Paddy field management system

Abstract

To grasp the distribution of fertility in paddy fields with greater accuracy as compared to a conventional technology.SOLUTION: A paddy field management system, based on map information on a field (350) having an elevation and a position of a water intake (356), positioning results of a traveling vehicle body (1) by a positioning device (SN0), and an amount (V1, V2) of fertilizer sprayed at each position of the positioning results, calculates an amount of fertilizer flowing within the field (350) using the water taken in from the water intake (356) in the field (350), and corrects a distribution of soil fertility in the field (350) based on the calculated amount of fertilizer flow, and thereby can grasp the distribution of fertility in the paddy field with greater accuracy compared to a conventional technology.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] This invention relates to a paddy field management system for managing paddy fields, and particularly to a paddy field management system for managing the fertility of the soil in paddy fields.

Background Art

[0002] In the technology of managing paddy fields, there is a known technology related to an agricultural work support system that associates and stores field-related information such as field tillage information, driving route information, consumption material supply points, obstacles, water outlets, and the positions of ridges, with work-related information such as the type of work machine, type of work, working width, fertilization information, and fertility information in field map information (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the conventional technology, information related to the field and information related to the work are registered in the map information, but for the fertilization information and the fertility information, only the fertilization amount and the fertility (fertilizer concentration) at the time of fertilization are registered. However, in an actual paddy field, a situation where there is no elevation difference at all is extremely rare, and as the work vehicle travels, the soil becomes uneven, or when water is filled, part of the soil flows due to the flow of water. Therefore, in an actual paddy field, there are elevation differences within the paddy field, and when water is taken in from the water intake, water flows within the paddy field. Therefore, part of the fertilized fertilizer also flows along with the flow of water. In the conventional technology, although the information at the time of fertilization is registered, there is a problem that there is a deviation between the registered fertility at the time of fertilization and the actual distribution of the fertility in the paddy field with water flow.

[0005] The technical problem of the present invention is to enable accurate grasping of the distribution of the fertility of paddy fields as compared with the prior art.

Means for Solving the Problems

[0006] The above problems of the present invention are solved by the following solution means. The invention according to claim 1 includes a fertilizer application device (4) supported by a traveling vehicle body (1) of a work vehicle and spraying fertilizer onto a field (350), a positioning device (SN0) for measuring the position of the traveling vehicle body (1), map information of the field (350) having elevation and the position of a water intake (356), the positioning result of the traveling vehicle body (1) by the positioning device (SN0), and the fertilizer application amounts (V1, V2, …) at each position of the positioning result. Based on these, a fertilizer flow amount calculation means calculates the amount of the fertilizer flowing in the field (350) with water taken in from the water intake (356) in the field (350), and based on the calculated fertilizer flow amount, a fertility correction means (405) corrects the distribution of the soil fertility in the field (350). A paddy field management system characterized by comprising these is provided.

[0007] In the invention according to claim 2, the distribution of the fertility is registered for each field section (351) obtained by dividing the field (350) into predetermined sizes. When the size of the work section (352) based on the width of the work vehicle does not match the size of the field section (351), the application amounts (V1, V2, …) in all work sections (352) straddling the field section (351) are averaged and registered in the field section (351). The paddy field management system according to claim 1 is characterized by this.

Effects of the Invention

[0008] According to the invention described in claim 1, by calculating the amount of fertilizer flowing in the field (350) with water taken in from the water intake (356) in the field (350) and correcting the distribution of the soil fertility in the field (350) based on the calculated fertilizer flow amount, the distribution of the fertility of the paddy field can be grasped more accurately as compared with the prior art. According to the invention described in claim 2, in addition to the effects of the invention described in claim 1, when the size of the working section (352) based on the width of the work vehicle does not match the size of the field section (351), the spraying amounts (V1, V2, …) in all the working sections (352) straddling the field section (351) are averaged and registered in the field section (351), thereby suppressing the deviation of the spraying amount.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0010] Embodiments of the present invention will be described below. An example of the work vehicle of the present invention, a four-row riding rice transplanter which is an embodiment of a seedling transplanter, will be described in detail with reference to the drawings. As shown in the side view of FIG. 1 and the plan view of FIG. 2, a riding rice transplanter (work vehicle) mounts a seedling planting device (an example of a working machine) 3 on a traveling vehicle body 1 with a lifting link device 2 (an example of a lifting device), and is provided with a fertilizer application device (an example of a working machine) 4, and is configured to function as a riding fertilizer rice transplanter as a whole. The traveling vehicle body 1 is a four-wheel drive vehicle having a pair of left and right front wheels 6, 6 and rear wheels 7, 7 which are examples of traveling devices. In this specification, the left and right sides are referred to as the left side and the right side respectively toward the forward direction of the rice transplanter, the forward direction is referred to as the front side, and the reverse direction is referred to as the rear side.

[0011] As shown in FIG. 1, a transmission case 11 and a traveling motor 12 are disposed on the main frames 10a and 10b, a hydraulic pump 13 is integrally assembled with the transmission case 11 on the rear side surface of the transmission case 11, and a steering post 14 projects upward from the front part of the transmission case 11. A steering handle 16 is provided at the upper end of the steering post 14. A step floor 19 serving as a floor for operation is attached to the upper part of the machine body, and an operator's seat 20 is installed above the traveling motor 12. A shift operation lever (traveling operation member) 17 is provided on the right side of the steering handle 16.

[0012] An operation panel (not shown) is provided on the steering post 14 in front of the operator's seat 20. A ridge clutch lever 18 is provided on the right side of the operator's seat 20. The front wheels 6 and 6 are pivotally supported by front wheel support cases 22 and 22 provided on the side of the transmission case 11 so that the direction can be changed. Further, the rear wheels 7 and 7 are pivotally supported via rear wheel support bodies 30 by rear wheel transmission cases 24 and 24 attached to the left and right ends of the left and right frames 37. The left and right frames 37 are supported at the rear ends of the main frames 10a and 10b.

[0013] As shown in FIGS. 1 and 2 showing a part of the power transmission mechanism to the rear wheels 7, the rotational power of the traveling motor 12 is transmitted into the transmission case 11. The rear ends of the rear output shafts 11a and 11b project to the rear of the transmission case 11, and left and right rear wheel transmission shafts 35 and 35 for transmitting to the rear wheel transmission cases 24 and 24 are connected to the protruding end portions. The left and right rear wheels 7 and 7 are driven to rotate by the left and right rear wheel transmission shafts 35 and 35 respectively.

[0014] The seedling planting device 3 is attached to the traveling vehicle body 1 by a lifting link device 2 so as to be liftable. The upper end of the piston of a general lift cylinder 36 (Fig. 1) with its base rotatably provided on the traveling vehicle body 1 is connected to the lifting link device 2, and pressure oil is supplied to and discharged from the lift cylinder 36 through a lifting valve (not shown) by a hydraulic pump 13 provided on the traveling vehicle body 1, so that the piston of the lift cylinder 36 extends and retracts to move the seedling planting device 3 connected to the lifting link device 2 up and down.

[0015] The seedling planting device 3 includes a planting transmission case 38 that also serves as a frame rotatably mounted on the rear part of the lifting link device 2 via left and right frames 37, a seedling stage (seedling tank) 39 supported by a support member provided on the planting transmission case 38 and reciprocating in the left-right direction of the machine body, a seedling planting tool (an example of a planting part) 41 mounted on the rear end of the planting transmission case 38 for planting seedlings one by one in the field from the lower end of the seedling stage 39, and a center float (sensor float) 42 and a side float 43 which are leveling bodies with their rear parts pivotally supported at the lower part of the planting transmission case 38 and their front parts pivotally mounted to swing up and down. The center float 42 and the side float 43 are provided for leveling the field and leveling the front of the field where the seedlings are to be planted by the seedling planting tool 41.

[0016] The PTO drive shaft 45 (Fig. 1) has universal joints at both ends and is provided to transmit the power from a PTO motor (not shown) to the planting transmission case 38 of the seedling planting device 3. The seedling planting device 3 is configured for four-row planting and includes a planting transmission case 38 that also serves as a frame, a seedling stage 39 on which seedlings are placed and reciprocate left and right to supply the seedlings one by one to the seedling outlets 54a (Fig. 2) of each row, and a seedling planting tool 41 for planting the seedlings supplied to the seedling outlets 54a in the field.

[0017] That is, the seedling mounting table 39 is configured to be reciprocally movable in the width direction (left - right direction) of the traveling vehicle body 1 by a seedling tank reciprocating mechanism (shaft, motor, etc., not shown). Each time the seedling planting device 41 takes one plant of seedlings from the seedling mounting table 39, it moves in the width direction to move the position for taking seedlings from the seedling mat, so that the seedlings are evenly taken out (consumed) in the width direction from the mat seedlings. Since the seedling tank reciprocating mechanism for reciprocally moving the seedling mounting table 39 is well - known in the art, its illustration and detailed description are omitted.

[0018] The fertilizer application device 4 has a hopper 67 in which fertilizer is stored. The fertilizer in the hopper 67 is fed out in predetermined amounts by a feeding device 68. The fed - out fertilizer is sent through the duct 62 by the wind force of a blower 69 and is sprayed onto the field from the lower end 82 of a hose 80 connected to the duct 62. In the embodiment, the feeding device 68 and the hose 80 are arranged in four sets corresponding to the four - row seedling planting devices 41. It is possible to spray fertilizer from all of the four hoses 80, or it is also possible to selectively spray fertilizer from any one or a plurality of the four hoses 80.

[0019] (Description of the control unit) FIG. 3 is a functional block diagram of the control unit of the embodiment. In addition, in the block diagram of FIG. 3, the illustration and description of elements not related to the description of the embodiment of the present invention are omitted. The rice transplanter of the paddy field management system S of the embodiment is configured to be able to transmit and receive information to and from a tablet terminal 202 as an example of a terminal and a server 203 as an example of an information processing device via a communication line 201.

[0020] (Description of the control unit of the rice transplanter) The rice transplanter according to the embodiment has a control unit 300 that controls each function. The control unit 300 has an input / output interface I / O for inputting and outputting signals to and from the outside. Further, the control unit 300 has a ROM (Read Only Memory) in which programs, information, etc. necessary for performing processing are stored. Further, the control unit 300 has a RAM (Random Access Memory) for temporarily storing necessary data. Further, the control unit 300 has a CPU (Central Processing Unit) that performs processing according to the programs stored in the ROM and the like. Therefore, the control unit 300 of the embodiment is composed of a small information processing device, so-called a microcomputer. Thus, the control unit 300 can realize various functions by executing the programs stored in the ROM and the like.

[0021] Signals from signal input elements such as the touch panel 101 which is an example of an input unit and also an example of a display, the positioning device SN0, and various other sensors (not shown) are input to the control unit 300. The positioning device SN0 has a GNSS (Global Navigation Satellite System) receiver SN0a and an IMU (Inertial Measurement Unit) SN0b. The GNSS receiver SN0a can receive positioning signals from artificial satellites and measure the current position of the rice transplanter. The IMU SN0b can measure acceleration and angular velocity and measure the attitude of the rice transplanter (left and right inclinations and front and rear inclinations). Therefore, by correcting the measurement result of the GNSS receiver SN0a with the IMU SN0b, the current position can be measured more accurately than when measuring the current position only by the GNSS method.

[0022] Further, the control unit 300 transmits control signals to a fertilizer applicator 4, a traveling motor 12, a steering handle 16, a lift cylinder 36, a PTO motor M1 which is an example of a drive source, etc., which are examples of controlled elements, to control the traveling and stopping of the traveling vehicle body 1, the operation and stopping of the fertilizer applicator 4, the planting operation, lifting, etc. of the seedling planting device 3 which is an example of a working machine. In addition, the control unit 300 outputs a control signal to the touch panel 101, enabling the display of work information and work status. The control unit 300 of the embodiment has the following functional means (program modules).

[0023] FIG. 4 is an explanatory diagram of the field section and work section of the embodiment. The field information acquisition means 301 acquires information on the field where the rice transplanter performs work. The field information acquisition means 301 of the embodiment communicates with the server 203 to acquire the field information stored in the server 203. In the embodiment, as an example, the field information includes, in addition to the map information of the field (area, position, height (elevation), position of the field entrance, position of the water intake, etc.), information such as the travel route, travel speed, turning position, and turning angle during autonomous driving, and information such as the operating speed, operating position / stop position, and lifting position of the work machines (seedling planting device 3, fertilizer application device 4). In FIG. 4, the map information of the embodiment is composed of information obtained by dividing one field 350 into sections (field sections 351) of a predetermined area. In the embodiment, the field section 351 is exemplified as having a rectangular shape along one long side of the field 350, but it is not limited to this. It can also have any shape such as a square, trapezoid, parallelogram, triangle, or pentagon. Further, when there is a process of reciprocating in the travel route during the autonomous driving or straight-line assist of the rice transplanter, the field section 351 can also be a rectangle having sides parallel to the reciprocating direction. In the embodiment, the field section 351 is obtained by dividing the field from map information of an aerial view image such as a satellite image or an aerial image taken by a drone.

[0024] The positioning means 302 measures the current position of the rice transplanter based on the measurement results of the positioning device SN0. The positioning means 302 of the embodiment measures the current position by correcting the measurement results of the GNSS receiver SN0a with the IMU SN0b. Note that when the communication between the GNSS receiver SN0a and the artificial satellite is interrupted, the positioning means 302 measures (estimates) the current position using the rotation speed of the wheels 6, 7, the steering angle of the steering wheel 16, and the measurement results of the IMU SN0b from the current position information immediately before the interruption.

[0025] The traveling control means (autonomous traveling control means) 303 controls the traveling motor 12 and the steering handle 16 to control the traveling of the rice transplanter. The traveling control means 303 in the embodiment makes the rice transplanter travel according to the operations of the shift operation lever 17, the accelerator pedal (not shown), and the steering handle 16 during manual traveling. Also, during automatic traveling (autonomous traveling), the rice transplanter is made to travel along the traveling route acquired by the field information acquisition means 301 based on the current position measured by the positioning means 302.

[0026] The work control means 304 has a planting control means 304a and a fertilizer application control means 304b, and controls the lift cylinder 36, the PTO motor M1, etc. to control the working machine of the rice transplanter. The planting control means 304a controls the planting operation and the raising and lowering of the seedling planting device 3. The planting control means 304a in the embodiment operates / halts and raises / lowers the seedling planting device 3 according to the input of the operator to buttons, switches, etc. during manual traveling. Also, during autonomous traveling, the planting control means 304a operates / halts and raises / lowers the seedling planting device 3 based on the work information acquired by the field information acquisition means 301.

[0027] The fertilizer application control means 304b controls the fertilizer application device 4 to control the spreading of fertilizer on the field. The fertilizer application control means 304b in the embodiment operates / halts the fertilizer application device 4 according to the input of the operator to buttons, switches, etc. during manual traveling. Also, during autonomous traveling, the fertilizer application control means 304b operates / halts the fertilizer application device 4 based on the work information acquired by the field information acquisition means 301. The fertilizer application control means 304b also controls the feeding device 68 to control the feeding amount, thereby controlling the fertilizer application amount (spreading amount) on the field. Therefore, when a manual input to reduce the fertilizer application amount is made, or when an instruction to reduce the fertilizer application amount in a specific area of the field is given in the work information, the feeding amount is controlled to be small. Conversely, when increasing the fertilizer application amount, the fertilizer application control means 304b controls the fertilizer application device 4 to increase the feeding amount. Also, when selectively spreading fertilizer from the four hoses 80 of the fertilizer application device 4 in the embodiment, the fertilizer application control means 304b controls the fertilizer application device 4 so that only the feeding device 68 for which spreading is to be performed operates.

[0028] The work information transmission means 305 transmits the information of the work performed in the field to the server 203. As an example, the work information transmission means 305 in the embodiment transmits information such as the actual traveling route of the rice transplanter, the traveling speed, the turning position, the turning angle (cutting angle), the operation / stop and lifting of the seedling planting device 3, and the fertilization amount at each position in the field of the fertilization device 4 to the server 203. In FIG. 4, in the embodiment, the work information of the rice transplanter is acquired and transmitted to the server 203 for each work section 352 having a size based on the width of the rice transplanter (the width of the seedling planting device 3). The size of the work section 352 is changed for each work according to the width of the seedling planting device 3 which is the working machine. Therefore, the field section 351 and the work section 352 stored in the server 203 may or may not have the same size.

[0029] Note that the work section 352 preferably has a rectangular shape with a horizontal width based on the width L1 of the rice transplanter and a vertical length L2 corresponding to the vehicle speed. And it is possible to make the current position measured by the positioning device SN0 pass through the center 354 in the horizontal width direction of the work section 352. Also, in FIG. 4, when four-row planting is performed in a portion (work section 355) close to the edge of the field 350 during work, there is a risk of trampling down the inner seedlings during work at the edge. Therefore, for example, only two rows out of the four-row planting may be worked. In such a case, the width of the work section 355 is preferably the horizontal width L1' corresponding to the number of rows for which the work is performed. Furthermore, the horizontal width L1' is desirably the width of the working machine, but it is also possible to make it manually settable by the operator.

[0030] (Description of the control unit of the server) The server 203 in the embodiment has a control unit 400 that controls each function. The control unit 400 has an input / output interface I / O for inputting and outputting signals to and from the outside. The control unit 400 also has a ROM (Read Only Memory) in which programs, information, etc. necessary for performing processing are stored. The control unit 400 also has a RAM (Random Access Memory) for temporarily storing necessary data. The control unit 400 also has a CPU (Central Processing Unit) that performs processing according to the programs stored in the ROM and the like. Therefore, the control unit 400 in the embodiment is configured by an information processing device, a so-called computer device. Thus, the control unit 400 can realize various functions by executing the programs stored in the ROM and the like.

[0031] The field information storage means 401 of the control unit 400 stores the information of the fields managed by the paddy field management system S. For each field, the field information storage means 401 stores field map information (area, location, height (elevation), location of the field entrance and exit, location of the water intake, etc.), information such as the travel route, travel speed, turning position, and turning angle during autonomous travel registered in association with the field, and information such as the operating speed, operating position / stop position, and lifting position of the working machine as field information. Note that information such as the location of the field entrance and exit and the water intake can also be input and registered from the tablet terminal 202. Also, for the field entrance and exit and the water intake, it is also possible to register the location of the entrance and the like by selecting the field section 351 with the entrance.

[0032] The field information transmission / reception means 402 transmits and receives field information to and from the rice transplanter. Therefore, when a transmission request for field information is received from the rice transplanter, the requested field information is transmitted. When field information is transmitted from the rice transplanter, the transmitted field information is received and the field information in the field information storage means 401 is updated.

[0033] FIG. 5 is an explanatory diagram of the averaging of the fertilization amount in the embodiment. When the sizes of the work sections 352 and the field sections 351 do not match in the field information received by the field information transmission / reception means 402, the averaging means 403 averages the information in all the work sections straddling the field section 351. In the case of the fertilization amount (the amount of fertilizer application), for each fertilization amount of the work sections 352 straddling one field section 351, it is apportioned by the area overlapping with the field section 351 and averaged. In FIG. 5, as an example, when the entire work section 352-1 is included in the field section 351, the value of the fertilization amount V1 of the work section 352-1 is used as it is (100%), and when 20% of the area of the work section 352-2 is included in the field section 351, 20% (=V2×0.2) of the fertilization amount V2 of the work section 352-2 is used. Similarly for the other work sections 352-3 to 352-6, using the total value of the fertilization amount in the field section 351 (=V1+V2×0.2+V3×…) and the area S0, the fertilization amount per unit area in the field section 351 (the averaged value) is calculated as P=(V1+V2×0.2+V3×…) / S0, and the averaged value P is registered in the field information storage means 401.

[0034] If there is a large difference among the fertilization amounts V1, V2, … and they are not averaged, one of the values of the fertilization amounts V1, V2, … will be adopted as the fertilization amount in the field section 351, and there is a risk of a large deviation from the actual amount of fertilizer applied to the field section 351. In contrast, in the embodiment, the fertilization amounts V1, V2, … are averaged, and the deviation of the fertilization amount in the field section 351 is suppressed compared to the case where they are not averaged. It is also possible to similarly average and register other work information (the amount of seedlings planted, planting speed, etc.) other than the fertilization amount. Also, when detecting the elevation of the field, the depth and hardness of the soil, fertility, etc. with sensors, it is similarly possible to average.

[0035] When correcting the fertility, the target water level setting means 404 sets the target water level, which is the amount of water applied to the field. The target water level setting means 404 in the embodiment uses the target water level manually input by the operator from the tablet terminal 202, but it is also possible to predetermine a reference value (default value). Note that the default value of the target water level is preferably set to a value at which the seedlings are not submerged, based on the height of the seedlings. The height of the seedlings can be determined based on the height and planting depth of the seedling planting device 3 at the time of transplanting the seedlings with the rice transplanter, or a configuration can be adopted in which a camera is installed backward on the rice transplanter to photograph the seedlings after planting and detect the height. At this time, it is possible to set the target water level according to the height of the seedlings, based on the highest elevation position in the field, or it is also possible to use the lowest elevation position as a reference. When the highest or lowest elevation position in the field is registered in the field information, the registered information can be used. For example, the elevation information can be obtained by methods such as the GNSS measurement results when the rice transplanter was run in the past, the information on the height of the float, or detecting the elevation by flying a small unmanned aircraft such as a drone.

[0036] FIG. 6 is an explanatory diagram of the fertility correction method of the embodiment. FIG. 6(A) is an explanatory diagram of the main part of the field section of the water intake, and FIG. 6(B) is an explanatory diagram of the field section adjacent to the left of the field section of the water intake in FIG. 6(A). Based on the map information of the field having the elevation of the field 350 and the position of the water intake 356, the positioning result of the traveling vehicle body 1 by the positioning device SN0, and the fertilizer application amount at each position of the positioning result, the fertility correction means 405 calculates the amount of fertilizer flowing in the field 350 with the water taken in from the water intake 356 in the field 350, and corrects the distribution of the soil fertility in the field 350 based on the calculated fertilizer flow amount. The fertility correction means 405 in the embodiment simulates the water flow from the set target water level and calculates the amount of fertilizer washed away by the water flow. Then, the increase or decrease in the amount of fertilizer is calculated for each field section 351, and the fertility of each field section 351 is calculated.

[0037] In FIG. 6(A), as an example, the areas of the field sections 351a to 351d are the same, the height of the field section 351a with the water intake 356 is "10", and the heights of the adjacent field sections 351b, 351c, and 351d are "10", "8", and "12" respectively, and the target water level is "20". A case where water corresponding to the height "10" of the field section 351a is taken in per unit time from the water intake 356 will be described. In this case, water flows from the field section 351a with the water intake 356 to the adjacent field sections 351b to 351d. For the four sections 351a to 351d, if the water level after the flow is ha, the amounts of water (the increased water height) in the four sections 351a to 351d after the flow are ha - 10, ha - 10, ha - 8, and ha - 12 respectively. This sum value (= (ha - 10) + (ha - 10) + (ha - 8) + (ha - 12)) is equal to the amount of water "10" taken in from the water intake 356. Therefore, (ha - 10) + (ha - 10) + (ha - 8) + (ha - 12) = 10, By calculating, ha = 12.5 is derived.

[0038] As a result, 2.5 (= 12.5 - 10) of water flows into the field section 351b with a height of 10, 4.5 (= 12.5 - 8) of water flows into the field section 351c with a height of 8, and 0.5 (= 12.5 - 12) of water flows into the field section 351d with a height of 12. Therefore, it is calculated that fertilizers flow from the field section 351a with the water intake 356 to each of the field sections 351b to 351d at a ratio of 2.5:4.5:0.5 with respect to the total amount of water "10". Therefore, for the fertilization amount P1 of the farm plot 351a with the water intake 356, using the outflow coefficient α1 determined in advance by experiments or the like regarding the ease of fertilizer outflow, it is calculated that for the farm plot 351b, fertilizer flows in (increases) by P1×α1×(2.5 / 10), for the farm plot 351c, fertilizer flows in (increases) by P1×α1×(4.5 / 10), and for the farm plot 351d, fertilizer flows in (increases) by P1×α1×(0.5 / 10). And for the farm plot 351a with the water intake 356, fertilizer flows out (decreases) by the total value of the amounts flowing out to the three farm plots 351b - 351d (=P1×α1×(7.0 / 10)).

[0039] Therefore, when the fertilizer application amounts of the farm plots 351a - 351d before the water flows are P1 - P4, the fertilizer application amounts P1' - P4' of the farm plots 351a - 351d after the water flows are calculated as follows respectively. P1' = P1 - P1×α1×(7.5 / 10) P2' = P2 + P1×α1×(2.5 / 10) P3' = P3 + P1×α1×(4.5 / 10) P4' = P4 + P1×α1×(0.5 / 10) Note that the derived P1' - P4' and ha are updated as the new fertilizer application amounts P1 - P4 and the heights of the farm plots 351a - 351d, and are used in the calculations from the next time onwards.

[0040] In FIG. 6(B), when the calculation in FIG. 6(A) is performed, the calculations are performed for the farm plots 351b - 351d adjacent to the farm plot 351a with the water intake 356 respectively. That is, for the farm plot 351a for which the water flow calculation has been performed, the calculations for the farm plots 351b - 351d on the downstream side of the water flow are performed next. In FIG. 6(B), as an example, the case where the heights of the farm plots 351e and 351f adjacent to the farm plot 351b are "10" and "9" respectively will be described. Here, in the embodiment, it is simulated that water does not flow back to the upstream farmland section 351a side, but only flows to the adjacent farmland sections 351e and 351f. For the three sections 351b, 351e, and 351f, if the water level after flowing is ha′, the amounts of water in the three sections 351b, 351e, and 351f after flowing are ha′ - 10, ha′ - 10, and ha′ - 9 respectively. The sum value (=(ha′ - 10)+(ha′ - 10)+(ha′ - 9)) is the amount of water "2.5" that flows into the farmland section 351b. Therefore, (ha′ - 10)+(ha′ - 10)+(ha′ - 9)=2.5, By calculating, ha = 10.5 is derived. Thus, similar to FIG. 6(A), it is calculated that fertilizers flow into the adjacent farmland sections 351e and 351f at a ratio of (10.5 - 10):(10.5 - 9)=0.5:1.5. Similarly, the values of the fertilizer application amounts are also calculated and updated.

[0041] The other farmland sections 351c and 351d can be calculated in the same way. Note that for the farmland section 351 where the water level becomes negative during the calculation, it is calculated that no water flows and no movement (increase or decrease) of fertilizers occurs. In this way, for all the farmland sections 351, the water flow is simulated and the movement of fertilizers is calculated. Then, until the water level ha of the farmland section 351a with the water intake 356 reaches the target water level of "20", the calculation for all the farmland sections 351 is repeated. Then, from the final fertilizer application amounts of each farmland section 351 when the target water level of "20" is reached, the soil fertility of each farmland section 351 stored in the farmland information storage means 401 is recalculated (corrected). That is, where the fertilizer application amount is large, the increase in fertility is large, and where the application amount is small, the increase in fertility is small.

[0042] Note that, as an example of the condition for ending the calculation, the case where the farmland section 351a reaches the target water level is illustrated, but it is not limited to this. For example, it is also possible to calculate in advance the total amount of water that can be taken in from the target water level and the height of each farmland section 351a, and repeat the calculation until the calculated total amount is reached. In addition, in the embodiment, an example of a mode for calculating the fertilizer application rate was illustrated, but the present invention is not limited thereto. For example, it is also possible to calculate the cumulative value of the amount of water movement and finally estimate the amount of fertilizer movement from the amount of water movement. In this case, since water always flows in the farmland section 351a having the water intake 356, a large value will be obtained, so it is preferable to exclude it from the calculation.

[0043] Also, the outflow coefficient α1 was illustrated for the case of a constant value, but the present invention is not limited thereto. For example, it is also possible to set the outflow coefficient so that it increases as the calculated flow ratio increases. Furthermore, in the embodiment, during simulation, it was assumed that there is no backflow to the upstream farmland section 351 or that the water levels are the same in the target farmland section 351, but the present invention is not limited thereto. When the processing performance of the computer device is high, it is also possible to improve the accuracy by calculating while considering backflow. Conversely, in order to reduce the calculation load, for example, it is also possible to perform simulation such as calculating on the premise that all the water flowing into the farmland section 351a having the water intake 356 flows out to the other farmland sections 351b to 351d.

[0044] In the paddy field management system S of the embodiment having the above configuration, the fertilizer application rate when working with the rice transplanter is transmitted to the server 203. The server 203 does not directly reflect the application rate on the fertility, but simulates the water flow and calculates the movement of the fertilizer. Then, the fertility is corrected according to the movement of the fertilizer accompanying the water flow. Therefore, in the prior art that does not consider the water flow, when it is desired to know the accurate distribution of the fertility, it is necessary to perform a fertilization operation and then run a vehicle equipped with a fertility sensor after filling the water, which is time-consuming and may damage the crops when the vehicle is running. In contrast, in the embodiment, the fertility can be corrected without running the vehicle, and it is possible to accurately grasp the distribution of the fertility of the paddy field compared to the prior art.

[0045] Therefore, based on the obtained fertility distribution, it is also possible to create a top-dressing work plan, correct the fertilization amount according to the fertility for each field section 351 during top-dressing (increase or decrease fertilizer for each field section), predict the growth of crops, and so on. Note that in the paddy field management system S of the embodiment, a configuration in which the server 203 corrects the fertility is exemplified, but it is not limited to this. It is also possible to correct the fertility with a rice transplanter and only transmit the results to the server 203.

[0046] Also, in the embodiment, the case where the averaging means 403 averages the information acquired in the work section 352 is exemplified, but it is not limited to this. Depending on the relationship of the calculation formula, the required accuracy, the calculation load, etc., it is also possible to sum, use the maximum value, or use the minimum value instead of averaging.

Explanation of Reference Numerals

[0047] 1... Traveling vehicle body, 4... Fertilizer application device, 350... Field, 351... Field section, 352... Work section, 356... Water intake, 405... Fertility correction means, S... Paddy field management system, SN0... Positioning device, V1, V2... Spraying amount.

Claims

1. A fertilizer application device (4) supported by a traveling body (1) of a work vehicle and spraying fertilizer onto a field (350); A positioning device (SN0) for measuring the position of the traveling body (1); Based on map information of the field (350) having elevation and the position of a water intake (356), the positioning result of the traveling body (1) by the positioning device (SN0), and the fertilizer application amounts (V1, V2,...) at each position of the positioning result, calculating the amount of the fertilizer flowing in the field (350) with water taken in from the water intake (356) flowing in the field (350), and a fertility correction means (405) for correcting the distribution of soil fertility in the field (350) based on the calculated fertilizer flow amount; A paddy field management system, characterized by comprising the above.

2. The distribution of the fertility is registered for each field section (351) obtained by dividing the field (350) into a predetermined size, When the size of a work section (352) based on the width of the work vehicle does not match the size of the field section (351), averaging the application amounts (V1, V2,...) in all work sections (352) straddling the field section (351) and registering the average in the field section (351). The paddy field management system according to claim 1, characterized by the above.

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