Nitrogen mineralization amount 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 produce 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 an appropriate amount of organic material for plant growth, thereby preventing over-application of organic materials and suppressing the accumulation of soil nutrients that accompanies over-application. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-197340 A [Patent Document 2] JP 2006-61083 A [Patent Document 3] JP 2019-175440 A [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 measure accurately because it is determined by various factors such as soil temperature. It is particularly difficult to empirically measure the amount of nitrogen mineralization in winter crops, where the soil temperature drops. In addition, in warm regions, the amount of organic matter in the soil is likely 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 an appropriate amount of organic material can be applied to the soil.

[0007] An object of the present invention is to provide a nitrogen mineralization amount calculation device capable of accurately calculating 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 indicating 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 amount of nitrogen mineralization corresponding to the input data by inputting the input data into an equation indicating the relationship between the index, the soil temperature, the moisture content of the soil, and the amount of nitrogen mineralization, which is generated based on actual measured values ​​of the amount of nitrogen mineralization when the organic material is added to the soil, the index, the soil temperature, and the moisture content of the soil, respectively, and an output unit that outputs information including the calculated amount of nitrogen mineralization, wherein the index is the total amount of nitrogen in the organic material. Effect of the Invention

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

[0010] [Figure 1] FIG. 1 is a schematic diagram showing the process performed by the calculation device according to the present embodiment. [Diagram 2] FIG. 2 is a schematic diagram of the experimental results database in which each parameter used in the soil incubation experiment corresponds to the amount of nitrogen mineralization obtained in the experiment. [Diagram 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. [Diagram 5] FIG. 5 is a schematic diagram of a materials 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 PREFERRED EMBODIMENTS

[0011] FIG. 1 is a schematic diagram showing the process performed by the calculation device according to the present 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 added 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 input 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 (℃) of the soil to which the organic material is added, the moisture content Sm of the soil, 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 added to the soil, and the type of organic material. Note that the moisture content Sm is the percentage (%) of water relative to the maximum water holding capacity of the soil, but other soil moisture indicators such as water content may 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 added 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, and the higher the value, the faster the organic nitrogen decomposes in the soil. Thus, ADSON is an index that shows how easily 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 content to the total carbon content 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 the change in the amount of nitrogen mineralization Nmin depending on the soil moisture content Sm, and is defined by the following equation (3).

[0020]

number

[0021] Equation (1) is an equation 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] FIG. 2 is a schematic diagram of the experimental results database in which each parameter used in the soil incubation experiment corresponds to the amount of nitrogen mineralization Nmin obtained in the experiment.

[0023] As shown in FIG. 2, this experimental result database is a database in which 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 are associated with each other.

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

[0025] In addition, the units for Nin, ADSON, and nitrogen mineralization amount Nmin are all "mg N / 100 g 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 the coarsely crushed organic material were stirred with a glass rod.

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

[0028] Next, the plastic bottle was placed in an incubator set at the desired temperature and incubation was started. After that, the amount of water lost was added to the soil once every two weeks, and the weight of the plastic bottle containing the soil was recorded.

[0029] After the incubation period, the weight of the plastic bottle containing the soil 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] Next, the concentrations of ammonia nitrogen and nitrate nitrogen in the filtrate were measured.Then, based on the amount of KCl solution added and the amount of water in the soil, the total amount of ammonia nitrogen and nitrate nitrogen per dry soil (mg N / 100 g dry soil) was calculated as the amount of nitrogen mineralization.This amount was calculated by subtracting the amount of nitrogen mineralization in soil cultivated 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). According to equation (1), the ADSON 2 / (α1+ADSON 2) is included. This coefficient represents the nitrogen fertilizer efficiency, and it has become clear 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 reproduced well by formula (1). Therefore, by using formula (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 has an acquisition unit 2, a calculation unit 3, and an output unit 4.

[0035] Among 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 the organic material 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, information on whether the application amount of the organic material is excessive or insufficient, and the like.

[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 the input data P (step S1). As an example, a worker who is about to input an organic material into a farm field operates an input device such as a keyboard to input the input data P to 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 input to the field. In such a case, 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 is 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. Since there are multiple types of livestock manure compost with different compositions, 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. And "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 the worker 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. 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 in which ADSON is encoded, and is attached 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 materials contained 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 matter (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 large, the effect of organic materials as fertilizer is greater, and fertilizer can be reduced compared to when the nitrogen mineralization amount Nmin is small. Also, the nitrogen mineralization amount Nmin at which the effect as fertilizer is highest differs depending on the type of crop.

[0052] Therefore, the amount of nitrogen mineralization Nmin at which the effect as a fertilizer is the highest may be determined in advance as a reference value for each type of crop, and a database in which the reference value is associated with the type of crop may be stored in the storage device of the nitrogen mineralization amount calculation device 1. In this case, an 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 judges whether the calculated amount of nitrogen mineralization Nmin is greater or less than the reference value in the database.

[0053] When the calculated nitrogen mineralization amount 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. When the calculated nitrogen mineralization amount 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 process of the calculation method according to this embodiment.

[0055] According to the present embodiment described above, since the input data P includes the temperature, moisture content, and ADSON of the soil, 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 the effectiveness of the organic material as a nitrogen fertilizer when it is applied to the soil, and the operator can grasp the application amount of the organic material suitable for the soil.

[0056] Moreover, in this embodiment, the formula (1) is adopted, 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 close to the actual measurement value.

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

[0058] The above-described embodiment is a preferred example of the present invention, but the present invention is not limited to this embodiment and can be modified in various ways without departing from the scope 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 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 connected to each other via 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 reading device 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 that 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 thereon.

[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 manner, the memory 1b and the processor 1c cooperate to execute the nitrogen mineralization amount calculation program 100, whereby the acquisition unit 2, the calculation unit 3, and the output unit 4 in FIG. 3 are realized.

[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 the input parameters P to the nitrogen mineralization amount calculation device 1.

[0072] The medium reading device 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 an index indicating the ease of decomposition of organic nitrogen contained in organic materials in soil, the temperature of the soil, and the moisture content of the soil; a calculation unit that calculates the amount of nitrogen mineralization corresponding to the input data by inputting the input data into an equation that shows the relationship between the index, the soil temperature, the soil moisture content, and the amount of nitrogen mineralization, the equation being generated based on actual measurements of the amount of nitrogen mineralization, the index, the soil temperature, and the soil moisture content when the organic material is applied to the soil; and an output unit that outputs information including the calculated amount of nitrogen mineralization; The nitrogen mineralization amount calculation device is characterized in that the index is a total nitrogen amount of the organic material.

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