JP3007969B1 - Soil organism density detection method - Google Patents

Abstract

The present invention provides a precise nematode density distribution easily and in a short time. In a first step, a natural potential of a field is measured by a natural potential measuring device to generate a natural potential distribution of the field. In the second step, soil is collected at a point where the natural potential shows a different value in the natural potential distribution obtained in the first step. Next, in a third step, the underground density of the nematode in the soil obtained in the second step is measured, and a correlation between the measured density and the natural potential at the sampled point is determined. In the fourth step, based on the correlation between the soil organism density determined in the third step and the natural potential, the density of the soil organisms in the field 3 is determined in accordance with the natural potential obtained in the first step. I try to detect it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting the density of soil organisms on agricultural land.

[0002]

2. Description of the Related Art In an agricultural land, soil is formed by self-active nematodes, while damage to crops by parasitic nematodes is a problem. It is indispensable to understand the distribution of parasitic nematodes in order to effectively control harmful nematodes. Conventionally, to understand the distribution of such parasitic nematodes, the soil was collected at many points, the nematodes in the collected samples were separated, the separated nematodes were identified under a microscope, and the number was counted. Then, the nematode density at each point is grasped on the surface.

[0003]

However, in the conventional method of grasping the nematode density distribution, one to two samples are analyzed.
It took about a day, and the larger the number of samples, the more labor and time required for separation and counting of nematodes. For this reason, it is difficult to analyze a large amount of sample,
There is a problem that it is difficult to obtain a precise nematode density distribution per unit area, and it is difficult to predict nematode damage or obtain information necessary for countermeasures. Further, in order to obtain a nematode density distribution that changes over time, it is necessary to sample the soil many times. Furthermore, if the number of samples taken is small,
Variations in the number of nematodes are likely to occur, and there is a fear of losing the meaning as a specimen. If an accurate nematode density distribution cannot be obtained,
There is a problem that an excessive input of pesticides for soil disinfection may be caused, or crops may be damaged due to insufficient disinfection.

SUMMARY OF THE INVENTION The present invention has been made to eliminate the above-mentioned problems, and has a simple configuration to save labor for measurement and to obtain a soil nematode density distribution that can easily and precisely obtain a precise nematode density distribution. It is intended to provide a density detection method.

[0005]

The method for detecting the density of soil organisms according to the present invention comprises a first step of measuring a natural potential of a predetermined land by a natural potential measuring device and forming a natural potential distribution of the land. A second step of collecting soil at a point where the natural potential shows a different value in the natural potential distribution obtained in the first step, and an underground density of a predetermined organism from the soil obtained in the second step. And a third step of determining the correlation between the measured density and the natural potential at the sampled point, and a correlation between the soil biological density and the natural potential determined by the third step, And a fourth step of detecting the density of soil organisms on the land corresponding to the natural potential obtained in the first step.

In the method for detecting the density of soil organisms according to the present invention,
First, in a first step, the natural potential of a predetermined range of land is measured by a natural potential measuring device in a first step, a natural potential distribution of the land is created, and in a second step, the natural potential obtained in the first step is obtained. The soil was collected at a point where the potential shows a different value in the distribution, and the underground density of a predetermined organism was measured from the soil obtained in the second step in the third step, and the measured density was collected. The correlation between the natural potential at the point and the natural potential obtained in the first step is determined based on the correlation between the soil biological density and the natural potential determined in the third step in the fourth step. The density of soil organisms on the land is then detected. For this reason, arbitrarily select points showing different values of energy, and the number of sampling points is determined according to the number of the selected points, so that the number of sampling points can be reduced as compared with the conventional one, A more precise distribution of soil biodensity can be obtained with a small number of samplings. In the third step, since the correlation between the natural potential and the density of the soil organism is determined, the soil organism to be detected is specified based on the strength of the correlation. Therefore, the density of the soil organism is estimated based on the distribution of the natural potential. For this reason, once a soil organism whose correlation has been determined by sampling is narrowed down and the soil organism density of the soil organism is found, the distribution of the soil organism density can be obtained only by examining the self potential distribution.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual diagram showing one embodiment of a self-potential measuring device used in the density detection method for soil organisms of the present invention. Self potential measuring device 2 of the present invention
Are non-polarizable electrodes 1-1 to 1-15 as shown in FIG.
And a self-potential measuring device 5 electrically connected to the electrode switching device 4 and the reference electrode (non-polarizable electrode) S, respectively. The non-polarizable electrodes 1-1 to 1-15 are uniformly arranged at predetermined intervals in the field 3 where the density of soil organisms is to be searched. The non-polarizable electrodes 1-1 to 1-15 used here have a small influence of the ground resistance between the electrode and the soil. The self-potential measuring device 2 uses the electrode switch 4 to control the potential difference between the reference electrode S and the non-polarizable electrode 1-1, the reference electrode S and the non-polarizable electrode 1-2.
, And the natural potential of the field 3 is measured by switching sequentially. Based on this measurement, the natural potential distribution of the field 3 is obtained. The reference electrode S is
Electrode at a certain point in the field (see Standard Point in Fig. 3)
Is standardized as 0 mV.

FIG. 2 is a natural potential monitor diagram showing a change in the natural potential of a certain experimental field 3 with time. As shown in FIG. 2, various factors act on the self-potential distribution in the soil, and change depending on temperature, rainfall, and the like. However, the change width of the self potential due to such a short-term factor is about 10 to 20 mV (see FIG. 2). However, in the experimental field (hereinafter referred to as the field) 3,
As shown in FIG. 3, there is a steady spontaneous potential distribution having a variation width of 70 mV or more. Such a self-potential distribution is expected to affect the root activity of plants and the growth of nematodes.

[0009] Then, in field 3, when the measurement of the nematode density and the distribution of the spontaneous potential were investigated, it was found that there was a correlation between the density of certain nematodes and the spontaneous potential ( (See FIG. 4). Therefore, the inventors of the present application have paid attention to this correlation, and have succeeded in grasping the density of certain kinds of nematodes, particularly the density of harmful nematodes in agricultural lands, by measuring the natural potential. That is, in the method for detecting the density of soil organisms of the present invention, first, the natural potential of the field 3 is measured by the self-potential measuring device 2 to create a self-potential distribution of the field 3 (hereinafter, referred to as a first step, FIG. 3). FIG.
It is a self potential distribution by the average of 13 self potential surveys performed from April 12 to 25, 1998, and X = 60.
In this example, the electrodes at the points m and Y = 0m are displayed as normalized with 0V. This point (X = 60 m, Y = 0 m) is the monitor point of the natural potential shown in FIG. The soil is collected at a point where the natural potential shows a different value in the obtained self-potential distribution (hereinafter, referred to as a second step). At this time, it is preferable that the sampling point is a point where the natural potential shows the maximum value, the minimum value, and the intermediate value.

The underground density of a given organism is measured from the soil obtained in the second step, and the correlation between the measured density and the natural potential at the sampled point is determined (hereinafter referred to as the third). Process). In the present embodiment, as shown in FIG. 4, when soil organisms were examined for harmful nematode and nematode-free self-acting nematodes, the underground density and natural potential of And a positive correlation was observed between them, and no correlation was found between the ground density of self-active nematodes and the self potential. Then, as shown in FIG. 4, a regression line L of natural potential-negusare nematode density is derived for the underground density of the nematode and the natural potential. At this time, after determining the correlation between the underground density of a certain soil organism (for example, a nematode nematode, a self-acting nematode, etc.) and the natural potential, a soil organism having a strong correlation (for example, a nexare nematode, etc.) May be targeted for density distribution detection, and soil organisms (for example, self-acting nematodes) whose correlation is not clear may be excluded from the target.

On the basis of the correlation between the density of soil organisms and the natural potential derived in the third step (see the regression line L of the self-potential-negusa nematode density in FIG. 4), the natural state obtained in the first step is obtained. A density distribution of soil organisms (negusa nematodes) in the field 3 is created corresponding to the potential distribution (see FIG. 3) (hereinafter, referred to as a fourth step). Therefore, once the soil organism density is found for the correlated soil organisms by sampling, the distribution of the soil organism density can be obtained only by examining the self-potential distribution, so that the measurement is labor-saving with a simple configuration. A precise nematode density distribution can be obtained in a short time. In the present embodiment, a certain soil organism (for example, Negusare nematode,
Judgment of the relationship between the underground density of self-acting nematodes, etc.) and the natural potential, and only those soil organisms (for example, Negusare nematode, etc.) that were found to be related to the density distribution detection. Organisms (e.g., self-acting nematodes) are excluded from the target, but are not limited to this. In the third step, the presence or absence of a correlation between the underground density of a certain soil organism and the natural potential is determined. A step of discriminating and identifying a soil organism (for example, a nematode nematode or the like) having a correlation may be provided, and only the identified soil organism may be targeted for density distribution detection.

As shown in FIG. 2, the natural potential changes depending on the temperature, rainfall, and the like. For this reason, it is preferable that the correlation between the weather condition and the natural potential is derived in advance, and the natural potential distribution is corrected according to the weather condition at the time of soil collection, and then the density distribution of the soil organisms is created. Further, the spontaneous potential changes depending on the yearly seasonal conditions (season and the like). For this reason, it is preferable that the correlation between the seasonal conditions of the year and the natural potential is derived in advance, and the natural potential distribution is corrected according to the time at which the soil was collected, and then the density distribution of the soil organisms is created. Furthermore, the first to fourth steps can be repeated at intervals of time to correct the climatic and temporal conditions, and create a time-dependent density distribution of soil organisms. In this way, it is possible to obtain a distribution of soil organism density that changes with time, and thus it is possible to predict soil organism (nematode) density in advance.

In the above-described embodiment, the correlation between the natural potential and the harmful soil organisms (Nexare nematodes) has been described. However, the present invention is not limited to this, as long as it has a relationship with the density of soil organisms. The energy is not limited to the natural potential, but may be natural energy such as a magnetic field (electromagnetic field) or radiation. In the above-described embodiment, the soil nematode is described as a soil creature, but is not limited thereto, and may be another harmful creature or a beneficial creature. In the above embodiment, the density distribution of soil organisms is created based on the self-potential distribution. However, the present invention is not limited to this, and the density of soil organisms at a certain point in the Needless to say, the detection may be performed in accordance with the potential.

[0014]

Next, an embodiment in which an experiment was conducted using the self potential measuring apparatus having the above-described configuration will be described. The experiment was performed in the applicant's upland irrigation field. In a predetermined range of the field 3 shown in FIG. 3, non-polarizable electrodes are installed at a total of 96 points, 12 columns at 6 m intervals in the X direction, 7 rows at 6 m intervals in the Y direction, and 1 row at 14 m intervals. Out of measurement range by 2
The potential difference between the non-polarizable electrode placed at the 00 m point and each electrode in the field was measured as a natural potential. To explain the chart,
FIG. 1 is a conceptual diagram of the self-potential measuring device 2, and FIG. The measured value in FIG. 2 is X = 60 in FIG.
m, Y = potential difference between non-polarizable electrodes installed at 0 m point and 200 m point outside the measurement range, and the fluctuation width is within 20 mV. FIG. 3 is a self-potential distribution diagram of 96 non-polarizable electrodes installed in a 66 × 50 m area (field 3).
The points indicated by black circles (●) are the electrode points. The displayed value is
13 measurements taken from April 12 to 25, 1998 are averaged, and the points at X = 60 m and Y = 0 m are normalized to 0 mV. The change width of the self potential distribution is 70
mV. FIG. 4 is a graph showing the correlation between the nematode density of the soil collected at the electrode point marked + in FIG. 3 and the natural potential. During the exploration period, the field 3 was left uncultivated.

In FIG. 3, X = 0m, X = 6m, and X = 12 in a row of Y = 12m indicating a high potential to a low potential in proximity.
m, X = 18 m and X = 42 m indicating low potential;
Soil samples were collected at 5 points of Y = 36m,
A nematode density measurement was performed. As a result, as shown in FIG.
No correlation was found between the self-acting nematode density and the spontaneous potential, but a positive correlation was observed between the nematode density and the spontaneous potential of the harmful nematodes, Nexare nematodes. From this result, it was confirmed that the nematode density distribution can be detected from the spontaneous potential distribution.

[0016]

As described above, the method for detecting the density of soil organisms according to the present invention comprises the first step of measuring the natural potential of a predetermined land with a natural potential measuring device, and creating the natural potential distribution of the land. A second step of collecting soil at a point where the natural potential shows a different value in the natural potential distribution obtained in the first step, and an underground density of a predetermined organism from the soil obtained in the second step. And a third step of determining the correlation between the measured density and the natural potential at the sampled point, and a correlation between the soil biological density and the natural potential determined by the third step, Since the method includes the fourth step of detecting the density of the soil organisms on the land corresponding to the natural potential obtained in the first step, the measurement can be saved with a simple configuration. In addition, a precise soil biodensity distribution can be obtained easily and in a short time. Further, once the soil biodensity is determined by sampling, the soil biodensity distribution can be obtained only by examining the self-potential distribution, so that it is possible to predict the soil biodensity distribution, which has been difficult in the past. In addition, since a precise soil organism density distribution can be obtained, if the target soil organism is a harmful nematode, the amount of pesticides used for soil disinfection, etc. on agricultural land can be reduced to the minimum necessary amount, thus reducing costs. This has the effect of reducing agricultural consumption and realizing agriculture with low pesticide input.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a self-potential measuring device used for a density detection method for soil organisms according to an embodiment of the present invention.

FIG. 2 is a spontaneous potential monitor diagram showing a temporal change of a spontaneous potential at a reference point.

FIG. 3 is a diagram showing a natural potential distribution and a sampling position in a field.

FIG. 4 is a correlation diagram showing the correlation between the nematode density of soil and the natural potential.

[Explanation of symbols]

 2 Self-potential measuring device 3 Field

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroaki Yoshida 2-1-2-2 Kannondai, Tsukuba, Ibaraki Pref. Agricultural Engineering Research Institute (58) Field surveyed (Int. Cl. ⁷ , DB name) A01M 1/00 G01N 33/24 BIOSIS (DIALOG) JICST file (JOIS)

Claims (7)

(57) [Claims] A first step of measuring a natural potential of a predetermined land by a self-potential measuring device and generating a self-potential distribution of the land; and a self-potential of the self-potential distribution obtained in the first step. A second step of collecting soil at a point at which a different value is obtained, and measuring an underground density of a predetermined organism from the soil obtained by the second step, and measuring the measured density and the natural potential of the sampled point. A third step of determining the correlation between the land and the land based on the correlation between the soil organism density and the natural potential determined in the third step, and corresponding to the natural potential obtained in the first step. And a fourth step of detecting the density of the soil organisms. 2. The density of soil organisms according to claim 1, further comprising a step of previously determining the correlation between the underground density of the soil organisms and the natural potential and identifying the soil organism to be detected. Detection method. 3. The method according to claim 1, further comprising the step of repeating the first to fourth steps at time intervals to create a time-dependent density distribution of the soil organism. Method for detecting the density of soil organisms. 4. The method according to claim 1, wherein a correlation between the seasonal conditions of the year and the self-potential is derived in advance, and the self-potential distribution is corrected according to the time at which the soil is collected, and then a density distribution of soil organisms is created. The method for detecting the density of soil organisms according to any one of claims 1 to 3. 5. The method according to claim 1, wherein a correlation between the weather condition and the natural potential is derived in advance, and the natural potential distribution is corrected according to the weather condition at the time of collecting the soil, and then a density distribution of the soil organism is created. 5. The method for detecting the density of a soil organism according to any one of 1 to 4. 6. The method according to claim 1, wherein in the second step, sampling is performed at a point where the self potential shows a maximum value, a minimum value, and an intermediate value.
2. The method for detecting the density of soil organisms according to claim 1. 7. The method for detecting the density of soil organisms according to claim 1, wherein in the third step, organisms in the soil are harmful nematodes.