JPH0577263B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention uses microwaves to continuously measure the existing amount of plants, including grasses, etc. growing in fields, non-destructively without mowing, and without the influence of soil. This invention relates to a method for measuring the amount of existing plants in which the plant community is irradiated from the side.

[Prior Art] Knowing the existing amount of plants including grass growing in a field is important for analyzing pasture yield and plant growth, but conventional methods for measuring this are , many measurement methods are used that involve cutting and destruction. In addition, a measurement method using a grass meter (a device that measures capacitance) that measures capacitance without cutting is also well known.

[Problem to be solved by the invention]

By the way, in the case of the above-mentioned measurement method that involves cutting and destruction, there is a problem that the work is not only troublesome but also requires a lot of labor and time. In addition, in the case of the above-mentioned grass meter, there was a problem that measurement became difficult when the height (length) of the plant community to be measured was high (long).

[Means to solve the problem]

The present invention was made to solve the above-mentioned problems, and includes a microwave transmitting/receiving device and a microwave reflecting device on both sides of a grass-like plant community growing in a field. A reflector plate, or a microwave transmitter and a microwave receiver, each movable in the vertical direction and along the plant community, are provided, and microwaves are transmitted from the microwave transmitter/receiver or the microwave transmitter to the plant community. The weight and height of fresh plants are measured from the height and strength of the received voltage value of the waveform indicating the reflected and received microwave energy, and from the correlation between the scattering coefficient detected by the measurement and the received voltage value, The existing amount of plant communities,
It is characterized by being able to measure continuously, non-destructively, without mowing, and by eliminating the influence of soil.

[Effect]

The method of measuring the amount of existing plants by side irradiation with microwaves according to the present invention by the above means measures the amount of existing plants such as grass growing in a field.
Measurement is performed non-destructively without mowing, and continuously, eliminating the influence of soil. Then, the measurement range (object) to be measured is widened, and the measurement accuracy is also improved.

【Example】

Embodiments of the present invention will be described below with reference to the drawings. In Fig. 1, reference numeral 1 indicates a grass growing in the field, and this grass 1 belongs to the leguminous family, the leguminous family, and
Either single sowing or mixed sowing may be used. A microwave (C band) transmitting/receiving device 2 is vertically arranged on one side of the grass 1, and the other side of the grass 1 opposite to the side where the microwave transmitting/receiving device 2 is arranged is , an aluminum plate 3 as a reflector is arranged vertically, and microwave transmission/
The microwaves emitted from the receiving device 2 are reflected by the aluminum plate 3 and received by the microwave transmitting/receiving device 2 without being affected by the soil, and from the changes in reflected and received microwave energy at that time, the grass 1 It constitutes a radar that measures biometric information (existing amount). The above microwave transmitting/receiving device 2 and aluminum plate 3
is supported by a light truck, which is the measuring vehicle, and is moved to a measurement location such as a pasture, and the microwave transmitting/receiving device 2 is connected to the main body of the measuring device loaded on the bed of the light truck. There is. The wave-shaped voltage value V data received from the microwave transmitting/receiving device 2 is processed and analyzed by a computer. Note that the aluminum plate 3 is not limited to aluminum, and may be any other metal plate as long as it reflects microwaves. The above received voltage value V is the reaction value of the microwave in response to the existing amount, and a high received voltage value means that there are few objects (existing amount) that affect the microwave, so the reflected and transmitted energy of the microwave is Shows how big it is. Therefore, in the present invention, there is a relationship between the existing amount and the received voltage value such that when the existing amount is large, the received voltage value is low, and conversely, when the existing amount is small, the received voltage value is high. The existing amount can be measured based on the level of the received voltage value, that is, the strength of the received microwave energy. In place of the microwave transmitting/receiving device 2 and aluminum plate 3, a microwave transmitting device 4 and a microwave receiving device 5 may be used as shown in FIG. 2. In this case, both devices 4 and 5 are linked to the main body of the measuring device. Next, the test results that led to the completion of the present invention will be explained. The device used in this test was set up with a microwave transmitting/receiving antenna above the grass community from the measuring device itself, which was loaded onto the back of a light truck, and the microwave was transmitted from the antenna and reflected from the pasture. They received microwaves and measured biological information about crops and soil information from the changes in energy. The data of the received waveform voltage value V was processed and analyzed by a computer. The survey location was September 1984.
Single sowing of tall fescue (TF) and orchid grass (OG), mixed seeding of TF, OG, perennial ryegrass (PR), and meadow fescue (MF), updated monthly, established in June 1985 as shown in Appendix Table 1. It was a grassland that was renovated in 1979, and a pastureland that was renewed in 1979. The results are shown in FIGS. 3 to 8. Figure 3 shows the change in the received voltage value for each grassland, including the standing state, treading pressure state, and after mowing. A relationship was recognized. Mean at this time, Max
The scattering coefficient (Fig. 4) determined from the above showed a pattern as shown in Fig. 3. The microwave received voltage values (Fig. 5) in the same grassland the following spring were in a relationship of magnitude after mowing > hair standing. A positive correlation was observed between the legume rate and the received voltage value (Figure 6). The received voltage values (Figure 7) and scattering coefficients (Figure 8) of the grassland differed depending on the planting style. Here, the microwave scattering coefficient dB is calculated on the assumption that the scatterer in the observation target is measured as a flat object like the ground, and it represents the average scattering cross section per unit area. is the differential scattering coefficient. This coefficient is obtained using a calculation formula, and the logarithm is taken and expressed in dB. A large absolute value of the scattering coefficient indicates that there are many scatterers. In the present invention, this scatterer is the standing amount of grasses. Therefore, in the case of the present invention, the absolute value of the scattering coefficient of microwaves is determined by The larger is the weight of the living organism in g, or the grass height is measured when the grass is fully stretched, and is the length from the ground to the cutting edge of the grass.
Indicates cm, the longer the value, the larger the value. The above results demonstrate that microwaves respond to quantitative and morphological differences in pasture. Using a device similar to the above-mentioned measuring device, we investigated the relationship between microwave reception voltage values, scattering coefficients, and grass amount in order to explore the possibility of estimating the amount of grass. The results are shown in Tables 2 to 4 in the appendix.

【table】

【table】

【table】

[Table] Looking at the correlation coefficient between the measured values and fresh grass weight in autumn (4th plant) and the following spring (1st plant) (Table 2), in autumn, OG,
Although a negative correlation was observed between TF and the amount of fresh grass,
No definite trend was observed in spring. O.G.
In TF and RT single-seeded grasslands, a higher correlation was observed by tilting the transmitting and receiving antennas than in the horizontal position, but in mixed-seeded grasslands, on the contrary, the correlation became smaller (Table 3). In addition, a high negative correlation was observed between dry weight and scattering coefficient when the antenna was tilted, except for mixed-seeded grassland. The multiple correlation coefficient between the amount of grass and the measured values when the antenna is horizontal and tilted is MIN of RT in single-seeded grassland,
Both fresh grass weight and dry weight showed high values except for RANGE, but the multiple correlation coefficient showed low values with some exceptions in mixed-seeded grasslands (Table 4). As a result, in single-seeded grassland, there was a negative correlation between the microwave transmission voltage value, scattering coefficient, and fresh grass weight or dry weight, and the possibility of estimating the grass amount was recognized. Further consideration is required regarding application conditions, etc. Based on the above test results, in the present invention, by arranging the microwave transmitting/receiving device in a vertical direction with the grass in the middle, the grass can be grown without being affected by the soil, while remaining as a vegetation in the field. It is now possible to measure the amount of grass (existing amount).
It is also applicable to a wide range of grass species, including land slopes,
The angles of the microwave transmitting/receiving device 2, aluminum plate 3, microwave transmitting device 4, and microwave receiving device 5 may be adjusted in the vertical direction by taking into consideration the ups and downs and the like. The existing amount of plants is expressed as fresh weight or dry weight as described above, but is generally regulated by the solid density and height of the plants. The amount of existing plants increases as the density increases and the height of the plant community increases. For example, in pastures, unlike rice paddies and fields, individual densities are maintained at a high level, so factors such as the height of the grass community (indicated by plant height and grass height) affect the amount of existing grasses. As shown in FIGS. 9 and 10, the microwave response (scattering coefficient) can be understood from the fact that similar trends are observed in fresh plant weight and plant height, which indicate the amount of existing plants. In the present invention, biological information such as plant height and fresh plant weight is detected as described above, but since the aim is to quantitatively evaluate the amount of existing plants, it is sufficient to focus on the relationship between the amount of existing plants and microwaves. . That is, if a regression equation between the existing amount and microwaves is obtained, the existing amount can be evaluated from the strength of the microwave reaction. In addition, when measuring a meadow, it is possible to estimate the total amount of grass by measuring a certain surface area out of the total area, but in the present invention, measurement can be performed while the measuring vehicle is moving, so it is possible to measure a large area. But it doesn't take much time. In addition, when using the measuring device of the present invention for other grass plants, it is possible to perform measurements in the same way by determining the optimal wavelength for the condition of the community and then examining the regression equation between the existing amount and the microwave response. can do.

【Effect of the invention】

As explained above, according to the method of measuring the amount of existing plants using microwave irradiation from the side of the present invention, crops growing in a field can be measured non-destructively and continuously without the influence of soil. Since the amount of vegetation in the field can be measured quickly and accurately, the amount of plants growing in the field can be measured quickly and accurately. In addition, the measurement range of plant communities growing in fields is wide and versatile.

[Brief explanation of drawings]

FIG. 1 is a schematic front view showing an embodiment of the present invention;
FIG. 2 is a schematic front view showing another embodiment of the present invention;
Figures 3 to 8 are graphs of basic tests that completed the present invention. Figure 3 is the relationship between the microwave reception voltage value and the grass community condition, and Figure 4 is the relationship between the scattering coefficient and the grass community condition. , Figure 5 shows the change in the microwave received voltage value before and after reaping, Figure 6 shows the relationship between the microwave received voltage value (Max-Min) and the leguminous rate, and Figure 7 shows the cultivation style of grassland and the microwave Figure 8 shows the scattering coefficient before and after watering in the grassland in relation to the received voltage value. FIG. 9 is a graph showing the relationship between fresh grass weight and scattering coefficient, and FIG. 10 is a graph showing the relationship between plant height and scattering coefficient. 1... Grass, 2... Microwave transmitting/receiving device, 3... Aluminum plate (reflection plate), 4... Microwave transmitting device, 5... Microwave receiving device.

Claims (1)

[Scope of Claims] 1. A microwave transmitting/receiving device and a reflector that reflects microwaves, or a microwave transmitting device and a microwave the receiving device,
Each device is movable in the vertical direction and along the plant community, and the microwave transmitting/receiving device or the microwave transmitting device irradiates the plant community with microwaves and receives a waveform indicating the reflected and received microwave energy. The weight and height of fresh plants are measured from the height and strength of the voltage value, and the existing amount of the plant community is determined from the correlation between the scattering coefficient detected by the measurement and the received voltage value.
A method for measuring the amount of existing plants by irradiating microwaves from the side, characterized in that the measurement is carried out non-destructively without cutting, and continuously while eliminating the influence of soil.