JP2021108649A - Fertilizer application amount derivation device and fertilizer application amount derivation method - Google Patents

Abstract

To derive an appropriate fertilizer application amount based on slow release fertilizer being supplied in fertilization with respect to a fertilizer application amount of additional fertilization to be carried out after having supplied slow release fertilizer in one phase.SOLUTION: A fertilizer application amount derivation device 1 acquires the accumulated temperature before additional fertilization after initial fertilization of this term, derives this term fertilizer remaining amount being a remaining amount of slow release fertilizer or a remaining amount difference being the difference of the remaining amount of the slow release fertilizer between an average year and this term on the basis of the acquired accumulated temperature, derives a fertilizer application amount at additional fertilization by reflecting the derived this term fertilizer remaining amount or the remaining amount difference, and thereby derives the additional fertilization fertilizer application amount reflecting the remaining amount of fertilizer given at the beginning of this term.SELECTED DRAWING: Figure 1

Description

The present invention relates to a fertilizer application amount derivation device for deriving a fertilizer application amount at the time of top dressing of agricultural products and a fertilizer application amount derivation method.

Conventionally, there is a technique for providing useful information on the amount of fertilizer regarding the supply of fertilizer performed when cultivating crops. For example, in Patent Document 1, the leaf color and the number of stems of rice (paddy rice) growing in this term are measured, the amount of absorbed nitrogen is obtained from the leaf color and the number of stems, and the amount of nitrogen applied already added is subtracted from the amount of absorbed nitrogen. A technique for obtaining the amount of nitrogen in the soil and the amount of nitrogen applied (fertilizer application amount) required for the next rice cultivation from the amount of nitrogen in the soil and the appropriate amount of nitrogen set in advance is described.

JP-A-2018-82648

By the way, in rice cultivation and cultivation of other crops, additional fertilizer may be applied after applying slow-release fertilizer in one period. For example, in rice cultivation, after applying a slow-release fertilizer, topdressing called panicle fertilizer may be performed at a predetermined timing from the ear formation time to the heading time. Since the amount of fertilizer supplied at the time of top dressing has a great influence on the quality and yield of crops, an appropriate amount is determined for the amount of fertilizer applied at the time of top dressing performed after fertilization of slow-release fertilizer in one period. Has been required in the past. In particular, since slow-release fertilizer is supplied at the time of fertilizer application, it has been required to determine an appropriate amount of fertilizer application based on factors related to nutrient elution of the slow-release fertilizer. The technique described in Patent Document 1 is to obtain the amount of fertilizer applied in the next term based on the factors related to the cultivation of agricultural products in the current term, and also provides knowledge on the technique considering the factors related to the elution of nutrients in slow-release fertilizer. It does not do, and cannot meet such demands.

The present invention has been made to solve such a problem, and the slow-release fertilizer is supplied at the time of fertilization with respect to the amount of top-dressing fertilizer applied after the slow-release fertilizer is supplied in one period. The purpose is to be able to determine the appropriate amount of fertilizer to be applied.

In order to solve the above-mentioned problems, in the present invention, the integrated temperature from the initial fertilizer application to the pre-fertilizer addition in the current period is acquired, and based on the acquired integrated temperature, the residual amount of slow-release fertilizer is obtained in the current period. The difference in the residual amount of fertilizer or the difference in the residual amount of slow-release fertilizer between the normal year and the current term is derived, and the amount of fertilizer applied at the time of top dressing is derived by reflecting the derived residual amount of fertilizer in the current term or the difference in the residual amount. ing.

As for slow-release fertilizer, the amount of nutrient elution changes depending on the integrated temperature after fertilization, and if the amount of slow-release fertilizer supplied at the time of initial fertilization is constant, the amount of fertilizer remaining in the soil depends on the integrated temperature after fertilization. Change. Furthermore, there is a certain relationship between the integrated temperature and the nutrient elution amount, and it is possible to derive the nutrient elution amount based on the integrated temperature. Then, according to the present invention configured as described above, the residual amount of slow-release fertilizer at the time of top dressing, or normal and this term, based on the integrated temperature from the initial fertilizer application to the pre-fertilizer application in this term. After obtaining the difference in the residual amount of the slow-release fertilizer, the residual amount or the difference is reflected to derive the fertilizer application amount at the time of top dressing. Therefore, it is possible to derive an appropriate amount of fertilizer application based on the situation that slow-release fertilizer is supplied at the time of initial fertilizer application and the state of residual fertilizer at the time of topdressing.

It is a block diagram which shows the functional structure example of the fertilizer application amount derivation apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the relationship between the NDVI at the measurement timing and the fertilizer application amount at the time of top dressing. It is a figure which shows the relationship between the integrated temperature and the amount of nitrogen elution per unit area about the nitrogen-based slow-release fertilizer. It is a flowchart which shows the operation example of the fertilizer application amount derivation apparatus which concerns on 1st Embodiment of this invention. It is a block diagram which shows the functional structure example of the fertilizer application amount derivation apparatus which concerns on 2nd Embodiment of this invention. It is a block diagram which shows the functional structure example of the fertilizer application amount derivation apparatus which concerns on 3rd Embodiment of this invention.

<First Embodiment>
Hereinafter, the first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a functional configuration example of the fertilizer application amount derivation device 1 according to the present embodiment. The fertilizer application amount derivation device 1 derives the amount of fertilizer to be applied at the time of top dressing (details of the top dressing will be described later) (hereinafter referred to as “the amount of fertilizer applied at the time of top dressing”), and provides the user with information indicating the amount of fertilizer applied at the time of top dressing. It is a device. The user can appropriately determine the amount of fertilizer to be actually applied by referring to the information indicating the amount of fertilizer applied at the time of topdressing provided by the fertilizer amount derivation device 1 for topdressing.

In the following explanation, regarding the target rice and rice cultivation, the rice varieties, the environment in which the rice is cultivated (regions (cold regions, warm regions, dry regions, etc.), altitude, scale of the field), and the method of rice cultivation , The type of fertilizer, and other external factors that affect the growth of rice shall be common. Therefore, the fertilizer application amount at the time of topdressing derived by the fertilizer application amount derivation device 1 is an appropriate fertilizer application amount when applying a specific type of fertilizer to a specific variety of rice cultivated by a specific method in a specific environment. become. Further, in the following description, for convenience of explanation, the fertilizer application amount derivation device 1 shall derive the fertilizer application amount at the time of top dressing for one field. However, it goes without saying that a plurality of cohesive fields may be targeted and a part of the field may be targeted. Further, the term "fertilizer application amount" in the present embodiment means the amount of fertilizer per unit area unless otherwise specified.

In the present embodiment, "initial fertilizer application" and "additional fertilizer" mean the following. That is, in one general stage, after the rice is transplanted from the seedling to the field by rice planting, the tiller stage → the ear formation stage → the heading stage → the flowering / pollination stage → the panicle stage → the ripening stage → the maturation stage. It grows through the stage. Normally, nitrogen-based slow-release fertilizers are applied when transplanting from rice fields to fields. In the present embodiment, the "initial fertilizer application" means the fertilization of a nitrogen-based slow-release fertilizer performed at the time of transplantation from the rice field to the field. Initial fertilization corresponds to so-called basal fertilizer.

In addition, during the period from around the panicle formation stage to around the heading stage (hereinafter referred to as the "topdressing target period"), the purpose is to increase the number of paddy that grows on the spikes and increase the amount of starch that clogs the paddy. As a result, fertilizer called ear fertilizer may be added at a predetermined timing. And in this embodiment, "additional fertilizer" means addition of fertilizer performed at a predetermined timing in the period for which additional fertilizer is applied.

As shown in FIG. 1, a display device 2 such as a liquid crystal display or an organic EL display and an input device 3 such as a mouse or a keyboard are connected to the fertilizer application amount derivation device 1. Further, as shown in FIG. 1, the fertilizer application amount derivation device 1 includes a fertilizer application amount derivation unit 10, a temporary fertilizer application amount derivation unit 11, and a residual amount derivation unit 12 as a functional configuration. Each of the above functional blocks 10 to 12 can be configured by any of hardware, DSP (Digital Signal Processor), and software. For example, when configured by software, each of the functional blocks 10 to 12 is actually configured to include a computer CPU, RAM, ROM, etc., and is a program stored in a recording medium such as RAM, ROM, hard disk, or semiconductor memory. Is realized by the operation of. Further, the fertilizer application amount derivation device 1 includes a storage unit 13 as a storage means. The data stored in the storage unit 13 will be described later.

In the present embodiment, the fertilizer application amount derivation device 1 is triggered by an instruction from the user to provide information indicating the fertilizer application amount at the time of fertilizer application to the input device 3 (hereinafter referred to as “information provision instruction”), and at the time of fertilizer application. The amount of fertilizer applied is derived and the information is provided. Hereinafter, the operation of the fertilizer application amount derivation device 1 when the user gives an information provision instruction to the input device 3 will be described in detail. The trigger for deriving the amount of fertilizer applied at the time of top dressing is not limited to that exemplified in this embodiment, and may be, for example, the arrival of a predetermined date and time as a trigger.

When the fertilizer application amount derivation unit 10 detects that the input device 3 has been instructed to provide information, the fertilizer application amount derivation unit 10 requests the temporary fertilizer amount derivation unit 11 to derive the fertilizer application amount (described later) at the time of temporary topdressing.

When the temporary fertilizer amount derivation unit 11 requests the derivation of the fertilizer application amount at the time of temporary topdressing, the temporary fertilizer amount derivation unit 11 executes the following processing. That is, first, the temporary fertilizer application amount derivation unit 11 acquires the analysis image data stored in the storage unit 13. The image data for analysis is a field to which fertilizer is to be topped up (hereinafter referred to as "target field") by a multispectral sensor mounted on the drone at a predetermined timing (hereinafter referred to as "measurement timing") before topdressing. It is image data generated by photographing a community of rice from the sky. The measurement timing is a predetermined timing as a timing for taking an image for obtaining image data for analysis used for deriving the amount of fertilizer applied at the time of topdressing. For example, immediately before the timing of topdressing or 3 weeks before heading. , 4 weeks before heading, etc. The temporary fertilizer application amount derivation unit 11 analyzes the acquired image data for analysis, calculates the NDVI by a well-known method, and acquires it. In the present embodiment, for convenience of explanation, the actual value of the index value of NDVI as an index is expressed as "NDVI". The NDVI acquired here corresponds to the "vegetation-related value" and the "first index value" in the claims.

In the present embodiment, in calculating and acquiring the NDVI, image data for analysis based on the imaging result of the multispectral sensor mounted on the drone is used. Here, as an index value used when deriving the fertilizer application amount at the time of topdressing, it is also possible to use a SPAD value that can be used as an index for measuring the activity of rice derived from leaf color like NDVI, instead of NDVI. However, when the SPAD value is used, it is necessary to measure the leaves one by one using a chlorophyll meter, which is highly difficult to work with. In particular, when the field is large-scale, in order to calculate the SPAD value with high accuracy, it is necessary to perform measurement using a chlorophyll meter at appropriately dispersed points, which is highly difficult to work with. It is also possible to use the leaf color plate value obtained by sensing on the ground using a leaf color plate (color scale) as in the SPAD value, but in this case as well, the difficulty is high as in the SPAD value. It is also possible for an operator to measure NDVI on the ground using a portable NDVI sensor and use it. However, in this case as well, it is necessary for the worker to walk around the field to perform geodesy, which makes the work highly difficult. Especially when the field is large and large, the work is very difficult. On the other hand, in the present embodiment, since the data necessary for calculating the NDVI is collected by using the drone, the work performed when calculating the NDVI is simple and the field is large-scale. But you can work speedily. However, instead of excluding the use of the SPAD value, the SPAD value or an index based on the SPAD value may be used. Further, it is not excluded to use "NDVI obtained by measurement on the ground using an NDVI sensor" and "leaf color plate value obtained by measurement on the ground using a leaf color plate (color scale)".

The above-mentioned effect is not to measure the leaves one by one using a chlorophyll meter, but to use the index value obtained by remote observation of the rice community as an index to be used when determining the amount of fertilizer applied at the time of topdressing. It can be obtained by using it as a value. Therefore, the device used for observation (sensing) is not limited to the multispectral sensor, and may be, for example, infrared thermography. Moreover, the index value is not limited to NDVI. In addition, the observation does not necessarily have to be performed using a drone, and may be performed using a device installed on the upper part of the tower or a device operated by a human being mounted on a stepladder. In addition, satellite images may be used for the calculation of NDVI (or an index value corresponding thereto). Further, instead of the temporary fertilizer application amount derivation unit 11 calculating and acquiring the NDVI, the temporary fertilizer application amount derivation unit 11 may acquire the NDVI calculated by an external device.

Hereinafter, the NDVI acquired by the temporary fertilizer application amount derivation unit 11 is particularly referred to as "acquired NDVI".

After acquiring the acquired NDVI, the temporary fertilizer application amount derivation unit 11 uses the fertilizer application amount derivation calculation formula, and based on the acquired acquired NDVI, the temporary fertilizer application amount (“temporary fertilizer application amount during the provisional fertilizer application” in the claims. "Equivalent to) is derived. The fertilizer application amount derivation calculation formula is an expression that inputs NDVI and outputs fertilizer application amount, and is not only a simple mathematical formula, but also a function (model) defined on the program and a function (model) that can be called from the program. Is conceptually represented. This also applies to the dissolution rate calculation formula described later.

The fertilizer application amount output when the acquired NDVI is input to the fertilizer application amount derivation calculation formula is the crop (agricultural product) for a predetermined category when the NDVI (value) at the measurement timing of the field is the acquired NDVI (value). The amount of fertilizer applied is necessary and appropriate to achieve the target state (including the harvested product). The amount of fertilizer applied here is based on the premise that the amount of fertilizer remaining in the field at the time of topdressing is zero for the reason described later. Then, the fertilizer application amount obtained as an output by inputting the acquired NDVI into the fertilizer application amount derivation calculation formula corresponds to the “temporary topdressing fertilizer application amount”.

In the present embodiment, the state of the crop for a predetermined category is, for example, the appearance or taste quality of the harvested product, the yield of the harvested product, the number of paddy, an index of the growth process after topdressing, and the like. The index of the growth process after topdressing is, for example, the total chlorophyll value (SPAD value) at the earing stage after topdressing. When the total chlorophyll value (SPAD value) at the earing stage is above a certain value, it can be said that the quality is good.

For example, the output of the fertilizer amount derivation calculation formula is the amount of fertilizer applied at the time of topdressing, which is necessary and appropriate for the yield (yield per unit) of the harvested product to be XX kg. In this case, the yield of the harvested product corresponds to the "state of the crop for a predetermined category", and the state where the yield is XX kg corresponds to the "target state". In this case, by applying fertilizer corresponding to the output value of the fertilizer application amount derivation formula at the time of top dressing (however, it is assumed that no fertilizer remains at the time of top dressing), the yield of the harvested product becomes XX kg. It is expected. In addition, for example, the output of the fertilizer application amount derivation formula is the amount of fertilizer applied at the time of topdressing, which is necessary and appropriate for setting the ratio of low-appearance quality crops to the total crop (hereinafter referred to as "low quality ratio") to XX%. be. The low-appearance quality harvested products include, for example, white immature grains (belly white grains, spine white grains, base immature grains, heart white grains, milky white grains, etc.), other immature grains, damaged grains, dead rice, etc. Colored grains and the like. In this case, the low quality ratio corresponds to the "state of the crop for a predetermined category", and the low quality ratio corresponds to the "target state". In this case, by applying fertilizer equivalent to the output value of the fertilizer application amount derivation formula at the time of top dressing (however, it is assumed that no fertilizer remains at the time of top dressing), the low quality ratio becomes XX%. There is expected. Of course, instead of the low quality ratio, the ratio of "grain size" of the harvested product may be used.

FIG. 2 shows the above-mentioned low quality ratio (state of crops for a predetermined category) by a linear equation drawn in a two-dimensional space with NDVI at the measurement timing as the vertical axis and fertilizer application amount at the time of topdressing as the horizontal axis. The relationship between the NDVI at the measurement timing and the fertilizer application amount at the time of topdressing at the time of 5% (target state) is shown in a simplified manner. As shown in FIG. 2, there is a relationship between the amount of fertilizer applied at the time of top dressing when the low quality ratio is 5% and the NDVI at the measurement timing, the larger the NDVI, the smaller the amount of fertilizer applied. As described above, there is a strong correlation between the NDVI at the measurement timing and the fertilizer application amount at the time of topdressing when the state of the crop for a predetermined category is set as the target state.

In the present embodiment, the fertilizer application amount derivation calculation formula aims at the state of the agricultural product with respect to the relationship between the accumulated past fertilizer application amount at the time of actual top dressing and the combination of NDVI (vegetation-related value) at the measurement timing and the state of the agricultural product. It is obtained based on the multiple regression equation obtained by performing multiple regression analysis using the amount of fertilizer applied at the time of topdressing and the vegetation-related values at the measurement timing as explanatory variables.

More specifically, by conducting experiments and observing existing fields in advance, data showing the relationship between the combination of NDVI at the time of topdressing and the measurement timing and the condition of the crop, that is, the amount of fertilizer applied at the time of topdressing is ○○. Therefore, when the NDVI at the measurement timing is XX, the data that the state of the crop for a predetermined category is XX is accumulated. At this time, it is assumed that the amount of fertilizer remaining at the time of topdressing is zero for all data. This is because it is very difficult to unify the conditions for the amount of fertilizer applied at the time of top dressing for all data, and to unify the amount of remaining fertilizer to a fixed amount other than zero when unifying the conditions. be.

Then, the accumulated data is subjected to multiple regression analysis using the state of the crop as the objective variable and the amount of fertilizer applied at the time of topdressing and NDVI at the measurement timing as the explanatory variables, and the state of the crop is set as the target state at the time of topdressing. A multiple regression equation is calculated in which the relationship between the amount of fertilizer applied and the NDVI at the measurement timing is defined. For example, when the quality of the harvested product is the above-mentioned low quality ratio, the relationship between the amount of fertilizer applied at the time of topdressing and the NDVI at the measurement timing is defined in order to set the low quality ratio as the target value (5% as an example). The calculated multiple regression equation is calculated. Then, based on the multiple regression equation, a fertilizer application amount derivation calculation formula is generated in which NDVI is input and the fertilizer application amount determined from the relationship between the NDVI expressed by the multiple regression equation and the fertilizer application amount is output. The output of this fertilizer application amount derivation formula is necessary to set the state of the crop as the target state when the NDVI at the measurement timing is the input value under the condition that no slow-release fertilizer remains at the time of top dressing. And it corresponds to the amount of fertilizer applied at the time of appropriate top dressing. The multiple regression equation may be created for each growing season of rice, for example, 30 days, 25 days, 20 days, 15 days, 10 days, and 5 days before heading. In this case, in order to determine how many days before heading the growth diagnosis is made, it is estimated from the planting point, variety, transplanting date, leaf age and seedling appearance of seedlings, temperature, long day, etc., or young ears. It can be estimated from the length of. Since the state of crops is affected by the amount of fertilizer nitrogen expression after topdressing (details will be described later), the output value of the fertilizer application amount derivation calculation formula generated by the above method is naturally affected by the amount of fertilizer nitrogen expression. The value will be added.

The content of the fertilizer application amount derivation calculation formula of this embodiment is just an example of simplification. The fertilizer application amount derivation calculation formula is any calculation formula that uses NDVI at the measurement timing as one of the inputs and outputs the fertilizer application amount at the time of topdressing that is necessary and appropriate for setting the state of the crop to the target state. May be. As an example, in addition to the NDVI at the measurement timing, an element value of an element that affects the state of the crop may be input, and the fertilizer application amount at the time of topdressing may be output in consideration of the element. As an example, the factors include the temperature in a specific period (expected temperature for a period that has not arrived (for example, the ripening period)), the amount of rainfall in a specific period, and the like. In addition, the fertilizer application amount derivation calculation formula does not have to be generated by multiple regression analysis, and various machine learning (machine learning using a neural network as an example) can be applied to the generation of the fertilizer application amount derivation computer. ..

By the way, the temporary fertilizer amount derivation unit 11 derives the fertilizer application amount at the time of temporary fertilizer application based on the acquired acquired NDVI by using the fertilizer application amount derivation calculation formula. That is, the temporary fertilizer amount derivation unit 11 inputs the acquired NDVI into the fertilizer amount derivation calculation formula, and uses the output as the fertilizer application amount at the time of temporary fertilizer application. The temporary fertilizer amount derivation unit 11 responds to the fertilizer application amount derivation unit 10 with the derived fertilizer application amount at the time of temporary topdressing.

Further, when the fertilizer application amount derivation unit 10 detects that the input device 3 has been instructed to provide information, the fertilizer application amount derivation unit 10 requests the residual amount derivation unit 12 to derive the fertilizer residual amount (described later) in the current period.

When the fertilizer application amount derivation unit 10 requests the derivation of the fertilizer residual amount charge for the current term, the residual amount derivation unit 12 executes the following processing. That is, first, the residual amount derivation unit 12 acquires the integrated temperature data stored in the storage unit 13. The integrated temperature data is data in which the integrated temperature from the initial fertilization to the present time is recorded. The integrated temperature is the sum of the daily average temperatures during the period. Further, in the present embodiment, it is assumed that the top dressing is performed within an extremely short period from the present time, and the current time and the timing at which the top dressing is performed can be equated.

The integrated temperature data may be configured so that the fertilizer application amount derivation device 1 can be connected to the Internet, and the residual amount derivation unit 12 may acquire the integrated temperature data from an external server, or the integrated temperature data is artificially integrated under artificial observation. The data may be created and stored in the storage unit 13.

After acquiring the integrated temperature data, the residual amount derivation unit 12 acquires the integrated temperature recorded in the data and derives the nitrogen elution rate (nutrient elution rate) by the elution rate calculation formula. Hereinafter, the integrated temperature acquired by the residual amount derivation unit 12 is referred to as "acquired integrated temperature". FIG. 3 is a graph showing the relationship between the integrated temperature and the nitrogen elution rate for nitrogen-based slow-release fertilizers in a two-dimensional space with the integrated temperature after initial fertilization on the horizontal axis and the nitrogen elution rate on the vertical axis. It is a figure which shows. As shown in FIG. 3, for nitrogen-based slow-release fertilizers, the integrated temperature after fertilization and the nitrogen elution rate are in a proportional relationship, and the larger the integrated temperature after fertilization, the larger the nitrogen elution rate. Become. The elution rate calculation formula is a calculation formula that inputs the integrated temperature and outputs the nitrogen elution rate. The nitrogen elution rate output when the acquired integrated temperature is input as the integrated temperature in the dissolution rate calculation formula is the nitrogen elution rate expected when the integrated temperature from the initial fertilizer application to the time of topdressing is the acquired integrated temperature. Is.

The content of the dissolution rate calculation formula of this embodiment is just an example of simplification. The elution rate calculation formula may be any calculation formula that takes the integrated temperature as one of the inputs and outputs the nitrogen elution rate. As an example, a calculation formula may be used in which an element value of an element that affects the elution of nitrogen is input in addition to the integrated temperature, and the nitrogen elution rate is output in consideration of the element. The factor is, for example, the amount of solar radiation in a specific period. In addition to multiple regression analysis, existing machine learning can be widely applied to the generation of the elution rate calculation formula. Further, in the present embodiment, the integrated temperature is the sum of the daily average temperatures in the corresponding period, but the integrated temperature is not limited to this. That is, the integrated temperature may be anything as long as it is based on the integrated temperature (not limited to the air temperature) in the corresponding period and is an input of the calculation formula for outputting the nitrogen elution rate. For example, it may be the soil temperature of a paddy field. In this case, the paddy soil temperature may be estimated from various conditions such as air temperature and amount of solar radiation, and the growth condition of the plant such as the leaf area index.

By the way, the residual amount derivation unit 12 derives the nitrogen elution rate based on the acquired integrated temperature obtained by using the elution rate calculation formula. That is, the residual amount derivation unit 12 inputs the acquired integrated temperature into the elution rate calculation formula, and uses the output as the nitrogen elution rate.

Next, the residual amount derivation unit 12 acquires the initial fertilizer application amount data stored in the storage unit 13. The initial fertilizer application amount data is data in which the fertilizer application amount at the time of initial fertilization (expressed as the amount per unit area) is recorded. Next, the residual amount derivation unit 12 acquires the fertilizer application amount recorded in the data. Next, the residual amount derivation unit 12 multiplies the acquired fertilizer application amount (= fertilizer application amount at the time of initial fertilizer application) by the derived nitrogen elution rate to obtain the nitrogen elution amount, and further calculates the nitrogen from the acquired fertilizer application amount. Subtract the elution amount to derive the remaining fertilizer amount for this term (expressed as the amount per unit area). Next, the residual amount derivation unit 12 responds to the fertilizer application amount derivation unit 10 with the derived current fertilizer residual amount. In other words, the remaining amount of fertilizer in this term is the residual amount of slow-release fertilizer applied at the time of initial fertilizer application at the time of top dressing.

In the present embodiment, the nitrogen elution rate is obtained from the integrated temperature, the nitrogen elution amount is obtained by multiplying the fertilizer application amount at the initial fertilizer application by the nitrogen elution rate, and the nitrogen elution amount is subtracted from the fertilizer application amount at the initial fertilizer application. The composition is to obtain the residual amount of fertilizer for this term. However, the flow for finding the remaining amount of fertilizer in this term does not have to be exactly the same as this flow. For example, using a formula for calculating the nitrogen residual rate from the integrated temperature, the nitrogen residual rate is calculated by inputting the integrated temperature into this formula, and the amount of fertilizer applied at the time of initial fertilizer is multiplied by the nitrogen residual rate to determine the residual fertilizer for this term. You may ask for the amount. Alternatively, the nitrogen elution rate is first obtained, the nitrogen elution rate is subtracted from "1" to obtain the nitrogen residual rate, and the fertilizer residual rate at the time of initial fertilization is multiplied by the nitrogen residual rate to obtain the fertilizer residual amount for this term. good.

When the fertilizer application amount derivation unit 10 receives the response of the fertilizer application amount at the time of temporary topdressing from the temporary fertilizer amount derivation unit 11 and the response of the fertilizer residual amount in the current period from the residual amount derivation unit 12, the following processing is executed. That is, the fertilizer application amount derivation unit 10 obtains a value obtained by subtracting the fertilizer residual amount in the current period derived by the residual amount derivation unit 12 from the fertilizer application amount at the time of temporary topdressing derived by the temporary fertilizer amount derivation unit 11 at the time of final topdressing. Derived as the amount of fertilizer applied.

For example, it is assumed that the amount of fertilizer applied at the time of temporary topdressing derived by the temporary fertilizer amount derivation unit 11 is 4 kg in terms of the amount of nitrogen component per 10 ares. Further, it is assumed that the residual amount of fertilizer in this term derived by the residual amount deriving unit 12 is 2 kg in terms of the amount of nitrogen component per 10 ares. In this case, the fertilizer application amount derivation unit 10 derives and determines 2 kg, which is obtained by subtracting 2 kg from 4 kg in terms of the amount of nitrogen component per 10 ares, as the final fertilizer application amount at the time of top dressing.

The reason why the fertilizer application amount deriving unit 10 derives the final fertilizer application amount at the time of top dressing in this way is as follows. That is, the amount of fertilizer applied at the time of temporary topdressing is an appropriate amount of fertilizer applied at the time of topdressing under the condition that no slow-release fertilizer remains at the time of topdressing. However, in reality, the slow-release fertilizer may remain at the time of top dressing, and the residual amount of fertilizer for this term derived by the residual amount derivation unit 12 is the fertilizer when the slow-release fertilizer remains at the time of top dressing. Residual amount. Therefore, the value obtained by subtracting the residual amount of fertilizer in the current period derived by the residual amount derivation unit 12 from the amount of fertilizer applied at the time of temporary topdressing derived by the temporary fertilizer amount derivation unit 11 is used as the final amount of fertilizer applied at the time of top dressing. The final amount of fertilizer applied at the time of top dressing can be set to an appropriate value that reflects the residual amount of slow-release fertilizer.

After deriving the final amount of fertilizer applied at the time of topdressing, the fertilizer amount deriving unit 10 controls the display device 2 to display information indicating the derived amount of fertilizer applied at the time of topdressing in the display area of the display device 2. By referring to the display device 2, the user can recognize the fertilizer application amount at the time of topdressing derived by the fertilizer application amount derivation device 1, and can refer to the fertilizer application amount at the time of topdressing.

Next, the operation of the fertilizer application amount derivation device 1 according to the present embodiment will be described with reference to the flowchart of FIG. FIG. 4A shows the operation of the fertilizer application amount derivation unit 10, FIG. 4B shows the operation of the temporary fertilizer application amount derivation unit 11, and FIG. 4C shows the operation of the residual amount derivation unit 12. ..

As shown in FIG. 4A, the fertilizer application amount derivation unit 10 monitors whether or not there is an information provision instruction (step SA1). When there is an information provision instruction (step SA1: YES), the provisional fertilizer amount derivation unit 11 is requested to derive the fertilizer application amount at the time of temporary topdressing (step SA2). Further, the fertilizer application amount derivation unit 10 requests the residual amount derivation unit 12 to derive the fertilizer residual amount (step SA3). The order of processing in step SA2 and step SA3 is in no particular order, and they may be executed at the same time.

As shown in FIG. 4B, the temporary fertilizer amount derivation unit 11 monitors whether or not there is a request from the fertilizer application amount derivation unit 10 to derive the fertilizer application amount at the time of temporary topdressing (step SB1). When the request is made (step SB1: YES), the temporary fertilizer application amount derivation unit 11 acquires the analysis image data stored in the storage unit 13 (step SB2). Next, the temporary fertilizer application amount derivation unit 11 analyzes the analysis image data acquired in step SB2 and acquires the acquired NDVI (step SB3). Next, the temporary fertilizer amount derivation unit 11 derives the fertilizer application amount at the time of temporary topdressing based on the acquired acquired NDVI by using the fertilizer application amount derivation calculation formula (step SB4). Next, the temporary fertilizer amount derivation unit 11 responds to the fertilizer application amount derivation unit 10 with the fertilizer application amount at the time of temporary topdressing derived in step SB4 (step SB5).

As shown in FIG. 4C, the residual amount derivation unit 12 monitors whether or not there is a request from the fertilizer application amount derivation unit 10 to derive the fertilizer residual charge (step SC1). When the request is made (step SC1: YES), the residual amount derivation unit 12 acquires the integrated temperature data stored in the storage unit 13 (step SC2). Next, the residual amount derivation unit 12 acquires the acquired integrated temperature recorded in the data (step SC3). Next, the residual amount derivation unit 12 derives the nitrogen elution rate using the elution rate calculation formula based on the acquired integrated temperature acquired in step SC3 (step SC4).

Next, the residual amount derivation unit 12 acquires the initial fertilizer application amount data (step SC5). Next, the residual amount derivation unit 12 acquires the fertilizer application amount recorded in the initial fertilizer application amount data acquired in step SC5 (step SC6). Next, the residual amount derivation unit 12 multiplies the fertilizer application amount acquired in step SC6 by the nitrogen elution rate derived in step SC4 to obtain the nitrogen elution amount, and subtracts the nitrogen elution amount from the fertilizer application amount. The residual amount of fertilizer for this term is derived (step SC7). Next, the residual amount derivation unit 12 responds to the fertilizer application amount derivation unit 10 with the current fertilizer residual amount derived in step SC7 (step SC8).

As shown in FIG. 4A, after the treatment of step SA3, the fertilizer application amount derivation unit 10 responds to the fertilizer application amount at the time of temporary topdressing from the temporary fertilizer amount derivation unit 11 and the current fertilizer from the residual amount derivation unit 12. Monitor whether there was both a residual amount response (step SA4). When both responses are received (step SA4: YES), the fertilizer application amount derivation unit 10 is derived from the fertilizer application amount at the time of temporary topdressing derived by the temporary fertilizer amount derivation unit 11 to the residual amount fertilizer residual amount derived by the residual amount derivation unit 12. The value obtained by subtracting is derived as the final amount of fertilizer applied at the time of topdressing (step SA5). Next, the fertilizer application amount derivation unit 10 displays the information indicating the fertilizer application amount at the time of topdressing derived in step SA5 in the display area of the display device 2 (step SA6).

As described in detail above, the fertilizer application amount derivation device 1 according to the present embodiment acquires the integrated temperature from the initial fertilizer application in the current period to before the top dressing, and based on the acquired integrated temperature, the slow-release fertilizer. The residual amount of fertilizer for this term, which is the residual amount of fertilizer, is derived, and the amount of fertilizer applied at the time of top dressing is derived by reflecting the derived residual amount of fertilizer for this term. More specifically, the fertilizer application amount derivation device 1 according to the present embodiment acquires the NDVI at the measurement timing, and uses the fertilizer application amount derivation calculation formula that uses the NDVI as one of the inputs and outputs the fertilizer amount. The amount of fertilizer applied at the time of temporary topdressing is derived based on. Further, the fertilizer application amount derivation device 1 according to the present embodiment acquires the integrated temperature from the initial fertilizer application in the current period to before the topdressing, obtains the nutrient elution rate based on the acquired integrated temperature, and relaxes from the nutrient elution rate. Derivation of the residual amount of effective fertilizer. Then, the fertilizer application amount derivation device 1 according to the present embodiment subtracts the residual amount from the provisional fertilizer application amount at the time of topdressing to determine the final fertilizer application amount at the time of topdressing.

According to this configuration, the residual amount of slow-release fertilizer at the time of topdressing is determined based on the accumulated temperature from the initial fertilizer application to the prefertilizer before topdressing, and this residual amount is reflected and topdressing is performed. The amount of fertilizer applied at the time is derived. Therefore, it is possible to derive an appropriate amount of fertilizer application based on the situation that slow-release fertilizer is supplied at the time of initial fertilizer application and the state of residual fertilizer at the time of topdressing. More specifically, the fertilizer application amount derived by the fertilizer application amount derivation formula based on the NDVI at the time of topdressing is not simply the final fertilizer application amount at the time of topdressing, but the nutrient elution rate and the slowness based on the integrated temperature. After the residual amount of effective fertilizer is derived, the value obtained by subtracting this residual amount from the provisional fertilizer application amount derived by the formula for deriving the fertilizer amount is determined as the final fertilizer application amount. NS. Therefore, an appropriate amount of fertilizer can be determined based on the fact that the slow-release fertilizer is supplied at the time of initial fertilizer application.

<Modified example of the first embodiment>
Next, a modified example of the first embodiment will be described. In the above embodiment, the fertilizer application amount derivation unit 10 is a value obtained by subtracting the fertilizer residual amount derived by the residual amount derivation unit 12 from the fertilizer application amount at the time of temporary topdressing derived by the temporary fertilizer amount derivation unit 11 (hereinafter, "first value"). ") Was determined as the final amount of fertilizer applied at the time of top dressing. On the other hand, if the fertilizer application amount derivation unit 10 derives the first value and then the first value exceeds a predetermined upper limit value (expressed as an amount per unit area), this upper limit value is reached. May be determined as the final amount of fertilizer applied at the time of top dressing. Here, the upper limit value is set to a value that may adversely affect the quality of the harvested product when fertilizer is supplied in excess of this upper limit value regardless of the amount of NDVI at the time of top dressing. The upper limit is determined based on prior experiments and simulations.

<Second Embodiment>
Next, the second embodiment will be described. FIG. 5 is a block diagram showing a functional configuration example of the fertilizer application amount derivation device 1A according to the present embodiment. As is clear from the comparison between FIGS. 1 and 5, the fertilizer application amount derivation device 1A includes a fertilizer application amount derivation unit 10A instead of the fertilizer application amount derivation unit 10 according to the first embodiment. Further, the fertilizer application amount derivation device 1A includes a soil nitrogen predicted expression amount acquisition unit 20. Hereinafter, the operation of the fertilizer application amount derivation device 1A when the user gives an instruction to provide information to the input device 3 will be described in detail.

The fertilizer application amount derivation unit 10A requests the temporary fertilizer amount derivation unit 11 to respond to the fertilizer application amount at the time of temporary topdressing, and requests the residual amount derivation unit 12 to respond to the fertilizer residual amount in the current period in response to the information provision instruction. In addition to this, the response of the predicted expression level of soil nitrogen (described later) is requested from the soil nitrogen predicted expression level acquisition unit 20.

The soil nitrogen predicted expression level acquisition unit 20 acquires the soil nitrogen predicted expression level in response to a request from the fertilizer application amount derivation unit 10A. The predicted expression level of soil nitrogen is a predicted value of the expression level of soil nitrogen in the period from after topdressing to before harvesting. As is well known, fertilizer nitrogen is not artificially fertilized fertilizer, but nitrogen remaining in the soil. It is known that soil nitrogen is gradually decomposed by microorganisms and absorbed by crops, thereby affecting the growth of crops.

To elaborate on the operation of the soil nitrogen predicted expression amount acquisition unit 20, when the fertilizer application amount derivation unit 10A requests a response of the soil nitrogen predicted expression amount acquisition unit 20, the soil nitrogen predicted expression amount acquisition unit 20 is stored in the storage unit 13. Obtain data on the predicted expression level of soil nitrogen. The soil nitrogen predicted expression level data is data in which the soil nitrogen predicted expression level derived in advance is recorded. The predicted expression level of soil nitrogen is various factors that affect the expression level of soil nitrogen during the period from top dressing to pre-harvest (for example, predicted integrated temperature (soil temperature including temperature and paddy soil temperature)). , Crop varieties, soil conditions, cultivation method conditions, timing when crops are in a predetermined state (for example, timing when young ears are formed, timing of heading, timing expected to ripen, etc.) Derived in advance based on. The soil nitrogen predicted expression amount acquisition unit 20 recognizes the soil nitrogen predicted expression amount based on the acquired soil nitrogen predicted expression amount data, and responds to the fertilizer application amount derivation unit 10.

A model in which the soil nitrogen predicted expression level acquisition unit 20 inputs various factors that affect the soil nitrogen expression level during the period from top dressing to before harvesting and outputs the soil nitrogen predicted expression level. It may be configured to derive the predicted expression level of soil nitrogen by utilizing it. In this case, the various elements are stored in the storage unit 13 in advance or input to the user each time.

The fertilizer application amount derivation unit 10A acquires the fertilizer application amount at the time of temporary topdressing from the temporary fertilizer amount derivation unit 11, acquires the fertilizer residual amount for this term from the residual amount derivation unit 12, and the fertilizer nitrogen prediction expression amount acquisition unit 20. Get the quantity. Next, the fertilizer application amount derivation unit 10A determines the level of the acquired soil nitrogen predicted expression level. In the present embodiment, three levels of large level, medium level, and small level are preset according to the magnitude of the predicted expression level of soil nitrogen, and the threshold value for dividing each level is preset. .. Next, the fertilizer application amount derivation unit 10A sets a corresponding value set in advance according to the level (the significance of the corresponding value will be described later). The larger the level, the larger the corresponding value of each level. That is, "corresponding value corresponding to the large level> corresponding value corresponding to the medium level> corresponding value corresponding to the small level".

Next, the fertilizer application amount derivation unit 10A is a value obtained by subtracting the fertilizer residual amount in the current term from the fertilizer application amount at the time of temporary topdressing based on the fertilizer application amount at the time of temporary topdressing and the residual amount of fertilizer in this term (hereinafter, this provisional value is referred to as a "provisional value". (Corresponding to the final amount of fertilizer applied at the time of topdressing) derived in one embodiment) is derived. Next, the fertilizer application amount derivation unit 10A obtains a value obtained by subtracting the corresponding value corresponding to the level of the predicted fertilizer nitrogen expression level from the provisional value, and derives this value as the final fertilizer application amount at the time of top dressing. Similar to the first embodiment, the fertilizer application amount deriving unit 10A displays the derived information indicating the fertilizer application amount at the time of top dressing on the display device 2.

Here, as described above, the fertilizer application amount at the time of temporary topdressing is a value derived by using the fertilizer application amount derivation calculation formula generated by reflecting the actual fertilizer nitrogen expression level in the past, and is naturally a provisional value. However, the actual amount of soil nitrogen expressed in the past is reflected. However, it cannot be said that the provisional value accurately reflects the amount of soil nitrogen expression (= predicted expression level of soil nitrogen) that is predicted to be expressed in this term. Then, the process of "subtracting the corresponding value corresponding to the level of the predicted expression level of soil nitrogen from the provisional value" is to accurately reflect the predicted expression level of soil nitrogen in the current period in the fertilizer application amount at the time of topdressing that is finally derived. It is the processing of. More specifically, in the treatment, the larger the predicted expression level of soil nitrogen, the smaller the amount of fertilizer applied at the time of topdressing, which is finally derived, according to the magnitude of the predicted expression level of soil nitrogen. This is a process for adjusting and improving the accuracy of the amount of fertilizer applied at the time of topdressing, which is finally derived. The corresponding value of each level is appropriately set based on the results of tests and simulations from the viewpoint of adjusting the amount of fertilizer applied at the time of topdressing, which is finally derived according to the predicted expression level of soil nitrogen.

According to this embodiment, the following effects are obtained. That is, the nitrogen absorbed by the crops after topdressing includes not only nitrogen derived from fertilizer artificially provided at the time of topdressing, but also soil nitrogen. According to the present embodiment, since the fertilizer application amount at the time of topdressing is derived in consideration of the predicted expression level of soil nitrogen, it is possible to derive a more accurate fertilizer application amount at the time of topdressing.

The second embodiment may be configured as follows by applying a modified example of the first embodiment. That is, when the value obtained by subtracting the corresponding value from the provisional value exceeds a predetermined upper limit value, the fertilizer application amount deriving unit 10A may determine this upper limit value as the final fertilizer application amount at the time of top dressing.

Further, in the second embodiment, the value obtained by subtracting the corresponding value according to the predicted expression level of soil nitrogen from the provisional value as the final fertilizer application amount at the time of top dressing is a simplified example, and is finalized by another method. The fertilizer application amount at the time of top dressing may be derived. That is, the fertilizer application amount derivation unit 10A derives the final fertilizer application amount at the time of top dressing by reflecting the predicted expression amount of fertilizer nitrogen with respect to the provisional value (value obtained by subtracting the fertilizer residual amount at this term from the fertilizer application amount at the time of provisional fertilizer application). It should be. As an example, the fertilizer application amount derivation unit 10A derives a value obtained by multiplying the predicted expression amount of soil nitrogen by a predetermined coefficient, and subtracts this value from the provisional value to obtain the value as the final fertilizer application amount at the time of top dressing. It may be configured. In this case, the predetermined coefficient is a coefficient that adjusts the value of the predicted expression level of soil nitrogen in order to make the final fertilizer application amount an appropriate value, and is appropriately determined by prior tests and simulations. NS. In addition, grasp the amount of soil nitrogen expression that the fertilizer application derivation formula presupposes to derive the output value, and the fertilizer nitrogen expression that the fertilizer derivation formula presupposes and the predicted value for this term. The difference from the amount of soil nitrogen expressed may be reflected in the provisional value.

Further, the second embodiment may have the following configuration. That is, the second embodiment was premised on applying a slow-release fertilizer at the time of initial fertilizer application (at the time of basal fertilizer). On the other hand, there are cases where fast-acting fertilizer is applied at the time of initial fertilizer application. In this case, it is not necessary to consider the residual amount of fertilizer when determining the amount of topdressing at the time of topdressing. On the other hand, as described above, it is possible to improve the accuracy by considering the expression level of soil nitrogen after topdressing. Then, assuming the above case, the fertilizer application amount derivation device 1A according to the second embodiment can have the following configuration.

The fertilizer application amount derivation device 1A according to the second embodiment is configured not to have a residual amount derivation unit 12. Then, when the user gives an instruction to provide information to the input device 3, the fertilizer application amount derivation device 2A executes the following processing. That is, the fertilizer application amount derivation unit 10A requests the provisional fertilizer amount derivation unit 11 to respond to the fertilizer application amount at the time of temporary topdressing in response to the information provision instruction, and the soil fertilizer nitrogen prediction expression amount acquisition unit 20 is requested to express the soil fertilizer nitrogen prediction expression. Request a quantity response.

The temporary fertilizer amount derivation unit 11 derives the fertilizer application amount at the time of temporary topdressing by using the fertilizer amount derivation calculation formula. In this fertilizer application amount derivation calculation formula, the NDVI at the measurement timing is input, and in an environment where fast-acting fertilizer is applied at the initial fertilizer application, the fertilizer application amount at the time of topdressing necessary and appropriate for setting the state of the crop to the target state is obtained. It is a calculation formula to be output. The temporary fertilizer amount derivation unit 11 responds to the fertilizer application amount derivation unit 10A with the derived fertilizer application amount at the time of temporary topdressing. Further, the soil nitrogen predicted expression amount acquisition unit 20 acquires the soil nitrogen predicted expression amount and responds to the fertilizer application amount derivation unit 10A.

The fertilizer application amount derivation unit 10A acquires the fertilizer application amount at the time of temporary topdressing from the temporary fertilizer amount derivation unit 11, and acquires the fertilizer nitrogen predicted expression amount from the soil nitrogen predicted expression amount acquisition unit 20. The fertilizer application amount deriving unit 10A derives the final fertilizer application amount at the time of topdressing by reflecting the predicted expression amount of soil nitrogen in the fertilizer application amount at the time of provisional fertilizer application. An example of a method of reflecting the predicted fertilizer expression level in the amount of fertilizer applied at the time of temporary topdressing is as described in the second embodiment. The value is subtracted, and for example, the value obtained by multiplying the predicted fertilizer expression level by a predetermined coefficient is subtracted from the fertilizer application amount at the time of temporary topdressing. According to the above configuration, even in the case where the fast-acting fertilizer is applied at the time of the initial fertilizer application, the accuracy of the derived fertilizer application amount at the time of top dressing is improved by reflecting the expected expression level of fertilizer nitrogen. can.

<Third Embodiment>
Next, the third embodiment will be described. FIG. 6 is a block diagram showing a functional configuration example of the fertilizer application amount derivation device 1B according to the present embodiment. As is clear from the comparison between FIGS. 1 and 6, the fertilizer application amount derivation device 1B includes a fertilizer application amount derivation unit 10B instead of the fertilizer application amount derivation unit 10 according to the first embodiment. Further, the fertilizer application amount derivation device 1B includes a residual amount derivation unit 12B instead of the residual amount derivation unit 12 according to the first embodiment. Further, the fertilizer application amount derivation device 1B does not include the temporary fertilizer application amount derivation unit 11 according to the first embodiment. Hereinafter, the operation of the fertilizer application amount derivation device 1B when the user gives an information provision instruction to the input device 3 will be described in detail.

The fertilizer application amount derivation unit 10B requests the residual amount derivation unit 12B to respond with a residual amount difference (described later) in response to the information provision instruction. The residual amount derivation unit 12B executes the following processing in response to the request from the fertilizer application amount derivation unit 10B. That is, first, the residual amount deriving unit 12B derives the fertilizer residual amount in this term based on the integrated temperature by the same method as in the first embodiment. Next, the residual amount deriving unit 12B refers to the average fertilizer residual amount data stored in the storage unit 13 and recognizes the average fertilizer residual amount recorded in the data. The normal fertilizer residual amount means the residual amount of slow-release fertilizer (residual amount of fertilizer applied in the initial fertilizer application) at the time of top dressing in normal years. The average fertilizer residual amount is derived in advance based on the actual value of the residual amount in the actual field in the past and the test / simulation regarding the residual amount of the slow-release fertilizer.

Next, the residual amount derivation unit 12B derives the difference between the normal fertilizer residual amount and the derived current fertilizer residual amount (normal year fertilizer residual amount-current term fertilizer residual amount) as the residual amount difference. The difference in the residual amount derived in this way indicates the excess or deficiency of the residual amount of fertilizer in this term with respect to the residual amount of fertilizer in the normal year. The difference in residual amount is positive if "normal fertilizer residual amount> current term fertilizer residual amount", and negative if "normal year fertilizer residual amount <current term fertilizer residual amount". The residual amount derivation unit 12B responds to the fertilizer application amount derivation unit 10B with the derived residual amount difference.

When the residual amount difference is obtained from the residual amount derivation unit 12B, the fertilizer application amount derivation unit 10B executes the following processing. That is, the fertilizer application amount deriving unit 10B refers to the conventional fertilizer application amount data stored in the storage unit 13 and recognizes the conventional fertilizer application amount recorded in the data. The conventional fertilizer application amount at the time of topdressing is the conventional fertilizer application amount at the time of topdressing, and means the reference value of the fertilizer application amount at the time of topdressing set assuming that the residual amount of fertilizer at the time of topdressing is the above-mentioned normal fertilizer residual amount. is doing. Next, the fertilizer application amount derivation unit 10B adds the residual amount difference to the conventional fertilizer application amount at the time of top dressing to derive the final fertilizer application amount at the time of top dressing.

If the difference in residual amount is positive, it means that the residual amount of slow-release fertilizer applied in the initial fertilizer application is smaller than in the normal period. In this case, the value obtained by adding the residual amount difference (> 0) to the conventional fertilizer application amount is regarded as the final fertilizer application amount, so that the final fertilizer application amount is insufficient compared to the normal year. The amount of fertilizer is properly supplemented. On the other hand, if the residual amount value is negative, it means that the residual amount of slow-release fertilizer applied in the initial fertilizer application is larger than in the normal year. In this case, the final fertilizer application amount is the value obtained by adding the residual amount difference (<0) to the conventional fertilizer application amount (that is, the value obtained by subtracting the absolute value of the residual amount difference). The amount of fertilizer applied at the time of top dressing is a value in which excess fertilizer is appropriately reduced compared to the average year.

As described above, according to the present embodiment, the difference in the residual amount, which is the difference in the residual amount of the slow-release fertilizer between the normal year and the current period, is obtained based on the integrated temperature from the initial fertilizer application in the current period to before the top dressing. After that, the amount of fertilizer applied at the time of topdressing is derived by reflecting this difference in the residual amount. Therefore, it is possible to derive an appropriate amount of fertilizer application based on the situation that slow-release fertilizer is supplied at the time of initial fertilizer application and the state of residual fertilizer at the time of topdressing.

<Modified example of the third embodiment>
Next, a modified example of the third embodiment will be described. In the third embodiment, the residual amount deriving unit 12B derives the residual amount of fertilizer for the current term, and subtracts the residual amount of fertilizer for the current term derived from the residual amount of fertilizer for the normal year to derive the difference in the residual amount. In this regard, the following configuration may be used.

That is, the cumulative temperature of the normal year (as described in the first embodiment, the cumulative temperature of the period from the initial fertilizer application to the time of topdressing) and the cumulative temperature of the current term are input, and the difference in the residual amount (the residual amount of the normal fertilizer and the fertilizer for the current term) is input. A model with the output (difference from the residual amount) is generated in advance. Since there is a strong correlation between the "difference between the accumulated temperature in the normal year and the accumulated temperature in the current term" and the "difference between the residual amount of fertilizer in the normal year and the residual amount of fertilizer in the current term (residual amount difference)", the correlation should be determined. By analyzing, the above-mentioned model can be generated. In addition, instead of inputting the integrated temperature of the normal year and the integrated temperature of the current period into the model, the difference between these integrated temperatures may be input. In addition, the input of the model includes the element values of one or more factors that affect the residual amount of fertilizer other than the integrated temperature of the normal year and the integrated temperature of this period (or the difference between these integrated temperatures), and the model is The residual amount difference may be derived by reflecting one or more element values.

The residual amount deriving unit 12B executes the following processing when deriving the residual amount difference. That is, the residual amount derivation unit 12B recognizes the integrated temperature in the normal year and the integrated temperature in the current period. These are recorded in advance in the data stored in the storage unit 13. However, the configuration may be such that the user inputs each time. Then, the residual amount derivation unit 12B inputs the integrated temperature of the normal year and the integrated temperature of the current period into the model, and sets the output as the residual amount difference. The above configuration may be used.

Although one embodiment (including a modified example) of the present invention has been described above, each of the above embodiments is merely an example of embodiment of the present invention, whereby the technique of the present invention is described. The scope should not be construed in a limited way. That is, the present invention can be implemented in various forms without departing from its gist or its main features.

For example, in each of the above embodiments, the fertilizer application amount derivation device 1 derives the fertilizer application amount at the time of top dressing of rice cultivation for rice. However, the target crops are not limited to rice. That is, the present invention can be widely applied to agricultural products in which topdressing is performed after fertilization of slow-release fertilizer is performed during cultivation. As an example, it can be applied to wheat, barley, soybeans and other grains, vegetables, fruits and the like.

Further, in the first embodiment (including a modified example), the slow-release fertilizer was a nitrogen-based fertilizer. However, the slow-release fertilizer targeted by the present invention is not limited to nitrogen-based fertilizers, and any fertilizer may have some relationship between the integrated temperature and the nutrient elution rate, and the nutrient elution rate can be predicted based on the integrated temperature. Anything is fine. As an example, it may be soil nitrogen that can be estimated from the integrated temperature of the paddy soil.

Further, the storage unit 13 may have a configuration of an external storage device different from the fertilizer application amount derivation device 1.

Further, the fertilizer application amount derivation device 1 is configured as a server on the Internet, and when a client requests to provide information indicating the fertilizer application amount at the time of topdressing via the Internet, the fertilizer application amount at the time of topdressing is derived by the above-mentioned method. However, it may be configured to be provided to the client.

Further, the fertilizer application amount derivation device 1 does not have to be a single computer, and may be composed of a plurality of computers. For example, the terminal connected via the Internet and the cloud server may cooperate to function as the fertilizer application amount derivation device 1, and the terminal may appropriately cooperate with the cloud server to execute processing.

Further, in the present embodiment, the initial fertilizer is defined as "the fertilization of a nitrogen-based slow-release fertilizer performed at the time of transplantation to a field", but this is just an example of the initial fertilizer. The initial fertilizer may be fertilizer applied at a predetermined timing before top dressing in a certain period.

1, 1A, 1B fertilizer application amount derivation device 10, 10A, 10B fertilizer application amount derivation unit 11 Temporary fertilizer application amount derivation unit 12, 12B residual amount derivation unit 20 geological nitrogen predicted expression amount acquisition unit

Claims (13)

It is a fertilizer amount derivation device that derives the amount of fertilizer applied at the time of topdressing, which is the amount of fertilizer applied at the time of topdressing performed after the application of slow-release fertilizer at the beginning of this term.
Obtain the integrated temperature from the initial fertilizer application to the pre-fertilizer before the current period, and based on the acquired integrated temperature, the residual amount of slow-release fertilizer at the time of top-dressing, or the slowness between normal and current period. The residual amount derivation unit that derives the residual amount difference, which is the difference in the residual amount of effective fertilizer,
A fertilizer application amount derivation unit that derives the fertilizer application amount at the time of top dressing by reflecting the fertilizer residual amount in the current period or the difference in the residual amount derived by the residual amount derivation unit.
A fertilizer application amount derivation device characterized by being provided with. Use the fertilizer amount derivation formula that acquires the vegetation-related value related to the vegetation of the crop before topdressing, uses the vegetation-related value as one of the inputs, and outputs the fertilizer amount as the output, and temporarily topdresses based on the acquired vegetation-related value. It is further equipped with a temporary fertilizer amount derivation unit that derives the hourly fertilizer amount.
The residual amount derivation unit obtains the nutrient elution rate or the nutrient residual rate based on the integrated temperature from the initial fertilizer application to the top dressing in the current period, and derives the fertilizer residual amount in the current period from the nutrient elution rate or the nutrient residual rate. death,
The fertilizer application amount derivation unit subtracts the fertilizer residual amount of the current term derived by the residual amount derivation unit from the temporary fertilizer application amount derived by the temporary fertilizer amount derivation unit, and finally fertilizer application amount at the time of top dressing. The fertilizer application amount derivation device according to claim 1, wherein the fertilizer is derived. In the fertilizer application amount derivation unit, a value obtained by subtracting the fertilizer residual amount in the current period derived by the residual amount derivation unit from the fertilizer application amount at the time of provisional fertilizer derived by the temporary fertilizer amount derivation unit is a predetermined upper limit. The fertilizer application amount derivation device according to claim 2, wherein when the value exceeds the value, the upper limit value is derived as the final fertilizer application amount at the time of top dressing. It is further equipped with a soil nitrogen predicted expression level acquisition unit that acquires the soil nitrogen predicted expression level, which is the predicted value of the soil nitrogen expression level from after topdressing to before harvesting.
The fertilizer application amount derivation unit further predicts the fertilizer nitrogen to a value obtained by subtracting the fertilizer residual amount of this term derived by the residual amount derivation unit from the fertilizer application amount at the time of provisional fertilizer derived by the temporary fertilizer amount derivation unit. The fertilizer application amount deriving device according to claim 2, wherein the final fertilizer application amount at the time of topdressing is derived by reflecting the predicted expression amount of soil nitrogen acquired by the expression amount acquisition unit. The fertilizer application amount derivation unit is a value obtained by subtracting the residual amount of the slow-release fertilizer derived by the residual amount derivation unit from the temporary fertilizer application amount at the time of topdressing derived by the temporary fertilizer amount derivation unit, and further the soil force. If the value derived by reflecting the predicted fertilizer expression level acquired by the nitrogen predicted expression level acquisition unit exceeds a predetermined upper limit value, the upper limit value is derived as the final fertilizer application amount at the time of topdressing. The fertilizer application amount derivation device according to claim 4, wherein the fertilizer is applied. The temporary fertilizer amount derivation unit uses the state of the agricultural product as an objective variable for the relationship between the accumulated past actual amount of fertilizer applied at the time of topdressing and the combination of vegetation-related values before topdressing and the state of the agricultural product, and fertilizer is applied at the time of topdressing. The formula based on the multiple regression formula obtained by performing multiple regression analysis using the amount and the vegetation-related value before topdressing as explanatory variables is used as the fertilizer amount derivation calculation formula to derive the provisional fertilizer application amount at the time of topdressing. The fertilizer application amount derivation device according to any one of claims 2 to 5, wherein the fertilizer application amount is derived. The fertilizer application according to any one of claims 2 to 6, wherein the temporary fertilizer application amount derivation unit acquires a first index value obtained by remote observation of a crop community as the vegetation-related value. Quantity derivation device. The fertilizer application amount according to claim 7, wherein the temporary fertilizer application amount deriving unit acquires an NDVI obtained by sensing from the sky using a drone or an NDVI based on a satellite image as the first index value. Derivation device. The temporary fertilizer application amount derivation unit is obtained by NDVI obtained by measurement on the ground using an NDVI sensor, SPAD value obtained by measurement on the ground using a vegetation meter, or measurement on the ground using a leaf color plate. The fertilizer application amount derivation device according to any one of claims 2 to 6, wherein the leaf color plate value to be obtained is acquired as the vegetation-related value. The residual amount derivation unit derives the residual amount of fertilizer for this term based on the integrated temperature, and the residual amount of fertilizer for this term, which is the residual amount of slow-release fertilizer at the time of top dressing in normal year, and the derived residual amount of fertilizer for this term. By finding the difference, the residual amount difference is derived,
The first aspect of claim 1 is characterized in that the fertilizer application amount derivation unit derives the fertilizer application amount at the time of top dressing by reflecting the difference in the residual amount derived by the residual amount derivation unit in the conventional fertilizer application amount at the time of top dressing. The fertilizer application amount derivation device described. The residual amount derivation unit derives the residual amount difference based on the difference between the integrated temperature in the normal year and the integrated temperature in the current period.
The first aspect of claim 1 is characterized in that the fertilizer application amount derivation unit derives the fertilizer application amount at the time of top dressing by reflecting the difference in the residual amount derived by the residual amount derivation unit in the fertilizer application amount at the time of conventional top dressing. The fertilizer application amount derivation device described. Instead of the residual amount derivation unit, it has a soil nitrogen predicted expression amount acquisition unit that acquires a soil nitrogen predicted expression amount, which is a predicted value of the soil nitrogen expression amount from after topdressing to before harvesting.
When the fast-acting fertilizer is applied at the beginning of this term, the fertilizer application amount derivation unit derives the fertilizer application amount at the time of top dressing by reflecting the soil nitrogen predicted expression amount acquired by the soil nitrogen predicted expression amount acquisition unit. The fertilizer application amount derivation device according to claim 1, wherein the fertilizer application amount is derived. It is a fertilizer amount derivation method that derives the fertilizer application amount at the time of top dressing, which is the fertilizer application amount at the time of top dressing performed after the fertilization of the slow-release fertilizer at the initial stage of this term.
Obtain the integrated temperature from the initial fertilizer application to the pre-fertilizer before the current period, and based on the acquired integrated temperature, the residual amount of slow-release fertilizer at the time of top-dressing, or the slowness between normal and current period. The step of deriving the residual amount difference, which is the difference in the residual amount of effective fertilizer, and
The step of deriving the fertilizer application amount at the time of top dressing by reflecting the derived fertilizer residual amount in this term or the difference in the residual amount, and
A method for deriving the amount of fertilizer applied, which comprises.

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