Method, device and equipment for measuring and calculating recommended nitrogen topdressing amount of corn

Abstract

The invention relates to a method, device and equipment for measuring and calculating the recommended nitrogen topdressing amount of corn, and the method comprises the steps: calculating the time for reaching the next growth stage through meteorological data and the current growth stage of corn; future meteorological data of the next growth stage is combined with the current corn growth state, the daily potential nitrogen demand of the growth stage is calculated based on the corn growth law, and daily accumulation is the total nitrogen demand of the growth stage; and calculating the optimal recommended nitrogen topdressing amount according to the corn nitrogen demand quantity and the pre-obtained nitrogen fertilizer utilization efficiency. It can be understood that by means of the method, real-time accurate matching of the nitrogen application amount and the corn growth nitrogen demand is achieved, a scientific basis is provided for accurate nitrogen management of corn, and therefore the nitrogen fertilizer utilization rate is increased, the environmental load is reduced, and the growth performance and yield of corn are optimized.

Description

Technical Field

[0001] The present invention relates to the field of agricultural planting technology, and in particular to a method, device and equipment for calculating the recommended nitrogen topdressing amount for corn. Background Art

[0002] The existing technology calculates the amount of topdressing nitrogen based on the target corn yield, the basic nitrogen supply capacity of the soil, the empirical corn nitrogen demand law and the nitrogen fertilizer utilization efficiency. (1) First, calculate the total nitrogen requirement of corn based on the target yield. The target yield is a reasonable indicator set based on historical data, regional climate conditions, variety characteristics and planting management level. According to the nitrogen absorption law of corn, the total amount of nitrogen required to meet the target yield is obtained through the relationship formula between the target yield and the nitrogen requirement per unit yield. (2) Secondly, deduct the nitrogen requirement based on the basic nitrogen supply capacity of the soil and the amount of nitrogen in the base fertilizer. The basic nitrogen supply capacity of the soil includes the empirical amount of nitrogen released by the mineralization of soil organic matter and the residual nitrogen in the soil. Determine the amount of effective nitrogen that can be provided through soil test data or estimation models, and deduct it from the nitrogen requirement of the crop. (3) Finally, divide the deducted nitrogen requirement by the empirical nitrogen fertilizer utilization rate to obtain the amount of nitrogen fertilizer required for topdressing.

[0003] Although the target yield method is scientific in the application of nitrogen fertilizer recommendation, it also has some limitations and disadvantages:

[0004] Strong dependence on target yield: The precise setting of target yield is the key to this method, and this process is highly dependent on data accuracy and experience. Target yields often rely on historical data, expert experience or regional statistics, while ignoring the differences between individual plots. If the target yield is set too high, it may lead to excessive fertilization, which not only wastes resources but also increases the risk of environmental pollution; if the target yield is set too low, it may cause insufficient fertilization, affecting crop yields and farmers' income.

[0005] Ignoring environmental and climatic uncertainties: The target yield method usually assumes that the crop growth environment is relatively stable. However, in actual production, the complexity and uncertainty of climatic conditions may significantly affect the growth and nitrogen demand of crops. For example, extreme weather such as drought, floods or extreme high temperatures may significantly reduce the ability of crops to absorb nitrogen. This makes the target yield method inadequate in dynamically responding to climate change and abnormal weather, reducing its actual guiding value.

[0006] Insufficient environmental impact assessment: The target yield method mainly focuses on increasing yields and the economic benefits of nitrogen fertilizers, but pays less attention to the environmental impacts of nitrogen fertilizer application. Excessive nitrogen application may cause nitrogen to enter groundwater through leaching, causing eutrophication of water bodies; or be emitted into the atmosphere in the form of nitrous oxide, becoming a greenhouse gas, which has a negative impact on ecosystems and climate change. In addition, excessive nitrogen application may also destroy the ecological balance of the soil and reduce soil fertility. The lack of a systematic environmental assessment and constraint mechanism makes it difficult for the target yield method to fully meet the needs of ecological protection in sustainable agricultural development. Summary of the invention

[0007] In view of this, the purpose of the present invention is to provide a method, device and equipment for calculating the recommended topdressing nitrogen amount for corn, so as to solve the problem of insufficient accuracy of the topdressing nitrogen amount calculation method in the prior art.

[0008] According to a first aspect of an embodiment of the present invention, a method for calculating a recommended topdressing nitrogen amount for corn is provided, comprising:

[0009] Obtain meteorological data, and calculate the time when the corn will reach the next growth and development stage based on future meteorological data and the current growth and development stage of the corn;

[0010] According to future meteorological data and the current corn growth status, the daily potential nitrogen demand in the current growth stage is calculated based on the corn growth law;

[0011] According to the time when corn reaches the next growth and development stage, the daily potential nitrogen demand of the current growth stage is accumulated to calculate the nitrogen demand of corn when it reaches the next growth and development stage;

[0012] The optimal recommended amount of nitrogen topdressing is calculated based on the nitrogen demand of corn and the nitrogen fertilizer use efficiency obtained in advance.

[0013] Preferably, the time when the corn reaches the next growth and development stage is calculated based on future meteorological data and the current growth and development stage of the corn, including:

[0014] Calculate the future effective accumulated temperature data based on future meteorological data;

[0015] Based on the future effective accumulated temperature data and the current growth and development stage of corn, the time when corn reaches the next growth and development stage can be calculated.

[0016] Preferably, the daily potential nitrogen demand at the current growth stage is calculated based on the future meteorological data and the current corn growth status and the corn growth law, including:

[0017] According to the current corn growth status and future meteorological data, the daily dry matter growth is calculated;

[0018] Obtain the effective accumulated temperature accumulation according to the effective accumulated temperature data;

[0019] According to the cumulative effective temperature, the nitrogen concentration of the plant is calculated;

[0020] The daily potential nitrogen requirement is calculated based on the daily dry matter growth and plant nitrogen concentration.

[0021] Preferably, the daily dry matter increase is calculated based on the current corn growth status and future meteorological data, including:

[0022] According to the leaf area index in the current growth state of corn, the light energy interception ratio is calculated;

[0023] The daily dry matter growth is calculated based on the light energy interception ratio and future meteorological data.

[0024] Preferably, the method for calculating the recommended topdressing nitrogen amount for corn further comprises:

[0025] The leaf area index LAI is calculated based on the effective accumulated temperature. i , the formula is as follows:

[0026]

[0027] Among them, LAI max It indicates the growth upper limit of corn leaf area index under certain environmental conditions; a indicates the basic state parameter; b indicates the growth rate coefficient; GDD sum Indicates the effective accumulated temperature.

[0028] Preferably, the daily dry matter growth ΔW is calculated based on the light energy interception ratio and future meteorological data. i , the calculation formula is as follows:

[0029] ΔW i =0.5*RS i *f int *LUE max *f W *f T

[0030]

[0031] Among them, 0.5 represents the proportion of photosynthetically active radiation to total radiation; RS i is the total radiation; f int is the light energy interception ratio; k is the extinction coefficient, is a parameter; LUE max is the light energy utilization efficiency under the optimal conditions; f W is the correction factor of water on light energy utilization efficiency; f TIt is the correction factor of air temperature on light energy utilization efficiency.

[0032] Preferably, the method for calculating the recommended topdressing nitrogen amount for corn further comprises:

[0033] The effective accumulated temperature data are calculated based on the daily minimum temperature, daily maximum temperature, the maximum threshold of corn growth and development, and the minimum threshold of corn growth and development in the meteorological data.

[0034] Preferably, the method for calculating the recommended topdressing nitrogen amount for corn further comprises:

[0035] The effective accumulated temperature data is used to calculate each corn growth and development stage. The formula is as follows:

[0036]

[0037] Among them, S represents the growth and development stage of corn, GDD is the effective accumulated temperature, and GDD stage is the accumulated temperature at each development stage, and is the parameter.

[0038] According to a second aspect of an embodiment of the present invention, a device for calculating the recommended nitrogen topdressing amount for corn is provided, comprising:

[0039] The time calculation module is used to obtain meteorological data and calculate the time when the corn reaches the next growth and development stage based on the future meteorological data and the current growth and development stage of the corn;

[0040] The nitrogen demand calculation module is used to calculate the daily potential nitrogen demand of the current growth stage based on the future meteorological data and the current corn growth status and the growth law of corn; according to the time when the corn reaches the next growth and development stage, the daily potential nitrogen demand of the current growth stage is accumulated to calculate the nitrogen demand of the corn when it reaches the next growth and development stage;

[0041] The topdressing nitrogen amount calculation module is used to calculate the optimal recommended topdressing nitrogen amount based on the nitrogen demand of corn and the nitrogen fertilizer utilization efficiency obtained in advance.

[0042] According to a third aspect of an embodiment of the present invention, a device for calculating the recommended nitrogen topdressing amount for corn is provided, comprising:

[0043] A main controller, and a memory connected to the main controller;

[0044] a memory in which program instructions are stored;

[0045] The main controller is used to execute program instructions stored in the memory to perform any of the above methods.

[0046] The technical solution provided by the embodiments of the present invention may have the following beneficial effects:

[0047] It is understandable that the technical solution shown in the present invention can calculate the time to reach the next growth stage through meteorological data and the current growth stage of corn; then by combining the future meteorological data before reaching the next growth stage with the current corn growth state, the potential nitrogen demand of the growth stage is calculated based on the growth law of corn, and the daily accumulation is the total nitrogen demand of the growth stage; according to the nitrogen demand of corn and the nitrogen fertilizer utilization efficiency obtained in advance, the optimal recommended nitrogen topdressing amount is calculated. It is understandable that through this method, the real-time and accurate matching of nitrogen application amount and nitrogen demand of corn growth is achieved, providing a scientific basis for the precise nitrogen management of corn, thereby improving the utilization rate of nitrogen fertilizer, reducing environmental load, and optimizing the growth performance and yield of corn.

[0048] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0050] Figure 1 It is a schematic diagram of the steps of a method for calculating the recommended topdressing nitrogen amount for corn according to an exemplary embodiment;

[0051] Figure 2 It is a data calculation flow chart of a method for calculating the recommended topdressing nitrogen amount for corn according to an exemplary embodiment. DETAILED DESCRIPTION

[0052] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

[0053] In one embodiment, Figure 1 is a schematic diagram of a method for calculating the recommended amount of topdressing nitrogen for corn according to an exemplary embodiment. Figure 1 , a method for calculating the recommended amount of nitrogen for corn is provided, including:

[0054] Step S11, obtaining meteorological data, and calculating the time when the corn reaches the next growth and development stage according to the future meteorological data and the current growth and development stage of the corn.

[0055] Step S12: According to future meteorological data and the current corn growth status, the daily potential nitrogen demand in the current growth stage is calculated based on the corn growth law.

[0056] Step S13, according to the time when the corn reaches the next growth and development stage, the daily potential nitrogen demand of the current growth stage is accumulated to calculate the nitrogen demand of the corn when it reaches the next growth and development stage.

[0057] Step S14: Calculate the optimal recommended nitrogen topdressing amount based on the nitrogen demand of corn and the nitrogen fertilizer utilization efficiency obtained in advance.

[0058] It is understandable that the technical solution shown in this embodiment can calculate the time to reach the next growth stage through meteorological data and the current growth stage of corn; then by combining the future meteorological data before reaching the next growth stage with the current corn growth state, the potential nitrogen demand of the growth stage is calculated based on the growth law of corn, and the daily accumulation is the total nitrogen demand of the growth stage; according to the nitrogen demand of corn and the nitrogen fertilizer utilization efficiency obtained in advance, the optimal recommended nitrogen topdressing amount is calculated. It is understandable that through this method, the real-time and accurate matching of nitrogen application amount and nitrogen demand of corn growth is achieved, providing a scientific basis for the precise nitrogen management of corn, thereby improving the utilization rate of nitrogen fertilizer, reducing environmental load, and optimizing the growth performance and yield of corn.

[0059] In specific practice, the specific data calculation process can be found in Figure 2 .

[0060] In step S11, it should be noted that the time for the corn to reach the next growth and development stage is calculated based on future meteorological data and the current growth and development stage of the corn, including:

[0061] The future effective accumulated temperature data is calculated based on the future meteorological data; the time when the corn reaches the next growth and development stage is calculated based on the future effective accumulated temperature data and the current growth and development stage of the corn.

[0062] It should be noted that the effective accumulated temperature can be obtained by the daily minimum temperature (T min ,℃), daily maximum temperature (T max ,℃), the highest threshold of corn growth and development (T h , ℃) and the minimum threshold (T l , ℃) calculation, the formula is as follows:

[0063]

[0064] Among them, GDD is the effective accumulated temperature, T mean (℃) is the average temperature, α, δ, β are all intermediate variables, and the calculation formula is as follows:

[0065]

[0066] When calculating the growth and development stage, it should be noted that the effective accumulated temperature data is used to calculate each corn growth and development stage. The formula is as follows:

[0067]

[0068] Among them, S represents the growth and development stage of corn, with a value range of 0-6. When S=0, it represents the seedling stage; when S=1, it represents the silking stage; when S=2, it represents R2; when S=3, it represents R3; when S=4, it represents R4; when S=5, it represents R5; when S=6, it represents R6; GDD is the effective accumulated temperature, GDD stage (℃) is the accumulated temperature at each development stage and is a parameter.

[0069] It is understandable that by accurately calculating the effective accumulated temperature data and combining the accumulated temperature parameters of the corn growth stage to determine the time to reach the next stage, a key time node basis is provided for the subsequent accurate prediction of corn nitrogen demand. Compared with traditional methods, it can more accurately grasp the growth rhythm of corn, closely combine the nitrogen demand prediction with the actual growth process of corn, and further improve the accuracy and scientificity of the entire recommended nitrogen topdressing amount calculation method.

[0070] It should be noted that, in step S12, the daily potential nitrogen demand at the current growth stage is calculated based on the future meteorological data and the current corn growth status and the corn growth law, including:

[0071] According to the current corn growth status and future meteorological data, the daily dry matter growth is calculated; the effective accumulated temperature accumulation is obtained according to the effective accumulated temperature data, and the effective accumulated temperature data can be historical effective accumulated temperature data and future effective accumulated temperature data; according to the effective accumulated temperature accumulation, the plant nitrogen concentration is calculated; according to the daily dry matter growth and the plant nitrogen concentration, the daily potential nitrogen demand is calculated.

[0072] It is understandable that through detailed multi-parameter calculation steps, the effects of light energy utilization, accumulated temperature accumulation and other factors on nitrogen demand during corn growth are fully considered. Compared with simple empirical estimates, this method can more accurately reflect the changes in nitrogen demand of corn under different growth environments and physiological conditions, and provide more reliable basic data for accurate recommendation of topdressing nitrogen, thereby improving nitrogen fertilizer utilization efficiency and promoting corn growth and yield increase.

[0073] It should be noted that in the calculation of the daily potential nitrogen demand, the daily dry matter growth is calculated based on the current corn growth status and future meteorological data, including:

[0074] The light energy interception ratio is calculated based on the leaf area index of the current corn growth status; the daily dry matter growth is calculated based on the light energy interception ratio and future meteorological data.

[0075] The leaf area index LAI is calculated based on the effective accumulated temperature. i , the formula is as follows:

[0076]

[0077] Among them, LAI max It indicates the growth upper limit of corn leaf area index under certain environmental conditions; a(-) indicates the basic state parameter; b(-) indicates the growth rate coefficient; GDD sum Indicates the cumulative effective temperature, which is obtained by accumulating the effective accumulated temperature during the seedling emergence period. i (m 2 m -2 ) represents the leaf area index on the i-th day after the current growth stage.

[0078] According to the light energy interception ratio and future meteorological data, the daily dry matter growth ΔW is calculated. i , the calculation formula is as follows:

[0079] ΔW i =0.5*RS i *fi int *LUE max *f W *f T

[0080]

[0081] Among them, 0.5 represents the proportion of photosynthetically active radiation to total radiation; RS i (MJ ha -1 ) is the total radiation, obtained through meteorological forecast; f int is the light energy interception ratio; k(-) is the extinction coefficient, which is a parameter; LUE max (kg MJ -1 ) is the light energy utilization efficiency under the optimal conditions; f W (-) is the correction factor of water on light energy utilization efficiency; f T (-) is the correction factor of air temperature on light energy utilization efficiency.

[0082] It is understandable that using leaf area index as the key parameter to calculate the light energy interception ratio and then calculate the dry matter growth fully considers the important impact of corn leaf growth on photosynthesis and nitrogen absorption and utilization. This calculation method based on the actual growth morphology of corn makes the nitrogen demand prediction more in line with the biological characteristics of corn, improves the pertinence and accuracy of the entire measurement method, and helps to achieve precise fertilization and reduce nitrogen fertilizer waste and environmental risks.

[0083] After the effective accumulated temperature is calculated in step S12, the plant nitrogen concentration NC can be calculated based on the effective accumulated temperature. i , the formula is as follows:

[0084]

[0085] A and B are both empirical parameters.

[0086] In step S12, the plant nitrogen concentration NC is calculated. i After that, the daily potential nitrogen requirement of the current growth and development stage is calculated by the following formula:

[0087] NDPD i =ΔW i *NC i

[0088] NDPD i (kg N ha -1 d -1 ) represents the daily potential nitrogen demand on the i-th day after the current growth stage, which is expressed by the daily dry matter increase (ΔW i , kg ha -1 ) and plant nitrogen concentration (NC i ,kg kg -1 )calculate.

[0089] After calculating the daily potential nitrogen demand of the current growth and development stage, step S13 can be executed to calculate the nitrogen demand of corn when it reaches the next growth and development stage. The formula is as follows:

[0090]

[0091] NDPD sum (kg N ha -1 ) represents the nitrogen requirement of corn at this growth stage; n(day) represents the number of days between the current growth stage and the next growth stage.

[0092] In step S14, the optimal recommended nitrogen topdressing amount N is calculated based on the nitrogen demand of corn and the nitrogen fertilizer utilization efficiency obtained in advance, and the formula is as follows:

[0093] N=NDPD sum / NUE

[0094] NUE (-) represents nitrogen utilization efficiency, which is an empirical parameter determined based on a large amount of field test data.

[0095] It can be understood that the method of the algorithm for recommending the amount of nitrogen topdressing based on the dynamic prediction of corn nitrogen demand provided in this embodiment is different from the prior art in the following aspects: (1) In the prior art, the determination of the amount of nitrogen topdressing for corn is often based on a fixed empirical formula or a single parameter, such as soil nitrogen content or fertilization history. However, this static method fails to dynamically respond to changes in nitrogen demand during corn growth. The present technical solution uses future meteorological data and the current growth status of corn to predict the potential nitrogen demand in the next growth stage and achieve dynamic tracking over time. (2) Traditional nitrogen application algorithms focus more on results, that is, the yield performance after nitrogen application, while ignoring the dynamic regulation and allocation optimization of the nitrogen fertilizer application process. The present technology implements a real-time update mechanism: combining meteorological forecasts with real-time growth data, the nitrogen demand forecast is updated every day to ensure that the recommended nitrogen application amount is dynamically adjusted to match actual demand.

[0096] According to a second aspect of an embodiment of the present invention, a device for calculating the recommended nitrogen topdressing amount for corn is provided, comprising:

[0097] The time calculation module is used to obtain meteorological data and calculate the time when the corn reaches the next growth and development stage based on the future meteorological data and the current growth and development stage of the corn;

[0098] The nitrogen demand calculation module is used to calculate the daily potential nitrogen demand of the current growth stage based on the future meteorological data and the current corn growth status and the growth law of corn; according to the time when the corn reaches the next growth and development stage, the daily potential nitrogen demand of the current growth stage is accumulated to calculate the nitrogen demand of the corn when it reaches the next growth and development stage;

[0099] The topdressing nitrogen amount calculation module is used to calculate the optimal recommended topdressing nitrogen amount based on the nitrogen demand of corn and the nitrogen fertilizer utilization efficiency obtained in advance.

[0100] According to a third aspect of an embodiment of the present invention, a device for calculating the recommended nitrogen topdressing amount for corn is provided, comprising:

[0101] A main controller, and a memory connected to the main controller;

[0102] a memory in which program instructions are stored;

[0103] The main controller is used to execute program instructions stored in the memory to perform any of the above methods.

[0104] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

[0105] It should be noted that, in the description of the present invention, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, the meaning of "plurality" refers to at least two.

[0106] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention belong.

[0107] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0108] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0109] In addition, each functional unit in each embodiment of the present invention may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0110] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0111] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0112] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for calculating the recommended amount of nitrogen for corn, characterized in that: include: Obtain meteorological data, and calculate the time when the corn will reach the next growth and development stage based on future meteorological data and the current growth and development stage of the corn; According to future meteorological data and the current corn growth status, the daily potential nitrogen demand in the current growth stage is calculated based on the corn growth law; According to the time when corn reaches the next growth and development stage, the daily potential nitrogen demand of the current growth stage is accumulated to calculate the nitrogen demand of corn when it reaches the next growth and development stage; The optimal recommended amount of nitrogen topdressing is calculated based on the nitrogen demand of corn and the nitrogen fertilizer use efficiency obtained in advance.

2. The method for calculating the recommended nitrogen topdressing amount for corn according to claim 1, characterized in that: Based on future meteorological data and the current growth and development stage of corn, the time when corn will reach the next growth and development stage is calculated, including: Calculate the future effective accumulated temperature data based on future meteorological data; Based on the future effective accumulated temperature data and the current growth and development stage of corn, the time when corn reaches the next growth and development stage can be calculated.

3. The method for calculating the recommended nitrogen topdressing amount for corn according to claim 1, characterized in that: According to future meteorological data and the current corn growth status, the daily potential nitrogen demand at the current growth stage is calculated based on the corn growth law, including: According to the current corn growth status and future meteorological data, the daily dry matter growth is calculated; Obtain the effective accumulated temperature accumulation according to the effective accumulated temperature data; According to the cumulative effective temperature, the nitrogen concentration of the plant is calculated; The daily potential nitrogen requirement is calculated based on the daily dry matter growth and plant nitrogen concentration.

4. The method for calculating the recommended nitrogen topdressing amount for corn according to claim 3, characterized in that: The daily dry matter increase is calculated based on the current corn growth status and future meteorological data, including: According to the leaf area index in the current growth state of corn, the light energy interception ratio is calculated; The daily dry matter growth is calculated based on the light energy interception ratio and future meteorological data.

5. The method for calculating the recommended nitrogen topdressing amount for corn according to claim 4, characterized in that: Also includes: The leaf area index LAI is calculated based on the effective accumulated temperature. i , the formula is as follows: Among them, LAI max It indicates the growth upper limit of corn leaf area index under certain environmental conditions; a indicates the basic state parameter; b indicates the growth rate coefficient; GDD sum Indicates the effective accumulated temperature.

6. The method for calculating the recommended nitrogen topdressing amount for corn according to claim 5, characterized in that: According to the light energy interception ratio and future meteorological data, the daily dry matter growth ΔW is calculated. i , the calculation formula is as follows: ΔW i =0.5*RS i *f int *LUE max *f W *f T Among them, 0.5 represents the proportion of photosynthetically active radiation to total radiation; RS i is the total radiation; f int is the light energy interception ratio; k is the extinction coefficient, is a parameter; LUE max is the light energy utilization efficiency under the optimal conditions; f W is the correction factor of water on light energy utilization efficiency; f T It is the correction factor of air temperature on light energy utilization efficiency.

7. The method for calculating the recommended nitrogen topdressing amount for corn according to claim 2, characterized in that: Also includes: The effective accumulated temperature data are calculated based on the daily minimum temperature, daily maximum temperature, the maximum threshold of corn growth and development, and the minimum threshold of corn growth and development in the meteorological data.

8. The method for calculating the recommended nitrogen topdressing amount for corn according to claim 7, characterized in that: Also includes: The effective accumulated temperature data is used to calculate each corn growth and development stage. The formula is as follows: Among them, S represents the growth and development stage of corn, GDD is the effective accumulated temperature, and GDD stage is the accumulated temperature at each development stage, and is the parameter.

9. A device for calculating the recommended nitrogen topdressing amount for corn, characterized in that: include: The time calculation module is used to obtain meteorological data and calculate the time when the corn reaches the next growth and development stage based on the future meteorological data and the current growth and development stage of the corn; The nitrogen demand calculation module is used to calculate the daily potential nitrogen demand of the current growth stage based on the future meteorological data and the current corn growth status and the growth law of corn; according to the time when the corn reaches the next growth and development stage, the daily potential nitrogen demand of the current growth stage is accumulated to calculate the nitrogen demand of the corn when it reaches the next growth and development stage; The topdressing nitrogen amount calculation module is used to calculate the optimal recommended topdressing nitrogen amount based on the nitrogen demand of corn and the nitrogen fertilizer utilization efficiency obtained in advance.

10. A device for calculating the recommended nitrogen topdressing amount for corn, characterized in that: include: A main controller, and a memory connected to the main controller; a memory in which program instructions are stored; The main controller is used to execute program instructions stored in the memory and execute the method according to any one of claims 1 to 8.

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