Liquid fertilizer applicator

Abstract

To provide an application unit capable of coping with an underground buried object and applying a large amount of liquid fertilizer to a deep layer in soil, and a liquid fertilizer applicator in which the application unit is arranged.SOLUTION: A liquid fertilizer applicator attachable to / detachable from a tractor, includes: a cutting / shaping blade that forms a cavity to a deep layer in soil; a unit holder that is a member to be fixed to the liquid fertilizer applicator; a link arm that is connected to the unit holder so as to be rotatable around a yaw axis; an extensible first arm in which one end is connected to the link arm so as to be rotatable around a pitch axis; a second arm having one end connected to the link arm so as to be rotationally turn around the pitch axis; a cutting blade arm that is rotationally connected to the second arm at one end, is fixed to the cutting / shaping blade at the other end such that the cutting / shaping blade extend substantially vertically, and is connected to the other end of the first arm by a partial arm extending from the one end side; an application unit that is disposed behind the cutting / shaping blade and has a liquid fertilizer insertion pipe that applies a liquid fertilizer supplied from a tank into soil; and a frame in which one or more application units can be disposed at any interval.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a working machine for applying liquid fertilizer to soil.

Background Art

[0002] The liquid portion of livestock manure, which is livestock excrement where the circulation within rural areas has stagnated, is a resource with low-cost fertilizer components, and its utilization has been studied in pastures and paddy fields. However, in upland farming with a large amount of chemical fertilizer input, the merit of its utilization was small because the substitution rate of the fertilizer component amount was low with the conventional spraying method and it was difficult to apply a sufficient amount. Therefore, by introducing new technologies centered on soil bulk application techniques that suppress ammonia volatilization of fertilizer components and enable fertilization substitution into the production site, it is required to establish a cultivation system that maximally utilizes regional organic resources such as livestock manure and enables fertilization substitution.

[0003] Conventionally, slurry and digestive fluid, which are liquid portions such as livestock manure and its fermentation residues, have been applied to farmland by spraying them on the surface using a spraying vehicle of a slurry lorry or a tractor-mounted spreader of a slurry tank. With this method, the application amount is within 40 t / ha. When the application amount exceeds this, not only does ammonia, which is a major fertilizer component, volatilize, but the slurry stagnates on the surface and, when there is an inclination in the terrain, it flows along the inclination and flows out of the field. Therefore, some slurry injector technologies for applying liquid fertilizer into the soil have been proposed. The working machine disclosed in Patent Document 1 can apply liquid fertilizer to a deep position in the soil by inserting slurry into the grooves of the claw marks formed by two subsoilers. However, since it is applied in two fixed-width rows and there is no mechanism for adjusting the application amount, agricultural utilization as a fertilization substitute was difficult, such as uneven application amounts. In Patent Document 2, a fertilizer and seeding apparatus using a slurry tank that enables fertilization and seeding by injecting slurry into the shallow layer of the soil cutting section is disclosed. In Patent Document 3, a slurry flow control device used in the shallow layer type slurry injector of Patent Document 2 is disclosed. In Patent Document 4, a slurry flow control device used in the shallow layer type slurry injector of Patent Documents 2 and 3 is disclosed. All of them are technologies that enable application in multiple rows. However, since the insertion depth into the soil is shallow and the application is by multiple injectors arranged at regular intervals, the width of the machine becomes long, which causes problems during the running of the machine. In Patent Document 5, an apparatus for cutting soil and spraying livestock manure urine thereon for soil application is disclosed. Similarly, in Non-Patent Documents 1 and 2, the surface of the ground is cut and slurry is inserted therein.

[0004] In these prior arts, it is difficult to apply a large amount of liquid fertilizers such as livestock manure urine slurry and digestive fluid to the deep layer of the soil. There is also no disclosure regarding a structure that enables flexible response to buried objects in the soil such as gravel.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Non-Patent Documents

[0006]

Non-Patent Document 1

Non - Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] The above - mentioned conventional technologies have the following problems. (1) It does not have a structure that can form a plurality of spaces in the soil that can apply a large amount of liquid fertilizers such as livestock manure slurry and digestive fluid deep into the soil, and whose size, shape, and combination can be set by replacing parts. (2) The number of rows, intervals, and depths of the application units mounted on the working machine cannot be set. (3) The machine width of the working machine cannot be shortened during movement. (4) It cannot respond to the terrain, machine running, and buried objects in the soil such as gravel during work with flexible movement. (5) It does not have a function of evenly distributing liquid fertilizers, etc. to a plurality of application units and cutting and granulating impurities and solids.

[0008] In view of the above situation, the object of the present invention is to provide a liquid - fertilizer applicator that can cope with buried objects in the soil and can apply a large amount of liquid fertilizer to the deep layer in the soil, including an application unit and a working machine for arranging it.

Means for Solving the Problems

[0009] To achieve the above object, the present invention provides the following configuration. 1) An aspect of the present invention is a liquid fertilizer applicator that is detachable from a tractor and applies liquid fertilizer to a field, a cutting and forming blade that forms a cavity to a deep layer in the soil, a unit holder that is a member fixed to the liquid fertilizer applicator, a link arm rotatably connected to the unit holder around a yaw axis, a first arm having one end rotatably connected to the link arm around a pitch axis and being telescopic, a second arm having one end rotatably connected to the link arm around a pitch axis, a cutting blade arm having one end rotatably connected to the second arm and the other end fixed so that the cutting and forming blade extends substantially vertically therefrom and connected to the other end of the first arm by a partial arm extending from one end side, and a liquid fertilizer insertion tube disposed behind the cutting and forming blade and for applying liquid fertilizer supplied from a tank into the soil, a frame on which one or more of the above application units can be arranged at arbitrary intervals, wherein the link arm, the first arm, the second arm, and the partial arm are connected in a rectangular shape, and the first arm is provided with an elastic body such that an elastic force acts in the reverse direction when the first arm contracts. 2) In the above aspect, the forming cutting blade can be fixed to the cutting blade arm by adjusting the length extending from the cutting blade arm in the soil direction, and the pitch angle and yaw angle of the frame with respect to the tractor can be adjusted by a hydraulic device of the tractor, and the construction depth of the forming cutting blade can be adjusted in the range of 0 to 40 cm by adjusting the pitch angle. 3) In the above aspect, the connection between the partial arm and the first arm is made by a safety pin, and when a load equal to or greater than a certain value applied to the connection portion between the partial arm and the first arm breaks the safety pin, the connection between the cutting blade arm and the first arm is released. 4) In the above aspect, each of the one or more cutting and forming blades disposed on the frame, is composed of a member that is a substantially triangular prism and has a substantially triangular prism with a large bottom area near its lower end, is composed of a substantially triangular prism member and a flat plate member provided on the side thereof when the traveling direction is forward and inclined so as to rise from the front to the rear, or, is characterized in that it is either composed of a substantially triangular prism member, a flat plate member provided at the lower end thereof and inclined so as to rise from the front to the rear, and a member having a depth in a front view seen from the front and a width that becomes narrower toward the rear above the flat plate member. 5) In the above aspect, the application unit further includes an earth moving tool for covering the soil surface of the cavity formed in the soil during its progress with soil. 6) In the above aspect, the frame on which the application unit is disposed has a folding fulcrum, and a portion extending laterally of the frame by a hydraulic system can be rotated vertically upward about the folding fulcrum and folded. 7) In the above aspect, the liquid fertilizer applicator further has a liquid fertilizer distributor for distributing the liquid fertilizer supplied from the liquid fertilizer tank to a plurality of liquid fertilizer insertion pipes, the liquid fertilizer distributor has a cylindrical distribution container having a bottom surface, a distribution container lid covering the distribution container, a liquid fertilizer injection port provided on the distribution container lid, a rotating shaft located at the center of the distribution container and rotatable by a motor, a plurality of holes provided on the bottom surface at equal angular intervals around the rotating shaft and at an equal distance from the rotating shaft, a plurality of distribution plates extending from the rotating shaft to the vicinity of the inner surface of the distribution container and evenly partitioning the inside of the distribution container, and distribution plate blades provided at the upper edges in the vertical direction of each of the distribution plates, and the distribution plates are arranged so as to be inclined by 1 to 30 degrees in the rotating direction from a plane perpendicular to the bottom surface of the distribution container. 8) The aspect of the present invention is, an application unit mounted on a liquid fertilizer applicator that is towed by a tractor and applies liquid fertilizer to a field, A cutting and forming blade that forms a cavity deep into the soil, a unit holder attached to the liquid fertilizer applicator, a link arm rotatably connected to the unit holder about a yaw axis, a telescopic first arm having one end rotatably connected to the link arm about a pitch axis, a second arm having one end rotatably connected to the link arm about a pitch axis, a cutting blade arm having one end rotatably connected to the second arm and the cutting and forming blade fixed to the other end so as to extend substantially perpendicularly therefrom and connected to the other end of the first arm by a partial arm extending from one end side, and a liquid fertilizer insertion tube disposed behind the cutting and forming blade and for applying liquid fertilizer supplied from a tank into the soil. It is characterized in that, the first arm is provided with an elastic body so that an elastic force acts when the first arm contracts. 9) In the above aspect, the connection between the partial arm and the first arm is made by a safety pin, and, the safety pin is broken by a load equal to or greater than a certain value applied to the connection portion between the partial arm and the first arm, and the connection between the cutting blade arm and the first arm is released. 10) In the above aspect, It further has an earth moving tool for covering the soil surface of the cavity formed in the soil by the progress of the forming cutting blade with soil.

Advantages of the Invention

[0010] It is an application unit or a liquid fertilizer applicator capable of coping with underground buried objects, and it has become possible to apply a large amount of liquid fertilizer deep into the soil.

Brief Description of the Drawings

[0011]

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Figure 23

DETAILED DESCRIPTION OF THE INVENTION

[0012] The liquid fertilizer application unit 30 mounted on the liquid fertilizer applicator M according to the present invention will be described with reference to FIG. 1. As shown in FIG. 20, the liquid fertilizer applicator M according to the present invention can be connected to and towed by a tractor TR. In this specification, the front F shown in FIG. 1 refers to the direction in which the liquid fertilizer applicator M is connected to the tractor TR, that is, the direction (travel direction) in which it is towed by the tractor. The direction opposite to the front F is defined as the rear R. The liquid fertilizer applicator M is a working machine for applying the liquid fertilizer supplied from a slurry tank TN (see FIG. 20) into the soil. The liquid fertilizer applicator has one or more application units. Note that the liquid fertilizer in this specification refers to the liquid of slurry of manure which is livestock excrement, fermented digestive liquid which is its fermented liquid, adjusted liquid fertilizer, and the like.

[0013] FIG. 1(b) is a schematic side view of the application unit 30 viewed from the side. The main components of the application unit 30 are a cutting and forming blade 10 for forming a cavity in the soil for applying liquid fertilizer, a liquid fertilizer insertion pipe 20 for applying liquid fertilizer into the cavity, and each arm 12, 14, 15, 17 and shafts 81, 82, 85 for flexibly coping with gravel and the like in the soil. In this specification, one end of each arm refers to the vicinity of the front F end, and the other end refers to the vicinity of the rear R end.

[0014] The application unit 30 is connected to the liquid fertilizer applicator M by the unit holder 18. This unit holder 18 is provided with a yaw axis 85 that can rotate about a vertical axis (see Fig. 1(a)). The link arm 17 connected to the yaw axis 85 of the unit holder rotates as the yaw axis 85 rotates. The application unit 30 can rotate 90 degrees to the left and right around the yaw axis 85 from the perspective of Fig. 1(a) when the application unit 30 is viewed from the front. This angle can also be restricted to any angle.

[0015] Two arms 14, 15 are connected to the link arm 17 so as to be rotatable about axes 81, 82 perpendicular to the side surface of the link arm 17 visible in Fig. 1(b). The axis to which one end of the first arm 14 is connected is defined as the first pitch axis 81, and the axis to which one end of the second arm 15 is connected is defined as the second pitch axis 82.

[0016] The application unit 30 may have a coulter 16 to smooth the progress of the cutting and forming blade 10 (not shown in Fig. 1(a)). The coulter 16 is rotatably provided at the other end of the second arm 15, which is opposite to one end of the second arm 15 rotatably connected to the link arm 17. This rotation axis is defined as the coulter rotation axis 83.

[0017] One end of the cutting blade arm 12 is rotatably connected to the other end of the second arm 15 via the coulter rotation axis 83. The cutting blade arm 12 is an arm for holding the cutting and forming blade 10. The cutting and forming blade 10 may be held via a cutting blade holder 11 as shown in Fig. 1(b). A number of through holes 91 are opened in the cutting and forming blade 10, and by inserting the fastener 90 of the cutting blade holder 11 through the through holes 91, the length by which the cutting and forming blade 10 protrudes downward from the cutting blade arm 12 can be adjusted. Thereby, the depth of the cavity formed in the soil S when the application unit 30 advances can be adjusted to be 0 to 40 cm.

[0018] The cutting blade arm 12 is provided with a partial arm 13 at one end thereof in a direction substantially perpendicular to the direction in which the cutting blade arm 12 extends. By means of this partial arm 13, the cutting blade arm 12 and the other end of the first arm 17 are connected. As described above, the link arm 17, the first arm 14, the second arm 15, and the partial arm 13 are connected in a rectangular shape.

[0019] The first arm 14 has a telescopic cylinder structure, and the length from the connection point with the link arm 17 to the connection point with the partial arm 13 varies. The first arm 14 is provided with an elastic body 95 so that an elastic force acts in the reverse direction when the first arm 14 contracts. This elastic body may be a hollow silicone rubber or a spring. In the case of silicone rubber, it can prevent people and objects from being pinched, and can enhance safety and the certainty of operation by preventing the pinching of sundries during construction. If the first arm is cylindrical, it is preferable that the elastic body is also cylindrical. Regarding this telescopic structure and the installation position of the elastic body, it is sufficient as long as the functions described later can be realized, and it is not particularly limited. For example, whether the elastic body 95 is arranged outside or inside the cylinder structure constituting the first arm 14, the above-described actions can be realized.

[0020] The liquid fertilizer insertion pipe 20 communicates with a slurry tank TN (see FIG. 20) via a liquid fertilizer distribution hose 21. It is preferable to use a flexible material for the liquid fertilizer distribution hose 21. The liquid fertilizer insertion pipe 20 is arranged behind the cutting and forming blade 10 in order to perform the function of applying liquid fertilizer to the cavity in the soil formed by the cutting and forming blade 10. The liquid fertilizer insertion pipe 20 is fixed so that its position does not shift relative to the cutting blade arm 12 or the cutting and forming blade 10 during the liquid fertilizer application operation. The location to be fixed may be the cutting blade holder 11, the cutting blade arm 12, etc. As shown in FIG. 1(b), the liquid fertilizer insertion pipe 20 can be arranged, for example, by loosening the fastening screw 22, moving the liquid fertilizer insertion pipe 20 and the liquid fertilizer distribution hose 21 up and down, and adjusting the length protruding downward from the cutting arm 12, whereby the position for applying the liquid fertilizer 40 (see FIG. 2) can be adjusted.

[0021] The cutting and forming blade 10A of the application unit 30 shown in Fig. 1 is composed of a member that is a substantially triangular prism, and the vicinity of its lower end is a substantially triangular prism with a large bottom area as shown in Fig. 1(a). When the application unit 30 advances in the soil, a cavity elongated vertically as shown in Fig. 2(a) in a front cross-sectional view is formed in the soil by the cutting and forming blade 10A. The cavity formed by cutting the soil as the cutting and forming blade 10A advances is defined as a cutting cavity 41. In a plan view looking at the soil from above, the upper surface of the cutting cavity 41 as the locus through which the cutting and forming blade 10A has passed can be confirmed as shown in Fig. 2(b).

[0022] Liquid fertilizer 40 is to be applied from the liquid fertilizer insertion pipe 20 into the cutting cavity 41 formed as shown in Fig. 2(a). At this time, if a large amount of liquid fertilizer 40 is applied to the cavity, the liquid fertilizer 40 overflows from the cutting cavity 41 as shown in Fig. 2(c), and the liquid fertilizer 40 accumulates on the soil surface to form a liquid surface, that is, surface ponding 44 occurs. When the location where this surface ponding 44 occurs is viewed from the same viewpoint as Fig. 2(b), it becomes as shown in Fig. 2(d). When surface ponding 44 occurs, ammonia volatilizes by about 10 - 30% even in the short term from that part. Also, if surface runoff occurs due to heavy rain or the like after application, the liquid fertilizer 40 itself and its components flow out, and the effect of application is greatly reduced.

[0023] In order to prevent such surface ponding 44, it is preferable that the application unit 30 has an earth - gathering tool 26 for covering the soil surface of the cavity formed as shown in Fig. 3 with soil. The earth - gathering tool 26 functions to mound the soil surface of the cutting cavity 41 formed after the passage of the cutting and forming blade 10. The earth - gathering tool 26 shown in Fig. 3 has a shape with depth in a front view seen from the front, and its width becomes narrower toward the rear. It has a shape as shown in Fig. 3(b) from a viewpoint from above. In the front view, both side portions of the U - shape may be in a V - shape or may extend vertically to the upper part.

[0024] The soil gathering tool 26 is connected by adding a soil gathering tool arm 24 behind R of the cutting blade arm 12. As shown in Fig. 3(a), for example, one end of the soil gathering tool arm 24 is fixed to the fastening screw 22 at the other end of the cutting blade arm 12, a soil gathering tool fixing part 25 is fixed to the other end, and the soil gathering tool 26 is connected thereto. The soil gathering tool 26 and the soil gathering tool fixing part 25 are taken as a soil gathering unit 31. The application unit 30 becomes a standard equipment with the soil gathering unit 31 mounted thereon.

[0025] As shown in Fig. 3(b), when the soil gathering tool 26 moves substantially simultaneously or immediately after the cutting cavity 41 formed by the cutting and forming blade 10A moving in the soil, a soil mound 27 is formed. Since both sides of the soil gathering tool 26 in the shape of a front-view portal move in the soil, the soil mound 27 formed after its passage becomes square or substantially trapezoidal in the front view as shown in Figs. 4(a) and (b).

[0026] Not only when a small amount of liquid fertilizer 40 is applied with respect to the volume of the cutting cavity 41 as shown in Fig. 4(b), but also when a large amount of liquid fertilizer 40 is applied with respect to the volume of the cutting cavity 41 as shown in Fig. 4(a) and the liquid fertilizer 40 overflows from the soil surface of the cutting cavity 41, the soil mound 27 is formed so that the liquid fertilizer is completely covered in the soil. In this way, by completely burying the liquid fertilizer 40 in the soil S and not exposing it to the atmosphere, ammonia, which is a nitrogen fertilizer component, can be prevented from volatilizing into the atmosphere, and the utilization rate of the nitrogen fertilizer can be increased.

[0027] The soil gathering tool is not limited to the soil gathering tool 26 in Fig. 3 as long as it can form a soil mound so that the liquid fertilizer 40 does not expose from the cavity in the soil formed by the cutting and forming blade 10. The soil gathering unit 31 is configured to be able to replace the soil gathering tool fixed to the soil gathering tool fixing part 25 (see Fig. 5(a)). Also, as shown in Figs. 5(b) and (c), by loosening the fastener 22 and the fastener 23, the angles of the soil gathering tool arm 24 and the soil gathering unit 31 with respect to the cutting blade arm 12 can be changed. By tightly fastening the fasteners 22 and 23 at any position, it is possible to construct so that the height of the embankment is forcibly made constant. Also, by leaving the fasteners 22 and 23 rotatable around them without tightly fastening, for example, an embankment can be constructed while moving the soil gathering tool along the terrain of the ground surface.

[0028] In FIG. 6, a modified example is shown in the case of using a soil gathering tool 28 different from the soil gathering tool 26 used in FIG. 3. FIG. 6(a) is different from FIG. 3(a) only in that the soil gathering tool fixed ahead of the soil gathering tool fixing part 25 is different. The soil gathering tool 28 used in FIG. 6 has a shallow bowl shape as shown in FIG. 6(b). From the viewpoint above the soil, by gathering the soil on one side shifted from the central axis of the linearly formed cutting cavity 41 to construct an embankment 29, leakage of the liquid fertilizer 40 to the atmosphere is prevented (see FIG. 6(d)). Regarding the embankment 29 to be constructed, the cross-sectional view in the front view is as shown in FIG. 6(c), and the schematic plan view seen from above is as shown in FIG. 6(d). Also, the bowl-shaped soil gathering tool 28 is relatively small and has a characteristic of being difficult to get entangled with the harvesting residues on the ground surface such as straw.

[0029] As another embodiment, as shown in FIGS. 7(a) and 7(b), the application unit 30 may be provided with a cutting and forming blade 10B having a shape different from the above-described cutting and forming blade 10A. This cutting and forming blade 10B is composed of a substantially triangular prism member and a flat plate member provided on the side of its lower part, and the cutting and forming blade 10 has an L-shaped as a whole (see FIG. 7(a)). This flat plate is inclined so as to rise in the range of about 1 to 60 degrees from the front F to the rear R (see FIG. 7(b)). In the viewpoint of FIG. 7(a), the width of the flat plate is optimally 5 to 7 cm in the range of 1 to 20 cm, and the depth is optimally 10 to 15 cm in the range of 5 to 30 cm.

[0030] As the cutting and shaping blade 10B advances through the soil, an L-shaped cavity is formed in the soil in the front cross-sectional view seen from the front F shown in Fig. 10(c). The cavity extending thinly from the surface of the soil S toward the deeper layers is the cutting cavity 41, and the square cavity formed at the lowermost lateral side is the shaping cavity 42. With the above-mentioned inclination angle of the flat plate, the soil is lifted by about 5 to 10 cm, and the shaping cavity 42 is formed. Compared with the cavity having only the cutting cavity 41 shown in FIG. 2(a), the volume of the cavity is increased by the presence of the forming cavity 42, and the amount of liquid fertilizer 40 to be applied can be significantly increased.

[0031] FIG. 8(a) shows a state in which the application unit 30 equipped with the cutting and shaping blade 10B of this embodiment is further equipped with the soil collector 26 shown in FIG. In the front cross-sectional view from the front F, a square or approximately trapezoidal mound of soil 27 is formed, which prevents the liquid fertilizer 40 from leaking out of the cavity or coming into contact with the atmosphere, as explained using Figure 3.

[0032] As yet another embodiment, as shown in FIG. 9, the application unit 30 may be provided with a cutting and shaping blade 10C having a shape different from the above-mentioned cutting and shaping blades 10A and 10B. The cutting and shaping blade 10C is composed of a substantially triangular prism member at the center, a flat plate member at the bottom end of the triangular prism member that is inclined upward from the front to the rear, and a gate-shaped member with depth when viewed from the front and narrowing toward the rear above the flat plate. Fig. 9(a) shows the cutting and shaping blade 10C as viewed from the front, Fig. 9(b) shows a side view, and Fig. 9(c) shows a plan view. The gate-shaped member has a front width of about 20 to 50 cm, optimally 30 to 40 cm, a rear width of about 15 to 30 cm, optimally 20 to 30 cm, a depth of 20 to 50 cm, optimally 30 to 40 cm, and a height of 5 to 15 cm, optimally 5 to 10 cm, as viewed from Fig. 9(a).

[0033] As the cutting and forming blade 10C advances in the soil, the flat member of the cutting and forming blade 10C lifts the soil, and a cavity is formed therein. Above the formed cavity, that is, below the lifted soil, a U-shaped member moves the soil from the left and right towards the center to fill it. As a result, in the front cross-sectional view seen from the front F shown in Fig. 10(d), a forming cavity 43 is formed below the cutting cavity 41, that is, in the part of the cavity initially formed by the flat member that was not filled by the moved soil. Further, forming cavities 43 are formed on both sides of the cutting cavity 41, that is, in the original space where the moved soil existed and through which the U-shaped member passed. As shown in the figure, since these cavities communicate with each other, when liquid fertilizer 40 is applied from near the soil surface of the cutting cavity 41, the liquid fertilizer enters each of the cavities 41 and 43.

[0034] By forming more forming cavities 43 than the cavities formed by the cutting and forming blade 10B shown in Fig. 7(c), a larger amount of liquid fertilizer can be applied deep and in large quantities. While the normal application rate is 2 - 4 t / 10a, it can be increased to a maximum of about 15 t / 10a. Also, since the shape of each forming cavity 43 is maintained by the force of the soil block structure, the application amount of the liquid fertilizer 40 can be ensured.

[0035] Fig. 10(a) shows a state where the application unit 30 equipped with the cutting and forming blade 10C of this embodiment further includes the soil mover 26 shown in Fig. 3. Similar to the above, a square or substantially trapezoidal soil mound 27 is formed in the front cross-sectional view seen from the front F (see Fig. 10(b)), preventing the liquid fertilizer 40 from leaking from the cavity and preventing the liquid fertilizer 40 from coming into contact with the atmosphere. Thereby, ammonia, which is a nitrogen fertilizer component, is not volatilized into the atmosphere, and by preventing runoff due to rainfall, the utilization rate of the nitrogen fertilizer component can be increased by about 30 - 50% compared to surface application of the same amount of liquid fertilizer 40.

[0036] Using Fig. 11, the structure of the application unit 30 that realizes flexible response to buried objects such as gravel in the soil will be described. Fig. 11 shows an example using the cutting and forming blade 10A shown in Fig. 1, but the following description is also applicable to other cutting and forming blades 10. Response to gravel and the like is realized by yaw rotation around the yaw axis 85 and pitch rotation around the other axes 81, 82, 83 described above.

[0037] First, by yaw rotation centered on the yaw axis 85 having an axis in the vertical direction, the entire application unit 30 turns left and right from the front F so as not to resist the force applied by the collision with gravel and the like, thereby avoiding gravel and the like or mitigating the impact. The same behavior occurs when the colter 16 collides with gravel and the like instead of the cutting and forming blade 10. Considering that a plurality of application units 30 are mounted on the liquid fertilizer applicator M, this rotation around the yaw axis 85 is preferably limited to a rotation of about 45 degrees to the left and right from the front F in a plan view in order to avoid contact between the application units 30.

[0038] Next, when the cutting and forming blade 10 collides with a stone PS, which is a buried object in the soil, by pitch rotation centered on the first pitch axis 81, the second pitch axis 82, and the colter rotation axis 83 (see Fig. 11(a)), from the viewpoint of Fig. 11(b), the cutting blade arm 12 rotates counterclockwise around the colter rotation axis, so that the cutting blade arm 10 is lifted upward so as not to resist the force applied by the collision with the stone PS. Furthermore, the behavior of the cutting blade arm 10 being lifted upward to avoid the impact with the stone PS is also realized by the first arm 14 rotating counterclockwise around the first pitch axis 81 and the second arm 15 rotating counterclockwise around the second pitch axis. In this way, by the arms 14, 15, 12 rotating around the respective axes 81, 82, 83, it is also possible to avoid gravel and the like.

[0039] When the colter 16 comes into contact with gravel and the like, the first arm 14 and the second arm 15 rotate, causing the colter 16 to be lifted upward, that is, the entire application unit 30 to be lifted upward.

[0040] Also, as described above, the telescopic first arm 14 can be provided with an elastic body 95. When the cutting and forming blade 10 contacts the stone PS and the cutting blade arm 12 starts to rotate counterclockwise around the cutter rotation shaft 83, the first arm contracts, and the elastic force from the elastic body 95 acts in the direction of extending the first arm 14, so that the impact associated with the contact with the gravel can be mitigated.

[0041] The connections forming the square shapes of the respective arms 12, 14, 15, and 17 enable the cutting blade arm 12 to move up and down together when the cutter 16 or the cutting and forming blade 10 encounters resistance due to the unevenness of the land, terrain, soil density, gravel, etc. Further, by avoiding sudden behavior by the elastic body 95, the stability of the operation of the entire application unit 30 is ensured. By such a flexible response to buried objects such as gravel, not only damage to the application unit 30 but also damage caused by the collision of the liquid fertilizer applicator can be avoided, and further, the influence on the tractor TR and the slurry tank TA can also be avoided.

[0042] Using FIG. 12, the response of the application unit 30 when the buried object that hinders the progress of the application unit is a larger boulder PB will be described. The application unit 30 can be connected to the partial arm 13, which is a part of the cutting blade arm 12, and the first arm 14 by a safety pin 19 (see FIG. 12(a)). The safety pin 19 is broken by a load equal to or greater than a certain value applied to the connection portion between the partial arm 13 and the first arm 14, such as when a load equal to or greater than a certain value is applied in the direction of contracting the first arm 12 described above. When the boulder PB collides with the cutting and forming blade 10, the cutting and forming blade 10 is lifted as described above, and the first arm 17 contracts. Then, the elastic force of the elastic body 95 acts to mitigate the impact. However, when the boulder PB cannot be completely avoided within the movable range in the state where the arms are connected, or when the impact due to the collision with the boulder PB is excessively strong, the safety pin 19 is broken, and the connection between the cutting blade arm 12 and the first arm 14 is released (see FIG. 12(b)).

[0043] When the safety pin 19 is broken and the cutting blade arm 12 becomes free to move with respect to the first arm 14, the cutting and forming blade 10 and the coulter 16 can be lifted up to the ground surface excellently against the force received from the boulder PB (see Fig. 12(b)). Therefore, damage to the application unit 30, the liquid fertilizer applicator M, and the tractor TR due to a collision with the boulder PB can be prevented.

[0044] Even when the coulter 16 rather than the cutting and forming blade 10 collides with the boulder PB, if the impact is excessively strong, a strong impact can be applied to the connection point between the partial arm 13 and the first arm 14 without shrinking the first arm 17. Also in this case, the connection between the cutting blade arm 12 and the first arm 14 is released by the breaking of the safety pin 19.

[0045] Hereinafter, the liquid fertilizer applicator M to which the above-described application unit 30 is attached will be described. The liquid fertilizer applicator M has a frame, and this frame includes a three-point link connection frame 50 which is a sub-frame mainly for connecting to the tractor TR by a so-called three-point link, and an application unit arrangement frame 51 which is a sub-frame for attaching the application unit 30, and a tank connection frame 77 for connecting a slurry tank (see Fig. 20). Each sub-frame is for convenience of explanation, and may be manufactured separately or may be integrally manufactured in whole or in part.

[0046] FIG. 13 is a schematic front view of the liquid fertilizer applicator M as viewed from the front. As shown in this figure, the application unit arrangement frame 51 extends horizontally. It may extend in a direction perpendicular to the front F, or it may extend so as to slope downward toward the rear as it goes from side to side. The application units 30 can be mounted on this application unit arrangement frame 51 at free intervals and positions within the range of 1 to 10 units. FIG. 13 shows an example in which five application units 30 are mounted on each of the left and right sides. FIG. 14 shows an example in which four application units 30 are mounted on the application unit arrangement frame 51 on the left side of the drawing and three application units 30 are mounted on the right side. As shown in this figure, the application units 30 may be mounted asymmetrically on the left and right. At the extreme, only one application unit 30 can be mounted at an arbitrary position. Preferably, it is provided such that the distance from the center of one cutting and forming blade 10 to the center of the adjacent cutting and forming blade 10 is about 60 to 120 cm.

[0047] In FIG. 15, the position of the tire 54 of the tractor TR or the slurry tanker TA in a front view is virtually shown by a two-dot chain line. The application unit 30 may be mounted on the application unit arrangement frame 51 so as to avoid the running part of this tire 54. Thereby, it is possible to prevent the cavities formed by the above-described cutting and forming blades 10 and the mounds formed by the soil gathering tools from interfering with the running part of the tire 54.

[0048] The application unit 30 mounted on the application unit arrangement frame 51 may be provided with any of the cutting and forming blades 10 and does not have to be all the same cutting and forming blade 10. Therefore, as shown in FIG. 16, application units 30 each having any one of the three types of cutting and forming blades 10 exemplified above may be mixed and mounted. When the application unit 30 is provided with a soil gathering tool, the cutting and forming blade 10 can be combined with any type of soil gathering tool. Typically, the width of the substantially triangular prism member of the cutting and forming blade 10A is about 5 cm, the width of the U-shaped member of the cutting and forming blade 10C is about 25 cm, and the flat plate members of the cutting and forming blades 10B and 10C are installed at a position about 10 to 30 cm deep in the soil. As the liquid fertilizer applicator M equipped with a plurality of types of cutting and forming blades 10 progresses, various types of cavities will be formed in the soil.

[0049] The application unit placement frame 51 is provided with folding fulcrums 52 near the intermediate positions extending on the left and right so that it can be folded by itself when traveling on a public road or the like (see FIG. 13). In order to realize this folding operation, a foldable hydraulic cylinder 53 that can be expanded and contracted is provided by using the hydraulic system of the tractor TR. The state in which the folding hydraulic cylinder 53 is contracted and the application unit placement frame 51 is folded is shown in FIG. 17.

[0050] The liquid fertilizer applicator M may have a liquid fertilizer distributor 59 in order to distribute the liquid fertilizer supplied from the slurry tank TN to the application unit 30 (see FIGS. 13 and 20). The liquid fertilizer distributor 59 communicates with the slurry tank TN via a transport pipe 71 and communicates with the liquid fertilizer insertion pipe 20 and the liquid fertilizer distribution hose 21 of the application unit 30.

[0051] The liquid fertilizer distributor 59 will be described with reference to FIG. 18. As shown in FIG. 18(b), the liquid fertilizer distributor 59 includes a distribution container 60 and a distribution container lid 63 that covers it. The distribution container 60 has a cylindrical shape with a bottom surface 61. The transport pipe 71 is connected to a hole opened at the center of the distribution container lid 63, and the liquid fertilizer 40 is injected from the slurry tank TN into the distribution container 60 by its own weight. At this time, the distribution container lid 63 and the distribution container 60 are tightly sealed, for example, by a distribution container fastener 64 so that the liquid fertilizer 30 does not leak from the distribution container 60.

[0052] As shown in Fig. 18(a), the interior of the distribution container 60 includes a rotating shaft 66 that can be rotated by a motor 65 (see Fig. 18(b)) provided on the lower side of the distribution container 60, a plurality of holes 62 provided on the bottom surface 61 at equal angular intervals around the rotating shaft 66 and at an equal distance from the rotating shaft, a plurality of distribution plates 68 extending from the rotating shaft 66 to the vicinity of the inner surface of the distribution container 60 and evenly partitioning the interior of the distribution container 60, and distribution plate blades 67 provided at the edges on the upper side in the vertical direction of each distribution plate 68, i.e., on the side of the liquid fertilizer inlet 69. The distribution plates 68 and the distribution plate blades 67 may be integrally manufactured or manufactured as separate members. It is preferable that the number of distribution plates is equal to the number of holes 62. More preferably, the number is also equal to the number of liquid fertilizer insertion pipes 20.

[0053] Each distribution plate 68 is arranged at an angle of about 1 to 30 degrees in the rotation direction from a plane perpendicular to the bottom surface of the distribution container 60. Therefore, as shown in Fig. 18(a), the side surface of the distribution plate 68 can be visually recognized in a plan view.

[0054] The liquid fertilizer distributor 59 and the liquid fertilizer insertion pipes 20 are connected by a liquid fertilizer distribution hose 21. One end of each liquid fertilizer distribution hose 21 connected to each liquid fertilizer insertion pipe 20 provided in each application unit 30 is installed in each hole 62 as shown in Fig. 18(b).

[0055] As the rotating shaft 66 rotates, the distribution plates 68 rotate, and the distribution plate blades 67 with an angle cut the impurities of the liquid fertilizer 40 injected from the liquid fertilizer inlet 69. By this rotating action, an equal amount of liquid fertilizer 40 flows into the distribution container 60 partitioned by the distribution plates and then flows into each liquid fertilizer distribution hose 36 through each hole 62 in the bottom surface 61.

[0056] The distribution container lid 63 is provided with a transparent container window 70 that enables visual recognition of the interior of the distribution container 60 (Fig. 18(b)). This allows confirmation of the rotation state of the rotating shaft 66 described above, the state of the liquid fertilizer 40 being cut, the distribution status of the liquid fertilizer 40, etc. For example, a container window 70 of a size shown in the position indicated by the two-dot chain line in Fig. 18(a) can be provided.

[0057] In the example shown in Fig. 18(a), six holes 62 are provided, and the internal space of the distribution container 60 is partitioned into six parts by six distribution plates 68. In this case, it is mainly assumed to be used for a total of six liquid fertilizer insertion pipes 20 provided in each of the six connected application units 30 mounted on the application unit arrangement frame 51 as shown in Fig. 16.

[0058] As a modification, the example shown in Fig. 19(a) shows an example in which eight holes 62 are provided, and the internal space of the distribution container 60 is partitioned into eight parts by eight distribution plates 68. In this case, it is mainly assumed to be used for a total of eight liquid fertilizer insertion pipes 20 provided in each of the eight connected application units 30 mounted on the application unit arrangement frame 51 as shown in Fig. 15.

[0059] As another modification, the example shown in Fig. 19(b) shows an example in which four holes 62 are provided, and the internal space of the distribution container 60 is partitioned into four parts by four distribution plates 68. In this case, it is mainly assumed to be used for a total of four liquid fertilizer insertion pipes 20 provided in each of the four connected application units 30 mounted on the application unit arrangement frame 51.

[0060] With the structure of the above liquid fertilizer distributor 59, it provides a function of evenly distributing liquid fertilizer 40 etc. to a plurality of application units 30 and cutting and granulating impurities. The liquid fertilizer distributor 59 itself can be widely used in a device that distributes liquid fertilizer mixed with impurities to a plurality of pipes, and can be used regardless of the scale of the device.

[0061] Fig. 20 shows a state where the liquid fertilizer applicator M equipped with the present application unit 30 is connected to the tractor TR in the front and the slurry tank TA in the rear. By providing the above-described frames 50 and 51, the liquid fertilizer applicator M according to the present invention can be connected to an existing slurry tank and an existing tractor without any problem.

[0062] The connection between the liquid fertilizer applicator M with a three-point linkage and the tractor TR is made using the hydraulic system of the tractor TR so that the relative position of the liquid fertilizer applicator M with respect to the tractor TR can be displaced vertically, horizontally, and in all directions. Thus, when the liquid fertilizer applicator M is advancing due to the traction of the tractor TR, fine adjustments in the horizontal and inclined directions can be made to control the posture of the liquid fertilizer applicator M, particularly the posture of the application unit placement frame 51, so as to maintain the appropriate position of the cutting and forming blade 10. Specifically, fine adjustment of the insertion part of the cutting and forming blade 10 can be performed by displacing the liquid fertilizer applicator M horizontally, and adjustment of the insertion depth of the cutting and forming blade 10 can be performed by displacing it vertically.

[0063] In the settings before liquid fertilizer application, the fixed position of the cutting and forming blade 10 within the cutting blade holder 11 can be used to determine the assumed insertion depth of the cutting and forming blade 10, that is, the depth of the cavity formed during its advancement in the soil. During actual application, it is possible to appropriately fine-tune the posture control of the liquid fertilizer applicator M so that the assumed insertion depth is maintained.

[0064] The slurry tank TN communicates with the liquid fertilizer insertion pipe 20 of the application unit 30. As an example of the connection, although a member for spraying liquid fertilizer is usually provided at the lower rear of the slurry tank TN (not shown), this is removed, and a transport pipe 71 extending to the upper part of the tank via a connection hose unit and a transport pipe 71 further extending forward F via a connection unit 75 are provided. Further, a liquid fertilizer distributor 59 is provided via the connection unit 75, and is connected thereto from each liquid fertilizer insertion pipe 20 via a liquid fertilizer distribution hose 21. In this flow, the liquid fertilizer is sent from the slurry tank TN to the liquid fertilizer insertion pipe 20.

[0065] While being towed and advancing, the liquid fertilizer applicator M can construct cutting cavities or forming cavities in the soil to a deep layer so that liquid fertilizer can be applied deep into the soil being prepared and the layer directly below it, and thus the inserted liquid fertilizer can be easily applied in any amount without being exposed on the ground surface. Also, in order to enhance the practical usefulness considering the application efficiency and the tire widths of various tractors and slurry tankers, not only the depth but also the application interval and the number of applications of the liquid fertilizer can be changed. In addition, the earth embankment tool arranged at the rearmost part of the application unit covers the soil immediately after the application to the liquid fertilizer insertion port, preventing the surface exposure of the liquid fertilizer and preventing the volatilization or dissipation of ammonia, which is the main fertilizer component. It can prevent the uneven distribution and runoff of the liquid fertilizer caused by the terrain, prevent the outflow of the liquid fertilizer outside the farmland due to surface runoff, and prevent losses such as phosphoric acid and bases. As a result, it enables the large-scale application of liquid fertilizer into the soil and realizes the application of a uniform amount. Furthermore, the liquid fertilizer applicator of the present invention can be connected to existing or off-the-shelf tractors and slurry tanks, enabling farmers to easily carry out fertilization using the liquid fertilizer applicator of the present invention and contributing to enhancing the soil fertility of farmland, which is the place of agricultural production. By using liquids such as the slurry of livestock manure and urine, the fermentation digestion liquid which is its fermentation liquid, and the adjusted liquid fertilizer with a high substitution rate of the fertilizer component amount, it can also contribute to the realization of an environmentally friendly regional circulation type agriculture.

[0066] [Example 1] Examples of the present invention are shown below. Assuming a liquid fertilizer applicator M having an application unit 30 shown in FIG. 7, a deep soil application area of liquid fertilizer 40 was set up, and the concentration distribution of ammonia nitrogen in the soil during deep soil application was measured. The results of the cross-sectional distribution diagram of the components are shown in FIG. 21. The test conditions are as follows. · Test date: November 29, 2021 · Test location: Black clay soil field (wheat field) of the Rural Engineering Research Department in Tsukuba City, Ibaraki Prefecture · Tractor used: Kubota SL38 38-horsepower wheel tractor · Working machine used: For the test application, a liquid fertilizer applicator M with only one set of application unit 30 having a cutting and forming blade 10B was used for the test application. A trench digging machine with an L-shaped blade of Cut Drain mini and a surf unit was used. · Liquid fertilizer used: Methane fermentation digestion liquid (livestock manure, food residue system) Ammonia nitrogen concentration 0.2% · Planned application depth: About 20 - 25 cm · Application amount: 3.4 t / 10a · Chemical fertilizer (nitrogen conversion): Equivalent to 6.8 kgN / 10a

[0067] As shown in Fig. 21, the concentration of ammonia nitrogen in the soil application area was higher the deeper it was. In the surface layer at a depth of 0 to 10 cm, the liquid fertilizer 40 was applied to the soil without being exposed. Also, immediately after application, there was no movement of ammonia components from the application part to the surroundings, and it was found that they were retained in the application part.

[0068] [Example 2] Assuming a liquid fertilizer applicator M having the application unit 30 shown in Fig. 3, a deep soil application area of the liquid fertilizer 40 was set up, and the volatilization amount of ammonia gas from the ground surface after applying the liquid fertilizer was measured. The results are shown in Fig. 23 as the ammonia gas starting rate. The test conditions are as follows. · Test date: November 7, 2022 · Test location: Black peat soil field (Dent cone) in Hokkaido · Tractor used: Kubota M7 132 - horsepower wheel tractor · Working machine used: Conducted with a liquid fertilizer applicator M with 8 application units mounted as a field demonstration test · Liquid fertilizer used: Methane fermentation digestate (livestock manure - based, food residue - based) Ammonia nitrogen concentration 0.2% · Application rate: 3.4 t / 10a (the same amount for both the surface spreading area and the soil application area) · Chemical fertilizer (nitrogen equivalent): Equivalent to 6.8 kgN / 10a

[0069] As shown in Fig. 24, the ammonia gas volatilization rate in the soil application area applied using the liquid fertilizer applicator M according to the present invention was zero. This indicates that by applying the liquid fertilizer 40 into the soil and completely covering it with soil, the volatilization of ammonia gas can be suppressed.

[0070] [Comparative Example 1] Assuming surface spreading by the conventional method, the liquid fertilizer 40 was spread on the ground surface to measure the distribution status of ammonia nitrogen in the soil, and the results of the cross - sectional distribution diagram of the components are shown in Fig. 22. The test conditions are as follows. · Test date: November 29, 2021 · Test site: Black peat soil field (wheat field) of the Rural Engineering Research Department in Tsukuba City, Ibaraki Prefecture · Application method: Manual application · Liquid fertilizer used: Methane fermentation digestate (livestock manure, food residue-based) Ammoniacal nitrogen concentration 0.2% · Application location: Surface spraying onto the ground surface · Application rate: 3.4 t / 10a (the same amount for both the surface spraying area and the soil application area) · Chemical fertilizer (in terms of nitrogen): Equivalent to 6.8 kg N / 10a

[0071] As shown in Fig. 22, the position with a high concentration of ammoniacal nitrogen in the surface spraying of the conventional method is the surface layer with a depth of 0 - 10 cm from the application part, and most of it is on the surface. Immediately after application, there is no movement of nutrients to the lower layer, and it is a condition where the volatilization of ammonia gas is likely to occur.

[0072] As shown in Fig. 23, the ammonia gas volatilization rate in the surface spraying area of the conventional method is high after application and gradually decreases, but continues for a relatively long time. As long as there is liquid fertilizer 40 on the ground surface, the volatilization of ammonia gas continues, promoting the reduction of nitrogen components.

[0073] The presence or absence, arrangement position, arrangement relationship of each component in the liquid fertilizer application device and application unit, the method of piping between each component, the material of the piping, the fixing method of the liquid fertilizer insertion pipe, etc. are all examples and do not limit the invention content as long as the object of the present invention can be achieved. The combinations of the liquid fertilizer application unit, cutting and forming blade, and soil gathering tool disclosed above are also included in the disclosed range as long as they are included in the description of the claims.

Explanation of symbols

[0074] M Liquid fertilizer applicator S Soil PS Stone PB Boulder TA Slurry tank TN Slurry tank TR Tractor 10 Cutting and forming blade 10A Cutting and forming blade 10B Cutting and forming blade 10C Cutting and forming blade 11 Cutting blade holder 12 Cutting blade arm 13 Partial arm 14 First arm 15 Second arm 16 Colta 17 Link arm 18 Unit holder 19 Safety pin 20 Liquid fertilizer insertion pipe 21 Liquid fertilizer distribution hose 22 Tightening screw 23 Tightening screw 24 Earth banking tool arm 25 Earth banking tool fixing part 26 Earth banking tool 27 Earth mound 28 Earth banking tool 29 Earth mound 30 Application unit 31 Earth banking unit 40 Liquid fertilizer 41 Cutting cavity 42 Forming cavity 43 Forming cavity 44 Surface waterlogging 50 Three-point link connection frame 51 Application unit placement frame 52 Folding fulcrum 53 Folding hydraulic cylinder 54 Tire 59 Liquid fertilizer distributor 60 Distribution container 61 Bottom surface 62 Hole 63 Distribution container lid 64 Distribution container lid fastener 65 Motor 66 Rotating shaft 67 Distribution plate blade 68 Distribution plate 69 Liquid fertilizer injection port 70 Container window 71 Transport pipe 75 Connection unit 77 Tank connection frame 81 First pitch axis 82 Second pitch axis 83 Colter rotation axis 85 Yaw axis 90 Fastener 91 Through hole 93 Hole for safety pin 94 Hole for safety pin 95 Elastic body F Front R Rear

Claims

1. A liquid fertilizer applicator that is detachable from a tractor and applies liquid fertilizer to a field, comprising: a cutting and forming blade that forms a cavity to a deep layer in the soil; a unit holder that is a member fixed to the liquid fertilizer applicator; a link arm rotatably connected to the unit holder around a yaw axis; a first arm having one end rotatably connected to the link arm around a pitch axis and being telescopic; a second arm having one end rotatably connected to the link arm around a pitch axis; a cutting blade arm having one end rotatably connected to the second arm and the cutting and forming blade fixed thereto so as to extend substantially vertically therefrom and the other end connected to the other end of the first arm by a partial arm extending from one end side; and a liquid fertilizer insertion tube disposed behind the cutting and forming blade and for applying liquid fertilizer supplied from a tank into the soil. a frame on which one or more of the application units can be arranged at arbitrary intervals. The link arm, the first arm, the second arm, and the partial arm are connected in a square shape, and The liquid fertilizer applicator is characterized in that the first arm is provided with an elastic body such that an elastic force acts in the reverse direction when the first arm contracts.

2. The forming cutting blade can be fixed to the cutting blade arm by adjusting the length extending from the cutting blade arm in the soil direction, and The pitch angle and yaw angle of the frame with respect to the tractor can be adjusted by a hydraulic device of the tractor, and the construction depth of the forming cutting blade can be adjusted in the range of 0 to 40 cm by adjusting the pitch angle. The liquid fertilizer applicator according to Claim 1.

3. The connection between the partial arm and the first arm is made by a safety pin, and The liquid fertilizer applicator according to Claim 2, characterized in that the safety pin is broken by a load equal to or greater than a certain value applied to the connection portion between the partial arm and the first arm, and the connection between the cutting blade arm and the first arm is released.

4. Each of the one or more cutting and forming blades arranged on the frame is composed of a member that is a substantially triangular prism and has a substantially triangular prism with a large bottom area near its lower end, composed of a member of a substantially triangular prism and a member of a flat plate provided on the side thereof when the traveling direction is forward and inclined so as to rise from the front to the rear, or Either the liquid fertilizer applicator according to claim 1, characterized in that it is composed of a slightly triangular prism-shaped member, a flat plate member provided at its lower end and inclined so as to rise from the front to the rear, and a member having a depth in a front view as viewed from the front and having a width that narrows toward the rear.

5. The liquid fertilizer applicator according to claim 4, characterized in that the application unit further comprises an earth moving tool for covering the soil surface of the cavity formed in the soil during its progress with soil.

6. The liquid fertilizer applicator according to claim 1, characterized in that the frame on which the application unit is arranged has a folding fulcrum, and a portion extending laterally of the frame can be rotated vertically upward about the folding fulcrum by a hydraulic system and is foldable.

7. The liquid fertilizer applicator further has a liquid fertilizer distributor for distributing the liquid fertilizer supplied from the liquid fertilizer tank to a plurality of liquid fertilizer insertion pipes. The liquid fertilizer distributor has a cylindrical distribution container having a bottom surface, a distribution container lid covering the distribution container, a liquid fertilizer injection port provided on the distribution container lid, a rotating shaft located at the center of the distribution container and rotatable by a motor, a plurality of holes provided on the bottom surface at equal angular intervals around the rotating shaft and at equal distances from the rotating shaft, a plurality of distribution plates extending from the rotating shaft to the vicinity of the inner surface of the distribution container and evenly partitioning the inside of the distribution container, and distribution plate blades provided at the upper edges in the vertical direction of each of the distribution plates. The liquid fertilizer applicator according to any one of claims 1 to 6, characterized in that the distribution plates are arranged at an inclination of 1 to 30 degrees in the rotation direction from a plane perpendicular to the bottom surface of the distribution container.

8. An application unit mounted on a liquid fertilizer applicator towed by a tractor for applying liquid fertilizer to a field, A cutting and forming blade for forming a cavity to a deep layer in the soil, A unit holder mounted on the liquid fertilizer applicator, A link arm rotatably connected to the unit holder around a yaw axis, A telescopic first arm having one end rotatably connected to the link arm around a pitch axis, A second arm having one end rotatably connected to the link arm around a pitch axis, A cutting blade arm having one end rotatably connected to the second arm and the cutting and forming blade fixed to the other end so as to extend substantially vertically therefrom and connected to the other end of the first arm by a partial arm extending from one end side. A liquid fertilizer insertion tube that is disposed behind the cutting and forming blade and is for applying the liquid fertilizer supplied from the tank into the soil. An application unit, characterized in that the first arm is provided with an elastic body such that an elastic force acts when the first arm contracts.

9. The connection between the partial arm and the first arm is made by a safety pin, and The application unit according to claim 8, characterized in that the safety pin is broken by a load equal to or greater than a certain level applied to the connection portion between the partial arm and the first arm, and the connection between the cutting blade arm and the first arm is released.

10. The application unit according to claim 9, further comprising an earth moving tool for covering the soil surface of the cavity formed in the soil by the advancement of the forming cutting blade with soil.

Images