electricity generated by the modules (i.e., the electricity exceeding the system's operational requirements) can also be used to charge the batteries. The electricity stored in the batteries can be used when fluctuations in weather conditions prevent the wind-solar hybrid power supply modules from meeting operational needs. The diesel generator primarily serves as an emergency backup, ensuring uninterrupted power supply to the integrated governance system when extreme weather conditions prevent the wind-solar hybrid power supply modules and batteries from supporting its power demands.

[0068] In one possible implementation of this application, charging of the battery can be stopped when the SOC (State of Charge) of the battery is not less than 80%; and when the integrated treatment system is powered by the battery, the diesel generator can be started when the battery charge is used to less than 20%.

[0069] In one example, the wind power generation system can use a 1.5 kW micro-wind turbine for wind power generation, with a rated wind speed of 10 m / s, a cut-in wind speed of 2.5 m / s, and a cut-out wind speed of 25 m / s. The tower is 12 meters high and made of hot-dip galvanized steel. A PWM (Pulse Width Modulation) type wind turbine controller can be used for control of the micro-wind turbine, featuring overspeed and overvoltage protection and microgrid grid-connection switching functions. The photovoltaic power generation system can use monocrystalline silicon solar panels, each 250 watts, with an efficiency of no less than 19%, an installed capacity of 10 kW, and a total of 40 panels, tilted at a 30-degree angle facing south. The support structure is a ground-fixed steel structure with powder coating. Two 5 kW dual-channel MPPT (Maximum Power Point Tracking) photovoltaic inverters are used for inverter and combiner functions, featuring islanding detection and grid-connection switching capabilities. A 10 kW diesel generator can be used.

[0070] Energy storage and power distribution systems can include two parts: batteries and intelligent distribution cabinets. In one example, the batteries can be lithium iron phosphate battery packs with a capacity of 100 Ah / 3.2V in series (32 strings), providing a total energy storage of 102.4 kWh. They are equipped with a BMS (Battery Management System) intelligent management system, providing overcharge, over-discharge, battery balancing, and temperature control functions. The intelligent distribution cabinet can be a 68A / 230V DC power distribution unit, including photovoltaic disconnect switches, wind power disconnect switches, battery disconnect switches, load disconnect switches, and monitoring terminals.

[0071] In addition, to facilitate the operation and maintenance of the energy supply system, a SCADA (Supervisory Control and Data Acquisition) system can be used to monitor the voltage, current, and power output of the wind turbine and photovoltaic power generation systems in real time, as well as the external ambient wind speed and solar intensity. Furthermore, monthly dust cleaning of the photovoltaic panels can be performed on the photovoltaic power generation system, semi-annual lubrication of the bearings and blade crack inspection of the micro-wind turbines, and annual infrared thermography of the cables.

[0072] In one embodiment of this application, the rainwater to be collected by the aforementioned water collection system may specifically include surface runoff during the rainy season. To achieve this, the water collection system can be located along natural catchment areas in valleys for rainwater collection. Furthermore, when selecting a site for the water collection system, the site geology can be controlled to be predominantly gravel and sandy soil, which is conducive to infiltration control.

[0073] In this embodiment, the water collection system may include water collection equipment, a collection ditch, and an underground storage tank. The water collection equipment includes a rainwater collection area with a confluence zone at a certain angle. Rainwater collected in the rainwater collection area flows through this confluence zone into the inlet of the collection ditch and is then sent to the underground storage tank by the collection ditch.

[0074] In addition, the water collection equipment may also include a brackish water collection device for collecting shallow brackish water, and the shallow brackish water collected by the brackish water collection device may also be sent to an underground reservoir for storage. In this embodiment, the specific form of the brackish water collection device is not limited.

[0075] In one example, a water collection system could be installed on an area of ​​0.5-1 hectares. An underground reservoir could be constructed using a C30 reinforced concrete impermeable structure, measuring 50 meters long, 20 meters wide, and 3 meters deep, with a volume of approximately 3000 cubic meters. It would be lined with a 1.5 mm HDPE (High-Density Polyethylene) geomembrane, and joint leak detection would be implemented. The top of the underground reservoir could be equipped with a 1000 square meter rain canopy collection area, which would be impermeable and hardened, with a 150 mm slope to collect the water into a drainage ditch.

[0076] The water stored in the underground reservoir is specifically used to be sent to the water collection and storage system for purification and desalination. In one example, the water in the underground reservoir can be sent to the water collection and storage system through a water pumping system. For example, the water pumping system can use a photovoltaic direct-drive submersible pump with a rated power of 2.2 kW, a head of 15 meters, and a maximum flow rate of 40 cubic meters per hour. Two redundant sets are connected in parallel and controlled by a PLC (Programmable Logic Controller) and an intelligent water level controller. The start-up and shutdown thresholds are set at a low water level of 0.5 meters and a high water level of 2.8 meters, respectively.

[0077] In one embodiment of this application, the water collection and storage system includes a sedimentation zone, a filtration zone, an ion exchange desalination device, and a storage tank arranged sequentially.

[0078] Specifically, the rainwater and shallow brackish water collected by the water source collection system are purified by passing through the sedimentation zone and filtration zone in sequence after entering the water source treatment and storage system. Then, they enter the ion exchange desalination equipment for desalination treatment. After being treated by the ion exchange desalination equipment to meet the target conditions, they are placed into the storage tank. The target conditions are: conductivity less than 1.5 mS / cm and sodium ion concentration less than 35 mg / L.

[0079] In one example, a 2-cubic-meter sedimentation tank can be set up at the front end of the storage tank as a sedimentation zone. The water entering the sedimentation tank should have a residence time of no less than 30 minutes, removing no less than 60% of suspended solids. The filtration zone can be two-stage: the first stage is a sand filter with a packing particle size of 0.8 to 1.2 mm and a filtration rate of 5 cubic meters per hour per square meter; the second stage is an activated carbon adsorption bed with a packing particle size of 0.5 to 1.0 mm and a filtration rate of 3 cubic meters per hour per square meter, used to remove organic matter and small amounts of heavy metals.

[0080] In one example, the ion exchange desalination equipment can use a mixed-bed column of anions and cations, with a strong-strength resin, an exchange capacity of 2.0 equivalents / L, and influent conditions where the TDS (Total Dissolved Solids) is not higher than 2 g / L, the flow rate is 2 m / h, the processing capacity is about 4 cubic meters / hour, and regeneration is carried out alternately with 2% hydrochloric acid and 2% sodium hydroxide. Each bed can be continuously operated for 800 cubic meters before regeneration. The waste liquid is neutralized and then returned to the modified material reaction zone.

[0081] In one example, the storage tank could be a C20 concrete tank with a volume of 500 cubic meters, equipped with a horizontal agitator to prevent scaling.

[0082] Furthermore, the integrated management system may also include a distribution network for transporting water from the storage tank to the drip irrigation network for irrigation. In one example, the distribution network may use PE pipes with diameters between DN63 and DN32, equipped with automatic solenoid valves, flow meters, and pressure sensors, with the pipes buried 0.7 meters deep and insulated against freezing.

[0083] Referring to Figure 2, and based on the descriptions in the above embodiments of this application, a comprehensive governance system integrating "water source regulation - energy drive - crop adaptation - ecological cycle" is constructed by setting up a water source collection system, a water source collection and storage system, an intelligent irrigation system, an energy supply system, an energy storage and power distribution system, a crop rotation system, and a land improvement system. This system can comprehensively improve the ecology of saline-alkali land and increase crop yields. Verification has shown that applying this comprehensive governance system to the saline-alkali land of Zizhou Dianshi Town, Yulin City, Shaanxi Province, can achieve an average annual water saving of approximately 2000 cubic meters per hectare, a freshwater substitution rate of 60%, an annual power generation of approximately 18 megawatt-hours, a self-sufficiency rate of 90%, and a reduction of carbon dioxide emissions by 15 tons per year. The average grain yield per mu (a Chinese unit of area, approximately 0.067 hectares) has increased from 350 kg to over 500 kg, and the forage yield has increased from 3 tons to 4.5 tons.

[0084] In practical applications, the aforementioned comprehensive governance system can be integrated with an information platform for system integration and operation management. This allows for the monitoring of soil moisture and salinity, weather conditions, and equipment status via IoT terminals. The cloud platform provides big data analysis and decision support, automatically scheduling irrigation, power generation, and microbial fertilizer replenishment to achieve automated ecological governance of saline-alkali land.

[0085] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0086] The various embodiments in this specification are described in a related manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0087] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application are included within the scope of protection of this application.

Claims

1. A comprehensive management system for saline-alkali land, characterized in that, include: Water collection system for collecting rainwater and shallow brackish water; A water treatment and storage system is used to purify and desalinate rainwater and shallow brackish water collected by the water collection system, and store the fresh water obtained after treatment in a storage tank. The intelligent irrigation system is used to irrigate the saline-alkali land with fresh water stored in the storage tank when the pore water conductivity of the saline-alkali land is detected to exceed a preset threshold, and to flush away the salt accumulated on the surface of the saline-alkali land with salt-flushing mixed water, which is a mixture of rainwater and shallow brackish water collected by the water source collection system.

2. The system according to claim 1, characterized in that, The salt concentration of the rinsing water is controlled between 1 g / L and 3.5 g / L.

3. The system according to claim 1, characterized in that, The system further includes a land improvement system for applying a pre-prepared land conditioner to the saline-alkali land to form an improved layer on the saline-alkali land; wherein the land conditioner is prepared by mixing and reacting coal gangue, straw ash and desulfurized gypsum as raw materials.

4. The system according to claim 3, characterized in that, The land conditioner is obtained as follows: coal gangue, straw ash, and desulfurized gypsum are placed in a sealed mixing tank according to a mass ratio of 1.5-2.5:0.8-1.2:1.5-2.5:coal gangue:straw ash:desulfurized gypsum. Water is added until the moisture content of the mixture is 15%-25%, and sodium humate and sodium silicate are added as adjuvants. The coal gangue, straw ash, and desulfurized gypsum are then reacted at room temperature in the sealed mixing tank for 20-28 hours to obtain the land conditioner.

5. The system according to claim 3, characterized in that, The land improvement system is specifically used to mix the land conditioner into the soil layer at a depth of 0-20cm in the saline-alkali land, and then rake and compact it to form the land improvement layer; wherein the amount of land conditioner mixed into the saline-alkali land is 3-5 tons per mu.

6. The system according to claim 1, characterized in that, The system also includes: an energy supply system, comprising a wind-solar hybrid energy supply module and a diesel generator, wherein the wind-solar hybrid energy supply module includes a wind power generation system and a photovoltaic power generation system; an energy storage and distribution system, used to supply power to the integrated governance system using the electricity generated by the wind-solar hybrid energy supply module, and to store redundant electricity in a battery; and to start the diesel generator to supply power to the integrated governance system when the electricity provided by the wind-solar hybrid energy supply module and the battery is insufficient.

7. The system according to claim 1, characterized in that, The saline-alkali land contains multiple work zones, and each work zone is rotated according to a rotation cycle as a first-class work zone, a second-class work zone, and a third-class work zone. The system also includes a crop rotation system for sowing salt-tolerant forage grasses in the first-class work zone of the saline-alkali land, sowing salt-tolerant grains in the second-class work zone of the saline-alkali land, and sowing sorghum or peas and applying microbial agents in the third-class work zone of the saline-alkali land; wherein the microbial agents are a mixture of nitrogen-fixing bacteria, phosphate-solubilizing bacteria, and root-promoting bacteria.

8. The system according to claim 7, characterized in that, The microbial agent is specifically a mixture of *Arthrobacter pastoris* and *Rhizobium*, and the concentration of the microbial agent is not less than... CFU / g。 9. The system according to claim 1, characterized in that, The water treatment and storage system includes a sedimentation zone, a filtration zone, an ion exchange desalination device, and a storage tank arranged sequentially. Rainwater and shallow brackish water collected by the water collection system are first purified by passing through the sedimentation zone and the filtration zone, then enter the ion exchange desalination device for desalination treatment. After being treated by the ion exchange desalination device to meet target conditions, the water is placed in the storage tank. The target conditions are: conductivity below 1.5 mS / cm and sodium ion concentration below 35 mg / L.

10. The system according to claim 1, characterized in that, The intelligent irrigation system includes a drip irrigation network deployed on the saline-alkali land, which includes multiple rotating irrigation zones. The drip irrigation network is independently controlled for irrigation of each rotating irrigation zone. Specifically, when the pore water conductivity of a rotating irrigation zone is detected to exceed a preset value, the intelligent irrigation system uses fresh water stored in the storage tank through the drip irrigation network to irrigate that rotating irrigation zone, and uses salt flushing mixed water to flush away the salt accumulated on the surface of that rotating irrigation zone.

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