Alfalfa planting management method based on high-altitude saline-alkali land

Abstract

The application discloses a kind of based on high altitude saline-alkali soil alfalfa planting management method, the present application relates to agricultural cultivation technical field, including the following steps: S1: irrigation water preheating step: make irrigation water flow through the dark pipeline laid on ground to carry out solar preheating;S2: drip irrigation step: using preheated irrigation water, field is irrigated by drip irrigation, and irrigation water volume is determined according to initial soil salt content and target salt washing depth.The based on high altitude saline-alkali soil alfalfa planting management method, by irrigation water preheating treatment and accurate drip irrigation are combined, effectively solve the contradiction between salt washing operation and ground temperature maintenance in high altitude area.Preheated irrigation water avoids the sudden drop of soil temperature caused by cold water irrigation, layered covering technology cooperates to inhibit water evaporation and salt return, while maintaining stable soil temperature, creates suitable water temperature salt environment for alfalfa seed germination, to improve the uniformity of emergence and seedling survival rate.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of agricultural cultivation technology, in particular to a method for alfalfa planting and management based on high-altitude saline-alkali land. BACKGROUND

[0002] Alfalfa planting in high-altitude saline-alkali land is a very challenging task, which is subject to both salt-alkali stress and low-temperature stress. In the prior art, the improvement of saline-alkali land generally relies on the core method of irrigation salt washing, which aims to dilute and remove the excess salt in the root layer through water leaching, so as to create a suitable living environment for crops. However, when this method is directly applied to high-altitude areas, it exposes significant limitations. The inherent low-temperature environment in high-altitude areas, especially the lower base soil temperature and the short effective accumulated temperature, make a large amount of irrigation water a negative factor that exacerbates heat stress. Cold water irrigation will quickly lower the soil temperature, making it difficult for the already low soil temperature to recover, and significantly prolonging the duration of low soil temperature. This artificially created low-temperature environment not only directly inhibits the germination vigor of alfalfa seeds, but also exacerbates the cold stress response of seedlings, leading to delayed emergence, weak seedlings, and a significant decrease in survival rate. As a result, although the traditional salt washing method theoretically reduces soil salinity, it fails to achieve successful alfalfa planting in practice due to the severe deterioration of soil heat conditions. Therefore, there is an urgent need for a planting method that can simultaneously manage water, temperature, and salt to resolve the conflict between irrigation salt washing and maintaining soil temperature. The technical problem to be solved at present is how to achieve the coordination of water management and temperature management in the process of alfalfa planting in high-altitude saline-alkali land, so as to ensure the emergence and survival of alfalfa. SUMMARY

[0003] To achieve the above purpose, the present application is implemented by the following technical scheme: a method for alfalfa planting and management based on high-altitude saline-alkali land, comprising the following steps:

[0004] S1: irrigation water preheating step: making irrigation water flow through dark-colored pipes laid on the ground surface for solar preheating;

[0005] S2: drip irrigation step: using preheated irrigation water, the field is irrigated by drip irrigation, and the irrigation water quantity is determined according to the initial soil salt content and the target salt washing depth;

[0006] S3: layered covering step: after drip irrigation and seeding, first lay a degradable soil conservation paper film with a microporous structure, and then cover a transparent mulch film;

[0007] S4: seeding decision step: based on real-time monitored soil temperature, soil salt data, and weather forecast information, the optimal seeding time is determined through a decision model.

[0008] Preferably, the dark pipeline is made of polymer material and is laid on the ground in a serpentine manner.

[0009] Preferably, in the drip irrigation step, the amount of irrigation water is controlled to the amount required to reduce the salt content of the root layer soil to the critical value for alfalfa germination.

[0010] Preferably, the microporous structure of the degradable soil conservation paper film is used to inhibit soil water evaporation and prevent salt upward migration.

[0011] Preferably, the thickness of the transparent mulch film is selected based on the light-heat conversion and heat preservation requirements.

[0012] Preferably, the salt and temperature tolerance thresholds in the decision model are determined through comparative tests at different altitudes.

[0013] An alfalfa planting management system based on high-altitude saline-alkali land is used to implement an alfalfa planting management method based on high-altitude saline-alkali land, comprising:

[0014] An irrigation unit comprising a water source, a dark preheating pipeline, and a drip irrigation device, the input end of the dark preheating pipeline being connected to the water source, and the output end being connected to the drip irrigation device;

[0015] A monitoring unit comprising a soil temperature sensor and a soil salt content sensor;

[0016] A control unit connected to the monitoring unit and having a built-in decision model for processing monitoring data and weather information;

[0017] A covering unit comprising a degradable soil conservation paper film and a transparent mulch film.

[0018] Preferably, the dark preheating pipeline is arranged in a serpentine manner to increase the water flow heating area and time.

[0019] Preferably, the decision model is optimized according to the correlation analysis of historical environmental data and emergence rate.

[0020] Preferably, the control unit comprises a data receiving module, a processing module, and an output module, the data receiving module being connected to the monitoring unit, the processing module running the decision model, and the output module providing sowing timing suggestions.

[0021] The present application provides an alfalfa planting management method based on high-altitude saline-alkali land.

[0022] The alfalfa planting management method based on high-altitude saline-alkali land effectively solves the contradiction between salt washing operation and soil temperature maintenance in high-altitude areas by combining preheating of irrigation water with precise drip irrigation. The preheated irrigation water avoids the sudden drop in soil temperature caused by cold water irrigation, and the layered mulching technology cooperatively inhibits water evaporation and salt upward movement while maintaining stable soil temperature, thereby creating a suitable water temperature and salt environment for alfalfa seed germination, thereby improving seedling emergence uniformity and seedling survival rate.

[0023] The alfalfa planting management method based on high-altitude saline-alkali land dynamically determines the seeding time by using a decision model, and realizes the precision and intelligence of planting management through multi-source data fusion analysis and self-adaptive optimization mechanism. The system method not only improves the reliability of alfalfa planting in high-altitude saline-alkali land, but also reduces the use of water resources and mulching materials through optimized resource allocation, providing a referenceable technical path for crop planting under similar environmental conditions. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a system module interaction schematic diagram of the alfalfa planting management method based on high-altitude saline-alkali land of the present application;

[0025] Figure 2 is a flowchart of the alfalfa planting management method based on high-altitude saline-alkali land of the present application. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0027] Please refer to Figure 1 and Figure 2 , the present application provides a technical solution: an alfalfa planting management method based on high-altitude saline-alkali land, comprising the following steps:

[0028] S1: irrigation water preheating step: making irrigation water flow through dark pipes laid on the ground for solar preheating;

[0029] S2: drip irrigation step: using preheated irrigation water to irrigate the field by drip irrigation, and the irrigation water amount is determined according to the initial salt content of the soil and the target salt washing depth;

[0030] In the drip irrigation step, the key parameters are first defined, including the following:

[0031] Initial soil salt content: expressed by soil electrical conductivity EC, detected by soil salt sensor or laboratory, 0-20 cm root layer soil sample is taken, EC is measured after extraction according to soil-water ratio 1:5, obtained, recorded as EC0;

[0032] Pre-set salt washing target: determined according to the critical salt tolerance of alfalfa germination, generally ECt≤3.0 mS / cm, different altitudes can be adjusted slightly, such as ECt≤2.5 mS / cm above 3500 m;

[0033] Soil leaching rate η: the actual leaching efficiency of high-altitude saline-alkali soil, such as chestnut soil and meadow soil, which is determined by field test, that is, different altitude gradient comparison test can be derived, generally 0.6-0.8;

[0034] Field water capacity θf: the maximum water retention capacity of soil, which is detected by the cutting ring method, about 15%-20% for sandy soil, about 20%-25% for loam soil, and about 25%-30% for clay soil;

[0035] Soil bulk density ρb: unit volume of dry soil, generally 1.3-1.5 g / cm 3 at high altitudes;

[0036] Cultivation layer thickness h: the main distribution layer of alfalfa seed germination and seedling root system, 0-20 cm, that is, 0.2 m;

[0037] Soil texture adjustment coefficient k: sandy soil k=0.8-0.9, indicating that the infiltration is fast, and the water quantity needs to be reduced; loam soil k=1.0-1.1, indicating that the infiltration is moderate; clay soil k=1.2-1.3, indicating that the infiltration is slow, and the water quantity needs to be increased.

[0038] Irrigation water quantity calculation formula: the total irrigation water quantity W per unit area is calculated according to the following formula: W=[(EC0EC t )×ρb×h×S] / (η×θf×EC t )×k; wherein S is the conversion coefficient per unit area, 1 mu=667 m 2 , ρb is converted to 1000 kg / m 3 , after substitution, it is simplified as: W=[(EC0EC t )×1.3×0.2×667] / (η×θf×EC t )×k, ρb=1.3×10 3 kg / m 3 .

[0039] The actual operation process is as follows:

[0040] 1. Early detection: 3 days before sowing, 0-20 cm soil layer soil sample is collected, 3 points are taken every 10 mu, EC0, θf, ρb are detected, soil texture is determined, and k value is selected;

[0041] 2. Water amount calculation: substitute the formula to calculate the total irrigation water amount W;

[0042] 3. Sub-period irrigation: the first irrigation applies 0.6W, 24 hours after irrigation, detect EC1 of 0-20cm soil layer; if EC1>EC t , supplement irrigation 0.3W, detect EC2 again; if EC2≤EC t , stop irrigation; if still not up to standard, supplement irrigation remaining 0.1W (ensure to avoid excessive irrigation leading to sudden drop of ground temperature).

[0043] For high-altitude saline-alkali land, i.e. loam soil at an altitude of 3000m:

[0044] Detection: EC0=5.0mS / cm, θf=22%, ρb=1.35g / cm 3 , k=1.05, η=0.7; preset ECt=2.8mS / cm;

[0045] Calculation: W=[(5.0-2.8)×1.35×0.2×667] / (0.7×0.22×2.8)×1.05≈120m 3 / mu;

[0046] Operation: the first irrigation is 72m 3 / mu, 24 hours later, measure EC1=3.2mS / cm, supplement irrigation 36m 3 / mu, re-measure EC2=2.7mS / cm (up to standard), stop irrigation.

[0047] S3: Layered covering step: after drip irrigation and sowing, first lay degradable soil moisture preservation paper film with micro-porous structure, then cover transparent mulch film;

[0048] S4: Sowing decision step: based on real-time monitored soil temperature, soil salt data and weather forecast information, determine the best sowing time through a decision model.

[0049] The explicit selection and basis of monitoring indicators meet the following table:

[0050]

[0051]

[0052] Based on comparative tests of different altitude gradients, the parameter threshold values are determined as follows: in the 2500m, 3000m and 3500m altitude test areas, each set 5 repeated plots, detect the correlation of "T, EC and emergence rate", determine the threshold value through regression analysis, including the following table:

[0053]

[0054] The model comprehensive analysis step includes the following:

[0055] Data preprocessing: remove outliers, including T <0℃ or EC >10mS / cm caused by sensor failure; and meteorological data takes the official platform 72-hour forecast, updated twice a day, and takes the latest data.

[0056] Single index comparison: if T ≥ corresponding altitude threshold, EC ≤ corresponding altitude threshold, and both meteorological indicators meet the standard, then enter "standard judgment"; if only one index does not meet the standard, such as T = 7℃ <8℃, but EC = 2.7mS / cm, and the weather meets the standard, then enter "weight supplementary judgment"; if two or more indicators do not meet the standard, then determine "not suitable for sowing", and re-analyze after 24 hours.

[0057] For single index non-compliance scenarios, weight supplementary judgment is performed, including the following:

[0058] Index weight: soil temperature (40%), soil salinity (40%), and weather forecast (20%);

[0059] Score calculation: standard indicators are scored according to weight, and non-standard indicators are scored according to "actual value / threshold x weight", such as T = 7℃ <8℃, scored as (7 / 8) x 40% = 35%;

[0060] Determination: total score ≥80%, then recommend sowing; total score <80%, then not suitable for sowing.

[0061] Output result: standard / weight supplementary judgment passes → output "best sowing time", such as "sow within the next 24 hours, and the expected germination rate is ≥85%"; if it does not pass, output "conditions to be waited for", such as "wait for 5cm soil temperature to be ≥8℃ for 3 consecutive days".

[0062] For 3000m altitude plots, real-time monitoring: T = 7.8℃, EC = 2.7mS / cm for 3 consecutive days;

[0063] Weather forecast: probability of daily average temperature ≥8℃ for the next 3 days is 82%, and probability of no ≥5mm precipitation is 85%;

[0064] Analysis: T = 7.8℃ <8℃ (non-compliance), EC and weather meet the standard;

[0065] Score: (7.8 / 8) x 40% + 40% + 20% = 39% + 40% + 20% = 99% ≥80%;

[0066] Result: recommend sowing within the next 24 hours.

[0067] It needs to be further explained that, in the specific implementation process, first, the irrigation water is preheated, the irrigation water is introduced into the dark polymer pipeline laid on the ground, and the water flow is naturally heated by using the sufficient solar radiation in high altitude areas. The pipeline is laid in a specific way to fully absorb heat energy.

[0068] Then, precise drip irrigation is carried out, the required irrigation water is calculated according to the real-time detected soil salt content and the preset salt washing target, and quantitative drip irrigation is carried out using preheated water, so that the salt in the root layer is fully leached by water and excessive irrigation is avoided.

[0069] Immediately after irrigation, alfalfa is sown, and then a layered covering operation is carried out: first, a layer of degradable soil conservation paper film with microporous structure is laid, and then transparent mulch film is covered, which effectively inhibits water evaporation and maintains soil temperature through this double-layer covering structure.

[0070] In the whole process, through the decision model, the real-time data collected by the soil temperature sensor and the salt sensor and the weather forecast information are comprehensively analyzed, and when the monitoring indicators show that the soil environment meets the temperature conditions and salt conditions required for alfalfa germination at the same time, it is determined that the best sowing opportunity is reached and the corresponding operation is performed; The threshold value of the decision model is determined by comparing the relationship between the emergence rate and the environmental data after multiple repeated tests under different altitude conditions.

[0071] The construction of the decision model is based on a large amount of field test data, and the method is: in a plurality of different altitude gradient typical saline-alkali land test areas, a test unit is set up, in each unit, by controlling the irrigation amount and the covering method, a series of soil environments with different soil salt concentrations and temperature levels are actively created. Sow alfalfa in each of these environments, and continuously monitor and record the soil temperature, soil solution conductivity, and final alfalfa emergence rate, seedling height and other growth indicators from sowing to emergence. After collecting enough sample data, the corresponding relationship between the soil environment parameters and the emergence indicators is processed by using the mathematical method of regression analysis, so as to accurately fit the upper limit critical value of soil salt and the lower limit critical value of soil temperature that can ensure the normal germination of alfalfa.

[0072] The dark pipeline is made of polymer material and is laid on the ground in a winding manner. It needs to be further explained that, in the specific implementation process, the dark pipeline is made of polymer composite material with good weather resistance, and its outer surface is specially treated to enhance the absorption capacity of solar radiation. The pipeline is laid in a continuous S-shaped winding way on the surface of the pre-graded field, which increases the contact area and contact time of the pipeline with sunlight. The inner wall of the pipeline is designed with a flow guide structure to make the water flow turbulent when passing through, improving the heat exchange efficiency.

[0073] The input end of the pipeline is connected to a water source through a detachable interface, and the output end is connected to the main pipeline of the drip irrigation system in a sealed and quick-connection manner, ensuring the integrity of the entire irrigation preheating system and facilitating disassembly and maintenance. Under sunlight conditions, the water flow passes through the pipeline at a specific flow rate, ensuring sufficient time for heating to the appropriate temperature range. The preheated water flow eventually flows into the drip irrigation system for subsequent operations.

[0074] The dark-colored pipeline preferably uses high-density polyethylene as the base material and incorporates carbon black masterbatch during material production to make the entire pipeline dark, thereby enhancing the absorption of solar radiation heat. The inner wall of the pipeline is designed with continuous low-protrusion spiral flow lines. When the water flow passes through, this structure disrupts the laminar flow state of the water flow, promoting the formation of turbulent flow, thereby enhancing the heat exchange efficiency between the water and the inner wall of the pipeline, ensuring that the water flow is sufficiently and uniformly heated within a limited pipeline distance.

[0075] During the drip irrigation step, the irrigation water volume is controlled to the amount required to reduce the salt content of the root layer soil to the critical value for alfalfa germination. It should be further noted that in the specific implementation process, the determination of the irrigation water volume needs to consider multiple factors. First, the actual salt content data of the cultivated layer soil is obtained through soil sampling detection, and the target salt threshold value to be reached is determined in combination with the salt tolerance characteristics of the alfalfa variety. According to the soil texture type and initial water content, the leaching water volume per unit area is calculated. For sandy soil, the water volume is appropriately reduced, and for clay soil, the water volume is correspondingly increased but the irrigation rate is controlled.

[0076] In actual operation, the irrigation is carried out in multiple stages. First, a portion of the calculated water volume is used for preliminary leaching, and after a certain interval, the soil electrical conductivity is detected. If the target value is not reached, the remaining water volume is supplemented. Throughout the irrigation process, the drip head water outlet rate is kept matched with the soil infiltration rate to ensure that the water infiltrates uniformly in the root layer without producing surface runoff, ultimately reducing the soil salt content to the appropriate range for alfalfa seed germination while maintaining the soil temperature at a level conducive to germination.

[0077] The microporous structure of the biodegradable soil conservation paper film is used to inhibit soil water evaporation and prevent salt upward movement. It should be further noted that in the specific implementation process, the biodegradable soil conservation paper film is made of plant fiber-based materials, and its surface is uniformly distributed with microporous structures of a specific pore size range, with a pore size range of several microns to several tens of microns. The size of these micropores is carefully designed to allow appropriate gas exchange while effectively blocking the passage of water vapor. When the paper film is laid on the soil surface, its microporous structure can regulate the water vapor transmission rate between the soil and the atmosphere, keeping the soil at an appropriate humidity level. At the same time, this structure can break the capillary action of the soil, block the path of salt upward movement with water, and prevent salt accumulation in the surface soil.

[0078] The degradation characteristics of the paper film are specially treated to maintain its structural integrity during the initial growth period of the alfalfa, and to begin to gradually decompose after the plant has established a good root system, eventually fully integrating into the soil without leaving any residue. During the actual laying process, the paper film needs to be closely attached to the soil surface, and the edges are fixed by soil compaction to ensure the effective functioning of the paper film.

[0079] During the alfalfa seedling stage, the soil is usually kept moist, and under these conditions, the degradable soil conservation paper film can maintain its structural integrity for several tens of days to function. When the soil moisture content is within the field water holding capacity range and the temperature is within the average temperature range of the local planting season, the mechanical properties of the degradable soil conservation paper film can remain intact and not less than the critical growth period required for alfalfa emergence, and then its strength begins to slowly decrease and gradually breaks down within a few months, eventually being completely decomposed by soil microorganisms. The degradation products are mainly organic matter and carbon dioxide.

[0080] The thickness of the transparent mulch film is selected based on the light-heat conversion and heat preservation needs. It should be further noted that in the specific implementation process, the selection of the transparent mulch film needs to consider the light characteristics and temperature maintenance needs of the high-altitude environment. The thickness of the mulch film should ensure sufficient mechanical strength to withstand strong winds, while maintaining good light transmission performance. In the case of sufficient sunlight but low air temperature, selecting an appropriate thickness of the mulch film can effectively transmit solar radiation while reducing soil heat loss. When the mulch film is laid on the soil conservation paper film, the two work together: the lower paper film prevents salt from rising and retains water, and the upper mulch film creates a heat preservation layer, together maintaining the stability of the soil temperature and humidity environment.

[0081] In practical applications, the specific thickness needs to be determined based on the thermal conductivity of the mulch film material, the local solar intensity, and the expected heat preservation effect, to ensure that it can fully absorb solar energy during the day and effectively slow down heat loss at night. When laying, the surface of the mulch film should be flat, and the edges should be buried in the soil and compacted to avoid damage caused by strong winds. As the seasons change and the alfalfa grows, the function of the mulch film and the degradation of the lower paper film remain coordinated, together providing a suitable microenvironment for crop growth.

[0082] The salt and temperature tolerance thresholds in the decision model are determined through comparative tests at different altitude gradients. It should be further noted that in the specific implementation process, the determination of the salt and temperature tolerance thresholds in the decision model is completed through systematic field tests. Multiple test units are set up in different altitude gradient test areas, each independently controlling the soil salt concentration and temperature conditions, and recording the corresponding alfalfa emergence and seedling growth status. During the test process, the soil environmental parameters are continuously monitored, including soil temperature changes at different depths, soil solution conductivity, and meteorological data.

[0083] By comparing and analyzing the seedling emergence rate, uniformity and survival rate of alfalfa under different environmental conditions, the corresponding relationship between soil environmental parameters and planting effect is established. According to the statistical analysis of a large amount of test data, the upper limit value of soil salt content and the lower limit value of temperature that can ensure the normal germination and growth of alfalfa are determined, which will be the core parameters of the decision model. In practical application, the decision model will compare the current monitoring data with these threshold parameters in real time, and only when the soil environment meets the requirements of salt and temperature at the same time, the system will recommend to carry out seeding operation.

[0084] An alfalfa planting management system based on high-altitude saline-alkali land is used to realize an alfalfa planting management method based on high-altitude saline-alkali land, comprising:

[0085] An irrigation unit comprising a water source, a dark preheating pipeline and a drip irrigation device, the input end of the dark preheating pipeline being connected to the water source, and the output end being connected to the drip irrigation device;

[0086] A monitoring unit comprising a soil temperature sensor and a soil salt content sensor;

[0087] A control unit connected to the monitoring unit, having a decision model built-in, for processing monitoring data and weather information;

[0088] A covering unit comprising degradable soil conservation paper film and transparent mulch film.

[0089] It should be further explained that in the specific implementation process, the alfalfa planting system realizes planting management through the cooperation of each unit. In the irrigation unit, the dark preheating pipeline is laid in a specific meandering shape on the surface of the field, the water inlet end is connected to the water source through a water pump, and the water outlet end is connected to the drip irrigation belt through a shunt device. The soil temperature sensor and the soil salt content sensor of the monitoring unit are buried in the soil at different depths, and the monitoring data is transmitted to the control unit through wired or wireless means.

[0090] The decision model built-in the control unit receives monitoring data and external weather information, and outputs the seeding timing judgment result after data processing and analysis. The degradable soil conservation paper film and the transparent mulch film in the covering unit are laid in order, the paper film is directly covered on the soil surface, and the mulch film is covered on the paper film, and the edges of the two films are fixed with soil compaction. Through the systematic connection and cooperation of each unit, the coordinated regulation of water, temperature and salt is realized, and the normal germination and growth of alfalfa under the condition of high-altitude saline-alkali land are ensured.

[0091] In the irrigation unit, the water pump is connected to the dark preheating pipeline, and the pipeline is connected to the drip irrigation belt through a quick sealing interface, ensuring that the waterway is unobstructed and leak-free. The sensors of the monitoring unit are connected to the data receiving interface of the control unit through waterproof cables or wireless transmission modules, and the transmission protocol uses the standard Modbus protocol. After analyzing the data, the processing module of the control unit generates operation instructions, which are sent to the water pump, valve, and other actuators through a relay output circuit or industrial bus instructions. The system software has a self-diagnosis program that can monitor water pressure, data flow anomalies, and other conditions in real time and trigger audible and visual alarms.

[0092] The dark preheating pipeline is arranged in a meandering and coiled manner to increase the heating area and time of the water flow. It should be further noted that in the specific implementation process, the dark preheating pipeline is laid out in a systematic manner in the field, with the pipeline extending in a continuous undulating path and maintaining a uniform distance between adjacent pipelines. This meandering and coiled arrangement allows the pipeline to have a larger exposed surface area per unit area, with the pipeline orientation being adapted to the local solar angle to ensure that it can fully receive solar radiation at different times. The pipeline is fixed using adjustable ground anchors that can be adjusted adaptively according to the terrain, ensuring that the pipeline maintains stable contact with the ground.

[0093] The flow guide structure designed on the inner wall of the pipeline causes the water flow to generate moderate turbulence when passing through, enhancing the heat exchange efficiency between the water and the pipeline wall. The overall layout of the pipeline system takes into account the needs of subsequent farmland operations, leaving enough space for mechanical access. In the implementation process, the curvature radius of the pipeline laying is optimized to ensure smooth water flow and maximize solar radiation absorption area, ensuring that the irrigation water is fully heated during its passage through the pipeline.

[0094] The decision model optimizes model parameters based on the correlation analysis of historical environmental data and emergence rate. It should be further noted that in the specific implementation process, the decision model collects environmental monitoring data and corresponding alfalfa emergence rate data from different test areas to establish a correlation database between environmental parameters and planting results. The system regularly analyzes historical data to identify key environmental factors affecting emergence rate and their weight relationships. When new data deviates from the original model prediction, the system automatically starts the parameter optimization program to adjust parameters such as temperature compensation coefficients and salinity influence factors through iterative calculations.

[0095] During optimization, factors such as different altitudes, soil types, and seasonal changes are considered to ensure that model parameters adapt to specific application environments. Verified optimized parameters are updated to the decision model, allowing the model to more accurately reflect the relationship between local environmental conditions and alfalfa growth response, thereby improving the accuracy of sowing timing recommendations.

[0096] Among them, the model parameter optimization is an iterative process: firstly, the collected historical environmental data and emergence rate data are preprocessed to eliminate invalid and abnormal data. Subsequently, the sensitivity analysis method is used to evaluate the weight of the influence degree of temperature, salinity and other parameters on the emergence rate. The optimization objective function is defined as the minimization of the error between the predicted emergence rate and the actual emergence rate. The system uses optimization algorithms such as gradient descent to automatically adjust the temperature compensation coefficient and salinity influence factor and other parameters in the model. When the error value calculated by continuous multiple iterations is less than the preset convergence threshold, it is determined that the optimization is completed, and the new parameters are updated to the decision model.

[0097] The control unit includes a data receiving module, a processing module and an output module. The data receiving module is connected to the monitoring unit, the processing module runs the decision model, and the output module provides sowing timing suggestions. It needs to be further explained that in the specific implementation process, the data receiving module of the control unit continuously collects the soil temperature and soil salinity data sent by the monitoring unit through wired or wireless transmission mode, and simultaneously accesses the environmental information of the external weather forecasting system. The decision algorithm built-in processing module fuses and analyzes the received multi-source data, first performs data validity check to exclude abnormal monitoring values, and then inputs the processed data into the parameter-optimized decision model for calculation.

[0098] The output module generates specific operation suggestions according to the model operation results. When the environmental parameters meet the temperature threshold and salinity threshold conditions at the same time, the output module will issue a signal that sowing operation can be performed, and will present the recommended operation time, predicted environmental condition trend and other information to the operator through the human-machine interface.

[0099] The whole control process adopts a closed-loop feedback mechanism, and continues to monitor the emergence after sowing operation, and returns the actual planting effect data to the processing module for subsequent model parameter optimization and decision precision improvement.

[0100] The control unit adopts modular design, and the data receiving module includes a multi-channel analog-digital conversion circuit and a wireless communication module for receiving voltage and current signals from sensors and converting them into digital signals. The processing module takes an embedded microcontroller as the core, on which the decision algorithm software runs. The output module includes a liquid crystal display screen for displaying environmental data and suggestions, and provides relay switching output to directly control the irrigation valve, and has an RS485 communication interface for sending data to the upper computer. Each module is connected through the internal circuit board bus for data and power connection and works cooperatively.

[0101] It needs to be further explained that in the specific implementation process, first of all, it is necessary to build an irrigation water preheating system. The dark high polymer pipeline is laid on the surface of the field in a specific meandering form, the pipeline water inlet end is connected with the water source, and the water outlet end is connected with the drip irrigation system. Under the condition of sunlight, the water flowing through the pipeline absorbs solar energy and is heated, and the inner wall of the pipeline is designed to facilitate heat exchange. The heated water is applied to the field through the drip irrigation system, and the irrigation water quantity needs to be determined comprehensively according to the soil salt content detection result and the target salt washing requirement, to ensure that the salt content of the root layer is effectively leached while excessive irrigation is avoided.

[0102] Immediately after irrigation is completed, seeding operation is carried out, and then layered covering is implemented. First, a layer of degradable soil moisture preservation paper film with a microporous structure is laid on the surface of the soil, which can regulate soil moisture evaporation and inhibit salt rise. A layer of transparent mulch film is covered on the paper film, and the thickness of the mulch film is selected to consider the light transmission and heat preservation. The edges of the two layers of covering materials are fixed with soil compaction. This covering structure can effectively maintain the soil temperature and humidity environment.

[0103] The construction and application of the decision model are key technical links. Through field tests at different altitudes, the corresponding relationship between soil temperature, soil salt content and alfalfa emergence rate is recorded, and an environmental parameter database is established. Based on a large amount of test data, the temperature critical value and salt critical value of alfalfa germination are determined. In actual application, the monitoring system collects soil environmental data in real time, and the decision model analyzes and calculates based on the current monitoring data and weather forecast information. When the soil temperature is continuously higher than the critical temperature and the soil salt content is lower than the critical salt content, the system determines that it is the appropriate seeding time.

[0104] The system components work together. The irrigation unit ensures water heating and accurate delivery; the monitoring unit collects environmental data through a sensor network buried in the soil; the control unit processes data and runs the decision algorithm; the covering unit provides physical protection. Through systematic connection and cooperation, each unit realizes the coordinated regulation of environmental factors such as water, temperature, salt, etc.

[0105] The decision model has a self-learning optimization function. The system continuously collects planting effect data, and when there is a difference between the actual emergence and the prediction, the parameter optimization program is automatically started, the model parameters are adjusted through iterative calculation, so that the decision model continuously adapts to the local environmental conditions, and the accuracy of the recommended seeding time is improved.

[0106] During the entire implementation process, attention is paid to the connection and cooperation of each link. The pipeline laying considers the topographic factors and the sunlight angle, the irrigation operation considers the soil texture and the infiltration characteristics, the covering operation considers the material characteristics and the fixing method, and the decision system considers the data accuracy and the real-time performance. Through systematic management measures, alfalfa can normally germinate and grow in high-altitude saline-alkali land conditions.

[0107] A high-altitude saline-alkali land-based alfalfa planting management method, comprising the following steps:

[0108] Step S1: Laying a dark preheating pipeline system, arranging the pipeline in a serpentine manner on the field surface, connecting the water source and the drip irrigation system, and heating the irrigation water flowing through the pipeline using solar radiation;

[0109] Step S2: Calculating the required irrigation water volume according to the real-time detected soil salt content and target salt washing requirements, and implementing split drip irrigation operation using preheated water to reduce the soil salt content to the suitable range for alfalfa germination;

[0110] Step S3: Immediately after irrigation, alfalfa is sown, and then layered mulching is implemented, first laying a degradable soil conservation paper film with a microporous structure, and then covering a transparent mulch film, with the edges fixed by soil compaction;

[0111] Step S4: Real-time collection of soil temperature and salt data through a monitoring system, combined with weather forecast information, using a decision model to analyze environmental parameters, and determining the optimal sowing time when the soil temperature is continuously higher than the germination threshold and the salt content is lower than the threshold;

[0112] Step S5: Continuously collecting germination rate and environmental data during planting, and automatically optimizing the decision model parameters when there is a difference between the actual growth and the prediction, to improve the accuracy of subsequent sowing time recommendations.

[0113] Through the combination of preheating of irrigation water and precise drip irrigation, the contradiction between salt washing operation and soil temperature maintenance in high-altitude areas is effectively solved. Preheating of irrigation water avoids the sudden drop in soil temperature caused by cold water irrigation, and layered mulching technology cooperatively inhibits water evaporation and salt upward movement while maintaining stable soil temperature, creating a suitable water temperature and salt environment for alfalfa seed germination, thereby improving the uniformity of emergence and the survival rate of seedlings.

[0114] The decision model is used to dynamically determine the sowing time, and through multi-source data fusion analysis and adaptive optimization mechanism, the precision and intelligence of planting management are realized. This system method not only improves the reliability of alfalfa planting in high-altitude saline-alkali land, but also reduces the use of water resources and mulching materials through optimized resource allocation, providing a referenceable technical path for crop planting under similar environmental conditions.

[0115] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting; it is not intended to exclude myriad other embodiments of the present application that other inventors can develop based on the same general inventive concepts embodied by the described embodiments. That is, although the present application is described in terms of particular embodiments and implementations, it is to be understood that the terminology used is for the purpose of descriptive clarity and that it should be taken in its broadest possible sense. For example, the terms "a", "an", and "the" include both singular and plural referents unless the context clearly dictates otherwise. The terms "comprises", "comprising", "includes", "including" and the like can be used in conjunction with the term "consisting of to include the elements or steps listed after such conjunctive language, but not to the exclusion of other elements or steps. The singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. The term "plurality" means two or more. The term "consisting essentially of to provide that the composition or process include additional steps, elements, compounds, compositions of matter, or materials not specifically recited. The use of the terms "first", "second", and the like does not imply any particular ordering, but rather are used to denote distinct and separate steps. Where the context requires, the singular forms "a", "an" and "the" include their corresponding plural referents unless the context clearly dictates otherwise. Terms such as "above" and "below" refer to positions relative to the orientation of the figures and are used for purposes of illustration and description only. Terms such as "first" and "second" are used to identify various elements, but the elements should not be limited by these terms. The use of the terms "first" and "second" are not necessarily intended to connote chronological order, but rather serve as labels to distinguish one element from another. The use of the terms "a", "an", and "the" and / or the use of articles in the singular and plural sense are intended to cover a

[0116] While the embodiments of the application have been shown and described herein, it is understood that modifications, substitutions, combinations, and variations of the embodiments can be undertaken by those skilled in the art without departing from the spirit and scope of the present application, which is defined by the following claims and their equivalents.

Claims

1. A method for alfalfa planting and management in high-altitude saline-alkali land, characterized in that, Includes the following steps: S1: Irrigation water preheating step: The irrigation water is preheated by solar energy by flowing through dark pipes laid on the ground. S2: Drip Irrigation Procedure: Preheated irrigation water is used to irrigate the field via drip irrigation. The irrigation water volume is determined based on the initial soil salinity and the target salt leaching depth. Specifically: the initial soil salinity is defined as the soil electrical conductivity EC0 of the 0-20cm root zone. EC0 is obtained through a soil salinity sensor or laboratory testing, measured after extraction at a soil-to-water ratio of 1:5; the target salt leaching depth corresponds to the critical value EC0 of the root zone soil electrical conductivity. t The critical salt tolerance for alfalfa germination was set at EC. t ≤3.0mS / cm, adjusted to EC for altitudes above 3500m. t ≤2.5 mS / cm; simultaneously, soil leaching rate η, field water holding capacity θf, soil bulk density ρb, topsoil thickness h, and soil texture adjustment coefficient k were obtained, where η ranged from 0.6 to 0.8 and was determined through field trials; θf was measured using the ring cutter method, with 15%–20% for sandy soil, 20%–25% for loam, and 25%–30% for clay soil; and ρb was 1.3–1.5 g / cm³. 3 h is taken as 0.2m, and k is set according to soil texture: 0.8-0.9 for sandy soil, 1.0-1.1 for loam, and 1.2-1.3 for clay soil; irrigation water volume is calculated according to the formula W=[(EC0-EC t )×ρb×h×667] / (η×θf×EC t )×k, unit is m 3 / mu; A multi-stage irrigation method was adopted. The first irrigation applied 0.6W of fertilizer. 24 hours after irrigation, the EC1 of the 0-20cm soil layer was measured. If EC1 > EC t Then supplement with 0.3W of irrigation and check EC2 again. If EC2 ≤ EC t Stop irrigation immediately; if the standard is still not met, replenish the remaining 0.1W. S3: Layered covering steps: After drip irrigation and sowing, first lay a biodegradable moisture-retaining paper film with a microporous structure, and then cover it with a transparent mulch film; S4: Sowing Decision Steps: Based on real-time monitoring of soil temperature, soil salinity data, and weather forecast information, the optimal sowing time is determined through a decision model. Specifically, the monitoring indicators include the average daily temperature (T) of the 5cm soil layer for three consecutive days, the electrical conductivity (EC) of the 0-20cm soil layer, the probability of the average daily temperature ≥T threshold for the next three days, and the probability of no ≥5mm precipitation in the next three days. T is detected by soil temperature sensors, with one sensor deployed for every 5 acres. EC is detected by soil salinity sensors at the same locations as the temperature sensors. Weather forecast information is sourced from official meteorological platforms. The thresholds for T and EC are determined based on altitude gradients: at 2500m altitude, T ≥ 10℃ and EC ≤ 3.0mS / cm; at 3000m altitude, T ≥ 8℃ and EC ≤ 2.8mS / cm; at 3500m altitude, T ≥ 10℃ and EC ≤ 2.8mS / cm. For soil samples with T≥6℃ and EC≤2.5mS / cm, the probabilities of the average daily temperature ≥T threshold in the next 3 days are ≥90%, ≥85%, and ≥80%, respectively, and the probabilities of no ≥5mm precipitation in the next 3 days are ≥85%, ≥80%, and ≥75%, respectively. The decision model first removes abnormal data with T<0℃ or EC>10mS / cm, and then performs single-indicator comparison. If all indicators meet the standards, the soil is deemed suitable for sowing. If only one indicator fails to meet the standards, the soil temperature, soil salinity, and weather forecast are weighted at 40%, 40%, and 20%, respectively. The indicators that meet the standards are scored according to their weights, and the indicators that fail to meet the standards are scored by multiplying the ratio of the actual value to the threshold by the weight. If the total score is ≥80%, sowing is recommended; otherwise, sowing is deemed unsuitable. The salinity and temperature tolerance thresholds of this model were determined through comparative experiments at different altitude gradients.

2. The alfalfa planting and management method based on high-altitude saline-alkali land according to claim 1, characterized in that: The dark-colored pipes are made of polymer materials and are laid on the ground in a winding manner.

3. The alfalfa planting and management method based on high-altitude saline-alkali land according to claim 1, characterized in that: In the drip irrigation step, the irrigation water volume is controlled at the amount required to reduce the soil salinity in the root zone to the critical value for alfalfa germination.

4. The alfalfa planting and management method based on high-altitude saline-alkali land according to claim 1, characterized in that: The microporous structure of the biodegradable moisture-retaining paper film is used to inhibit soil moisture evaporation and prevent salt from returning to the soil.

5. The alfalfa planting and management method based on high-altitude saline-alkali land according to claim 1, characterized in that: The thickness of the transparent mulch film is selected based on the requirements for photothermal conversion and heat preservation.

6. The alfalfa planting and management method based on high-altitude saline-alkali land according to claim 1, characterized in that: The salinity and temperature tolerance thresholds in the decision-making model were determined through comparative experiments at different altitude gradients.

7. An alfalfa planting management system based on high-altitude saline-alkali land, used to implement the method described in any one of claims 1-6, characterized in that, include: An irrigation unit includes a water source, a dark preheating pipe, and a drip irrigation device. The dark preheating pipe is connected to the water source at its inlet and to the drip irrigation device at its outlet. The monitoring unit includes a soil temperature sensor and a soil salinity sensor; The control unit, connected to the monitoring unit, has a built-in decision model for processing monitoring data and meteorological information; Covering units include biodegradable moisture-retaining paper film and transparent mulch film.

8. The alfalfa planting management system based on high-altitude saline-alkali land according to claim 7, characterized in that: The dark-colored preheating pipes are arranged in a winding and coiled manner to increase the heating area and time of the water flow.

9. The alfalfa planting management system based on high-altitude saline-alkali land according to claim 7, characterized in that: The decision-making model optimizes its parameters based on the correlation analysis between historical environmental data and seedling emergence rate.

10. An alfalfa planting management system based on high-altitude saline-alkali land according to claim 7, characterized in that: The control unit includes a data receiving module, a processing module, and an output module. The data receiving module is connected to the monitoring unit, the processing module runs a decision model, and the output module provides suggestions on planting timing.

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