JP2000214089A - Decision method for fertilization amount - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a decision method in which whether a fertilization amount is proper or not can be decided with good accuracy. SOLUTION: In this decision method for a fertilization amount, whether the amount of a fertilizer executed to a sample is within a prescribed range or not is decided. A step wherein the sample to which the fertilizer is executed is irradiated with excitation light is provided. A step wherein delay fluorescence generated from the sample which is irradiated with the excitation light is detected for a prescribed time is provided. A step (S 101) and a step (S 102) which calculated attenuation data as the relationship between the detection time of the delay fluorescence and the luminous intensity of the delay fluorescence are provided. A step (S 103) which finds the decision amount of the fertilization amount on the basis of the attenuation data is provided. In addition, a step (S 104) and a step (S 105) which decide whether the decision value of the fertilization amount is within a predetermined range or not are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for determining whether the amount of fertilizer applied to a sample is appropriate.

[0002]

2. Description of the Related Art In a tea plantation or the like, a large amount of fertilizer is applied in comparison with other crops in order to increase umami. However, when fertilizer is excessively applied, the growth of new shoots is delayed, and roots wither and other obstacles occur. In addition, it can induce nitrate acidification of rivers and groundwater, and excessive fertilization causes environmental problems.

[0003] As a method of determining the amount of fertilization to prevent such excessive fertilization, a method of collecting soil and analyzing the concentration of fertilizer or a method of digging up soil and visually determining a root state has been conventionally used. There are known ways to do this.

[0004]

However, in the former method, not only the observation on the spot is not possible, but also the number of days after fertilization and the environment such as rainwater, etc., greatly affect the fertilization amount within an appropriate range. It is difficult to accurately determine whether there is.
Further, in the latter method, it is often possible to visually recognize the symptoms such as root wilt due to excessive fertilization, and it is often too late to recover the sample.
For this reason, similarly to the former method, it is difficult to accurately determine the fertilization amount.

[0005] The present invention has been made in view of such circumstances, and has as its object to provide a fertilization amount determination method capable of accurately determining whether or not a fertilization amount is appropriate.

[0006]

According to the present invention, there is provided a fertilizer application determining method for determining whether an amount of a fertilizer applied to a sample is within a predetermined range. Irradiating the fertilizer-treated sample with excitation light, detecting the delayed fluorescence generated from the sample irradiated with the excitation light for a predetermined time, and determining the relationship between the detection time of the delayed fluorescence and the emission intensity of the delayed fluorescence. A step of calculating a certain attenuation data, a step of calculating a fertilization amount determination value based on the attenuation data, and a step of determining whether the fertilization amount determination value is within a predetermined range,
It is characterized by having.

[0007] According to the fertilizer application amount judging method according to the present invention, first, excitation light is applied to a sample such as a leaf of a fertilized plant. Then, delayed fluorescence is generated from the leaves of the plant and the like. Such delayed fluorescence is one in which the excitation light is once converted into chemical energy inside the chloroplast and then emitted again as light energy after a certain delay time.If such delayed fluorescence is monitored, It is possible to obtain not only superficial information but also information on molecules that receive the chemical energy, that is, information on the inside.

The delayed fluorescence generated from the sample is detected for a predetermined time by a photodetector such as a photomultiplier tube. Thereafter, attenuation data, which is a relationship between the detection time of the delayed fluorescence and the emission intensity of the delayed fluorescence, is calculated, and a fertilization amount determination value is obtained based on the attenuation data. Then, it is determined whether or not the fertilization amount determination value is within a range obtained in advance, and whether or not the fertilization amount to the sample is within a predetermined range. Here, if the allowable range is determined based on the fertilization amount determination value when the fertilization amount is appropriate, it can be determined whether the amount of the fertilizer applied to the sample is appropriate.

Further, in the fertilizer application amount determining apparatus of the present invention,
It is desirable that the fertilization amount determination value is a value of a ratio of a slope of two points of an attenuation curve created based on the attenuation data.

In this case, for example, if the slope of the decay curve at the early stage of detection of delayed fluorescence is k1, and the slope of the decay curve at the late stage of detection is k2, k2 / k1 or k1 / k
The value of 2 is the fertilization amount determination value. As a result of earnest research by the present inventors, it has been found that the fertilization amount determination value represented by k2 / k1 or the like has a certain relationship with the amount of fertilizer applied to the sample. Therefore, it is possible to accumulate the fertilization amount determination value in advance when the fertilization amount is appropriate or when the sample is withered due to excessive application of fertilizer, and determine the allowable range of the fertilization amount determination value based on this data. it can.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the method for determining fertilizer application according to the present invention will be described below in detail with reference to the accompanying drawings. Note that the same reference numerals are used for the same elements, and duplicate descriptions are omitted.

FIG. 1 is a configuration diagram of a fertilizer application amount judging device 2 used in the fertilizer application amount judging method of the present embodiment. The fertilizer application amount determination device 2 includes a delayed fluorescence measurement device 4, a determination device 6 connected to the delayed fluorescence measurement device 4 via a cable 10, and a display 8. The delayed fluorescence measurement device 4 is a portable device that can be detached from the determination device 6.

First, the configuration of the delayed fluorescence measuring device 4 will be described. The delayed fluorescence measurement device 4 is provided with a sample setting section 14 which has a clip shape capable of holding the sample 12 and is configured to block external light. In this embodiment, tea leaves are used as the sample 12.

In the present embodiment, a photomultiplier tube (PMT) 16 is used as a photodetector for detecting delayed fluorescence. A substantially cylindrical shaped delayed fluorescence passage section 18 capable of blocking the light of the above-described type is formed. The photomultiplier tube 16 is equipped with a multi-alkali photocathode, and can detect light having a delayed fluorescence wavelength of 720 to 760 nm from its spectral sensitivity characteristics.

The sample setting section 14 in the delayed fluorescence passage section 18
In the vicinity, a laser diode (LD) 20 which is a light source of excitation light for exciting the sample 12 is arranged. The laser light emitted from the laser diode 20 has a wavelength of 68
At 0 nm, the intensity of the laser light at the irradiation position of the sample 12 is 10 mW / cm ² . In addition, the delayed fluorescence passing section 1
8, shutters 2 are arranged in order from the sample setting unit 14 side.
2, a condenser lens 24 and a filter 26 are arranged.
A 1: 1 relay lens of f50 is used as the condenser lens 24, and a cut-off filter that cuts light having a wavelength shorter than 720 nm is used as the filter 26.

On the left side of the photomultiplier tube 16 in FIG. 1, the turning on and off of the LD 20, the opening and closing of the shutter 22, the opening and closing of the shutter 22,
Control device 30 for controlling the reception time of delayed fluorescence by
Is arranged. In the vicinity of the control device 30, a battery 32, which is a drive source of the photomultiplier tube 16, the LD 20, and the shutter 22, is exchangeably disposed.

Next, the configurations of the determination device 6 and the display 8 connected to the delayed fluorescence measurement device 4 will be described with reference to the block diagram of FIG. As shown in FIG. 2, the determination device 6 includes the photomultiplier tube 1 in the delayed fluorescence measurement device 4.
6, a preamplifier 34 for amplifying the signal from the counter 6, a counter 36 for counting the amplified signal,
A CPU 40 for calculating a fertilization amount determination value, determining whether or not the calculated fertilization amount determination value is within an allowable range (predetermined range), and in detail, an allowable range of the fertilization amount determination value described later is stored in advance for a plurality of fertilizers. And a tolerance data storage unit 38. Further, a display 8 capable of displaying an attenuation curve, a fertilization amount determination value, a determination result, and the like is connected to the CPU 40.

Here, a general attenuation curve will be described with reference to FIG. FIG. 3 is a graph in which the horizontal axis represents the detection time of the delayed fluorescence and the vertical axis represents the emission intensity of the delayed fluorescence, and the curve shown in this figure is the attenuation curve. Here, tea leaves (circles) collected from agricultural land where the fertilization rate is appropriate (nitrogen component is about 50 kg / 10a / year), and fertilizer excess (about 70 kg / year / year)
0a) tea leaves A (squares) collected from the agricultural land, excessive fertilizers (about 80 kg / 10 a year), tea leaves B (triangles) collected from the agricultural land, excess fertilizer (about 100 kg / 10 annually)
Four kinds of samples of tea leaves C (crosses) collected from the agricultural land of a) are used. In addition, in order to prevent variation in the measurement, 33 tea leaves were randomly collected from several trees in each field.

With respect to the tea leaves C, the influence of excess fertilizer cannot be determined by observing the portion that appears on the ground. However, when the soil was dug up and the roots were observed, it was found that troubles due to excess fertilizer had started to occur. In addition, tea leaves A and B
Could not determine the effect of fertilizer on the appearance. Note that FIG. 3 shows that the total amount of the delayed fluorescence emission decreases as the fertilization amount increases.

FIG. 4 shows the decay rates (gradients) k1 and 15-40 of the decay curve shown in FIG.
6 is a graph in which an attenuation rate (slope) k2 after seconds is calculated and these are two-dimensionally mapped. As for the tea leaves A to C with excess fertilizer, it can be seen that the initial attenuation becomes slower than the distribution of k1 and the attenuation rate in the latter period becomes larger than the distribution of k2 as compared to when the fertilization amount is appropriate. . In particular, as for the tea leaves C (crosses) with the largest amount of fertilization, the decay rate in the latter period is extremely higher than when the amount of fertilization is appropriate. Note that the positions of two points on the attenuation curve for obtaining k1 and k2 can be appropriately changed.

Based on k1 and k2 obtained in FIG. 4, the present inventors have found that the value of k1 / k2 is related to the amount of fertilization applied to the sample, and call the value a fertilization amount determination value. did. FIG. 5 shows the fertilization amount determination value as a histogram. The horizontal axis was the fertilization amount determination value, and the vertical axis was the frequency. From FIG. 5, it can be seen that the average value of the fertilization amount determination values decreases as the amount of fertilizer becomes excessive. At this time, for example, by setting the allowable range of the fertilization amount determination value to 5.00 or more, when the fertilization amount determination value is 5.00 or more, the fertilization amount is determined to be appropriate, and when the fertilization amount is smaller than 5.00, It can be determined that fertilizer is excessive. In addition, if the allowable range is set to 4.5 or more, when the fertilization amount determination value is smaller than 4.5, it can be determined that a failure has occurred in the root as in tea leaves C. Note that these tolerances are
It can be used when the same tea leaves and fertilizers used in this experiment are used. Further, data on such an allowable range is stored in the allowable range data storage unit 38 of the determination device 6.

Next, a method for determining whether or not the fertilization amount is appropriate will be described.

First, the process up to detection of delayed fluorescence will be described with reference to FIG. First, the sample 12 to be subjected to the determination of the amount of fertilization is set in the sample setting unit 14, and then left in a light-shielded state for about 2 minutes. Then, the operator operates the drive switch 2
When the shutter 8 is turned on, the LD 20 is turned on for about 30 seconds with the shutter 22 closed, and the sample 12 is excited. After the light excitation for 30 seconds is completed, the control device 30
Opens the shutter 22 and turns off the power supply to the LD 20 at the same time. After the LD 20 is turned off, delayed fluorescence is generated from the sample 12, and the delayed fluorescence passes through the shutter 22, is collected by the condenser lens 24, and reaches the photomultiplier 16. At this time, the filter 26
Light with a wavelength shorter than 20 nm is blocked. Control device 3
Under the command of 0, the photomultiplier tube 16 measures 200 times of sampling of 200 ms, that is, changes over time of about 40 seconds.

Next, referring to FIG. 2 and FIG. 6, the C built in the determination device 6 from the reading of the delayed fluorescence detected by the photomultiplier tube 16 to the display of the determination result of the fertilization amount.
The control procedure of the PU 40 will be described. After the photomultiplier tube 16 detects the delayed fluorescence for a predetermined time, the CPU 40 reads out delayed fluorescence data, which is an electrical signal of the delayed fluorescence, from the photomultiplier tube 16 (S101). The delayed fluorescence data read from the photomultiplier tube 16 is amplified by a preamplifier 34, and the amplified delayed fluorescence data is counted by a counter 36. Next, the CPU 40 calculates an attenuation curve indicating the relationship between the detection time of the delayed fluorescence and the emission intensity based on the count value of the delayed fluorescence data (S102).

After calculating the attenuation curve, the CPU 40 calculates a fertilization amount determination value (S103). In this embodiment,
As described above, the CPU 40 starts detection of delayed fluorescence 1 to 1
Slope k1 after 0 seconds and slope k2 15 to 40 seconds after the start of detection
Is calculated, and the value of k1 / k2 which is the fertilization amount determination value is calculated. In practice, an average value of the determination values obtained from several samples is calculated. After calculating the fertilization amount determination value, the CP
U40 reads data on the allowable range of the fertilization amount determination value from the allowable range data storage unit 38 (S104).

Then, the CPU 40 determines whether or not the fertilization amount applied to the sample 12 is appropriate by determining whether or not the fertilization amount determination value exceeds the allowable range (S10).
5). Note that, as described above, when the fertilization amount determination value is within the allowable range, the fertilization amount is determined to be appropriate, and when the fertilization amount determination value is smaller than the lower limit of the allowable range, the fertilization amount is excessive. Is determined. In the present embodiment, it is not necessary to set an upper limit of the allowable range because only the excess of the fertilization amount is determined, and the determination is not made of the excessively small amount. However, if an upper limit of the allowable range, that is, an allowable value when the amount of fertilization is too small is also determined, it is possible to prevent the amount of fertilization from being too small. Further, the allowable range of the fertilization amount determination value can be appropriately changed.

After determining the amount of fertilizer, the display 8
Then, a command to display the attenuation curve, the fertilization amount determination value, and the determination result of the fertilization amount is sent (S106), and the control operation of the CPU 40 ends. Using the determination result of the amount of fertilization displayed on the display 8, for example, controlling over fertilization,
This can be used as a reference when determining the amount of fertilizer to be applied thereafter.

According to the fertilizer application amount determining apparatus 2 of the present embodiment,
The amount of fertilizer applied can be easily determined at the site where the sample is located.In addition, since the delayed fluorescence emitted from the sample is used, the internal information of the sample can be known more accurately than when it is visually observed. it can. Therefore, it is possible to easily and accurately determine the amount of fertilizer.

As described above, the invention made by the present inventor has been specifically described based on the embodiments. However, the present invention is not limited to the above embodiments. For example, the determination unit and the display may be incorporated in the delayed fluorescence measurement device.
In this case, use on the site such as farmland is further facilitated.
Further, the fertilization amount can be determined even when the fertilization amount determination value is set to k2 / k1 instead of k1 / k2.

[0030]

As described above, according to the fertilization rate determination method according to the present invention, after detecting the delayed fluorescence emitted from the sample for a predetermined time, the detection time of the delayed fluorescence and the emission intensity of the delayed fluorescence are determined. Attenuation data as a relationship is calculated, and a fertilization amount determination value is determined based on the attenuation data. And
It is determined whether or not the fertilization amount determination value is within an allowable range determined in advance, and whether or not the fertilization amount to the sample is within a predetermined range. Here, if the above-mentioned allowable range is determined based on the fertilization amount determination value when the fertilization amount is appropriate,
It can be determined whether the amount of fertilizer applied to the sample is appropriate.

Here, in the present invention, since delayed fluorescence emitted from the sample is used, not only so-called surface information but also information inside the sample can be obtained. Therefore, it is possible to accurately determine whether or not the fertilization amount is appropriate.

[Brief description of the drawings]

FIG. 1 is a diagram showing a fertilization amount determination device used in a fertilization amount determination method of the present invention.

FIG. 2 is a block diagram showing a configuration of a determination unit of the fertilizer application amount determination device in detail.

FIG. 3 is a graph showing an attenuation curve obtained based on a sample with an appropriate amount of fertilization and a sample with an excessive amount of fertilization.

FIG. 4 shows k1 and k obtained from the attenuation curve shown in FIG.
2 is a graph obtained by two-dimensionally mapping values of 2.

FIG. 5 is a histogram showing fertilization amount determination values obtained from the attenuation curve shown in FIG. 3;

FIG. 6 is a flowchart illustrating a control procedure of a CPU of a determination unit.

[Explanation of symbols]

2 ... fertilizer application amount judging device, 4 ... delayed fluorescence measuring device, 6 ... judging device, 12 ... sample, 14 ... sample setting section, 16 ... photomultiplier tube, 20 ... laser diode, 22 ... shutter, 24 ... condensing lens , 26 ... Filter, 28 ... Drive Switch, 30 ... Control Device, 32 ... Battery, 34 ... Preamplifier, 36 ... Counter, 38 ... Permissible Range Data Storage Unit.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Fumi Yamazaki, Inventor 1126 Nomachi, Hamamatsu City, Shizuoka Prefecture F-term in Hamamatsu Photonics Co., Ltd. HA01 HA11 JA03 KA05 LA02 NA01 NA06 NA11

Claims (2)

[Claims] 1. A fertilization amount determination method for determining whether an amount of fertilizer applied to a sample is within a predetermined range, comprising: irradiating the sample to which the fertilizer has been applied with excitation light; Detecting a delayed fluorescence generated from the sample irradiated with the excitation light for a predetermined time; calculating attenuation data that is a relationship between the detection time of the delayed fluorescence and the emission intensity of the delayed fluorescence; A fertilization amount determination method, comprising: determining a fertilization amount determination value based on attenuation data; and determining whether the fertilization amount determination value is within a predetermined range. 2. The fertilization amount determination method according to claim 1, wherein the fertilization amount determination value is a value of a ratio of a slope of two points of an attenuation curve created based on the attenuation data.