METHOD AND VEHICLE FOR APPLYING AN AGROCHEMICAL MIXTURE TO A WORKING AREA OF A FIELD

Abstract

A method for applying an agrochemical mixture to a working area of a field using a vehicle moving on the field is described. Thereby, a solid fertilizer is spread on the working area using a fertilizer spreading device mounted on the vehicle and a liquid fertilizer additive is sprayed on the working area using a field sprayer, mounted on the vehicle separately from the fertilizer spreading device. Therein, the liquid fertilizer additive is prevented from coming into contact with surfaces of the fertilizer spreading device, which also come into contact with the solid fertilizer. Moreover, a vehicle for applying an agrochemical mixture to a working area of a field while moving on the field is also described.

Claims

1. Method for applying an agrochemical mixture to a working area of a field using a vehicle moving on the field, the method comprising: spreading a solid fertilizer on the working area using a solid fertilizer spreading device mounted on the vehicle; and spraying a liquid fertilizer additive on the working area using a field sprayer mounted on the vehicle separately from the solid fertilizer spreading device, wherein the liquid fertilizer additive is prevented from coming into contact with surfaces of the solid fertilizer spreading device, which also come into contact with the solid fertilizer.

2. Method according to claim 1, further comprising: measuring a speed of the vehicle; and controlling rates of spreading the solid fertilizer and spraying the liquid fertilizer additive on the working area as a function of the speed of the vehicle and a longitudinal distance between an ejection opening of the solid fertilizer spreading device and a nozzle of the field sprayer such that a predetermined quantity of the solid fertilizer and a predetermined quantity of the liquid fertilizer additive are applied to the working area.

3. Method according to claim 1, further comprising: determining a geographical position of the vehicle; and controlling rates of spreading the solid fertilizer and spraying the liquid fertilizer additive on the working area as a function of the geographical position of the vehicle on the field.

4. Method according to claim 1, wherein the solid fertilizer is a solid nitrogen-containing fertilizer.

5. Method according to claim 1, wherein the liquid fertilizer additive comprises at least one of a nitrification inhibitor, a urease inhibitor, and a denitrification inhibitor.

6. Method according to claim 4, further comprising: detecting electromagnetic radiation emitted from plants on the working area of the field; analyzing the detected electromagnetic radiation to obtain a nitrogen status value for each segment of a plurality of segments of the field; calculating a ratio of liquid fertilizer additive to solid fertilizer for each segment of the field as a function of the obtained nitrogen status value for the respective segment; and applying the calculated ratio of liquid fertilizer additive to solid fertilizer to each segment of the field.

7. Vehicle for applying an agrochemical mixture to a working area of a field while moving on the field, the vehicle comprising: a solid fertilizer spreading device mounted on the vehicle for spreading a solid fertilizer on the working area; and a field sprayer mounted on the vehicle separately from the solid fertilizer spreading device, for spraying a liquid fertilizer additive on the working area, wherein the field sprayer is arranged relative to the solid fertilizer spreading device such that the liquid fertilizer additive is prevented from coming into contact with surfaces of the solid fertilizer spreading device, which also come into contact with the solid fertilizer.

8. Vehicle according to claim 7, wherein: the solid fertilizer spreading device comprises at least one ejection device having an ejection opening, and the field sprayer is arranged on the vehicle at in a distance from the ejection opening and in a direction relative to the ejection opening such that the liquid fertilizer additive, when sprayed, does not reach the ejection opening.

9. Vehicle according to claim 7, wherein the solid fertilizer spreading device is arranged at a rear of the vehicle in a direction of travel, and the field sprayer is arranged at a front of the vehicle in the direction of travel.

10. Vehicle according to claim 7, further comprising: a sensor to measure a speed of the vehicle; a control unit that controls rates of spreading the solid fertilizer and spraying the liquid fertilizer additive on the working area as a function of the speed of the vehicle and a longitudinal distance between an ejection opening of the solid fertilizer spreading device and a nozzle of the field sprayer such that a predetermined quantity of solid fertilizer and a predetermined quantity of liquid fertilizer additive are applied to the working area of the field.

11. Vehicle according to claim 7, further comprising: geographical locating means coupled to a control unit, wherein the control unit is adapted to control rates of spreading the solid fertilizer and spraying the liquid fertilizer additive on the working area as a function of a geographical position of the vehicle.

12. Vehicle according to claim 7, further comprising: an optical sensor for detecting electromagnetic radiation emitted from plants on the working area of the field; an analyzing unit for obtaining a nitrogen status value for each segment of a plurality of segments of the field based on the detected electro-magnetic radiation; a calculating unit for calculating a ratio of liquid fertilizer additive to solid fertilizer for each segment of the field as a function of the obtained nitrogen status value for the respective segment; and a control unit that controls application of the calculated ratio of liquid fertilizer additive to solid fertilizer to each segment of the field.

13. Method for applying an agrochemical mixture to a working area of a field using a vehicle moving on the field, the method comprising: spreading a fertilizer on the working area using a fertilizer spreading device mounted on the vehicle; spreading a fertilizer additive on the working area using a field spreader mounted on the vehicle separately from the fertilizer spreading device; determining a geographical position of the vehicle; and applying a predetermined quantity of fertilizer and a predetermined quantity of fertilizer additive to the field depending on the determined geographical position of the vehicle on the field.

14. Method according to claim 13, further comprising: measuring a speed of the vehicle; and controlling rates of spreading the fertilizer and spreading the fertilizer additive on the working area as a function of the speed of the vehicle and a longitudinal distance between the fertilizer spreading device and the field spreader such that a predetermined quantity of fertilizer and fertilizer additive, respectively, is applied to the working area of the field.

15. Vehicle for applying an agrochemical mixture to a working area of a field while moving on the field, the vehicle comprising: a fertilizer spreading device mounted on the vehicle for spreading a fertilizer on the working area; a field spreader mounted on the vehicle separately from the fertilizer spreading device for spreading a fertilizer additive on the working area; a control unit that controls rates of spreading the fertilizer and the fertilizer additive on the working area; and geographical locating means coupled to the control unit, wherein the control unit is adapted to control the rates of spreading the fertilizer and the fertilizer additive on the working area as a function of a geographical position of the vehicle.

Description

[0128] Embodiments of the present invention are now described with reference to the drawings.

[0129] FIG. 1 shows embodiments of a vehicle according to the present invention,

[0130] FIG. 2 shows schematically the configuration of a vehicle according to the invention,

[0131] FIG. 3 shows schematically another configuration of a vehicle according to the invention,

[0132] FIG. 4 shows an example of a field sprayer,

[0133] FIG. 5 shows an example of a centrifugal spreader,

[0134] FIG. 6 shows an example of the ejection device of a pneumatic spreader, and

[0135] FIG. 7 shows a graph with experimental data.

[0136] With reference to the FIGS. 1 and 2, a first embodiment of a vehicle 3 according to the invention is described.

[0137] A vehicle 3 is a tractor that may move on a field 1. However, the vehicle 3 may also comprise a tractor and/or a trailer. Furthermore, it comprises a velocity sensor 9 and geographical locating means 10, which are both coupled to a control unit 11. The control unit 11 controls a fertilizer spreading device 4 for spreading a fertilizer 6, in particular a solid nitrogen-containing fertilizer 6, and a field spreader 5 for spreading a fertilizer additive 7, which are mounted separately on the vehicle 3. The field spreader 5 is a field sprayer 5 if the fertilizer additive 7 is liquid. Especially, the pump or conveying rate of a pump or a conveyer of the field spreader 5 or field sprayer 5 is controlled as well as the speed at which fertilizer 6 is conveyed inside the fertilizer spreading device 4.

[0138] Another configuration of the vehicle 3 is shown in FIG. 3. In this case, an optical sensor 12 is mounted on the roof of the vehicle 3. The optical sensor 12 detects electromagnetic radiation that was reflected by the plants on the field 1. In moving direction of the vehicle, the optical sensor 12 is mounted in front of the fertilizer spreading device 4 and the field sprayer 5. Therefore, electromagnetic radiation is detected that has been emitted from plants to which fertilizer 6 as well as fertilizer additive 7 has not yet been applied. The optical sensor 12 detects the intensity of several wavelengths within the visible spectrum and the near-infrared spectrum. The data of the optical sensor 12 are transferred to an analyzing unit 13. The analyzing unit 13 is adapted to obtain a nitrogen status value for each segment of the field 1 based on the detected electromagnetic radiation. The light intensity in the visible spectrum is used to determine a plant chlorophyll content and the light intensity in the invisible near-infrared spectrum is used to detect the biomass. The nitrogen status value obtained by the analyzing unit 13 corresponds to the amount of nitrogen taken up by the plants. The nitrogen status value is then transferred to a calculating unit 14. The calculating unit 14 is adapted to calculate an amount of fertilizer 6 that is to be applied to the plants from which the electromagnetic radiation has been detected as a function of the obtained nitrogen status value. In addition, the calculating unit 14 calculates the ratio of fertilizer additive 7 to fertilizer 6 for the plants whose emission of electromagnetic radiation has been detected as a function of the obtained nitrogen status value. The data calculated by the calculating unit 14 are transferred to the control unit 11 that controls the fertilizer spreading device 4 as well as the field spreader 5 for spreading the fertilizer additive 7. Optionally, the geographic locating means 10 may be provided as described above.

[0139] In the following it is assumed, in accordance with a first embodiment, that the fertilizer additive 7 is liquid so that the field spreader 5 is a field sprayer 5 and that the fertilizer 6 is a solid nitrogen-containing fertilizer 6. However, in a second embodiment both the fertilizer additive 7 and the fertilizer 6 are liquid.

[0140] The spreading device 4 is mounted on the back of the vehicle 3 in the direction of travel, while the field sprayer 5 is mounted on the front of the vehicle 3. Thus, the distance between the two devices 4 and 5 is chosen as large as possible. In addition to that, the nozzles 5a of the field sprayer 5 are pointing downwards towards the soil, so that the liquid fertilizer additive 7, e. g. as a urease inhibitor, once it is sprayed, does not come into contact with the solid fertilizer spreading device 4, especially not with the parts that come into contact with the solid fertilizer 6 on their part. These parts are especially an ejection device 8 of the spreading device 4, which is described in greater detail further below.

[0141] In a further embodiment, the spreading device 4 is mounted at the front of the vehicle 3 in the direction of travel and the field sprayer 5 is mounted on the back of the vehicle 3. If the fertilizer 6 is solid the configuration is chosen to make sure that the liquid fertilizer additive 7 is prevented from coming into contact with surfaces of the solid fertilizer spreading device 4, which also come into contact with the solid fertilizer 6.

[0142] With reference to FIG. 4, an example of a field sprayer 5 is described.

[0143] The field sprayer 5 is mounted on the vehicle 3 shown in FIGS. 1 and 2. It is coupled to a liquid fertilizer additive reservoir 7a, which stores the liquid fertilizer additive 7. The liquid fertilizer additive 7 is sprayed onto the field 2 from a linear arrangement of nozzles 5a, which can be oriented and configured in a plurality of ways that are known to the expert. Thus, each segment of the working area 2 can be treated with the liquid fertilizer additive 7 in a controlled way. To control the dose of liquid fertilizer additive 7 that is applied to the field 1, the control unit 11 controls the spraying rate based on the geographical position of the vehicle 3 and the velocity v with which the vehicle 3 is moving over the field 1.

[0144] With reference to FIG. 5, an example of a spreading device 4 which is a centrifugal spreader 4 is described.

[0145] The centrifugal spreader 4 is mounted on the vehicle 3 shown in the FIGS. 1 and 2. FIG. 5 shows the main components of the ejection device 8 of the centrifugal spreader 4. The solid fertilizer 6, such as an urea granulate 6, is stored in a solid fertilizer reservoir 6a.

[0146] The centrifugal spreader 4 further comprises an opening 8a, where the urea granulate 6 leaves the solid fertilizer reservoir 6a on a rotating disk 8b, which is used to spread the granulate 6 by centrifugal force.

[0147] The rate at which the fertilizer granulate 6, e. g. the urea granulate 6, is spread onto each segment of the working area 2 of the field 1 is controlled by the control unit 11, based on the geographical position of the vehicle 3 and its velocity v on the field 1. The rate is mainly determined by the rate of fertilizer granulate 6, e. g. the urea granulate 6, that is brought to the rotating disk 8b. Furthermore, the size of the area, on which the centrifugal spreader 4 spreads the fertilizer granulate 6, e. g. the urea granulate 6, is determined by properties and the rotating speed of the rotating disk 8b.

[0148] Alternatively, the rate at which the fertilizer granulate 6 and liquid fertilizer additive 7 are spread onto each segment of the working area 2 of the field 1 is controlled by the control unit 11 based on the amount of fertilizer 6 as well as the ratio of fertilizer additive 7 to fertilizer 6 as calculated by the calculating unit 14.

[0149] To protect the centrifugal spreader 4, in particular the ejection device 8, from getting wet from the liquid fertilizer additive 7, it is oriented in the direction away from the field sprayer 5 to limit the possibility of liquid fertilizer additive 7 from the field sprayer 5 reaching the ejection device 8 of the centrifugal spreader 4.

[0150] With reference to FIG. 6, an example of a spreading device 4 which is a pneumatic spreader 4 is described. FIG. 6 shows the ejection device 8 of the pneumatic spreader 4.

[0151] The pneumatic spreader 4 is mounted on the vehicle 3 shown in the FIGS. 1 and 2. It comprises an ejection device 8 with an opening 8a, where the solid fertilizer 6 is conveyed to a deflection plate 8c, where the trajectories of the solid fertilizer 6 that in this case may be fertilizer granules 6 are deflected and they are distributed onto the working area 2 of the field 1.

[0152] The spreading characteristics, e.g. the area onto which the solid fertilizer 6 is spread and how evenly it is spread, are substantially determined by the properties of the deflection plate 8c and can be changed by the presence of the liquid fertilizer additive 7 on the plate 8c. Therefore, it needs to be protected and kept dry. As described with reference to FIG. 5 for the centrifugal spreader 4, the pneumatic spreader 4 is also arranged on the vehicle 3 and oriented so that the liquid fertilizer additive 7, once it leaves the nozzles 5a of the field sprayer 5, does not reach the ejection device 8.

[0153] As mentioned above the fertilizer 7 may be solid or liquid. If the fertilizer 7 is solid and the fertilizer additive 7 is liquid the field sprayer 5 is arranged relatively to the fertilizer spreading device 4 so that the liquid fertilizer additive 7 is prevented from coming into contact with surfaces of the fertilizer spreading device 4, which also come into contact with the solid fertilizer 6.

[0154] If, according to the second embodiment, both the fertilizer additive 7 and the fertilizer 6 are liquid the field spreader 5 might not be arranged relatively to the fertilizer spreading device 4 so that the liquid fertilizer additive 7 is prevented from coming into contact with surfaces of the fertilizer spreading device 4, which also come into contact with the fertilizer 6. In the second embodiment the control unit 11 preferably controls the rates of spreading the fertilizer 6 and the fertilizer additive 7 on the working area 2 as a function of the vehicle's 3 geographical position as described below.

[0155] With reference to the FIGS. 1 through 6, the method according to the invention is described.

[0156] Again it is assumed for a first embodiment that the fertilizer additive 7 is liquid so that the field spreader 5 is a field sprayer 5 and that the fertilizer 6 is a solid nitrogen-containing fertilizer 6. However, in the second embodiment both the fertilizer additive 7 and the fertilizer 6 are liquid.

[0157] The vehicle 3 moves with the velocity v over the field 1 and spreads solid nitrogen-containing fertilizer 6, specifically urea 6 in granulate form, and a liquid fertilizer additive 7, specifically a urease inhibitor 7, onto the working area 2 of the field 1. To this end, the spreading and spraying rates, respectively, of the fertilizer spreading device 4, specifically the centrifugal spreader 4, and the field sprayer 5 are controlled by the control unit 11. The velocity sensor 9 measures the velocity v of the vehicle 3 and the geographical positioning means 10 determine the position of the vehicle 3. The control unit 11 uses these pieces of information partly or in total to control the absolute quantity and the ratio of fertilizer 6 and fertilizer additive 7 that are applied to the soil. Thus, the absolute quantities and relative ratio of solid fertilizer 6 and liquid fertilizer additive 7 are determined individually for each segment of the working area 2.

[0158] If the absolute quantities as well as the relative ratio of fertilizer additive 7 to fertilizer 6 are not known in advance, the optical sensor 12, the analyzing unit 13 and the calculating unit 14 may be used to calculate the respective amounts and the ratio of fertilizer additive 7 to fertilizer 6 in the field 1 while the vehicle 3 moves on the field 1. The control unit 11 then uses the calculated data of the calculating unit 14 to control the absolute quantity and the ratio of fertilizer additive 7 and fertilizer 6 that are applied to the soil.

[0159] The centrifugal spreader 4 and the field sprayer 5 are configured such that the liquid fertilizer additive 7 does not reach the centrifugal spreader 4. Therefore, their longitudinal distance is chosen as large as possible, specifically by mounting the centrifugal spreader 4 at the back of the vehicle 3 and the field sprayer 5 on the front of the trailer 3a in the direction of travel.

[0160] It is mentioned that any solid fertilizer 6 listed above and any liquid fertilizer additive 7 listed above may be used in this method.

[0161] The invention is now described on the basis of experimental data with reference to the graph shown in FIG. 7.

[0162] The efficiency of a urease inhibitor in reducing ammonia (NH.sub.3) losses from three different soils treated with urea was measured. The time between the application of the urea fertilizer and the urease inhibitor was varied. Measurement methods to determine the nitrogen loss by ammonia volatilization are generally known (Fenn & Kissel, Ammonia volatilization from surface applications of ammonium compounds on calcareous soils. Soil Sci. So. Am. J. 37,855-859).

[0163] The characteristics of the soils and the dates of the experiments and measurements are given in table 1:

TABLE-US-00001 TABLE 1 Overview over the properties of the soils that were used in the experiments and the dates of experiments and measurements Limburgerhof Reithofen Aich Soil quality rating 30 75 48 Soil texture (0-30 cm) sand loamy silt loamy silt pH (0-30 cm) 6.8 6.9 6.6 P.sub.2O.sub.5 (mg/100 g soil, 0-30 cm) 17 16 3 K.sub.2O (mg/100 g soil, 0-30 cm) 8 23 11 Mg (mg/100 g soil, 0-30 cm) 5 11 12 Free lime (%, 0-30 cm) 0.5 <0.3 <0.3 Precrop winter rye winter wheat winter wheat Test crop Grain maize Grain maize Grain maize N.sub.min (kg N/ha, 0-90 cm) 69 83 57 (0-60 cm) Seeding date 24th April 29th April 27th April Fertilizer application 15th May 22nd May 22nd May 1st NH.sub.3 sampling 22nd May 29th May 29th May 2nd NH.sub.3 sampling 29th May 5th June 5th June

[0164] A solid urea fertilizer was spread on the different soils and a urease inhibitor (LIMUS?) was sprayed. Different time intervals between the application of urea and the urease inhibitor were tested: The urease inhibitor was applied 3, 2 and 1 days before (treatments no. T2 to T4) or after (treatments no. T9 to T11) urea was spread, respectively. Additionally, the inhibitor was applied to the field just before (treatment no. T5) and just after (treatment no. T8) urea was spread, respectively. The expression just before or just after means within some minutes. For the control measurements, urea was spread without any urease inhibitor present (treatment no. T6; negative control) and premixed with urea granules treated with urease inhibitor (application of a liquid urease inhibitor formulation on surface of urea granules) (treatment no. T7; positive control). The tested conditions are summed up in table 2:

TABLE-US-00002 TABLE 2 Protocol of the experiments Treatment no. LIMUS solo? .sup.1 N fertilizer T1 T2 3 days before N application Urea T3 2 days before N application Urea T4 1 day before N application Urea T5 Just before N application Urea T6 Urea T7 Urea + LIMUS? .sup.2 T8 Just after N application Urea T9 1 day after N application Urea T10 2 days after N application Urea T11 3 days after N application Urea .sup.1 application in 200 l water/ha with herbicide nozzles (0.37 kg LIMUS?/ha) .sup.2 contains 0.12% LIMUS? rel. to urea .fwdarw. 0.37 kg LIMUS?/ha

[0165] The parameters to be evaluated were the NH.sub.3-emissions within 0-6 and 7-12 days after N fertilization. The results of the experiments are shown in table 3 and FIG. 7 (0-12 days):

TABLE-US-00003 TABLE 3 % NH.sub.3-nitrogen loss of applied nitrogen from urea-treated soils with and without urease inhibitor (UI) wherein the UI was applied n days before, n days after or simultaneously with the urea fertilizer. Just before and just after denote a delay of few minutes, e. g. within 5 minutes. Measurements were made 12 days after urea treatment on each field. Just Just No UI n = ?3 n = ?2 n = ?1 before Simultaneously after n = +1 n = +2 n = +3 Mean 17.0 8.9 6.0 3.7 2.1 1.6 1.7 2.9 4.6 8.8 (% N loss) Limburgerhof 16.8 16.9 13.0 6.7 3.1 2.1 1.7 4.9 4.7 9.5 (% N loss) Relthofen 20.6 6.8 3.5 3.5 2.2 2.0 2.6 2.7 6.6 12.5 (% N loss) Aich 13.5 3.0 1.4 0.9 0.9 0.7 0.8 1.0 2.4 4.4 (% N loss)

[0166] The graph in FIG. 7 shows the relative loss of nitrogen within the first six days after urea treatment (A), within the six days after that period (B) and the total of relative loss of nitrogen within twelve days after urea treatment for treatments no. T2 to T11, respectively.

[0167] The mean loss of nitrogen from ammonia volatilization without the application of the urease inhibitor is 17% of the originally spread nitrogen. The urease inhibitor, if applied simultaneously with the urea fertilizer, reduces this value to 1.6%. However, if the urease inhibitor is applied to the soil short before or after spreading the urea is spread, the NH.sub.3-loss is similarly reduced to 2.1 and 1.7%, respectively. This result is surprising in the perspective of the general opinion that spraying the urease inhibitor onto the field would be too unspecific to affect the ammonia volatilization significantly. Increasing the time between spreading the urea fertilizer and applying the urease inhibitor increases the NH.sub.3-loss.

[0168] Thus, if applying a solid nitrogen-containing fertilizer and a liquid fertilizer additive separately, reducing the time span between the spreading of the solid fertilizer and applying the liquid fertilizer additive to below 1 h, preferably to few minutes, in particular below 5 minutes, is important to ensure the most efficient effect of the urease inhibitor.

LIST OF REFERENCE SIGNS

[0169] 1 Field [0170] 2 Working area [0171] 3 Vehicle [0172] 4 Fertilizer spreading device; centrifugal spreader; pneumatic spreader [0173] 5 Field sprayer; field spreader [0174] 5a Nozzle [0175] 6 Fertilizer; urea granulate [0176] 6a Solid fertilizer reservoir [0177] 7 Liquid fertilizer additive; urease inhibitor [0178] 7b Liquid fertilizer additive reservoir [0179] 8 Ejection device [0180] 8a Ejection opening [0181] 8b Rotating disk [0182] 8c Deflection plate [0183] 9 Velocity sensor [0184] 10 Geographical locating means [0185] 11 Control unit [0186] 12 Optical sensor [0187] 13 Analyzing unit [0188] 14 Calculating unit [0189] v Velocity of the vehicle 3