A method, device and equipment for dynamic decision-making and early warning of real-time nitrogen application for corn

Abstract

The present invention relates to a method, device and equipment for early warning of dynamic decision on real-time nitrogen application for corn, which can detect real-time soil temperature and humidity data to simulate the soil nitrogen cycle process, predict the content of ammonium nitrogen and nitrate nitrogen in the soil, and then use the content of ammonium nitrogen and nitrate nitrogen to calculate the nitrogen content in the soil available for corn absorption; further combine the daily potential nitrogen absorption predicted by the corn growth model to calculate the actual daily nitrogen absorption of corn; then the ratio of the actual daily nitrogen absorption of corn to the potential daily nitrogen absorption is used as the nitrogen nutrition index, and the real-time dynamic decision on nitrogen application of corn is obtained according to the nitrogen nutrition index data. The technical scheme shown in the present invention obtains accurate content of ammonium nitrogen and nitrate nitrogen in the soil, optimizes the timing of nitrogen fertilizer application by dynamically calculating the difference between the actual daily nitrogen absorption and the demand, effectively meets the nitrogen demand of corn during the whole growth period, and ensures the reasonable distribution of nitrogen fertilizer.

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 dynamic decision-making and early warning of real-time nitrogen application for corn. Background Art

[0002] In modern agricultural production, corn is one of the most important food crops in the world. Its yield and quality are of key significance to ensuring food security and meeting the demand for industrial raw materials. The rational application of nitrogen fertilizer plays a vital role in the corn planting process. Accurate nitrogen application strategy can effectively increase corn yield, optimize quality and reduce environmental pollution.

[0003] Traditional corn nitrogen application technology mainly relies on long-term accumulated planting experience to determine the key growth period (such as the small bell mouth period, large bell mouth period, etc.) and implement nitrogen fertilizer. Usually, with the help of corn growth period prediction models, growth conditions and environmental parameters such as meteorological data, soil conditions, and planting density are used as input information to predict the specific time point of the key growth period of corn, and then apply nitrogen fertilizer in the corresponding period. However, this traditional method has defects that cannot be ignored.

[0004] The main problems are as follows: Relying on experience to determine the key growth period: The division of the corn growth period relies on empirical identification, lacking dynamic adjustments for regions and planting conditions, which may lead to the predicted key time points not being completely consistent with the actual situation. Ignoring real-time dynamic changes: Relying on accumulated temperature calculation to predict the growth period of corn, the core of the accumulated temperature model is the cumulative effect of air temperature on crop growth and development. However, the actual growth process is not only affected by temperature, but also by multiple factors such as sudden climate change (such as extreme high temperature or cold damage), pests and diseases, soil moisture, and irrigation conditions. The existing prediction technology lacks the perception and feedback mechanism of these real-time dynamic changes, which may cause the fertilization time point to be out of touch with the actual needs of crops. For example, abnormal weather conditions such as drought or floods can affect the ability of corn to absorb nitrogen fertilizers, and fixed fertilization time may cause fertilizer waste or fail to achieve the expected effect. Not considering the demand for nitrogen fertilizers of different varieties: There are also differences in the demand curves for nitrogen fertilizers of different corn varieties. The unified fertilization guidance scheme in the existing technology is difficult to meet the diverse planting needs. This lack of targeted fertilization program may lead to excessive application of nitrogen fertilizer, which not only increases costs but also may cause environmental pollution; or insufficient nitrogen fertilizer, which affects crop yield and quality and makes it difficult to maximize benefits. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a method, device and equipment for dynamic decision-making and early warning of real-time nitrogen application of corn, so as to solve the problem that the nitrogen application prediction method in the prior art has certain defects.

[0006] According to a first aspect of an embodiment of the present invention, a method for dynamic decision-making and early warning of real-time nitrogen application for corn is provided, comprising:

[0007] Obtain soil moisture content and soil temperature in real time, and obtain nitrogen application data;

[0008] Based on the soil moisture data, soil temperature data and nitrogen application data, the ammonium nitrogen concentration and nitrate nitrogen concentration in each layer of soil at each moment are calculated;

[0009] Based on the ammonium nitrogen concentration data, nitrate nitrogen concentration data and soil moisture content data, the nitrogen content in the soil that can be absorbed by corn is calculated;

[0010] The corn growth model is used to obtain the daily potential nitrogen absorption data of corn. Based on the daily potential nitrogen absorption data of corn and the nitrogen content in the soil that can be absorbed by corn, the actual daily nitrogen absorption of corn is calculated.

[0011] The ratio of the actual daily nitrogen uptake of corn to the potential daily nitrogen uptake of corn is used as the nitrogen nutrition index.

[0012] Real-time dynamic nitrogen application decisions for corn are made based on nitrogen nutrition index data.

[0013] Preferably, the real-time dynamic decision of nitrogen application for corn is obtained according to the nitrogen nutrition index data, including:

[0014] The date when the nitrogen nutrition index is lower than the preset threshold is used as the nitrogen application date.

[0015] Preferably, the calculation of the ammonium nitrogen concentration and the nitrate nitrogen concentration in each layer of soil at each moment comprises:

[0016] The transport and distribution of nitrogen fertilizer concentration, ammonium nitrogen concentration and nitrate nitrogen concentration in soil were calculated using the advection-diffusion equation.

[0017] Discretize the advection-diffusion equation to obtain the algebraic equations of nitrogen fertilizer, ammonium nitrogen and nitrate nitrogen;

[0018] The pursuit method was used to solve the algebraic equations of nitrogen fertilizer, ammonium nitrogen and nitrate nitrogen, and the concentrations of nitrogen fertilizer, ammonium nitrogen and nitrate nitrogen in each layer of soil at each moment were obtained.

[0019] Preferably, the nitrogen content in the soil available for corn absorption is calculated, including:

[0020] According to the ammonium nitrogen concentration, nitrate nitrogen concentration and soil moisture content data in each layer of soil at each moment, the influencing factors of ammonium nitrogen concentration, nitrate nitrogen concentration and moisture content on the available ammonium nitrogen and nitrate nitrogen in the soil are calculated;

[0021] According to the ammonium nitrogen concentration in each layer of soil at each moment, the influencing factor of ammonium nitrogen concentration and the influencing factor of water content on the supply of ammonium nitrogen and nitrate nitrogen in the soil, the ammonium nitrogen concentration in each layer of soil available for corn absorption at each moment is calculated;

[0022] Based on the nitrate nitrogen concentration in each layer of soil at each moment, the influencing factor of nitrate nitrogen concentration and the influencing factor of water content on the supply of ammonium nitrogen and nitrate nitrogen in the soil, the nitrate nitrogen concentration available for corn absorption in each layer of soil at each moment was calculated.

[0023] Preferably, the corn growth model is used to obtain the corn daily potential nitrogen absorption data, and the actual corn daily nitrogen absorption is calculated based on the corn daily potential nitrogen absorption data and the nitrogen content in the soil available for corn absorption, including:

[0024] The net absorption rate of ammonium nitrogen and the net absorption rate of nitrate nitrogen were calculated by the Michaelis-Menten kinetic equation;

[0025] The normalized root length density distribution ratio and the potential daily nitrogen uptake of corn were simulated by the corn growth model, and the potential daily nitrogen uptake of corn in each soil layer was obtained according to the root length density distribution ratio and the potential daily nitrogen uptake of corn.

[0026] The actual absorption of ammonium nitrogen and nitrate nitrogen in each soil layer was calculated based on the potential daily nitrogen absorption of corn in each soil layer, the net absorption rate of ammonium nitrogen, the net absorption rate of nitrate nitrogen, the concentration of ammonium nitrogen available for corn absorption in each soil layer per unit area at each moment, and the concentration of nitrate nitrogen available for corn absorption in each soil layer per unit area at each moment;

[0027] The sum of the actual absorption of ammonium nitrogen and nitrate nitrogen by each layer of soil is taken as the actual daily nitrogen absorption of corn.

[0028] Preferably, real-time acquisition of soil moisture content and soil temperature includes:

[0029] Soil moisture content and soil temperature are monitored in real time using a soil moisture meter pre-buried in the soil.

[0030] According to a second aspect of an embodiment of the present invention, a dynamic decision-making and early warning device for real-time nitrogen application of corn is provided, comprising:

[0031] Soil data acquisition module, used to obtain soil moisture content and soil temperature in real time, and obtain nitrogen application data;

[0032] The soil nitrogen concentration calculation module is used to calculate the ammonium nitrogen concentration and nitrate nitrogen concentration in each layer of soil at each moment according to the soil moisture content data, soil temperature data and nitrogen application data;

[0033] The available nitrogen content calculation module is used to calculate the nitrogen content in the soil that can be absorbed by corn based on the ammonium nitrogen concentration data, the nitrate nitrogen concentration data and the soil moisture content data;

[0034] The actual nitrogen absorption calculation module is used to obtain the daily potential nitrogen absorption data of corn using the corn growth model, and calculate the actual daily nitrogen absorption of corn based on the daily potential nitrogen absorption data of corn and the nitrogen content in the soil that can be absorbed by corn;

[0035] The nitrogen nutrition index calculation module uses the ratio of the actual daily nitrogen absorption of corn to the potential daily nitrogen absorption of corn as the nitrogen nutrition index;

[0036] The nitrogen application decision generation module is used to obtain real-time dynamic nitrogen application decisions for corn based on nitrogen nutrition index data.

[0037] According to a third aspect of an embodiment of the present invention, a dynamic decision-making and early warning device for real-time nitrogen application of corn is provided, comprising:

[0038] A main controller, and a memory connected to the main controller;

[0039] a memory in which program instructions are stored;

[0040] The main controller is used to execute program instructions stored in the memory to perform any of the above methods.

[0041] The technical solution provided by the embodiments of the present invention may have the following beneficial effects:

[0042] It is understandable that the technical solution shown in the present invention can detect real-time soil temperature and humidity data to simulate the soil nitrogen cycle process, predict the content of ammonium nitrogen and nitrate nitrogen in the soil, and then use the content of ammonium nitrogen and nitrate nitrogen to calculate the nitrogen content in the soil available for corn absorption; further combine the daily potential nitrogen absorption predicted by the corn growth model to calculate the actual daily nitrogen absorption of corn; then the ratio of the actual daily nitrogen absorption of corn to the potential daily nitrogen absorption is used as the nitrogen nutrition index, and the dynamic decision of corn real-time nitrogen application is obtained according to the nitrogen nutrition index data. The technical solution shown in the present invention obtains accurate content of ammonium nitrogen and nitrate nitrogen in the soil, optimizes the timing of nitrogen fertilizer application by dynamically calculating the difference between the actual daily nitrogen absorption and the demand, effectively meets the nitrogen demand of corn throughout the growth period, and ensures the reasonable allocation of nitrogen fertilizer.

[0043] 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

[0044] 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.

[0045] Figure 1 It is a schematic diagram of the steps of a method for dynamic decision-making and early warning of real-time nitrogen application for corn according to an exemplary embodiment;

[0046] Figure 2 is a flow chart of a method for dynamic decision-making and early warning of real-time nitrogen application for corn according to an exemplary embodiment;

[0047] Figure 3 is a schematic diagram of a nitrogen cycle process according to an exemplary embodiment. DETAILED DESCRIPTION

[0048] 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.

[0049] In one embodiment, Figure 1 is a schematic diagram of a method for dynamic decision-making and early warning of real-time nitrogen application for corn according to an exemplary embodiment. Figure 1 , provides a corn real-time nitrogen application dynamic decision-making and early warning method, comprising:

[0050] Step S11, obtaining soil moisture content and soil temperature in real time, and obtaining nitrogen application data;

[0051] Step S12, calculating the ammonium nitrogen concentration and the nitrate nitrogen concentration in each layer of soil at each moment according to the soil moisture content data, the soil temperature data and the nitrogen application data;

[0052] Step S13, calculating the nitrogen content in the soil that can be absorbed by corn according to the ammonium nitrogen concentration data, the nitrate nitrogen concentration data and the soil moisture content data;

[0053] Step S14, using a corn growth model to obtain data on the daily potential nitrogen uptake of corn, and calculating the actual daily nitrogen uptake of corn based on the data on the daily potential nitrogen uptake of corn and the nitrogen content in the soil that can be absorbed by corn;

[0054] Step S15, taking the ratio of the actual daily nitrogen uptake of corn to the potential daily nitrogen uptake of corn as the nitrogen nutrition index;

[0055] Step S16: obtaining a real-time dynamic decision on nitrogen application to corn based on the nitrogen nutrition index data.

[0056] It can be understood that the technical solution shown in the present invention is compared with the traditional technical solution: 1. Traditional nitrogen application management usually relies on empirical methods or single detection data, and does not consider real-time tracking of soil nitrogen dynamics, which can easily lead to inaccurate nitrogen application time, nitrogen fertilizer waste or insufficient nitrogen absorption by corn. This technology obtains real-time soil temperature and humidity data, making the dynamic simulation of the soil nitrogen cycle process more accurate in terms of the amount of nitrogen available for plant absorption in the soil. 2. Traditional technical solutions usually ignore the dynamic changes in nitrogen demand during crop growth, and there are problems of "over-fertilization" or "stage-by-stage fertilizer deficiency". This technology combines the corn growth model to predict the daily potential nitrogen demand of corn, and optimizes the timing of nitrogen fertilizer application by dynamically calculating the difference between the actual daily nitrogen absorption and the demand, effectively meeting the nitrogen demand of corn throughout its growth period, ensuring the rational distribution of nitrogen fertilizer, and reducing groundwater nitrate pollution and soil degradation caused by improper fertilization.

[0057] In another specific embodiment, a method for dynamic decision-making and early warning of real-time nitrogen application for corn is shown. Figure 2 , as follows:

[0058] Step S11, real-time acquisition of soil moisture content and soil temperature, and acquisition of nitrogen application data. It should be noted that the soil moisture content and soil temperature are acquired by real-time monitoring using a soil moisture meter pre-buried in the soil.

[0059] Step S12, according to the soil moisture data, the soil temperature data and the nitrogen application data, calculate the ammonium nitrogen concentration and the nitrate nitrogen concentration in each layer of soil at each moment, which should be noted that includes:

[0060] The convection-diffusion equation is used to calculate the migration and distribution of nitrogen fertilizer concentration, ammonium nitrogen concentration and nitrate nitrogen concentration in the soil; the convection-diffusion equation is discretized to obtain the algebraic equations for nitrogen fertilizer, ammonium nitrogen and nitrate nitrogen; the algebraic equations for nitrogen fertilizer, ammonium nitrogen and nitrate nitrogen are solved using the pursuit method to obtain the nitrogen fertilizer concentration, ammonium nitrogen concentration and nitrate nitrogen concentration in each layer of soil at each moment.

[0061] In actual practice, the application of nitrogen fertilizer affects the concentration of ammonium nitrogen and nitrate nitrogen in the soil, and the migration and distribution of the applied nitrogen fertilizer in the soil is calculated. , mg N cm -3 water), ammonium nitrogen ( , mg N cm - 3 water) and nitrate nitrogen ( , mg N cm -3 The transport and distribution of nitrogen concentration in soil are calculated using the convection-diffusion equation, as shown in formulas (1)-(3). Figure 3 As shown in the figure, urea (nitrogen fertilizer) calculates the hydrolysis process in the soil; ammonium nitrogen calculates the application of ammonium nitrogen fertilizer, mineralization and fixation of organic nitrogen, ammonia volatilization, nitrification and plant absorption; nitrate nitrogen calculates the application of nitrate nitrogen fertilizer, nitrification, denitrification and plant absorption. The basic equations for the transport of urea, ammonium nitrogen and nitrate nitrogen are as follows:

[0062] Formula 1:

[0063]

[0064] Formula 2:

[0065]

[0066] Formula 3:

[0067]

[0068] The meaning and units of each parameter refer to Table 1:

[0069] Table 1 Parameter interpretation table

[0070]

[0071] Soil moisture content Soil bulk density was measured by soil moisture meter. and soil organic matter content Determined by field soil sampling.

[0072] Mineralization parameters See the following formula:

[0073]

[0074] Urea hydrolysis parameters See the following formula:

[0075]

[0076] Nitrification parameters See the following formula:

[0077]

[0078] Denitrification parameters See the following formula:

[0079]

[0080] Ammonia volatilization parameters See the following formula:

[0081]

[0082] The amount of ammonium nitrogen absorbed by roots in each soil layer Refer to the following formula, the amount of nitrate nitrogen absorbed by the roots in each layer of soil See the subsequent formula.

[0083] z Directional soil moisture flux See the following formula:

[0084]

[0085] The vertical component of the hydrodynamic diffusion coefficient tensor See the following formula:

[0086]

[0087]

[0088] , They represent the vertical diffusion of ammonium ions or nitrate ions in soil and the diffusion coefficient in still water, and their values ​​are 0.32cm and 57.6cm respectively. 2 d -1 .

[0089] In addition, the supplementary formula is as follows:

[0090]

[0091]

[0092] In the above formula, represents the temperature of the i-th layer of soil, measured by a soil moisture meter; , , , They represent the net mineralization rate, urea hydrolysis rate, nitrification rate, and denitrification rate under the optimum temperature and humidity conditions respectively; , , Represents soil depth (cm), wilting water content and field water holding capacity (cm 3 cm -3 ), and Varies according to soil quality.

[0093] The boundary conditions for the basic equations for the transport of urea, ammonium nitrogen, and nitrate nitrogen are as follows:

[0094] The lower boundary is set as a free drainage boundary: the change of soil moisture with depth is 0, and it is treated as a second-class boundary:

[0095]

[0096] The upper boundary considers irrigation (water-fertilizer integration). During the water infiltration stage, the concentration of the solute is known and is treated as a first-class boundary:

[0097]

[0098] in, Indicates irrigation intensity or rainfall intensity (cm d -1 ), Indicates the concentration of a solute in water (mg cm -3 ), is known.

[0099] The convection-dispersion equation is discretized. The differential equations to be solved, formulas (1)-(3), are discretized and the following results are obtained:

[0100] The algebraic equations for nitrogen fertilizer are as follows:

[0101]

[0102]

[0103]

[0104]

[0105]

[0106] The algebraic equations for ammonium nitrogen are as follows:

[0107]

[0108]

[0109]

[0110]

[0111]

[0112] Indicates the concentration of ammonium nitrogen in the irrigation solution when water and fertilizer are integrated, mg N cm -3 water.

[0113] The algebraic equations for nitrate nitrogen are as follows:

[0114]

[0115]

[0116]

[0117]

[0118]

[0119] Indicates the concentration of nitrate nitrogen in the irrigation solution when water and fertilizer are integrated, mg N cm -3 water.

[0120] Use the chasing method to solve the above three diagonal function groups to get the The concentrations of nitrogen fertilizer, ammonium nitrogen and nitrate nitrogen in each layer of soil at the moment, that is, , and The value of .

[0121] Step S13, calculating the nitrogen content in the soil that can be absorbed by corn based on the ammonium nitrogen concentration data, the nitrate nitrogen concentration data and the soil moisture content data, which should be noted includes:

[0122] According to the ammonium nitrogen concentration, nitrate nitrogen concentration and soil moisture data in each layer of soil at each moment, the influencing factor of ammonium nitrogen concentration, the influencing factor of nitrate nitrogen concentration and the influencing factor of water content on the available ammonium nitrogen and nitrate nitrogen in the soil are calculated; according to the ammonium nitrogen concentration, the influencing factor of ammonium nitrogen concentration and the influencing factor of water content on the available ammonium nitrogen in the soil in each layer of soil at each moment, the ammonium nitrogen content available for absorption by corn in each layer of soil at each moment is calculated; according to the nitrate nitrogen concentration, the influencing factor of nitrate nitrogen concentration and the influencing factor of water content on the available nitrate nitrogen in the soil in each layer of soil at each moment, the nitrate nitrogen content available for absorption by corn in each layer of soil at each moment is calculated.

[0123] In specific practice, the amount of ammonium nitrogen and nitrate nitrogen available for absorption in each layer of soil at time t is affected by the concentration of ammonium nitrogen, nitrate nitrogen and soil water content in the soil. Therefore, the calculation formula is as follows:

[0124] Formula 4:

[0125]

[0126] Formula 5:

[0127]

[0128] in, , Respectively represent the concentrations of ammonium nitrogen and nitrate nitrogen in the i-th layer of soil, in mg N cm -3water, predicting and simulating the soil nitrogen cycle algorithm shown in step S12; Indicates unit conversion, mg to kg; It represents the soil moisture content of the i-th layer, which is measured by a soil moisture meter; Indicates the thickness of the soil layer in cm; It indicates the volume of a single layer of soil per unit area (1 hectare); , , They represent the concentration of ammonium nitrogen in the soil, the concentration of nitrate nitrogen in the soil, and the influence factor of water content on the available ammonium nitrogen and nitrate nitrogen in the soil, respectively. They are dimensionless and the calculation formula is as follows:

[0129]

[0130]

[0131]

[0132] in, Indicates soil bulk density in g cm -3 , are model parameters, obtained through field soil sampling; , Respectively represent soil saturated water content and soil wilting water content, both in cm 3 cm -3 , are model parameters.

[0133] Step S14: using the corn growth model to obtain the corn's daily potential nitrogen absorption data, and calculating the corn's daily actual nitrogen absorption according to the corn's daily potential nitrogen absorption data and the nitrogen content in the soil available for corn absorption, which includes:

[0134] The net absorption rate of ammonium nitrogen and the net absorption rate of nitrate nitrogen were calculated by the Michaelis-Menten kinetic equation. The normalized root length density distribution ratio and the daily potential nitrogen uptake of corn were simulated by the corn growth model, and the daily potential nitrogen uptake of corn in each soil layer was obtained according to the root length density distribution ratio and the daily potential nitrogen uptake of corn. The actual absorption of ammonium nitrogen and the actual absorption of nitrate nitrogen in each soil layer were calculated according to the daily potential nitrogen uptake of corn in each soil layer, the net absorption rate of ammonium nitrogen, the net absorption rate of nitrate nitrogen, the ammonium nitrogen concentration available for corn absorption in each soil layer per unit area at each moment, and the nitrate nitrogen concentration available for corn absorption in each soil layer per unit area at each moment. The sum of the actual absorption of ammonium nitrogen and the actual absorption of nitrate nitrogen in each soil layer was taken as the actual daily nitrogen uptake of corn.

[0135] In practice, the actual daily absorption of corn ( , kg ha-1 d -1 ) is ammonium nitrogen ( ,kgha -1 d -1 ) and actual nitrate nitrogen absorption ( , kg ha -1 d -1 ) is the sum of:

[0136]

[0137] and The ammonium nitrogen in each layer of soil is , kg N d -1 )、Actual absorption of nitrate nitrogen( , kg N d -1 ), the formula is as follows:

[0138]

[0139]

[0140] Where i represents the i-th layer of soil, and m represents a total of m layers of soil. The calculation formula for the actual absorption of ammonium nitrogen and nitrate nitrogen in each layer of soil is as follows:

[0141]

[0142]

[0143] represents the potential daily nitrogen uptake of corn in the i-th soil layer, in kg ha -1 d -1 ; , They represent the amount of ammonium nitrogen and nitrate nitrogen available for absorption in the i-th layer of soil per unit area at time t, in kgha -1 layer -1 , the calculation formulas are shown in formula (4) and formula (5). They represent the net absorption rates of ammonium nitrogen and nitrate nitrogen (the amount of ammonium nitrogen absorbed per unit root mass per unit time), respectively, and are calculated using the Michaelis-Menten kinetic equation.

[0144] The calculation formula is as follows:

[0145]

[0146] Represents the normalized root length density distribution ratio, without any root quantity, simulated by the maize growth model.

[0147]

[0148]

[0149] , Represents the maximum absorption rate of ammonium nitrogen and nitrate nitrogen, mg N cm -3 water -1 ; , Respectively represent the affinity of the root absorption site for ammonium ions and nitrate ions, the unit is mgN cm -3 water. , Respectively represent the concentrations of ammonium nitrogen and nitrate nitrogen at time t, in mg N cm - 3 water.

[0150] Step S15: taking the ratio of the actual daily nitrogen uptake of corn to the potential daily nitrogen uptake of corn as the nitrogen nutrition index.

[0151] In practice, the nitrogen nutrition index (NNI) is used as a diagnostic indicator of the nitrogen status of corn. The NNI is calculated by using the actual nitrogen uptake of corn (NDAD, g ha -1 ) and potential demand (NDPD, g ha -1 ) is calculated using the following formula:

[0152]

[0153] Step S16, obtaining a dynamic decision on the real-time nitrogen application for corn according to the nitrogen nutrition index data. It should be noted that the decision includes: taking the date when the nitrogen nutrition index is lower than a preset threshold as the date for nitrogen application.

[0154] The threshold can be set to 0.95, and when the NNI is lower than the threshold 0.95, it is the recommended time for nitrogen fertilizer.

[0155] According to a second aspect of an embodiment of the present invention, a dynamic decision-making and early warning device for real-time nitrogen application of corn is provided, comprising:

[0156] Soil data acquisition module, used to obtain soil moisture content and soil temperature in real time, and obtain nitrogen application data;

[0157] The soil nitrogen concentration calculation module is used to calculate the nitrogen fertilizer concentration, ammonium nitrogen concentration and nitrate nitrogen concentration in each layer of soil at each moment according to the soil moisture content data, soil temperature data and nitrogen application data;

[0158] The available nitrogen content calculation module is used to calculate the nitrogen content in the soil that can be absorbed by corn based on the ammonium nitrogen concentration data, the nitrate nitrogen concentration data and the soil moisture content data;

[0159] The actual nitrogen absorption calculation module is used to obtain the daily potential nitrogen absorption data of corn using the corn growth model, and calculate the actual daily nitrogen absorption of corn based on the daily potential nitrogen absorption data of corn and the nitrogen content in the soil that can be absorbed by corn;

[0160] The nitrogen nutrition index calculation module uses the ratio of the actual daily nitrogen absorption of corn to the potential daily nitrogen absorption of corn as the nitrogen nutrition index;

[0161] The nitrogen application decision generation module is used to obtain real-time dynamic nitrogen application decisions for corn based on nitrogen nutrition index data.

[0162] According to a third aspect of an embodiment of the present invention, a dynamic decision-making and early warning device for real-time nitrogen application of corn is provided, comprising:

[0163] A main controller, and a memory connected to the main controller;

[0164] a memory in which program instructions are stored;

[0165] The main controller is used to execute program instructions stored in the memory to perform any of the above methods.

[0166] 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.

[0167] 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.

[0168] 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.

[0169] 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, multiple 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.

[0170] 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.

[0171] 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.

[0172] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0173] 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.

[0174] 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 dynamic decision-making and early warning of real-time nitrogen application for corn, characterized in that: include: Obtain soil moisture content and soil temperature in real time, and obtain nitrogen application data; Based on the soil moisture data, soil temperature data and nitrogen application data, the ammonium nitrogen concentration and nitrate nitrogen concentration in each layer of soil at each moment are calculated; Based on the ammonium nitrogen concentration data, nitrate nitrogen concentration data and soil moisture content data, the nitrogen content in the soil that can be absorbed by corn is calculated; The corn growth model is used to obtain the daily potential nitrogen absorption data of corn. Based on the daily potential nitrogen absorption data of corn and the nitrogen content in the soil that can be absorbed by corn, the actual daily nitrogen absorption of corn is calculated. The ratio of the actual daily nitrogen uptake of corn to the potential daily nitrogen uptake of corn is used as the nitrogen nutrition index. Get the real-time dynamic decision of nitrogen application for corn based on nitrogen nutrition index data; Calculate the amount of nitrogen in the soil available for corn to absorb, including: According to the ammonium nitrogen concentration, nitrate nitrogen concentration and soil moisture content data in each layer of soil at each moment, the influencing factors of ammonium nitrogen concentration, nitrate nitrogen concentration and moisture content on the available ammonium nitrogen and nitrate nitrogen in the soil are calculated; According to the ammonium nitrogen concentration in each layer of soil at each moment, the influencing factor of ammonium nitrogen concentration and the influencing factor of water content on the available ammonium nitrogen in the soil, the ammonium nitrogen content available for corn absorption in each layer of soil at each moment is calculated; According to the nitrate nitrogen concentration in each layer of soil at each moment, the influencing factor of nitrate nitrogen concentration and the influencing factor of water content on the nitrate nitrogen available in the soil, the nitrate nitrogen content available for corn absorption in each layer of soil at each moment was calculated; The corn growth model is used to obtain the potential daily nitrogen absorption data of corn. Based on the potential daily nitrogen absorption data of corn and the nitrogen content in the soil available for corn to absorb, the actual daily nitrogen absorption of corn is calculated, including: The net absorption rate of ammonium nitrogen and the net absorption rate of nitrate nitrogen were calculated by the Michaelis-Menten kinetic equation; The normalized root length density distribution ratio and the potential daily nitrogen uptake of corn were simulated by the corn growth model, and the potential daily nitrogen uptake of corn in each soil layer was obtained according to the root length density distribution ratio and the potential daily nitrogen uptake of corn. The actual absorption of ammonium nitrogen and nitrate nitrogen in each soil layer was calculated based on the potential daily nitrogen absorption of corn in each soil layer, the net absorption rate of ammonium nitrogen, the net absorption rate of nitrate nitrogen, the concentration of ammonium nitrogen available for corn absorption in each soil layer per unit area at each moment, and the concentration of nitrate nitrogen available for corn absorption in each soil layer per unit area at each moment; The sum of the actual absorption of ammonium nitrogen and nitrate nitrogen by each layer of soil is taken as the actual daily nitrogen absorption of corn.

2. The method according to claim 1, characterized in that Based on the nitrogen nutrition index data, the real-time dynamic decision of nitrogen application for corn is obtained, including: The date when the nitrogen nutrition index is lower than the preset threshold is used as the nitrogen application date.

3. The method according to claim 1, characterized in that The calculation results in the concentration of ammonium nitrogen and nitrate nitrogen in each layer of soil at each moment, including: The transport and distribution of nitrogen fertilizer concentration, ammonium nitrogen concentration and nitrate nitrogen concentration in soil were calculated using the advection-diffusion equation. Discretize the advection-diffusion equation to obtain the algebraic equations of nitrogen fertilizer, ammonium nitrogen and nitrate nitrogen; The pursuit method was used to solve the algebraic equations of nitrogen fertilizer, ammonium nitrogen and nitrate nitrogen, and the concentrations of nitrogen fertilizer, ammonium nitrogen and nitrate nitrogen in each layer of soil at each moment were obtained.

4. The method according to claim 1, characterized in that Get soil moisture and soil temperature in real time, including: Soil moisture content and soil temperature are monitored in real time using a soil moisture meter pre-buried in the soil.

5. A dynamic decision-making and early warning device for real-time nitrogen application of corn, characterized in that: include: Soil data acquisition module, used to obtain soil moisture content and soil temperature in real time, and obtain nitrogen application data; The soil nitrogen concentration calculation module is used to calculate the ammonium nitrogen concentration and nitrate nitrogen concentration in each layer of soil at each moment according to the soil moisture content data, soil temperature data and nitrogen application data; The available nitrogen content calculation module is used to calculate the nitrogen content in the soil that can be absorbed by corn based on the ammonium nitrogen concentration data, the nitrate nitrogen concentration data and the soil moisture content data; The actual nitrogen absorption calculation module is used to obtain the daily potential nitrogen absorption data of corn using the corn growth model, and calculate the actual daily nitrogen absorption of corn based on the daily potential nitrogen absorption data of corn and the nitrogen content in the soil that can be absorbed by corn; The nitrogen nutrition index calculation module uses the ratio of the actual daily nitrogen absorption of corn to the potential daily nitrogen absorption of corn as the nitrogen nutrition index; A nitrogen application decision generation module is used to obtain real-time dynamic nitrogen application decisions for corn based on nitrogen nutrition index data; Among them, the nitrogen content in the soil available for corn to absorb is calculated, including: According to the ammonium nitrogen concentration, nitrate nitrogen concentration and soil moisture content data in each layer of soil at each moment, the influencing factors of ammonium nitrogen concentration, nitrate nitrogen concentration and moisture content on the available ammonium nitrogen and nitrate nitrogen in the soil are calculated; According to the ammonium nitrogen concentration in each layer of soil at each moment, the influencing factor of ammonium nitrogen concentration and the influencing factor of water content on the available ammonium nitrogen in the soil, the ammonium nitrogen content available for corn absorption in each layer of soil at each moment is calculated; According to the nitrate nitrogen concentration in each layer of soil at each moment, the influencing factor of nitrate nitrogen concentration and the influencing factor of water content on the nitrate nitrogen available in the soil, the nitrate nitrogen content available for corn absorption in each layer of soil at each moment was calculated; The corn growth model is used to obtain the potential daily nitrogen absorption data of corn. Based on the potential daily nitrogen absorption data of corn and the nitrogen content in the soil available for corn to absorb, the actual daily nitrogen absorption of corn is calculated, including: The net absorption rate of ammonium nitrogen and the net absorption rate of nitrate nitrogen were calculated by the Michaelis-Menten kinetic equation; The normalized root length density distribution ratio and the potential daily nitrogen uptake of corn were simulated by the corn growth model, and the potential daily nitrogen uptake of corn in each soil layer was obtained according to the root length density distribution ratio and the potential daily nitrogen uptake of corn. The actual absorption of ammonium nitrogen and nitrate nitrogen in each soil layer was calculated based on the potential daily nitrogen absorption of corn in each soil layer, the net absorption rate of ammonium nitrogen, the net absorption rate of nitrate nitrogen, the concentration of ammonium nitrogen available for corn absorption in each soil layer per unit area at each moment, and the concentration of nitrate nitrogen available for corn absorption in each soil layer per unit area at each moment; The sum of the actual absorption of ammonium nitrogen and nitrate nitrogen by each layer of soil is taken as the actual daily nitrogen absorption of corn.

6. A dynamic decision-making and early warning device for real-time nitrogen application of 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 4.

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