JP7123381B2 - Soil physical property diagnostic method in the field - Google Patents

Description

TECHNICAL FIELD The present invention relates to a field soil physical property diagnosis method for diagnosing soil physical properties in a field diagnostic area.

Speaking of "soil diagnosis", it is common to perform soil chemical properties, and the development of a simple soil physical property diagnosis technology has been required. In recent years, agricultural machinery has become larger, and there is a tendency for poor drainage due to the formation of a plow bed layer and a thin layer of plowed soil. I've been
Soil physical properties are generally measured by taking core samples back to the laboratory, which is costly and time-consuming, and difficult to process a large number of samples. In addition, it is known that if the survey point shifts slightly, it will change, and a simple evaluation method that can be used in the field has been sought.
Patent Literature 1 proposes a soil hardness meter that is lightweight, portable, capable of highly accurate measurement, and has a function of storing measured values of soil hardness and penetration depth in a memory.
In addition, in Patent Document 1, position information and date and time information measured using GPS are obtained, stored in a memory together with the measurement data, and the stored data is output to a computer to display the measurement data on the map. We also propose to display

Japanese Patent No. 4417422

However, no method for diagnosing soil physical properties that affect crop productivity, such as poor drainage and the thickness of the topsoil layer, has been proposed so far.

The present invention aims to provide a soil physical property diagnostic method in a field for diagnosing soil physical properties that affect crop productivity using soil hardness data that can be measured with a soil hardness meter as proposed in Patent Document 1. aim.

The method for diagnosing soil physical properties in a field of the present invention according to claim 1 includes a positioning point determination step of determining a plurality of positioning points for a diagnosis area targeted for a field, and the positioning points determined in the positioning point determination step. a measuring step of measuring soil hardness for each depth; and a soil hardness contour map generating step of generating a soil hardness contour map for each depth from the soil hardness data measured in the measuring step and the position data of the positioning points. and a soil layer determination step of determining whether the soil stratum is plow soil or subsoil from the soil hardness contour map for each depth generated in the soil hardness contour map generation step, and the soil layer determination step. and a soil physical property diagnosis step of diagnosing the soil physical properties of the plowed soil or the subsoil , wherein the soil physical property diagnosis step discriminates a low hardness point from the deep soil hardness contour map. and a second step of discriminating a low hardness area including the low hardness point discriminated in the first rainwater retention area discrimination step from the shallow soil hardness contour map as a rainwater retention area. and a rainwater retention area determining step, wherein the rainwater retention area where rainwater collects in the plowed soil is determined from the soil hardness contour map for each depth .
According to a second aspect of the present invention, there is provided the method for diagnosing soil physical properties in a field according to the first aspect, wherein the soil physical properties are water retention or drainage properties of the cultivated soil.
The present invention according to claim 3 is the method for diagnosing soil physical properties in an agricultural field according to claim 1, wherein after measuring the soil hardness in the measuring step, a plowing step of plowing the diagnostic area with a farming machine. a post-plowing measurement step of measuring post-plowing soil hardness for each depth at the positioning point determined in the positioning point determination step after plowing in the plowing step; In the property diagnosis step, the change in soil physical properties is diagnosed from the soil hardness data measured in the measurement step and the post-plowing soil hardness data measured in the post-plowing measurement step.
According to a fourth aspect of the present invention, there is provided the method for diagnosing soil physical properties in an agricultural field according to the first aspect, wherein after measuring the soil hardness in the measuring step, a stepping step in which an agricultural work machine travels in the diagnostic area; a post-travel measurement step of measuring post-travel soil hardness for each depth at the positioning point determined in the positioning point determination step after traveling in the treading step, wherein the soil physical property diagnosis step includes the The change in soil physical properties is diagnosed from the soil hardness data measured in the measuring step and the post-running soil hardness data measured in the post-running measurement step.
The present invention according to claim 5 is the method for diagnosing soil physical properties in a field according to claim 1 or claim 2 , wherein the soil grain size composition is obtained from the soil hardness contour map in the cultivated soil discriminated in the soil layer discrimination step. It is characterized by discriminating.
According to a sixth aspect of the present invention, in the method for diagnosing soil physical properties in an agricultural field according to the first or second aspect, the amount of fertilizer applied is diagnosed from the soil hardness contour map in the cultivated soil determined in the soil layer determination step. characterized by
The present invention according to claim 7 is the soil physical property diagnosis method in a field according to claim 1 or claim 2 , wherein the laying position of the open ditch is determined from the soil hardness contour map in the cultivated soil determined in the soil layer determination step. is characterized by determining
The present invention according to claim 8 is the method for diagnosing soil physical properties in a field according to claim 1 or claim 2 , wherein the soil hardness contour map in the subsoil discriminated in the soil layer discriminating step determines the construction position of the underdrain. is characterized by determining

According to the present invention, soil physical properties that affect crop productivity such as poor drainage and thickness of the topsoil layer are evaluated for the entire diagnostic area, not for limited sampling of the topsoil and subsoil. It can be distinguished and diagnosed by three-dimensional distribution.

1 is a flow chart showing a soil physical property diagnostic method in a field according to an embodiment of the present invention; Explanatory diagram showing the soil physical property diagnosis method in the same field Soil hardness contour map for each depth generated by the soil physical property diagnosis method in the same field Diagram showing the relationship between the soil hardness contour map generated by the soil physical property diagnosis method in the same field and the soil moisture content at the time of harvest. A diagram showing the relationship between the soil hardness contour map generated by the soil physical property diagnosis method in the same field and the yield of crops. Flowchart showing a soil physical property diagnosis method in a field according to another embodiment of the present invention Graph showing evaluation results (contribution ratio) of principal components (physical parameters) extracted by principal component analysis without standardization for soil hardness Graph showing changes in soil hardness before and after plowing using PC1 and PC2 in FIG. 7 as indicators Flowchart showing a soil physical property diagnosis method in a field according to still another embodiment of the present invention Graph showing changes in soil hardness before and after running using PC1 and PC2 in FIG. 7 as indices Table showing precipitation and average temperature for 10 days before each survey date Soil hardness contour map of subsoil (40 cm depth) in the same field for each survey day Contour map of soil hardness in the same field (depth 12 cm) for each survey day Graph showing daily precipitation (AMEDAS data) before each survey date Soil moisture content contour map showing rainfall events and horizontal distribution of surface soil moisture over time Soil moisture content contour map and soil hardness contour map showing vertical distribution of soil moisture and soil hardness in plow soil in comparison Soil moisture content contour map and soil hardness contour map showing vertical distribution of soil moisture and soil hardness in subsoil in comparison Yield contour map showing wheat flour yield Contour map showing soil grain size composition and C humus in the surface layer Soil hardness contour map in the field shown in FIGS. 18 and 19 Contour maps showing soil chemistry in fields shown in FIGS. 18 to 20 Analysis maps showing soil chemistry in fields shown in FIGS. 18 to 20

A method for diagnosing soil physical properties in a field according to the first embodiment of the present invention includes a positioning point determination step for determining a plurality of positioning points for a diagnosis area targeted for a field, and positioning points determined in the positioning point determination step. , a soil hardness contour map generation step of generating a soil hardness contour map for each depth from a measurement step of measuring soil hardness for each depth, soil hardness data measured in the measurement step and position data of positioning points, soil A soil layer discrimination step of discriminating whether the soil stratum is top soil or subsoil from the soil hardness contour map for each depth generated in the hardness contour map generation step, and the top soil or subsoil discriminated in the soil layer discrimination step. and a soil physical property diagnosis step of diagnosing soil physical properties, the soil physical property diagnosis step includes a first rainwater retention area determination step of determining low hardness points from a deep soil hardness contour map, and a depth of a second rainwater retention area discrimination step of discriminating a low hardness area including a low hardness point discriminated in the first rainwater retention area discrimination step from a shallow soil hardness contour map as a rainwater retention area; From the map, a rainwater retention area where rainwater collects in the plowed soil is determined .
According to the present embodiment, soil physical properties that affect crop productivity, such as poor drainage and the thickness of the soil layer, are measured for the entire diagnosis area, instead of limited sampling of the soil and subsoil. can be diagnosed by three-dimensional distribution. In addition, by first identifying low hardness points as points where rainwater collects, the flow of rainwater can be predicted, and rainwater retention areas can be accurately determined. In addition, the low hardness area in the soil can be identified as a rainwater retention area because there is a permeation space due to low density and many gaps, or because the soil contains moisture and softens due to increased plasticity. By determining the rainwater retention area, it is possible to predict the wet damage area and drought damage area of crops in the field.

According to the second embodiment of the present invention, in the method for diagnosing physical properties of soil in a field according to the first embodiment, the physical property of the soil is the water holding property or drainage property of cultivated soil.
According to the present embodiment, it is possible to diagnose the water retention or drainage properties of the plowed soil, thereby effectively laying underdrains and open ditches and increasing the yield of crops.

According to a third embodiment of the present invention, in the method for diagnosing soil physical properties in an agricultural field according to the first embodiment, after the soil hardness is measured in the measurement step, a plowing step of plowing a diagnostic area with a farming machine; and a post-plowing measurement step of measuring post-plowing soil hardness for each depth at the positioning points determined in the positioning point determination step after plowing in the plowing step, and the soil physical property diagnosis step includes measuring Changes in soil physical properties are diagnosed from the soil hardness data measured in the step and the post-plowing soil hardness data measured in the post-plowing measurement step.
According to the present embodiment, it is possible to confirm the working effect of the agricultural implement, and to select the agricultural implement suitable for the field based on objective data.

According to a fourth embodiment of the present invention, in the method for diagnosing soil physical properties in an agricultural field according to the first embodiment, after the soil hardness is measured in the measurement step, a step of stepping the agricultural implement to travel through the diagnosis area; After traveling in the step, a post-travel measurement step of measuring post-travel soil hardness for each depth for the positioning points determined in the positioning point determination step, and in the soil physical property diagnosis step, the soil hardness measured in the measurement step. Changes in soil physical properties are diagnosed from data and post-running soil hardness data measured in the post-running measurement step.
According to this embodiment, it is possible to grasp the influence of the tread pressure of the agricultural implement, and to select a travel method and a travel route for the agricultural implement suitable for the field based on objective data.

According to a fifth embodiment of the present invention, in the field soil physical property diagnosis method according to the first or second embodiment, the grain size composition of the soil is determined from the soil hardness contour map in the plowed soil determined in the soil layer determination step. It is for discriminating.
According to the present embodiment, by determining the grain size composition of the soil, it is possible to predict the crop yield and adjust the fertilizer application amount.

According to a sixth embodiment of the present invention, in the method for diagnosing soil physical properties in a field according to the first or second embodiment, the amount of fertilizer applied is diagnosed from the soil hardness contour map in the cultivated soil discriminated in the soil layer discriminating step. It is.
According to this embodiment, fertilization can be reduced by analyzing soil chemistry together.

According to a seventh embodiment of the present invention, in the field soil physical property diagnosis method according to the first or second embodiment, the laying position of the open ditch is determined from the soil hardness contour map in the plowed soil determined in the soil layer determination step. to decide.
According to the present embodiment, it is possible to effectively lay open culverts by diagnosing the water retentivity or drainage of plowed soil.

According to the eighth embodiment of the present invention, in the field soil physical property diagnosis method according to the first or second embodiment, the laying position of the underdrain is determined from the soil hardness contour map in the subsoil determined in the soil layer determination step. to decide.
According to the present embodiment, it is possible to effectively lay underdrains by diagnosing the water retention or drainage properties of the subsoil.

A method for diagnosing soil physical properties in a field according to an embodiment of the present invention will be described below.
FIG. 1 is a flow chart showing a soil physical property diagnostic method in an agricultural field according to this embodiment.
The method for diagnosing soil physical properties in an agricultural field according to the present embodiment is performed in the following steps.
In positioning point determination step 1, a plurality of positioning points 2 (see FIG. 2) are determined for a diagnosis area 1 (see FIG. 2) targeting a field. For example, the positioning point 2 is determined to be approximately 10m mesh. Assuming that the diagnostic area 1 is 1 ha, the positioning points 2 are 64 by removing the outermost periphery of the diagnostic area 1 from the positioning points 2 .
In the measurement step 2, the soil hardness is measured for each depth at the positioning point 2 determined in the positioning point determination step 1. For measuring soil hardness, for example, a penetrating soil hardness meter as disclosed in Patent Document 1 is used. In addition, in the measurement in the measurement step 2, position data of the positioning point 2 is acquired using the global positioning system (GNSS).
In the soil hardness contour map generation step 3, a soil hardness contour map is generated for each depth from the soil hardness data measured in the measurement step 2 and the position data of the positioning points 2.
In the soil layer discrimination step 4, it is discriminated whether the soil horizon is open soil or subsoil from the soil hardness contour map for each depth generated in the soil hardness contour map generation step 3.

In the soil physical property diagnosis step 5, the physical properties of the plowed soil or the subsoil determined in the soil layer determination step 4 are diagnosed.
In the soil physical property diagnosis step 5, from the soil hardness contour map for each depth, the low hardness area 11 (see FIG. 3) in the soil is discriminated as the rainwater retention area where rainwater collects.
More specifically, in the soil physical property diagnosis step 5, a first rainwater retention area determination step 51 for determining the low hardness point 10 (see FIG. 3) from a deep soil hardness contour map, and a shallow soil hardness A second rainwater retention area determination step 52 for determining the low hardness area 11 including the low hardness point 10 determined in the first rainwater retention area determination step 51 as a rainwater retention area from the contour map.

FIG. 2 is an explanatory diagram showing a soil physical property diagnosis method in an agricultural field according to this embodiment.
FIG. 2(a) shows positioning points 2 in a diagnosis area 1 targeting a field. FIG. 2(b) shows the soil hardness for each depth at one positioning point 2. FIG. FIG. 2(b) shows the case of measuring up to a depth of 60 cm in 1 cm increments. FIG. 2(c) shows soil hardness contour maps at seven different depths in 5 cm increments.

FIG. 3 is a soil hardness contour map for each depth generated by the method for diagnosing soil physical properties in a field according to the present embodiment.
Fig. 3(a) is 15 cm deep, Fig. 3(b) is 20 cm deep, Fig. 3(c) is 30 cm deep, Fig. 3(d) is 40 cm deep, Fig. 3(e) is 50 cm deep, Fig. 3(f) is a soil hardness contour map at a depth of 60 cm.
As shown in FIG. 3, it can be seen that the subsoil is at a depth of 20 cm or more, and the topsoil is at least at a depth of less than 20 cm. A predetermined hardness is defined as a threshold, and it is possible to determine that the soil stratum is subsoil based on the ratio of hardness equal to or higher than the threshold.
In the soil hardness contour map shown in FIG. 3, for example, the low hardness point 10 is determined from the soil hardness contour map at a depth of 60 cm, which is a deep soil hardness contour map, and the soil at a depth of 15 cm, which is a shallow soil hardness contour map. A low-hardness area 11 including a low-hardness point 10 is determined as a rainwater retention area from the hardness contour map.

FIG. 4 is a diagram showing the relationship between the soil hardness contour map generated by the method for diagnosing soil physical properties in a field according to the present embodiment and the moisture content of the soil at the time of harvesting.
FIG. 4(a) shows a soil hardness contour map at a depth of 12 cm in the diagnosis area, and FIG. 4(b) shows the plowing soil moisture content measured at the time of harvesting crops in the same diagnosis area.
As shown in FIG. 4(a), low hardness areas 11a and 11b surrounded on three sides by high hardness areas have a high moisture content as shown in FIG. 4(b). On the other hand, the low hardness area 11c surrounded on three sides by high hardness areas has a low hardness area 11d that communicates with the low hardness area 11a. It can be considered that it flows into the low hardness area 11a.

FIG. 5 is a diagram showing the relationship between the soil hardness contour map generated by the method for diagnosing physical properties of soil in a field according to the present embodiment and the yield of crops.
Fig. 5(a) shows a soil hardness contour map at a depth of 12 cm in the diagnosis area, and Fig. 5(b) shows a wheat (Satonosora) grain weight (t/ha) contour map in the same diagnosis area. .
It can be seen that there is a correlation between the wet damage area 21 and the drought damage area 22 shown in FIG. 5(b) and the soil hardness shown in FIG. 5(a).

Thus, according to the present embodiment, soil physical properties that affect crop productivity, such as poor drainage and the thickness of the plowing layer, are investigated for the entire diagnostic area 1 instead of limited sampling. Diagnosis can be made by three-dimensional distribution by distinguishing between soil and subsoil.
In addition, according to this embodiment, the low hardness area 11 in the cultivated soil has a low density and many gaps, so there is an infiltration space, or when the soil contains moisture, the plasticity increases. It can be determined that it is an area, and by determining a rainwater retention area, a wet damage area 21 and a drought damage area 22 of crops in a field can be predicted.
Further, according to this embodiment, by first determining the low hardness point 10 as a point where rainwater collects, the flow of rainwater can be predicted and the rainwater retention area can be accurately determined.
In addition, as shown in this example, by diagnosing the water retention or drainage properties of the soil by diagnosing the water retention or drainage properties of the soil, it is possible to effectively lay underdrains and open conduits. , can increase crop yield.

FIG. 6 is a flow chart showing a method for diagnosing soil physical properties in a field according to another embodiment of the present invention. The same processing as in FIG. 1 is given the same reference numerals, and the description thereof is omitted.
The method for diagnosing soil physical properties in an agricultural field according to the present embodiment includes, after measuring the soil hardness in the measurement step 2, a plowing step 6 in which the diagnostic area 1 is plowed by an agricultural machine, and after plowing in the plowing step 6, A post-plowing measurement step 7 of measuring post-plowing soil hardness for each depth for the positioning point 2 determined in the positioning point determination step 1 is included.
Then, in the soil physical property diagnosis step 5, changes in soil physical properties of the crop soil or subsoil are determined from the soil hardness data measured in the measurement step 2 and the post-plowing soil hardness data measured in the post-plowing measurement step 7. Diagnose.

FIG. 7 shows evaluation results (contribution ratios) of principal components (physical parameters) extracted by principal component analysis without standardization for soil hardness. In FIG. 7, PC1 indicates the tendency due to the hardness of the subsoil, and PC2 indicates the tendency due to the hardness of the topsoil.

FIG. 8 is a graph showing changes in soil hardness before and after plowing using PC1 and PC2 in FIG. 7 as indices. The horizontal axis is PC1, and the vertical axis is PC2.
Stable cultivators, subsoilers, and plows were used as agricultural implements.
In Stubble Culch, plowing softens the topsoil and softens the subsoil a little. In the subsoiler, the subsoil is considerably softened by tillage. In a plow, plowing softens the topsoil, but the subsoil is somewhat stiff. The reason why the subsoil is hardened by using the plow is considered to be rubbing against the mouldboard.
When the subsoiler and stub cultivator are used, the subsoil becomes softest compared to when the subsoiler or stub cultivator is used alone. The soil becomes harder than the case.
Between the subsoiler's knives, there is almost no effect on topsoil and subsoil. In the ruts the soil is hardened.
As described above, according to the present embodiment, it is possible to confirm the work effect of the agricultural implement, and to select the agricultural implement suitable for the field based on objective data.

FIG. 9 is a flow chart showing a soil physical property diagnostic method in a field according to still another embodiment of the present invention. The same processing as in FIG. 1 is given the same reference numerals, and the description thereof is omitted.
The method for diagnosing soil physical properties in an agricultural field according to the present embodiment includes, after measuring the soil hardness in the measurement step 2, a step 8 in which the agricultural work machine travels in the diagnosis area 1, and after traveling in the step 8, a positioning point determination step and a post-travel measurement step 9 of measuring post-travel soil hardness for each depth at the positioning point 2 determined in 1.
Then, in the soil physical property diagnosis step 5, changes in soil physical property are diagnosed from the soil hardness data measured in the measurement step 2 and the post-travel soil hardness data measured in the post-travel measurement step 9 for the plowed soil or subsoil. .

FIG. 10 is a graph showing changes in soil hardness before and after running using PC1 and PC2 in FIG. 7 as indices. The horizontal axis is PC1, and the vertical axis is PC2.
FIG. 10(a) is a point without treading, FIG. 10(b) is a point treaded with a crawler, and FIG. 10(c) is a headland point. For paddy fields in which rice was cultivated by direct seeding in dry fields, measurements were taken before harvesting as measurement step 2 and after harvesting as measurement step 9 after running. Measurements were taken at 23 points without tread pressure, at 29 points with tread pressure, and at 10 headlands.
As shown by the average PC2 in FIGS. 10(a) and 10(b), the soil layer is hardly affected by the pressure of the crawler, and as shown by the average PC1 in FIGS. 10(a) and 10(b) In addition, the subsoil is hardened by an average of 9.4% due to the pressure of the crawler.
As described above, according to the present embodiment, it is possible to grasp the influence of the tread pressure of the agricultural implement, and to select the traveling method and the traveling route of the agricultural implement suitable for the field based on objective data.

Changes in soil hardness throughout the year will be described with reference to FIGS. 11 to 13 .
Figure 11 is a table showing precipitation and average temperature for 10 days before each survey day, Figure 12 is a soil hardness contour map of subsoil (40 cm depth) in the same field for each survey day, and Figure 13 is each survey day is a contour map of soil hardness in plowed soil (depth of 12 cm) in the same field.

As shown in FIG. 11 (a), the survey date of 2015/11/25 and the survey date of 2016/11/18 had a large amount of accumulated precipitation over the 10 days, and the survey date of 2016/3/2 and 2016/ The cumulative rainfall for the 10 days of the survey on June 1 is small. In addition, as shown in FIG. 11B, the cumulative average temperature for the 10-day survey date of June 1, 2016 is the highest.
12 and 13, the survey date of November 25, 2015 (Figures 12(a) and 13(a)) and the survey date of November 18, 2016 (Figure 12(d), FIG. 13(d)) are the investigation dates of March 2, 2016 (FIGS. 12(b), 13(b)) and the investigation dates of June 1, 2016 (FIG. 12(c) , and FIG. 13(c)).
As shown in FIGS. 12 and 13, although the absolute value of soil hardness varies depending on the amount of rainfall and temperature, the low hardness point 10 and the low hardness area 11 occur at approximately the same positions, and are points with high soil hardness throughout the year. The relative relationship of the low points remains unchanged.
Comprehensive consideration of the three-dimensional distribution of soil hardness and the AMeDAS data from 10 days ago shows that soil hardness tends to be higher when the cumulative rainfall amount is small and the cumulative average temperature is high. For this reason, if a soil hardness contour map is created in advance, when an agricultural machine is going to work in the field after rain, it is possible to check whether the field work can be done without delay by measuring the soil hardness at several points. can judge.

The relationship between the three-dimensional soil hardness distribution and the actual water flow will be described with reference to FIGS. 14 to 17. FIG.
Fig. 14 is a graph showing the daily precipitation (AMEDAS data) before each survey, and a soil hardness contour map of the cultivated soil (12 cm depth) in the field to be surveyed. Fig. 15 is the surface layer of the field on each survey day. 16 and 17 are soil moisture content contour maps and soil hardness contour maps at different depths on the same survey date (June 15, 2017).

The survey date of May 10, 2017 shown in Fig. 15(a) is immediately after the rain as shown in Fig. 14(a), As shown in FIG. 15(c), the soil is dry without rain, and the survey date of 2017/5/15 shown in FIG. On the survey date of June 6, 2017, as shown in FIG. 14A, four days have passed since the rainfall, and the soil is in a dry state.
FIG. 15 shows rainfall events and the horizontal distribution of surface soil moisture over time for soil moisture.
As shown in FIG. 15, although the absolute value of the moisture content varies depending on the amount of precipitation, the high moisture content area 12 in the same field overlaps the low hardness area 11, and rainwater actually accumulates in the low hardness area 11. I understand.
FIG. 16 compares the vertical distribution of soil moisture and soil hardness in plowed soil.
Figure 16 (a) is a soil moisture content contour map at a depth of 0 to 3 cm, Figure 16 (b) is a soil moisture content contour map at a depth of 9 to 12 cm, and Figure 16 (c) is a soil hardness contour map at a depth of 1 cm. , and FIG. 16(d) is a soil hardness contour map at a depth of 12 cm.
In the high water content area 12 shown in FIGS. 16(a) and 16(b), rainwater flows from the high hardness area 13 to the low hardness area 11 as shown by the arrows in FIGS. 16(c) and 16(d). I know it's leaking.
FIG. 17 shows the vertical distribution of soil moisture and soil hardness in the subsoil in comparison.
Figure 17 (a) is a soil moisture content contour map at a depth of 15 to 18 cm, Figure 17 (b) is a soil moisture content contour map at a depth of 24 to 27 cm, and Figure 17 (c) is a soil hardness contour map at a depth of 18 cm. , FIG. 17(d) is a soil hardness contour map at a depth of 27 cm.
In the high water content area 12 shown in FIGS. 17(a) and 17(b), rainwater flows from the high hardness area 13 to the low hardness area 11 as shown by the arrows in FIGS. 17(c) and 17(d). I know it's leaking.
As described above, from the soil hardness contour map for each depth, it is possible to grasp the rainwater flow and the rainwater retention area in the plow soil and the subsoil.

The relationship between the actual yield of wheat flour and the particle size composition of soil will be described with reference to FIGS. 18 and 19. FIG.
FIG. 18 is a yield contour map showing the actual yield of wheat flour, and FIG. 19 is a contour map showing the grain size composition of soil and C humus in the surface layer.

FIG. 19(a) is a contour map of coarse sand with a particle size of 2 mm to 0.2 mm, FIG. 19(b) is a contour map of fine sand with a particle size of 0.2 mm to 0.02 mm, and FIG. A contour map of silt with a particle size of 0.02 mm to 0.002 mm, FIG. 19(d) is a contour map of clay with a particle size of 0.002 mm or less, FIG. f) Contour map of C humus.
The low-yield area 14 and high-yield area 15 in FIG. 18 are shown in FIG.
As shown in FIG. 19( e ), it can be seen that the area with a high temporary specific gravity and a large sand fraction is the low-yield area 14 , and the area where different grain sizes are appropriately mixed is the high-yield area 15 . In addition, as shown in FIG. 19( f ), it can be seen that C humus is extremely low in areas with a high temporary specific gravity and a large amount of sand fraction. Areas with a high temporary specific gravity and a large amount of sand fraction can be expected to improve soil physical properties and nutrient retention capacity by applying organic matter such as compost.

FIG. 20 is a soil hardness contour map in the field shown in FIGS. 18 and 19, FIG. 20(a) is a soil hardness contour map in the surface layer, FIG. 20(b) is a soil hardness contour map at a depth of 12 cm, FIG. 20(c) is a soil hardness contour map at a depth of 40 cm.

Fig. 20(a), which is a soil hardness contour map in the surface layer, has a high correlation with the provisional specific gravity shown in Fig. 19(e).
In addition, the low hardness point 10 can be distinguished from the deep soil hardness contour map of FIG. 11 can be identified as a rainwater retention area, and the flow of rainwater can be estimated as shown in FIG. 20(b). FIG. 20 illustrates the high clay area 16 in FIG. 19(d).
In this way, since the distribution of the particle size composition shown in FIG. 19 is correlated with the flow of rainwater, the soil physical property diagnosis method according to the present embodiment can be used to measure silt fractions and clays with small particle sizes without measuring the particle size composition. Areas with high fractions can be identified.
In addition, the laying position of the open ditch can be determined from the soil hardness contour map in the surface layer shown in FIG. By doing so, the flow and retention of rainwater in the plowed soil can be adjusted, and areas with low yields can be improved.
Further, from the soil hardness contour map of the subsoil shown in FIG. 20(c), the laying position of the culvert can be determined. can be reduced, and the yield can be increased by improving the aeration in the soil.

FIG. 21 is a contour map showing the soil chemistry in the fields shown in FIGS. 18 to 20, FIG. 21(a) is a K ₂ O contour map, FIG. c) is a contour map of CaO, FIG. 21(d) is a contour map of Mg/K, and FIG. 21(e) is a contour map of Ca/Mg.
FIG. 22 is an analysis map showing soil chemistry in the field shown in FIGS. 18 to 20, FIG. 22(a) is an analysis map showing suitability for K ₂ O, and FIG. 22(b) shows suitability for MgO. Analysis map, FIG. 22(c) is an analysis map showing CaO suitability, FIG. 22(d) is an analysis map showing Mg/K suitability, FIG. 22(e) is an analysis map showing Ca/Mg suitability, FIG. 22(f) is an analysis map showing the suitability of ARk.

As shown in FIGS. 21(d) and 21(e), there are no unbalanced areas for Mg/K and Ca/Mg, but as shown in FIGS. It can be seen that the yield area 14 is deficient in K ₂ O, MgO and CaO.
On the other hand, as shown in FIGS. 22(d) to (f), Mg/K, Ca/Mg, and ARk are in the appropriate range in most regions, ), K ₂ O, MgO, and CaO are excessively fertilized beyond the appropriate range except for some areas.
Since the low-yield area 14 has a high temporary specific gravity and a large amount of sand fraction, it can be inferred that nutrients will not be retained in that area even if fertilization is performed.
Therefore, the low hardness area 11 in the soil determined by the soil physical property diagnosis method according to the present embodiment can easily accumulate rainwater and retain nutrients, so the amount of fertilizer applied can be reduced. On the other hand, the high hardness area in the soil. 13 is an area with a high temporary specific gravity and a large amount of sand fraction, and is an area where the yield does not increase even if the amount of fertilization is increased, so the amount of fertilization can be further reduced.
As described above, the soil physical property diagnostic method according to the present embodiment can formulate more detailed soil diagnosis and field management guideline by analyzing soil chemical properties together.

According to the method for diagnosing soil physical properties in a field according to the present invention, the thickness of the effective soil layer and the flow of water in the soil layer can be grasped, so there is a possibility that effective fertilization can be performed according to the area. It may be possible to predict the bias in the field and the distribution of weeds and pests.

1 Diagnosis area 2 Positioning point 10 Low hardness point 11, 11a, 11b, 11c, 11d Low hardness area 12 High water content area 13 High hardness area 14 Low yield area 15 High yield area 16 High clay area 21 Wet damage area 22 Drought damage area Step 1 Positioning point determination step Step 2 Measurement step Step 3 Soil hardness contour map generation step Step 4 Soil layer determination step Step 5 Soil physical property diagnosis step Step 6 Plowing step Step 7 Post-plowing measurement step Step 8 Tread pressure step Step 9 Travel Post-measurement step Step 51 First rainwater retention area determination step Step 52 Second rainwater retention area determination step

Claims (8)

A positioning point determination step of determining a plurality of positioning points for a diagnostic area targeting a field;
a measuring step of measuring soil hardness for each depth at the positioning point determined in the positioning point determining step;
a soil hardness contour map generation step of generating a soil hardness contour map for each depth from the soil hardness data measured in the measurement step and the position data of the positioning points;
a soil layer discrimination step of discriminating whether a soil stratum is plow soil or subsoil from the soil hardness contour map for each depth generated in the soil hardness contour map generation step;
a soil physical property diagnosis step of diagnosing soil physical properties of the plow soil or the subsoil determined in the soil layer determination step ;
In the soil physical property diagnosis step,
a first rainwater retention area discriminating step of discriminating a low hardness point from the deep soil hardness contour map;
a second rainwater retention area determination step of determining a low hardness area including the low hardness point determined in the first rainwater retention area determination step from the shallow soil hardness contour map as a rainwater retention area;
has
A method for diagnosing physical properties of soil in a field , wherein the rainwater retention area in the plowed soil where rainwater collects is determined from the soil hardness contour map for each depth . 2. The method for diagnosing soil physical properties in an agricultural field according to claim 1 , wherein the soil physical properties are water retention or drainage properties of the cultivated soil. a plowing step of plowing the diagnostic area with a farming machine after measuring the soil hardness in the measuring step;
a post-plowing measurement step of measuring post-plowing soil hardness for each depth at the positioning points determined in the positioning point determination step after plowing in the plowing step;
has
In the soil physical property diagnosis step,
2. The field according to claim 1, wherein the change in soil physical properties is diagnosed from the soil hardness data measured in the measuring step and the post-plowing soil hardness data measured in the post-plowing measurement step. Soil physical property diagnostic method in. a treading step in which the agricultural implement travels in the diagnostic area after measuring the soil hardness in the measuring step;
A post-travel measurement step of measuring post-travel soil hardness for each depth at the positioning point determined in the positioning point determination step after traveling in the step pressure step;
has
In the soil physical property diagnosis step,
2. The soil in the field according to claim 1, wherein the change in soil physical properties is diagnosed from the soil hardness data measured in the measuring step and the post-running soil hardness data measured in the post-running measurement step. Physical diagnostic method. 3. The method of diagnosing soil physical properties in an agricultural field according to claim 1, wherein a soil particle size composition is determined from the soil hardness contour map of the plowed soil determined in the soil layer determination step. 3. The method for diagnosing soil physical properties in a field according to claim 1, wherein the amount of fertilizer applied is diagnosed from the soil hardness contour map of the cultivated soil determined in the soil layer determination step. 3. The method for diagnosing physical physical properties of soil in a field according to claim 1, wherein a laying position of the open ditch is determined from the soil hardness contour map of the plowed soil determined in the soil layer determination step. 3. The method of diagnosing physical properties of soil in a field according to claim 1, wherein the construction position of the underdrain is determined from the soil hardness contour map of the subsoil determined in the soil layer determination step.

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