METHOD FOR CONTROLLING AN AGRICULTURAL SCREAMING MACHINE AND CORRESPONDING SYSTEM

Description

[0001] The invention relates to a method for controlling an agricultural spreading machine according to the preamble of claim 1 and a spreading system for distributing spreading material according to the preamble of claim 11.

[0002] For spreading grit on large agricultural areas, trailed spreaders are regularly used, which can carry a comparatively large quantity of grit thanks to a large-capacity hopper. Such spreaders often have a conveyor belt to transport the grit towards the spreading discs, where it is then discharged onto the discs.

[0003] To regulate the amount of spreading material applied to the spreading discs, slide gate systems are used in practice. These systems allow the free cross-section above the conveyor belt to be adjusted. Such slide gate systems have a main gate for presetting the amount of material. Downstream of the main gate and in the immediate vicinity of the conveyor belt's discharge point, two hydraulically actuated closing gates can be arranged. These gates allow the application of spreading material to the spreading discs to be stopped individually.

[0004] The known solutions for adjusting the quantity of material dispensed on spreaders that use a conveyor belt to transport the spreading material have two main disadvantages. When spreading wedge-shaped surfaces, one of the two closing gates is initially closed, causing the spreading material to accumulate in front of the closed gate due to the continuing movement of the conveyor belt. When the closing gate is subsequently opened, for example, in the next pass, the accumulation of material in front of the closing gate and the fluidity of the spreading material result in an excessive amount being dispensed onto the spreading disc, leading to localized mis-application. Particularly when spreading material over relatively long, wedge-shaped sections, the material can even overflow the closing gate or its upper edge, causing uncontrolled spreading onto the spreading discs and / or the surface being spread.Preventing such an overflow is extremely complex due to design-related requirements, as an upstream quantity adjustment is then no longer feasible.

[0005] A metering system operating without a main gate is known from publication EP 1 869 962 B1. However, in the spreading method described therein, when the spreading process is temporarily interrupted by stopping the conveyor belt, spreading material remains in close proximity to the discharge plane on at least a portion of the conveyor belt's width. When the belt conveyor resumes, spreading material is inevitably applied directly to the spreading disc on this side, regardless of whether this is intended or not. For this reason, unintentional spreading of material on the inside of a curve at the end of a turning maneuver in the headland cannot be avoided, resulting in over-fertilization in the inside of the curve during every turning maneuver between two parallel passes.Furthermore, because the spreading material lies in the immediate vicinity of the discharge plane when the spreading process is temporarily interrupted, there is a risk that, in the event of a bumpy ride, for example due to an uneven surface, spreading material will fall uncontrollably onto the spreading disc and / or the usable area.

[0006] From EP 2 792 228 A1, a spreading device is known which comprises a spreading unit with a distributor disc, wherein the spreading device includes a structure that ensures self-centering of the spreading unit. Spreading material can be fed from a storage container to the spreading unit by means of a conveying device. Furthermore, a control and / or regulating device is disclosed which controls and / or regulates the mass flow of spreading material conveyed by the conveying device as a function of at least one spreading parameter from the group consisting of spreading quantity per area, working width, and driving speed.

[0007] US Patent 2017 / 274397 A1 discloses a spreading device with a material distributor that is adjustable from side to side to adjust the distribution of the material flow as it passes over and is divided within the distributor. The distributor supports and moves longitudinally with a spreading unit. The geometry of the spreading patterns can be adjusted by laterally moving the position of the material distributor.

[0008] To address the problems described above, spreading machines are also used in practice which, instead of spreading discs, have a distribution linkage with multiple distribution elements, with pneumatic conveyance of the spreading material in these machines. Such a spreading machine is known, for example, from publication EP 3 662 734 A1.

[0009] The object underlying the invention is therefore to at least partially overcome the aforementioned disadvantages of spreading material with an agricultural spreading machine in which a conveyor belt is used for conveying the material.

[0010] The problem is solved by a method of the type mentioned at the outset, wherein a control device within the framework of the method according to the invention for temporarily interrupting the spreading of spreading material at a shutdown point on the agricultural land causes the conveying rate adjustment device to prevent the conveying of spreading material into the idle section early on before reaching the shutdown point, so that the idle section of the conveyor belt is empty when the shutdown point is reached, wherein the control device prevents the conveying of spreading material into the idle section at a calculated closing time, wherein the control device takes into account a current position and / or a position of the shutdown point for calculating the closing time, and wherein a satellite navigation system is used for position determination.

[0011] After a temporary interruption of the spreading process, no material remains in the immediate vicinity of the discharge plane, as the run-off area has already cleared. This eliminates the risk of material unintentionally falling onto the spreading disc during bumpy driving. Furthermore, when spreading resumes, no material remains in the immediate vicinity of the discharge plane. Therefore, when spreading resumes after or during a turning maneuver, material is never on the wrong side of the run-off area, preventing unintentional local over- or under-application. If the material being spread is fertilizer, over- or under-fertilization during turning maneuvers, such as on headlands, is effectively avoided. This also significantly reduces the risk of spreading in hazardous areas, such as field boundaries or bodies of water.

[0012] The control unit can be integrated into the spreader. Alternatively, the control unit can be an external device. For example, the control unit can be a terminal, particularly an ISOBUS terminal, which is connected to the spreader via a signal path. The temporary interruption of the spreading material occurs, for example, when transitioning to a headland or at the end of a wedge spreading operation. The spreading material is conveyed from a hopper towards the spreading discs by means of a conveyor belt. The conveyor belt is preferably circumferential and preferably has a belt drive. The spreading discs are preferably arranged side by side. The operation of the conveyor belt and the feed rate adjustment device is preferably controlled by the control unit.

[0013] In a preferred embodiment of the method according to the invention, the control device for continuing the spreading of spreading material at a switching point on the agricultural area causes the conveying rate control device to trigger the conveying of spreading material into the idle section well before reaching the switching point, so that the conveyor belt is loaded with spreading material at least over a portion of its entire idle section when the switching point is reached. Thus, when the switching point is reached, spreading material is present at least over a portion of the idle section up to the discharge level, so that the spreading material can be applied to the spreading discs immediately without delay as the switching point is passed.

[0014] In a further preferred embodiment of the method according to the invention, the spreading material leaving the idle section and located on a first section of the idle section is thrown from the conveyor belt in the discharge plane towards a first spreading disc of the spreading machine. Alternatively or additionally, the spreading material leaving the idle section and located on a second section of the idle section is thrown from the conveyor belt in the discharge plane towards a second spreading disc of the spreading machine. The first section of the idle section is thus assigned to a first spreading disc, and the second section of the idle section is assigned to a second spreading disc. Therefore, the spreading material feed to the first spreading disc can be adjusted by the load on the first section of the idle section, and the spreading material feed to the second spreading disc can be adjusted by the load on the second section of the idle section.

[0015] In a further development of the inventive method, the feed rate control device, in the feed rate control plane, uses a first feed rate limiter to adjust the feed rate of spreading material entering a first idle section. Alternatively or additionally, in the feed rate control plane, the feed rate control device uses a second feed rate limiter to adjust the feed rate of spreading material entering a second idle section. The idle section widths are sub-widths of the idle section; for example, the first idle section width is the left side and the second idle section width is the right side of the idle section. The feed rate limiters preferably each comprise a feed slide that can be lowered onto and lifted from the conveyor belt. The feed rate control device can therefore be a double slide device.The metering slides are preferably each connected to a slide drive, which allows the respective metering slide to be raised and lowered. The slide drives can preferably be controlled independently of each other. The slide drives can be electric. Alternatively, the slide drives can also be pneumatic or hydraulic. The free conveying cross-section above the conveyor belt can preferably be adjusted by means of the slide drives in the inlet area of ​​the first idle section and in the inlet area of ​​the second idle section.

[0016] Furthermore, a method is advantageous in which the control device, at a spreading boundary of the agricultural area running perpendicular to the direction of travel of the spreading machine, causes the first flow rate limiter and the second flow rate limiter of the flow rate setting device to simultaneously close at a common time before reaching the shutdown point, preventing the conveying of spreading material into the first idle section and the second idle section, so that the first idle section and the second idle section run empty synchronously before reaching the shutdown point.A spreading boundary running perpendicular to the direction of travel of the spreader results particularly in the transition areas to the headland, where the headland tramline runs perpendicular to the tramlines inside the field. Because the first and second sections of the idling track run dry synchronously before reaching the shut-off point, the spreading of the material is interrupted synchronously on both sides.

[0017] In a further preferred embodiment of the method according to the invention, the control device, at a spreading boundary of the agricultural area running obliquely to the direction of travel of the spreading machine, causes the first flow rate limiter of the flow rate adjustment device to close at a first closing time and the second flow rate limiter of the flow rate adjustment device at a second closing time, staggered from each other, to prevent the conveying of spreading material into the first idle section width and the second idle section width well before reaching the shutdown point, so that the first idle section width and the second idle section width run empty asynchronously before reaching the shutdown point.The asynchronous emptying of the first and second sections of the spreading track initially interrupts the spreading of the material on one side before it stops completely. For example, a spreading boundary that runs diagonally to the direction of travel of the spreader results in a wedge spreading situation or a slanted headland.

[0018] In a further development of the method according to the invention, the control device calculates the common closing time when the spreading boundary of the agricultural area runs perpendicular to the direction of travel of the spreader, depending on the intended driving speed until the shut-off point is reached. Alternatively or additionally, the control device calculates the first closing time and / or the second closing time when the spreading boundary of the agricultural area runs obliquely to the direction of travel of the spreader, depending on the intended driving speed until the shut-off point is reached. When calculating the closing time, the control device according to the invention also takes into account the current position and / or the position of the shut-off point, in particular the distance to the shut-off point.Furthermore, the control unit can also take into account the time it takes to reach the shutdown point when calculating the closing time. This time is determined by the distance to the shutdown point and the driving speed up to that point. A satellite navigation system, such as GPS or DGPS, is used to determine the position.

[0019] The control unit can calculate the common closing time or the first closing time and / or the second closing time alternatively or additionally taking into account the actual or current driving speed or taking into account a selected driving speed.

[0020] In a further preferred embodiment of the method according to the invention, the first and second flow rate limiters of the flow rate adjustment device each perform a closing process to completely prevent the conveyance of spreading material into the first and second sections of the idle track, respectively. This closing process extends over a specific closing duration. The flow rate of spreading material entering the first section of the idle track decreases during the closing duration of the first flow rate limiter. Alternatively or additionally, the flow rate of spreading material entering the second section of the idle track decreases during the closing duration of the second flow rate limiter.During the closing phase, the free conveying cross-section in the inlet area of ​​the idle section is increasingly blocked by the respective flow limiter, creating a loading ramp on the idle section during the closing process. During the closing process, the loading ramp slopes down in the opposite direction of conveying. The opening phases of the first and second flow limiters also extend over a period of time, during which a loading ramp also forms on the idle section. However, during the opening phase, the loading ramp slopes down in the direction of conveying.

[0021] In another preferred embodiment of the method according to the invention, the control device adjusts the conveyor belt speed during the closing process of the first and / or second flow limiter to the decreasing flow rate of spreading material on the first idle section and / or the second idle section. Preferably, the belt speed increases with the decreasing flow rate of spreading material on the first idle section and / or the second idle section. When adjusting the conveyor belt speed, the control device preferably also takes into account the spreading pattern to be produced, the travel speed, and / or the closing speed of the first and / or second flow limiter.

[0022] Furthermore, a method according to the invention is advantageous in which the conveying rate control device adjusts the conveying rate of spreading material entering the idle section by partially or completely blocking the free conveying cross-section above the conveyor belt. The adjustment of the free conveying cross-section above the conveyor belt is preferably achieved by lowering and raising the flow rate limiters.The problem underlying the invention is further solved by a spreading system of the type mentioned at the outset, wherein the spreading system according to the invention has a control device which is configured to cause the conveying rate control device to prevent the conveying of spreading material into the idle section at an early stage before reaching the point of shutdown, in order to temporarily interrupt the spreading of spreading material at a shutdown point on the agricultural area, so that the idle section of the conveyor belt is empty when the point of shutdown is reached, wherein the control device is further configured to prevent the conveying of spreading material into the idle section at a calculated closing time and to take into account a current position and / or a position of the shutdown point for calculating the closing time, wherein a satellite navigation system is used for position determination.

[0023] In a preferred embodiment, the spreading system according to the invention is configured to carry out the method for controlling an agricultural spreading machine during the application of spreading material to an agricultural area according to one of the embodiments described above. With regard to the advantages and modifications of the spreading system according to the invention, reference is therefore made to the advantages and modifications of the method according to the invention.

[0024] Preferred embodiments of the invention are explained and described in more detail below with reference to the accompanying drawings. These show: Fig. 1 an embodiment of the spreading system according to the invention in a perspective view; Fig. 2 a further embodiment of the spreading system according to the invention in a top view; Fig. 3 an agricultural spreading machine during the spreading of spreading material, wherein the agricultural spreading machine is controlled by the method according to the invention; Fig. 4 an agricultural spreading machine during the spreading of spreading material, wherein the agricultural spreading machine is controlled by the method according to the invention; Fig. 5 a spreading material load state of a partial width of the idle section including a flow rate limiter during the spreading of spreading material; Fig. 6 a further spreading material load state of a partial width of the idle section including a flow rate limiter during the spreading of spreading material; Fig. 7 a further spreading material load state of a partial width of the idle section including a flow rate limiter during the spreading of spreading material; Fig.Fig. 8 shows a further spreading material loading state of a partial width of the idle section including a flow rate limiter during the spreading of spreading material; and Fig. 9 shows a further spreading material loading state of a partial width of the idle section including a flow rate limiter during the spreading of spreading material.

[0025] The Fig. 1 Figure 10 shows a spreading system for applying spreading material S to an agricultural area. The spreading system can, for example, be part of an agricultural spreading machine, such as a twin-disc fertilizer spreader.

[0026] The spreading system 10 comprises a conveyor belt 12, by means of which spreading material can be transported from a storage container to a first spreading disc 16a and a second spreading disc 16b. The conveyor belt 12 conveys the spreading material S to be applied along an idle section 20, which relates to a longitudinal section LA of the conveyor belt 12 and lies between a quantity adjustment level ME and a discharge level AE. The quantity of spreading material S leaving the idle section 20 is discharged in the discharge level AE in the direction of the spreading discs 16a, 16b. Guide elements 14a, 14b, designed as funnels, are arranged between the conveyor belt 12 and the spreading discs 16a, 16b and gather the spreading material S leaving the conveyor belt 12 before it impacts the spreading discs 16a, 16b.

[0027] The spreading system 10 also has a delivery rate adjustment device 18, via which the delivery rate of spreading material S entering the idle section 20 can be adjusted in the quantity adjustment level ME.

[0028] The idle track 20 is divided into a first idle track section 22a and a second idle track section 22b. The spreading material S leaving the idle track 20 and located on the first idle track section 22a is discharged from the conveyor belt 12 in the discharge plane AE towards the first spreading disc 16a. The spreading material S leaving the idle track 20 and located on the second idle track section 22b is discharged from the conveyor belt 12 in the discharge plane AE towards the second spreading disc 16b.

[0029] The feed rate control device 18 has a first feed rate limiter 24a located in the feed rate control level ME. The feed rate S of spreading material entering the first idle section 22a can be set by means of the first feed rate limiter 24a. The feed rate control device 18 also has a second feed rate limiter 24b in the feed rate control level ME, by means of which the feed rate S of spreading material entering the second idle section 22b can be set.

[0030] The flow limiters 24a, 24b each comprise a flow slide 26a, 26b, which can be lowered onto and raised by the conveyor belt 12. The flow slides 26a, 26b are each connected to a slide drive 28a, 28b, by means of which the respective flow slide 26a, 26b can be raised and lowered. The slide drives 28a, 28b are electric drives.

[0031] The slide drives 28a, 28b and the belt drive of the conveyor belt 12 are connected to a control unit 30 of the spreading system 10 via signal transmission. The control unit 30 can be an internal or external control unit. For example, the control unit 30 is a terminal, in particular an ISOBUS terminal.

[0032] The control device 30 is designed to temporarily interrupt the spreading of grit at a shutdown point AO, AO2 (see Fig. 3 and 4) on the agricultural land, the conveying rate control device 18 is to cause the conveying rate control device 18 to prevent the conveying of spreading material S into the idle section 20 well before reaching the shutdown point AO, AO2, so that the idle section 20 of the conveyor belt 12 is empty when the shutdown point AO, AO2 is reached. Furthermore, the control device 30 is configured to resume spreading the spreading material at a switch-on point EO, EO1 (see Fig. 3 and 4 ) on the agricultural area to cause the conveying quantity control device to trigger the conveying of spreading material S into the idle section 20 early before reaching the switching point EO, EO1, so that the conveyor belt 12 is loaded with spreading material S at least on a partial width along the entire idle section 20 when reaching the switching point EO, EO1.

[0033] The Fig. 2This shows that the idle section widths 22a and 22b are adjacent sections of the idle section 20, which extend along a longitudinal section LA of the conveyor belt 12. The longitudinal section LA is located between the quantity setting level ME and the discharge level AE.

[0034] The Fig. 3 This shows a headland situation where the spreading line runs perpendicular to the direction of travel of the spreader. Fig. 3 shows the different loading states of the idle track sections 22a, 22b and the opening states of the flow rate limiters 24a, 24b during the execution of a turning operation in the headland.

[0035] Upon entering the headland lane, the idle track sections 22a and 22b are initially loaded continuously and evenly with spreading material S, and the flow rate limiters 24a and 24b are in an open state. Fig. 5shows in detail the loading status of the idle section width 22b and the opening status of the flow rate limiter 24b.

[0036] As the vehicle approaches the headland tramline, the control unit 30 initiates the closing of the flow rate limiters 24a and 24b well in advance of reaching a shutdown point AO on the agricultural land. The closing process is initiated by the control unit 30 at a specific closing time. Fig. 6 Figure 1 shows the loading status of the idle section 22b and the closed flow limiter 24b in detail. The illustration shows that the conveyed quantity of spreading material S on the idle section 22b has a loading ramp BR, which results from the movement of the conveyor belt 12 and the simultaneous closing movement of the flow gate 26b of the flow limiter 24b.

[0037] As the vehicle approaches the headland tramline further, both flow rate limiters 24a and 24b are already closed, thus preventing the conveying of spreading material S into the idle track sections 22a and 22b. The idle track sections 22a and 22b therefore run dry synchronously before reaching the shut-off point AO. The idle situation is in the Fig. 7 shown in detail.

[0038] Upon reaching the shutdown point AO before the headland tramline, both idle track sections 22a and 22b are completely empty, so the turning maneuver is carried out with an unloaded idle track 20. Fig. 8 shows the idled idle track section width 22b in detail.

[0039] After the turning process has been carried out, the idle track sections 22a, 22b are refilled with spreading material S by opening the feed rate limiters 24a, 24b early, before reaching the switch-on point EO. Fig. 9The figure shows the filling process of the idle track section 22b in detail. Due to the opening process of the flow rate limiter 24b, a loading ramp BR is again created on the idle track section 22b.

[0040] The control unit 30 calculates the closing time for the flow rate limiters 24a, 24b when approaching the headland and the opening time for the flow rate limiters 24a, 24b when exiting the headland, depending on an intended driving speed until reaching the switch-off point AO or the switch-on point EO.

[0041] The Fig. 4Figure 1 shows a spreading scenario with a spreading boundary of the agricultural area running diagonally to the direction of travel. In this scenario, the idle track sections 22a and 22b empty asynchronously. Initially, both idle track sections 22a and 22b are fully and evenly loaded with spreading material S, and the flow restrictors 24a and 24b are open. As the headland tramline is approached, the flow restrictor 24b on the outside of the curve closes first, so that the idle track section 22b empties as the approach to the headland tramline continues. Then, with a time delay, the flow restrictor 24a on the inside of the curve closes, so that the idle track section 22a empties as the approach to the headland tramline continues.The control device 30 causes the flow limiter 24b to close early before reaching the shutdown point AO1 and the flow limiter 24b to close early before reaching the shutdown point AO2. During the turning process, both idle track sections 22a and 22b are then completely empty.

[0042] When exiting the headland, the outer flow restrictor 24b is opened first, so that the outer idle section 22b is supplied with spreading material S. At a later time, the inner flow restrictor 24a is then opened, so that the inner idle section 22a is supplied with spreading material S. The opening of the flow restrictor 24b is thus initiated well before reaching the activation point EO1. The opening of the flow restrictor 24a is initiated well before reaching the activation point EO2.

[0043] Because in the in the Fig. 3 and 4 Since, in the depicted application situations, no spreading material S is present on the idle track 20 during the turning maneuver, there is no risk of spreading material S unintentionally falling onto the spreading discs 16a, 16b during bumpy driving. Furthermore, it is prevented that, if spreading is intended to continue after or during a turning maneuver, spreading material S is on the wrong side of the idle track 20, thus preventing unintentional local excessive application of spreading material, for example fertilizer, on the inside of the curve when performing turning maneuvers. Reference symbol list

[0044] 10 Spreading system 12 Conveyor belt 14a, 14b Guide body 16a, 16b Spreading discs 18 Flow rate adjustment device 20 Idle section 22a, 22b Idle section widths 24a, 24b Flow rate limiter 26a, 26b Metering gate 28a, 28b Gate drives 30 Control device ADrop-off level AO, AO1, AO2 Shut-off locations BR Loading ramp EO, EO1, EO2 Switch-on locations L Longitudinal section ME Quantity setting level SS Scatter material

Claims

1. Method for controlling an agricultural spreading machine during the dispensing of spreading material (S) onto an agriculturally useful area, comprising the step of: - a conveyor belt (12) of the spreading machine conveying, along an empty-running stretch (20), the spreading material (S) to be dispensed, the empty-running stretch (20) relating to a longitudinal portion (LA) of the conveyor belt (12) and being located between a quantity adjustment plane (ME), in which the conveying quantity of spreading material (S) entering the empty-running stretch (20) is adjusted by means of a conveying quantity adjusting device (18) of the spreading machine, and a discharge plane (AE), in which the conveying quantity of spreading material (S) leaving the empty-running stretch (20) is discharged from the conveyor belt (12) toward a first and a second spreading disk (16a, 16b), characterized in that, in order to temporarily interrupt the dispensing of spreading material at a switch-off location (AO, AO2) in the agriculturally useful area, a control device (30) causes the conveying quantity adjusting device (18) to prevent, at an early time before the switch-off location (AO, AO2) has been reached, the conveying of spreading material (S) into the empty-running stretch (20), with the result that the empty-running stretch (20) of the conveyor belt (12) has run until it has emptied itself by the time the switch-off location (AO, AO2) has been reached, the control device (30) preventing the conveying of spreading material (S) into the empty-running stretch (20) at a calculated closure time, the control device (30) taking into account a current position and / or a position of the switch-off location in order to calculate the closure time, and a satellite navigation system being used to determine the position.

2. Method according to claim 1, characterized in that, in order to resume the dispensing of spreading material at a switch-on location (EO, EO1) in the agriculturally useful area, the control device (30) causes the conveying quantity adjusting device (18) to trigger, at an early time before the switch-on location (EO, EO1) has been reached, the conveying of spreading material (S) into the empty-running stretch (20), with the result that the conveyor belt (12) has been loaded with spreading material (S) at least over a partial width along the entire empty-running stretch (20) by the time the switch-on location (EO, EO1) has been reached.

3. Method according to claim 1 or 2, characterized in that - the spreading material (S) leaving the empty-running stretch (20) and located on a first empty-running stretch partial width (22a) is discharged, in the discharge plane (AE), from the conveyor belt (12) toward a first spreading disk (16a) of the spreading machine; and / or - the spreading material (S) leaving the empty-running stretch (20) and located on a second empty-running stretch partial width (22b) is discharged, in the discharge plane (AE), from the conveyor belt (12) toward a second spreading disk (16b) of the spreading machine.

4. Method according to claim 3, characterized in that - in the quantity adjustment plane (ME), the conveying quantity adjusting device (18) adjusts the conveying quantity of spreading material (S) entering the first empty-running stretch partial width (22a) by means of a first conveying quantity limiter (24a); and / or - in the quantity adjustment plane (ME), the conveying quantity adjusting device (18) adjusts the conveying quantity of spreading material (S) entering the second empty-running stretch partial width (22b) by means of a second conveying quantity limiter (24b).

5. Method according to claim 4, characterized in that, at a spreading boundary of the agriculturally useful area running perpendicularly to the direction of travel of the spreading machine, the control device (30), on temporarily interrupting the dispensing of spreading material at a switch-off location (AO) in the agriculturally useful area, causes the first conveying quantity limiter (24a) and the second conveying quantity limiter (24b) of the conveying quantity adjusting device (18) simultaneously at a common closure time to prevent, at an early time before the switch-off location (AO) has been reached, the conveying of spreading material (S) into the first empty-running stretch partial width (22a) and the second empty-running stretch partial width (22b), with the result that the first empty-running stretch partial width (22a) and the second empty-running stretch partial width (22b) run synchronously until they have emptied themselves before the switch-off location (AO) has been reached.

6. Method according to claim 4 or 5, characterized in that, at a spreading boundary of the agriculturally useful area running obliquely to the direction of travel of the spreading machine, the control device (30), on temporarily interrupting the dispensing of spreading material at a switch-off location (AO2) in the agriculturally useful area, causes the first conveying quantity limiter (24a) of the conveying quantity adjusting device (18) and the second conveying quantity limiter (24b) of the conveying quantity adjusting device (18), respectively at a first closure time and at a second closure time that are temporally offset from one another, to prevent, at an early time before the switch-off location (AO2) has been reached, the conveying of spreading material (S) into the first empty-running stretch partial width (22a) and the second empty-running stretch partial width (22b), with the result that the first empty-running stretch partial width (22a) and the second empty-running stretch partial width (22b) run asynchronously until they have emptied themselves before the switch-off location (AO2) has been reached.

7. Method according to claim 5 or 6, characterized in that the control device (30) calculates the common closure time, the first closure time and / or the second closure time on the basis of an intended travel speed until the switch-off location (AO, AO2) has been reached.

8. Method according to any of claims 4 to 7, characterized in that the first conveying quantity limiter (24a) and the second conveying quantity limiter (24b) of the conveying quantity adjusting device (18) each perform a closure process to completely prevent the conveying of spreading material (S) into the first empty-running stretch partial width (22a) and the second empty-running stretch partial width (22b), which process lasts for a closure duration, - the conveying quantity of spreading material (S) entering the first empty-running stretch partial width (22a) decreasing during the closure duration of the first conveying quantity limiter (24a) due to the closure process of the first conveying quantity limiter (24a); and / or - the conveying quantity of spreading material (S) entering the second empty-running stretch partial width (22b) decreasing during the closure duration of the second conveying quantity limiter (24b) due to the closure process of the second conveying quantity limiter (24b).

9. Method according to claim 8, characterized in that the control device (30) matches the belt speed of the conveyor belt (12) during the closure process of the first and / or the second conveying quantity limiter (24a, 24b) to the decreasing conveying quantity of spreading material (S) on the first empty-running stretch partial width (22a) and / or the second empty-running stretch partial width (22b).

10. Method according to any of the preceding claims, characterized in that the conveying quantity adjusting device (18) adjusts the conveying quantity of spreading material (S) entering the empty-running stretch (20) by partially or completely blocking the free conveying cross section above the conveyor belt (12).

11. Spreading system (10) for dispensing spreading material (S) onto an agriculturally useful area, comprising - a first and a second spreading disk (16a, 16b); - a conveyor belt (12) for conveying, along an empty-running stretch (20), the spreading material (S) to be dispensed, which empty-running stretch relates to a longitudinal portion (LA) of the conveyor belt (12) and is located between a quantity adjustment plane (ME) and a discharge plane (AE), the conveyor belt (12) being configured to discharge, in the discharge plane (AE), the conveying quantity of spreading material (S) leaving the empty-running stretch (20) toward the first and the second spreading disk (16a, 16b); and - a conveying quantity adjusting device (18) which is configured to adjust, in the quantity adjustment plane (ME), the conveying quantity of spreading material (S) entering the empty-running stretch (20), characterized by a control device (30) which, in order to temporarily interrupt the dispensing of spreading material at a switch-off location (AO, AO2) in the agriculturally useful area, is configured to cause the conveying quantity adjusting device (18) to prevent, at an early time before the switch-off location (AO, AO2) has been reached, the conveying of spreading material (S) into the empty-running stretch (20), with the result that the empty-running stretch (20) of the conveyor belt (12) has run until it has emptied itself by the time the switch-off location (AO, AO2) has been reached, the control device (30) further being configured to prevent the conveying of spreading material (S) into the empty-running stretch (20) at a calculated closure time and to take into account a current position and / or a position of the switch-off location in order to calculate the closure time, a satellite navigation system being used to determine the position.

12. Spreading system (10) according to claim 11, characterized in that the spreading system (10) is configured to perform the method for controlling an agricultural spreading machine during the dispensing of spreading material (S) onto an agriculturally useful area according to any of claims 1 to 10.