Nitrogen mineralization calculation device

Abstract

To accurately calculate a nitrogen mineralization amount.SOLUTION: A nitrogen mineralization amount calculation device comprises: an acquisition unit that acquires input data including an index representing easiness of decomposition in the soil of organic nitrogen contained in organic materials, the temperature of the soil and a moisture content of the soil; a calculation unit that calculates a nitrogen mineralization amount corresponding to the input data by inputting the input data to a formula expressing the relation among the index, the temperature of the soil, the moisture content of the soil and the nitrogen mineralization amount generated on the basis of the measured value of each of the nitrogen mineralization amount, the index, the temperature of the soil and the moisture content of the soil when the organic materials are put into the soil; and an output unit that outputs information including the calculated nitrogen mineralization amount. The index is the total nitrogen content of the organic materials.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a nitrogen mineralization amount calculation device. [Background technology]

[0002] Organic materials used as fertilizers include livestock manure compost, vegetable oil cake, green manure, etc. These organic materials contain organic nitrogen, which decomposes in the soil to form inorganic nitrogen, which promotes plant growth.

[0003] If the amount of inorganic nitrogen (amount of nitrogen mineralization) can be determined before adding organic materials to the soil, it is possible to add the appropriate amount of organic materials to the soil for plant growth, thereby preventing excessive application of organic materials and suppressing the accumulation of soil nutrients that comes with excessive application. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-197340 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-61083 [Patent Document 3] Japanese Patent Application Publication No. 2019-175440 [Non-patent literature]

[0005] [Non-Patent Document 1] "Model prediction of nitrogen mineralization from organic materials corresponding to various soil temperatures and soil moistures" Abstracts of the National Conference of the Agricultural Meteorological Society of Japan Vol. 2019 Page. 73 (2019) Summary of the Invention [Problem to be solved by the invention]

[0006] However, the amount of nitrogen mineralization is difficult to accurately determine because it is determined by various factors, such as soil temperature. It is particularly difficult to empirically determine the amount of nitrogen mineralization during winter crops, when soil temperatures drop. Furthermore, in warm regions, the amount of organic matter in the soil tends to decrease, so from the perspective of maintaining soil fertility, it is desirable to grasp the amount of nitrogen mineralization as accurately as possible so that appropriate amounts of organic materials can be applied to the soil.

[0007] An object of the present invention is to provide a nitrogen mineralization amount calculation device that can accurately calculate the amount of nitrogen mineralization. [Means for solving the problem]

[0008] The nitrogen mineralization amount calculation device of the present invention has an acquisition unit that acquires input data including an index that indicates the ease of decomposition in soil of organic nitrogen contained in organic material, the temperature of the soil, and the moisture content of the soil; a calculation unit that calculates the nitrogen mineralization amount corresponding to the input data by inputting the input data into an equation that shows the relationship between the index, the soil temperature, the moisture content of the soil, and the nitrogen mineralization amount, which is generated based on actual measurements of the nitrogen mineralization amount when the organic material is added to the soil, the index, the soil temperature, and the moisture content of the soil; and an output unit that outputs information including the calculated nitrogen mineralization amount, wherein the index is the total nitrogen amount of the organic material. [Effects of the Invention]

[0009] The nitrogen mineralization amount calculation device of the present invention has the effect of being able to accurately calculate the nitrogen mineralization amount. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing the processing performed by the calculation device according to this embodiment. [Figure 2] Figure 2 is a schematic diagram of the experimental results database that associates each parameter used in the soil incubation experiment with the amount of nitrogen mineralization obtained in the experiment. [Figure 3]FIG. 3 is a functional configuration diagram of the nitrogen mineralization amount calculation device according to this embodiment. [Figure 4] FIG. 4 is a flowchart of the method for calculating the amount of nitrogen mineralization according to this embodiment. [Figure 5] FIG. 5 is a schematic diagram of the material table. [Figure 6] FIG. 6 is a schematic diagram showing a two-dimensional barcode. [Figure 7] FIG. 7 is a hardware configuration diagram of the nitrogen mineralization amount calculation device. DETAILED DESCRIPTION OF THE INVENTION

[0011] FIG. 1 is a schematic diagram showing the processing performed by the calculation device according to this embodiment.

[0012] The nitrogen mineralization amount calculation device 1 is a computer such as a PC (Personal Computer) or a server, and calculates the amount of nitrogen mineralization Nmin (mg N / 100 g dry soil) when organic material is applied to soil based on input data P. The type of organic material is not particularly limited, but examples of organic materials that can be used include livestock manure compost, green manure, crop harvest residues, vegetable oil cake, fish meal, rice bran, sludge fertilizer, and food waste compost.

[0013] In the following, it is assumed that an operator uses the nitrogen mineralization amount calculation device 1 to predict the amount of nitrogen mineralization that is expected when a certain amount of organic material is applied to soil.

[0014] In this case, the input data P includes the ADSON (mg N / 100g dry soil) of the organic material, the temperature T (°C) of the soil to which the organic material is applied, the soil moisture content Sm, the amount of organic nitrogen contained in the organic material added to the soil Nin (mg N / 100g dry soil), the time t (weeks) elapsed since the organic material was applied to the soil, and the type of organic material. Note that the moisture content Sm is the percentage (%) of water relative to the soil's maximum water capacity, but other soil moisture indicators such as water content can also be used. The input amount Nin is the amount of organic nitrogen contained in the organic material when a certain amount of organic material is applied to the soil.

[0015] On the other hand, ADSON is the AD-soluble organic nitrogen obtained by analyzing organic materials using the acid detergent (AD) analysis method. The higher the value, the faster the organic nitrogen decomposes in the soil. Thus, ADSON is an index that shows the ease with which the organic nitrogen contained in organic materials decomposes in the soil. Other such indices include the C / N ratio and total nitrogen content of organic materials, which may be used instead of ADSON. The C / N ratio is the ratio of the total nitrogen to the total carbon contained in organic materials.

[0016] Using such input data P, the nitrogen mineralization amount calculation device 1 calculates the nitrogen mineralization amount Nmin according to the following formula (1).

[0017]

number

[0018]

number

[0019] Furthermore, emf in equation (1) is a term that takes into account that the amount of nitrogen mineralization Nmin changes depending on the soil moisture content Sm, and is defined by the following equation (3).

[0020]

number

[0021] Equation (1) is a formula that fits the measured values ​​obtained in the following soil incubation experiment. In the soil incubation experiment, we investigated how the amount of nitrogen mineralization Nmin changes when each variable included in the input data P is changed. The results are shown in Figure 2.

[0022] Figure 2 is a schematic diagram of the experimental results database that associates each parameter used in the soil incubation experiment with the nitrogen mineralization amount Nmin obtained in the experiment.

[0023] As shown in Figure 2, this experimental result database is a database that associates the actual measured values ​​of soil temperature T, soil moisture content Sm, elapsed time t, soil type, input amount Nin, ADSON, and nitrogen mineralization amount Nmin.

[0024] In terms of soil type, "MIY_0" is an andosol collected in Miyakonojo City, Miyazaki Prefecture, and "MIY_12" is an andosol collected in a continuous compost application field adjacent to "MIY_0." "CHI" is a gray lowland soil collected in Chikugo City, Fukuoka Prefecture, and "NAG" is a red soil collected in Isahaya City, Nagasaki Prefecture. Andosol, gray lowland soil, and red soil are all representative agricultural soils in Japan.

[0025] The units for Nin, ADSON, and nitrogen mineralization amount Nmin are all "mg N / 100g dry soil."

[0026] The experimental procedure was as follows: First, air-dried fine soil equivalent to 10 g of dry soil was weighed and placed in a 100 ml plastic bottle. Next, air-dried coarsely crushed organic material was placed in the bottle, and the air-dried fine soil and coarsely crushed organic material were stirred with a glass rod.

[0027] Next, water was added to the plastic bottle to achieve the desired soil moisture content, and the weight of the plastic bottle after adding water was recorded.Then, the mouth of the plastic bottle was covered with polyethylene film and secured with a rubber band.This completes the preparation for cultivation.

[0028] The plastic bottle was then placed in an incubator set to the desired temperature, and cultivation began. After that, the amount of water lost was added to the soil every two weeks, and the weight of the plastic bottle containing the soil was recorded.

[0029] After the incubation period, the weight of the soil-containing plastic bottle was recorded again. Next, 50 ml of 10% KCl solution was added to the plastic bottle and shaken for 1 hour. The soil was then filtered to extract the filtrate, which was then stored in a refrigerator.

[0030] The concentrations of ammonia nitrogen and nitrate nitrogen in the filtrate were then measured. The total amount of ammonia nitrogen and nitrate nitrogen per 100 g dry soil (mg N / 100 g dry soil) was calculated as the amount of nitrogen mineralization, based on the amount of KCl solution added and the amount of water in the soil. This amount was subtracted from the amount of nitrogen mineralization in soil cultured for the same period without input of materials.

[0031] The equation that fits each measured value in this experimental result database is the above-mentioned equation (1). 2 / (α1+ADSON 2) is included. This coefficient represents the nitrogen fertilizer efficiency, and it has been clarified that by expressing it as a rational function of the square of ADSON as described above, the measured values ​​in the soil incubation experiment can be well reproduced by equation (1). Therefore, by using equation (1), the nitrogen mineralization amount calculation device 1 can accurately calculate the nitrogen mineralization amount Nmin.

[0032] Next, the functional configuration of the nitrogen mineralization amount calculation device 1 will be described.

[0033] FIG. 3 is a functional configuration diagram of the nitrogen mineralization amount calculation device 1 according to this embodiment.

[0034] As shown in FIG. 3, the nitrogen mineralization amount calculation device 1 includes an acquisition unit 2, a calculation unit 3, and an output unit 4.

[0035] Of these, the acquisition unit 2 is a processing unit that acquires input data P. The calculation unit 3 is a processing unit that calculates the nitrogen mineralization amount Nmin of organic materials by inputting the input data P into formula (1). The output unit 4 is a processing unit that outputs the calculated nitrogen mineralization amount Nmin, whether the amount of organic materials applied is excessive or insufficient, and other information.

[0036] FIG. 4 is a flowchart of the method for calculating the amount of nitrogen mineralization according to this embodiment.

[0037] First, the acquisition unit 2 acquires input data P (step S1). As an example, a worker who is about to input organic materials into a farm field operates an input device such as a keyboard to input the input data P into the nitrogen mineralization amount calculation device 1, and the input data P is acquired by the acquisition unit 2.

[0038] Although the input data P includes ADSON, it may be difficult for the worker to identify the ADSON of the organic material that he or she plans to apply to the field. In such cases, a material table that associates the type of organic material with the ADSON may be prepared in advance to assist the worker in inputting the information.

[0039] FIG. 5 is a schematic diagram of the material table 7.

[0040] As shown in FIG. 5, the material table 7 contains information in which "type of organic material," "total carbon amount," "total nitrogen amount," "C / N ratio," and "ADSON" are associated with each other.

[0041] Of these, "type of organic material" refers to the type of organic material, such as livestock manure compost, green manure, etc. Note that there are multiple types of livestock manure compost with different compositions, so they are distinguished as "livestock manure compost 1," "livestock manure compost 2," etc.

[0042] "Total carbon" and "total nitrogen" are the total carbon and nitrogen amounts contained in the organic material, respectively. "C / N ratio" is the ratio of these total carbon and total nitrogen amounts. "ADSON" is the ADSON contained in the organic material.

[0043] By referring to this material table 7, the worker can easily identify the ADSON of the organic material that he or she plans to use, and can input this into the nitrogen mineralization amount calculation device 1 by including it in the input parameter P.

[0044] The material table 7 may be stored in a storage device connected to the nitrogen mineralization amount calculation apparatus 1 via a network such as a LAN (Local Area Network) or the Internet. In this case, the acquisition unit 2 acquires the ADSON corresponding to the organic material input by the operator from the material table 7. Alternatively, the material table 7 may be stored in the storage device of the nitrogen mineralization amount calculation apparatus 1, and the acquisition unit 2 may read out the ADSON included in the material table 7. Furthermore, the acquisition unit 2 may acquire the C / N ratio of the material table 7 instead of the ADSON.

[0045] Alternatively, a two-dimensional barcode encoded with ADSON may be used as follows:

[0046] FIG. 6 is a schematic diagram showing the two-dimensional barcode.

[0047] The two-dimensional barcode 10 is identification information that encodes the ADSON, and is affixed to, for example, a fertilizer bag 11 of organic materials. In this case, a mobile terminal such as a smartphone is used as the nitrogen mineralization amount calculation device 1, and an operator photographs the two-dimensional barcode 10 with the camera of the mobile terminal. As a result, the acquisition unit 2 decodes the two-dimensional barcode 10 and acquires the ADSON of the organic material placed in the fertilizer bag 11.

[0048] Referring again to FIG.

[0049] Next, the calculation unit 3 inputs the input data P into the formula (1) to calculate the nitrogen mineralization amount Nmin of the organic material (step S2).

[0050] Thereafter, the output unit 4 outputs the nitrogen mineralization amount Nmin calculated by the calculation unit 3 (step S3). As an example, the output unit 4 outputs an instruction to display the nitrogen mineralization amount Nmin to a display device such as a liquid crystal display.

[0051] When the nitrogen mineralization amount Nmin is high, the effectiveness of organic materials as fertilizer increases, and less fertilizer can be used than when the nitrogen mineralization amount Nmin is low. Also, the nitrogen mineralization amount Nmin at which the effectiveness as fertilizer is highest varies depending on the type of crop.

[0052] Therefore, the amount of nitrogen mineralization Nmin that maximizes the effect as a fertilizer may be determined in advance as a reference value for each type of crop, and a database associating the reference value with the type of crop may be stored in the storage device of the nitrogen mineralization amount calculation device 1. In this case, the operator inputs the type of crop into the nitrogen mineralization amount calculation device 1, which is acquired by the acquisition unit 2. Thereafter, the calculation unit 3 determines whether the calculated amount of nitrogen mineralization Nmin is greater or less than the reference value in the database.

[0053] If the calculated amount of nitrogen mineralization Nmin is greater than the reference value, the output unit 4 may output text information indicating that the amount of organic material applied is excessive. If the calculated amount of nitrogen mineralization Nmin is less than the reference value, the output unit 4 may output text information indicating that the amount of organic material applied is insufficient.

[0054] This completes the basic processing of the calculation method according to this embodiment.

[0055] According to the present embodiment described above, the input data P includes the soil temperature, moisture content, and ADSON, so the nitrogen mineralization amount calculation device 1 can calculate the nitrogen mineralization amount Nmin, which can vary depending on these parameters. This allows the operator to predict in advance how effective the organic material will be as a nitrogen fertilizer when applied to the soil, and to know the amount of organic material to be applied that is appropriate for the soil.

[0056] Moreover, in this embodiment, Equation (1) is used, which fits each parameter in the input data P and each actual measurement value of the nitrogen mineralization amount (see FIG. 2). Therefore, the calculation unit 3 can calculate the nitrogen mineralization amount Nmin that is close to the actual measurement value.

[0057] In particular, by using ADSON as an index showing the ease of decomposition of organic nitrogen contained in organic materials in soil, the coefficient representing nitrogen fertilizer efficiency in equation (1) becomes ADSON 2 / (α1+ADSON 2 ) is a rational function of the square of the ADSON, which allows equation (1) to fit well to the measured values.

[0058] The above-described embodiment is a preferred example of the present invention, but the present invention is not limited to this and can be modified in various ways without departing from the spirit of the present invention.

[0059] (Hardware configuration) Next, the hardware configuration of the nitrogen mineralization amount calculation device 1 according to this embodiment will be described.

[0060] FIG. 7 is a hardware configuration diagram of the nitrogen mineralization amount calculation device 1.

[0061] 7, the nitrogen mineralization amount calculation device 1 includes a storage device 1a, a memory 1b, a processor 1c, a communication interface 1d, a display device 1e, an input device 1f, and a media reader 1g. These components are interconnected by a bus 1h.

[0062] Of these, the storage device 1a is a non-volatile storage such as a hard disk drive (HDD) or a solid state drive (SSD), and stores a nitrogen mineralization amount calculation program 100 according to this embodiment.

[0063] The nitrogen mineralization amount calculation program 100 may be recorded on a computer-readable recording medium 1k, and the processor 1c may read the nitrogen mineralization amount calculation program 100 via a medium reader 1g.

[0064] Such recording media 1k include physically portable recording media such as CD-ROMs (Compact Disc Read Only Memory), DVDs (Digital Versatile Discs), and USB (Universal Serial Bus) memories. Semiconductor memories such as flash memories and hard disk drives may also be used as the recording media 1k. These recording media 1k are not temporary media such as carrier waves that do not have a physical form.

[0065] Furthermore, the nitrogen mineralization amount calculation program 100 may be stored in a device connected to a public line, the Internet, a LAN, etc. In this case, the processor 1c may read and execute the nitrogen mineralization amount calculation program 100.

[0066] On the other hand, the memory 1b is hardware that temporarily stores data, such as a DRAM (Dynamic Random Access Memory), and the nitrogen mineralization amount calculation program 100 is developed on it.

[0067] The processor 1c is hardware such as a CPU (Central Processing Unit) or a GPU (Graphical Processing Unit) that controls each part of the nitrogen mineralization amount calculation device 1. The processor 1c also executes the nitrogen mineralization amount calculation program 100 in cooperation with the memory 1b.

[0068] In this way, the memory 1b and the processor 1c cooperate to execute the nitrogen mineralization amount calculation program 100, thereby realizing the acquisition unit 2, calculation unit 3, and output unit 4 in FIG.

[0069] Furthermore, the communication interface 1d is hardware such as a network interface card (NIC) for connecting the nitrogen mineralization amount calculation apparatus 1 to a network such as a LAN or the Internet.

[0070] The display device 1e is hardware such as a liquid crystal display or a touch panel for displaying the calculated nitrogen mineralization amount Nmin.

[0071] The input device 1f is hardware such as a keyboard and a mouse that allows an operator to input input parameters P to the nitrogen mineralization amount calculation device 1.

[0072] The medium reader 1g is hardware such as a CD drive, a DVD drive, or a USB interface for reading the recording medium 1k. [Explanation of symbols]

[0073] 1...nitrogen mineralization amount calculation device, 2...acquisition unit, 3...calculation unit, 4...output unit, 7...material table, 10...two-dimensional barcode, 11...fertilizer bag

Claims

[Claim 1] an acquisition unit that acquires input data including the total nitrogen amount of the organic material, which is an index showing the ease of decomposition of organic nitrogen contained in the organic material in the soil, the temperature of the soil, and the moisture amount of the soil; a calculation unit that calculates the amount of nitrogen mineralization when the organic material is applied to the soil by inputting the input data into an equation including the nitrogen fertilizer efficiency expressed as a function of the total nitrogen amount; an output unit that outputs information including the calculated amount of nitrogen mineralization; and When the total amount of nitrogen in the organic material is Nall, the amount of nitrogen input derived from the organic material is Nin, the amount of nitrogen mineralization is Nmin, the elapsed time is t, and the constants determined for each type of organic material are α1 and ki, the formula is as follows: [Equation 1] and If the soil temperature is T and the constant determined for each type of organic material is Q10, then the etf is: [Equation 2] is expressed as If the amount of moisture in the soil is Sm and the constant determined for each type of organic material is bsoil, then emf is: [Equation 3] is expressed as A nitrogen mineralization amount calculation device characterized by the above.

Images