A METHOD AND DEVICE FOR PERIODIC DEPOSITING OF LIQUID MANURE SUCH AS SLURRY IN A SOIL

Abstract: In a method for periodic depositing of liquid manure such as slurry in a soil (80) the slurry is injected in a concentrated jet (9) under pressure, with the result that the slurry forms and fills a groove (6) in the soil, which groove (6) is preferably closed after the injection. A device (1) for use in the method comprises at least one nozzle (5) with a breaker element (10) for periodic interruption of or opening for an injection jet (9) in an outlet direction (P2), the nozzle preferably being provided as an opening from a chamber (3, 29, 35, 38, 52, 72) pressurized with slurry. The breaker element (10) may be rotatably mounted about a rotation axis (22) which is parallel to the nozzle's outlet direction (P2) and is located beside the nozzle (5), with the result that during a rotational movement the breaker element periodically interrupts the injection jet (9).

Description: A method and device for periodic depositing of liquid manure such as slurry in a soil The invention concerns a method for periodic depositing of liquid manure such as slurry in a soil, preferably performed by a device which is pulled behind a vehicle. The invention also concerns devices for periodic depositing of liquid manure such as slurry in a soil, for the supply of slurry under pressure. Slurry, i.e. a mixture of animal manure, urine and water, is used in agriculture for fertilizing soils. The simplest method of spreading liquid manure, such as slurry, is to spray it or pour it over the soil. This leads to substantial evaporation of components in the slurry, odour problems and often also run-off problems, especially in sloping terrain. In order to reduce the problems associated with evaporation, odour and run- off, while at the same time increasing the soil's absorption of the nutrients in the slurry, it is advantageous to plough the slurry down into the soil or place it in grooves which are preferably closed after the slurry has been deposited in the groove. Finnish patent application no. 60 949 describes a tool for depositing slurry manure in a soil, wherein a number of discs cut furrows in the soil, whereupon harrow tines with pipes for the supply of slurry manure fill the furrows with manure. The bottom section of the harrow tines is provided with triangular cutting edges which extend the furrow at the bottom, thus providing more room for the manure. Finnish patent application no. 45 285 describes a tool for injection of a gas or liquid, e.g. ammonia, into a soil, wherein a system of injection tines and harrow tines are pulled behind a vehicle and are moved forwards and backwards down into the soil, across the direction of travel. The injection tines are located in the direction of travel in front of the harrow tines, and the injection is thus performed in a zigzag pattern, whereupon the harrow tines by means of their zigzag movements close the grooves behind the injection tines. Norwegian patent application no. 893 658 describes a method for depositing manure in a field, wherein the soil is slit with parallel furrows by means of the rotavator part of a sowing machine, and manure is fed out by means of the sowing machine's lugs. Norwegian patent no. 169 81 IB describes equipment for spreading slurry, wherein a spreading nozzle is arranged in a shoe which is pulled along the ground. The spreading nozzle is in the form of a cone with the base pointing downwards, and can be closed by a corresponding conical sealing element. Thus when the spreading equipment is employed, a fan-shaped scattered jet is produced which is directed towards the soil. Devices therefore exist which cut grooves in the ground, place liquid manure therein as well as closing the groove afterwards. However, the digging up or cutting up of the soil involved in the existing devices requires them to be employed together with a heavy vehicle with substantial tractive power. For the same reason the devices are highly subject to wear. Other disadvantages are that they only work well in earth which is free of stones, and are not of much use on a soil which is in growth, since the plant roots and green parts can be badly damaged. Moreover, the devices do not work well in sloping terrain, since the slurry has a tendency to run along the grooves. The spreading device which is described in Norwegian patent no. 169 81 IB is located above the ground, and is therefore not encumbered with the drawbacks incurred by parts which are moved down in the earth. With this device the slurry is distributed over the soil and will to some extent penetrate down into the uppermost layer of soil. The device described in Norwegian patent no. 169 81 IB thus represents an improvement compared with traditional spraying, but the device is not capable of depositing the slurry down into the earth in the same way as the other above-mentioned patent publications. The object of the invention is to provide a method for depositing liquid manure such as slurry in a soil, where evaporation, run-off and odour problems are avoided, and where the method is not encumbered with the above-mentioned disadvantages. A further object is to provide devices for use in implementing the method. The object is achieved according to the invention with a method and devices for use in implementing the method of the type mentioned in the introduction, characterized by the features which are indicated in the claims. Thus the object of the invention is to inject slurry into a soil with a concentrated jet under pressure, with the result that the slurry forms and fills a discontinuous groove in the soil, and preferably closes the groove after the injection. The invention will now be explained in more detail in connection with the description of several embodiments, and with reference to the drawing, in which fig. 1 illustrates a tractor pulling an injection device according to the invention, fig. 2 illustrates the injection device, partially in a longitudinal section made in the tractor's direction of movement, and a groove which is formed by the injection device, fig. 3 is a cross section of the groove in fig. 2, where the section is made across the tractor's direction of movement, fig. 4 is a longitudinal section of a preferred embodiment of the injection device according to the invention, figs. 5a, b and c illustrate different designs of a breaker element for use together with the injection device illustrated in fig. 4, fig. 6 illustrates an alternative injection device, figs 7a and b illustrate designs of alternative breaker elements, fig. 8 illustrates a second alternative design of a breaker element, fig. 9 illustrates a design of a third injection device, fig. 10 illustrates a design of a fourth injection device and fig. 1 1 illustrates a design of a fifth injection device. Fig. 1 illustrates a tractor 2 pulling an injection device 1 according to the invention in a direction of movement indicated by the arrow P, . The injection device forms part of an agricultural tool which is preferably composed of several injection devices, a slurry tank, one or more pumps for pressurizing the slurry, pipes or hoses for the supply of slurry to the injection devices and the necessary supporting and securing elements. With the exception of the injection device all of these elements are known, and will not be described in more detail. Fig. 2 illustrates the injection device in closer detail. A pressure chamber 3 is supplied with slurry through a supply pipe 4. The pressure chamber is arranged on top of a shoe 7 which is dragged along a soil 80 by the tractor. A nozzle 5 provided in an opening in the shoe 7 generates a concentrated jet 9 of slurry directed towards the soil 80. The jet is interrupted periodically, thus forming a discontinuous groove 6 in the soil. The groove 6 is shown in a longitudinal section, i.e. a section formed in the tractor's and the injection device's direction of movement. The injection and the formation of the groove 6 are performed over a length 1, , whereupon the injection is interrupted over a length 1 2 . The object of the interrupted injection is to prevent run-off in sloping terrain. Tests have shown that the length li should be between 15 and 20 cm, and 1 2 approximately 5 cm, but the optimum sizes for li and 1 2 can of course vary depending on the amount of slurry which is injected, the soil and the slope of the terrain. The lengths 1 ] and 1 2 are preferably obtained by a synchronization of the vehicle's speed and the periodic injection. Fig. 3 shows a section of the groove 6 in fig. 2, made across the direction of movement. A pocket 8 can be seen here which is formed by the jet 9. The size and shape of the pocket 8 will depend on the soil, the speed of the jet and the volume of flow, but generally an injection groove will be formed with a relatively narrow upper section and an extended pocket where the slurry is mixed with earth. This shape of groove is very advantageous, since it reduces evaporation and odour problems. Fig. 4 shows the injection device in closer detail. It can be seen here how the pressure chamber 3 in the form of a square pipe 20 is arranged on top of the shoe 7, and further how the nozzle 5 is arranged as an opening from the pressure chamber 3, through the shoe 7, thus enabling it to produce the jet 9 in an outlet direction indicated by the arrow P 2 . A rotating breaker element 10 interrupts the jet 9 at regular intervals, thus causing it to form the discontinuous groove. The breaker element's 10 rotational movement is generated by a rotating drive shaft 12 which is provided inside a bearing sleeve 16 and receives its rotational movement from a chain wheel 18. The chain wheel 18 is preferably driven by a chain drive which receives its movement from a hydraulic motor, which in turn is driven by hydraulic oil from a hydraulic pump in the tractor. The drive shaft 12 will, however, be able to be operated in a number of known ways, and since this falls outside the scope of the invention, it will not be described further. The bearing sleeve 16 is attached by means of a sleeve flange 17 and fixing screws 19 to the pressure chamber 3, and the bearing sleeve is further provided with an upper slide bearing 13 and a lower slide bearing 14 for mounting the drive shaft 12. A compression spring 11 is provided between a bearing disc 15 and the breaker element 10, and apart from ensuring that the breaker element 10 is always forced into sealing abutment against the shoe 7, the spring 1 1 also compensates for wear of the breaker element. The shoe 7 is dragged along the soil, thus ensuring that the nozzle 5 is kept at an approximately constant height above the soil. The shoe prevents the slurry from splashing and concomitant evaporation during the injection. At the same time the shoe effects a closing of the groove after the injection. A shoe with a flat bottom will normally provide adequate closing of the groove, but the closing function may be improved by providing one or more cutting edges or ridges (not shown) in the bottom of the shoe or possibly separately behind the shoe. A plurality of injection devices may be assembled to form an agricultural tool (not shown) by giving the square pipe 3 an extension across the tractor's direction of movement, the square pipe thus forming a foundation and pressure chamber for affixing several shoes 7 with nozzles 5. Figs. 5a, b and c illustrate three different embodiments of the rotating breaker element 10 which is attached to the drive shaft 12, thus enabling it to rotate about an axis 22 as indicated by the arrows R. Fig. 5a illustrates a breaker element consisting of a rectangular plate 21 with two wings 23 which, during the rotation of the plate 21, pass and close off the nozzle 5, which provides a periodic interruption of the injection jet. Fig. 5b illustrates a design where the breaker element consists of a cross 24 with four wings 25. This design is preferred in relation to the design in fig. 5a, since it produces the same interruption frequency as the breaker element in fig. 5a at half the rotational speed, which means reduced wear on the rotating parts. Fig. 5c illustrates a breaker element in the form of a disc 26 with three openings 27. During the rotation of the disc the openings 27 are brought into correspondence with the nozzle 5, thus enabling the injection jet to pass. Compared with the designs illustrated in figs. 5a and b the design illustrated in fig. 5c has the advantage of providing better sealing against the shoe 7. Fig. 6 shows an alternative design of the injection device. Here a wheel 70 with a hollow hub 73 is dragged behind a vehicle. The hub 73 is stationary, while the wheel 70 is caused to rotate by the movement of the wheel in relation to the soil, indicated by the arrow R. A pressure chamber 72 which is located in the hub's 73 cavity is supplied with slurry from a supply pipe 75, and a downwardly directed nozzle 74 in the hub 73 is brought by means of the wheel's rotation into correspondence with radial openings 71 which extend from the hub 73 to the circumference of the wheel 70. Every time one of the radial openings 71 is located at the bottom of the wheel, in correspondence with the nozzle 74, a jet is thereby injected into the soil. Figs. 7a and b illustrate two embodiments of a breaker element which, like the breaker element illustrated in fig. 6, is rotatably mounted around a rotation axis which is perpendicular to the nozzle's outlet direction P 2 , and where the breaker element is arranged inside the pressure chamber. Fig. 7a and b is a cross section in a plane made through the nozzle's outlet direction P 2 , illustrating the principle of how the jet is interrupted. Fig. 7a illustrates a breaker element in the form of a star-shaped wheel 28 with four wings 30, arranged inside a pressure chamber 29. When the wheel 28 is rotated in a direction indicated by the arrow R the wings 30 will periodically close the nozzle 31, thus producing a periodic injection. Fig. 7b illustrates a similar principle where a pipe 37 is located in a pressure chamber 38 with a nozzle 39. Along a part of the pipe's circumference, in a plane made through the nozzle's 39 outlet direction P 2 , a slit is cut which, during rotation of the pipe as indicated by the arrow R, is brought into periodic correspondence with the nozzle. The remaining sections 37 of the pipe act as breaker elements for the nozzle 39. Fig. 8 illustrates a design where a breaker element in the form of a shaft 32 with a diametrical opening 33 is arranged in a housing 34. Here the housing 34 is located on the bottom of a pressure chamber 35, with the result that when the shaft 32 is rotated in a direction indicated by the arrow R, the opening 33 will periodically open to permit passage of a flow of slurry from the pressure chamber 35 to a nozzle 36 provided on the bottom of the housing 34. The principle designs illustrated in figs. 7a, 7b and 8 can be given a number of constructional designs with regard to mounting of the breaker element, sealings and generation of the rotation. A particularly advantageous design is obtained when several nozzles are connected to the same pressure chamber, so that the same breaker element is used to interrupt the injection jet to several nozzles. In this case the breaker operations can be slightly phase shifted in relation to one another in order to minimize pressure surges in the pressure chamber. An example of such a design is to let the pressure chamber consist of an external pipe arranged horizontally across the tractor's direction of movement, with a row of nozzles arranged in the bottom of the pipe. The breaker element may consist of an internally rotating pipe or shaft with suitable cut-outs or openings for the production of the periodic injection. Fig. 9 illustrates a design of the injection device where the breaker element is in the form of a movable belt 40 with openings 41. By means of two drums 42 which rotate as shown by the arrow R, the belt's 40 openings 41 are brought into periodic correspondence with nozzles 43, thus producing a periodic injection. Fig. 10 illustrates a design of an injection device where the breaker element is in the form of a slide valve 50 which can be moved forwards and backwards in a pressure chamber 52 as indicated by the arrow P 3 , e.g. by means of a camshaft (not shown). The slide valve 50 is provided with openings 51 which, when the slide is moved, can be brought into correspondence with nozzles 53, thus producing a periodic injection. Fig. 1 1 illustrates an injection device where breaker elements in the form of shut-off elements 60 with closing sections 62 can be moved up and down in a direction P 4 , thereby closing nozzles 63. A camshaft 61 which rotates as indicated by the arrow R provides a periodic upward and downward movement, with the result that the shut-off elements 60 periodically close the nozzles 63, producing a periodic injection. The return movement of the shut- off elements 60 can be generated by springs (not shown) or the pressure of the slurry against the closing sections 62. Thus by means of the described devices it is possible to implement the method according to the invention. By means of the method a number of advantages are obtained compared with prior art. The slurry is deposited in closed pockets down in the soil, thus virtually eliminating run-off, evaporation and troublesome odour. Compared with surface spreading, by this means a much better mixing of slurry in the soil is achieved, and tests have shown that compared with surface spreading the utilization factor of the slurry is increased by from 10-20% to 80-90%. This substantially reduces the need for other forms of fertilization, for example in the form of artificial fertilizer, thereby providing considerable financial savings, while at the same time contributing to the reduction of pollution from agriculture. Compared to the devices mentioned at the beginning for the depositing of slurry, several advantages are realized. The discontinuous groove ensures that the slurry remains in the earth in sloping terrain and prevents run-off. A second advantage is that the devices according to the invention in contrast to the devices mentioned at the beginning will also work efficiently on stony ground, since the injection jet will be deflected by the stones and penetrate down into the soil between them. A further advantage is that the device according to the invention requires far less tractive power, with the result that it can be employed together with a smaller tractor than the devices mentioned at the beginning. Furthermore, as a result of the fact that the device according to the invention has no parts which go down into the earth, it is subject to far less wear than the depositing devices mentioned at the beginning. The device according to the invention can also be used for injection of liquid mineral fertilizer, such as ammonia. Moreover, the device according to the invention can be employed on a soil with plants. Tests have shown that the device can be used on a soil with up to 20 cm high plant growth without the plants suffering any noticeable damage. The invention has been explained above with reference to several embodiments. It is clear, however, that several variations, where, e.g., the injection is achieved by means of pulsating magnetic valves, will be able to be designed by a person skilled in the art without deviating from the scope of the invention as it is defined in the claims.

Claims: PATENT CLAIMS 1. A method for periodic depositing of liquid manure such as slurry in a soil (80), preferably performed by a device (1 ) which is pulled behind a vehicle (2), and to which pressurized slurry is supplied from a pump or container, characterized in that the slurry is injected in a concentrated jet (9) under pressure, with the result that the slurry forms and fills a groove (6) in the soil, which groove (6) is preferably closed after the injection. 2. A method according to claim 1 , characterized in that the slurry is injected from a nozzle (5) which is located above the soil (80). 3. A method according to one of the preceding claims, characterized in that the slurry is injected under a protective shoe (7), thus preventing evaporation of volatile components and splashing of slurry. 4. A method according to one of the preceding claims, characterized in that the closing is performed by the protective shoe (7), or by a cutting edge or a ridge. 5. A method according to one of the preceding claims, characterized in that the vehicle's (2) speed and the periodic injection are synchronized so that the slurry is injected into the soil (80) over a length (li) of 15-20 cm, and the injection is interrupted over a length (1 2 ) of approximately 5 cm. 6. A method according to one of the preceding claims, characterized in that the periodic injection is produced by the regular interruption of the jet (9) by a rotating breaker element (10). 7. A method according to one of the preceding claims, characterized in that the periodic injection is produced by the regular interruption of the jet (9) by a pulsating valve. 8. A device (1) for periodic depositing of liquid manure such as slurry in a soil (80), for depositing slurry under pressure, wherein the device is supplied with pressurized slurry from a pump or container, characterized in that it comprises at least one nozzle (5) with a breaker element (10) for periodic interruption of or opening for a concentrated injection jet (9) in an outlet direction (P 2 ), the nozzle being preferably provided as an opening from a chamber (3, 29, 35, 38, 52, 72) pressurized with slurry. 9. A device according to claim 8, characterized in that the breaker element (10) is rotatably mounted about a rotation axis (22) which is parallel with the nozzle's outlet direction (P 2 ) and is located beside the nozzle (5), with the result that during a rotational movement the breaker element periodically interrupts the injection jet (9). 10. A device according to claim 8 or 9, characterized in that the breaker element (10) is arranged inside the pressure chamber (3). 1 1. A device according to one of the claims 8-10, characterized in that the nozzle (5) and the breaker element (10) are provided as integral parts of a protective shoe (7) which is arranged under the pressure chamber (3). 12. A device according to one of the claims 9-11, characterized in that the breaker element is in the form of a rectangular plate (21) or a cross (24). 13. A device according to one of the claims 9-11, characterized in that the breaker element is in the form of a disc (26) with openings (27) arranged to periodically correspond with the nozzle's (5) opening during rotation. 14. A device according to claim 8, characterized in that the breaker element (10) is rotatably mounted about a rotation axis which is perpendicular to the nozzle's outlet direction (P 2 ), and that the breaker element is preferably in the form of a wheel (28, 70), a shaft (32) or a pipe (37) with openings (33, 71) arranged radially, diametrically or along the circumference, which openings can be brought into correspondence with the nozzle (5, 31 , 36, 39, 74) during rotation. 15. A device according to claim 14, characterized in that the breaker elements for several nozzles in the form of one or more wheels (28, 70), shafts (32) or pipes (37) provided with openings are integrated and arranged for continuous rotation about a common axis, thus producing a breaker element which is common to several nozzles. 16. A device according to claim 15, characterized in that the breaker element for several nozzles in the form of a rotating pipe (37) provided with openings is arranged inside said pressure chamber (38) for slurry, and connected to the pump or container, thus enabling the slurry to be supplied through the rotating pipe (37) and injected every time an opening in the rotating pipe corresponds with a nozzle (39) arranged in the pressure chamber (38). 17. A device according to claim 8, characterized in that the breaker element is in the form of a movable belt (40) with openings (41) which, when the belt (40) is moved in a direction perpendicular to the nozzle's (43) outlet direction (P 2 ), can be brought into correspondence with the nozzle (43), and that the belt is preferably arranged to be conveyed past several nozzles, thus enabling the belt to form a breaker element for several nozzles. 18. A device according to claim 8, characterized in that the breaker element is in the form of a reciprocating slide valve (50) movable in a direction perpendicular to the nozzle's (53) outlet direction (P 2 ), with openings (51) which during the reciprocating movement can periodically be brought into correspondence with the nozzle (53), and that the pressure chamber (52) preferably has several nozzles and the slide valve preferably several corresponding openings, with the result that the slide valve forms a breaker element which is common to several nozzles. 19. A device according to claim 8, characterized in that the breaker element is in the form of a reciprocating shut-off element (60) movable in the nozzle's (63) outlet direction (P 2 ), arranged for influence by a camshaft (61), and that several shut-off elements (60) for several nozzles (63) are preferably arranged for influence by the same camshaft.

Inventors: HATLOE JAN KAARE, HATLOE, JAN, KAARE
Applicants: HATLOE JAN KAARE, HATLOE, JAN, KAARE
Application year: 1997
Main classification: A01C23
IPC codes: A01C23