Disinfection of soil by application of electric voltage

Abstract

A trailed implement for electrically disinfecting soil, comprising support plate(s) having group(s) of electrodes, sensor(s) to detect soil data, an electrical power source to provide power to the electrodes, and a processor. Each group of electrodes has at least one first electrode with a first polarity and at least one second electrode with a second polarity, first electrodes alternating with second electrodes. The first polarity and the second polarity are selected from positive, zero and negative and differ. The soil data are processed to determine the voltage, current and power required to kill or disable at least one type of pest. Each electrode comprises a plurality of fins extending downward from the support plate with the fins administering electrical power to the soil. Each row of fins forms a line parallel to the front edge of the support plate.

Description

DISINFECTION OF SOIL BY APPLICATION OF ELECTRIC VOLTAGEFIELD OF THE INVENTION

[0001] The present invention generally pertains to a system and method for destroying microorganisms in soil using electric voltage.BACKGROUND OF THE INVENTION

[0002] In agricultural soils used for intensive crops, pathogens and non-crop growth such as weeds often develop that impair crop yield, reduce crop growth rate, and reduce crop quality and quantity. The pathogens include nematodes, insects, mites, bacteria, fungi and viruses, most of which are land dwellers and most of which have found ways to persist in the soil from season to season.

[0003] Until 2005, methyl bromide was widely used for soil disinfection. It provided a good and inexpensive solution to prevent growth of most of the land-dwelling pathogens and therefore enabled large-scale farmers to have good crop yields. Since 2005, the use of methyl bromide has been gradually reduced due to its toxicity and the environmental damage it can cause, resulting in a search for efficient, environmentally friendly and economical solutions to the problem of reducing or eliminating the pests or pathogens. One technique that can be applied without fear of leaving environmentally damaging residues in the soil is disinfecting the soil via applying an electric current through the soil to be disinfected, with voltage and current sufficient to kill the pests or pathogens therein.

[0004] Patent US2429412 discloses a system, an apparatus and method of operation, enabled to apply intense electrical treatment to the soil to a considerable depth, the depth of treatment being only limited by the depth to which it is practicable to run a series or set of soil distributing electrodes. The depth of treatment is thus limited in practice only by such physical considerations as those which are ordinarily taken into account in determining maximum practicable depth of soil disturbance. However, US2429412 requires two sets of horizontal plates, the plates arranged in rows, with staggered rows for at least one set of plates and one set of plates passing through the ground at a depth beneath the surface, with all disinfection between the surface and the lower set of plates.

[0005] CN205813390 discloses a soil electric disinfection and pest control device, comprising two electrode plates arranged on the ground of a vegetable greenhouse. The soil electric disinfection and pest control device of the present invention comprises two electrode plate slots disposed on the ground of a vegetable greenhouse and a fixing rod fixed on the top of the vegetable greenhouse, and two electrodes. The plate slots are disposed in a parallel structure. The fixing rods are disposed laterally. The lower end of the fixing rods is provided with a rotating rod. The rotating rods and the fixed rods are arranged in a parallel structure. The bearing ring is fixedly connected to the outer ring surface of the rotating rod. The inner ring of the bearing is fixedly mounted with a supporting rod, and the supporting rod is fixedly mounted on the outer ring of the bearing. The upper end is connected to the fixed rod and the two rotating discs are fixedly mounted on the rotating rod. The lower end of the reel is provided with an electrode plate protection shell, the electrode plate protection shell and the reel are oppositely disposed, and the lower end of the electrode plate protection shell is open. A cover plate is fixedly mounted on the lower end of the electrode plate protective case through a hydraulic hinge. The upper end of the electrode plate protective case is provided with a through hole, and the electrode plate protective case is provided with an electrode plate. However, CN205813390 requires two sets of horizontal plates with the plates arranged in rows, a lower set of plates at ground level and an upper set of plates at a height near the top of a greenhouse. The device is stationary; there is neither teaching nor suggestion that the device can be transported horizontally during use. Furthermore, disinfection occurs for soil above the ground; if one set of plates were buried, disinfection would occur below ground but it would not be practicable for the device to be movable in use.

[0006] It is therefore a long felt need to provide a soil disinfection system which does not require chemicals, does not require use in a fixed position, does not require a set of horizontal plate electrodes at a depth under the ground and does not unduly damage the structure of the soil.SUMMARY OF THE INVENTION

[0007] It is an object of the present invention to disclose a system for destroying microorganisms in soil using electric voltage.

[0008] It is another object of the present invention to disclose a trailed implement for electrically disinfecting soil in a land, said trailed implement comprising:

[0009] a main frame comprising:

[0010] at least one support plate comprising at least one group of electrodes; in each said at least one group of electrodes, there is at least one first polarity electrode and at least one second polarity electrode, each of said first polarity electrode having a first polarity, each of said first electrode alternating with at least one second polarity electrode, said second polarity electrode having a second polarity, said first polarity and said second polarity being two selected from the group consisting of positive, zero and negative;

[0011] at least one sensor for detecting soil data;

[0012] an electrical power source for providing voltage and current to at least one of said at least one first polarity electrode and said at least one second polarity electrode; and

[0013] a processor for processing said soil data collected by said sensor, said at least one processor configured to determine, from soil data transmitted by said at least one sensor, a value for an electrical parameter selected from the group consisting of voltage, current, power level or any combination thereof required to kill or disable at least one type of pest; and to instruct said electrical power source to apply said electrical parameter to said at least one group of electrodes;

[0014] wherein each electrode in each said group of electrodes comprises a plurality of fins, said fins extending downward from said support plate, the front edges of each row of fins forming a line parallel to a front edge of the support plate, said fins being insertable in said soil, said fins administering said electrical power to said soil;

[0015] further wherein said fins are configured to be movably embedded in soil and to administer said electrical power to said soil; said at least one processor being configured to determine, from soil data transmitted by said at least one sensor, a value for an electrical parameter selected from the group consisting of voltage, current, power level or any combination thereof required to kill or disable at least one type of pest; and to instruct said electrical power source to apply said electrical parameter to said at least one group of electrodes.

[0016] It is another object of the present invention to disclose a method for disinfecting soil, said method comprising steps of:

[0017] obtaining a movable trailed implement comprising:

[0018] a main frame comprising:

[0019] at least one support plate comprising at least one group of electrodes; in each said at least one group of electrodes, there is at least one first polarity electrode and at least one second polarity electrode, each of said first polarity electrode having a first polarity, each of said first electrode alternating with at least one second polarity electrode, said second polarity electrode having a second polarity, said first polarity and said second polarity being two selected from the group consisting of positive, zero and negative;

[0020] at least one sensor for detecting soil data;

[0021] an electrical power source for providing voltage and current to at least one of said at least one first polarity electrode and said at least one second polarity electrode; and

[0022] a processor for processing said soil data collected by said sensor, said at least one processor configured to determine, from soil data transmitted by said at least one sensor, a value for an electrical parameter selected from the group consisting of voltage, current, power level or any combination thereof required to kill or disable at least one type of pest; and to instruct said electrical power source to apply said electrical parameter to said at least one group of electrodes; and

[0023] operating said trailed implement;

[0024] wherein each electrode in each said group of electrodes comprises a plurality of fins, said fins extending downward from said support plate, the front edges of each row of fins forming a line parallel to a front edge of the support plate, said fins being insertable in said soil, said fins administering said electrical power to said soil;

[0025] further wherein said fins are configured to be movably embedded in soil and to administer said electrical power to said soil; said at least one processor being configured to determine, from soil data transmitted by said at least one sensor, a value for an electrical parameter selected from the group consisting of voltage, current, power level or any combination thereof required to kill or disable at least one type of pest; and to instruct said electrical power source to apply said electrical parameter to said at least one group of electrodes.

[0026] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, wherein said at least one support plate is configured to have atleast two configurations, a raised configuration with the tips of the fins above a plane defined by bases of the wheels and a lowered configuration with the tips of the fins below the plane defined by bases of the wheels, said at least one support plate reciprocally translatable between said raised configuration and said lowered configuration.

[0027] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, wherein said at least one support plate comprises more than one support plate, said translation between said raised configuration and said lowered configuration being selected from the group consisting of at least two of said more than one support plate translate in a same direction, at least two of said more than one support plate translate in opposite directions, or any combination thereof.

[0028] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, additionally comprising a motor configured to induce said reciprocal translation.

[0029] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, wherein tips of said fins point in a direction opposite to the direction of travel of the trailed implement.

[0030] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, wherein a number of fins per electrode is selected from the group consisting of four or in a range from 2 to 10 or any range therebetween.

[0031] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, wherein a number of electrodes per group is selected from the group consisting of 15, in a range from 10 to 50 or any range therebetween.

[0032] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, wherein the at least one sensor is selected from the group consisting of a humidity sensor, a conductivity sensor, a temperature sensor, a voltage sensor, a current sensor, a power level sensor, a distance sensor, or any combination thereof.

[0033] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, wherein an absolute value of a voltage applicable to said at least one group of electrodes is in a range between 0.5 kV and 400 kV or any range therebetween.

[0034] It is another object of the present invention to disclose the trailed implement or the methodas described in any of the above, wherein a frequency of the applied power is selected from the group consisting of 50 Hz, 75 Hz, 100 Hz, in a range of 50 Hz to 1000 Hz or any range therebetween.

[0035] It is another object of the present invention to disclose the trailed implements or the method as described in any of the above, wherein said power level is in a range from 50 kW to 400 kW or any range therebetween.

[0036] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, wherein an applied current is selected from the group consisting of in a range from 10 A to 30 A, in a range from 0.5 A to 50 A or any range therebetween.

[0037] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, additionally comprising at least one circuit breaker.

[0038] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, additionally comprising a human-machine interface.

[0039] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, wherein the human-machine interface is configured to display a member of a group consisting of electrode voltage, load current, soil temperature, soil humidity, soil conductivity, track shoe temperature, electrode temperature, generator overload status, transformer overload status or any combination thereof.

[0040] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, wherein the human-machine interface is configured to provide at least one alert.

[0041] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, wherein the at least one alert is selected from the group consisting of alert as to the existence of a breakdown, alert as to the nature of the breakdown, alert as to the location in the system of the breakdown, alert of the probability of a breakdown, alert of an overload, alert of an electrical failure, alert of a short, alert of a failure of a power supply, alert of a failure in a transformer or any combination thereof.

[0042] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, wherein at least one of the following is true:

[0043] a. said soil data is selected from the group consisting of humidity, temperature, conductivity or any combination thereof;

[0044] b. said trailed implement is configured to be operable in a manner selected from the group consisting of manually, autonomously or any combination thereof; and

[0045] c. said trailed implement is configured to be remotely controllable.

[0046] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, wherein said at least one member of said at least one group of electrodes is configured to be heated by a method selected from the group consisting of induction heating, resistance heating, electric arc heating, dielectric heating or any combination thereof.

[0047] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, wherein at least one of the following is true:

[0048] a. a length of said fin is selected from the group consisting of 300 mm, in a range from 100 mm to 600 mm or any range therebetween.

[0049] b. a lateral center-to-center distance between fins is selected from the group consisting of 150 mm, in a range from 100 mm to 2000 mm or any range therebetween.

[0050] c. a longitudinal center-to-center distance between fins is selected from the group consisting of 50 mm, in a range from 100 mm to 3000 mm or any range therebetween.

[0051] d. wherein a distance between groups of electrodes is selected from the group consisting of 250 mm, in a range from 150 mm to 2000 mm or any range therebetween.

[0052] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, wherein there is one transformer per group of electrodes.

[0053] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, wherein a number of transformers is in a range from 1 to 12 or any range therebetween.

[0054] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, wherein said trailed implement is either self-contained or is configured to be attachable to another vehicle.

[0055] It is another object of the present invention to disclose the trailed implement or the methodas described in any of the above, wherein said self-contained trailed implement comprises a propulsion unit configured to move said trailed implement.

[0056] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, wherein said movement of said trailed implement is either autonomous or by remote control.

[0057] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, wherein said trailed implement is attachable to a power take off (PTO).

[0058] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, wherein soil to be disinfected is selected from the group consisting of soil in an open area or soil in an enclosed space.

[0059] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, wherein said soil in an open area is selected from the group consisting of a field, arable land, agricultural land, cropland, pasture, rangeland, grassland, shrubland, a nursery, an orchard, a garden, a lawn, forestry, silviculture, a sport field, cultivable land, a plantation, a berm, a verge, land requiring remediation, or any combination thereof.

[0060] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, wherein said land requiring remediation is selected from the group consisting of land requiring removal of plant-damaging pests, land requiring removal of plant-damaging pathogens, land requiring removal of animal-damaging pests, land requiring removal of animal-damaging pathogens, land requiring removal of chemicals or any combination thereof.

[0061] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, wherein said soil in an enclosed space is selected from the group consisting a barn, a greenhouse, a stable, a dovecot, soil for indoor remediation or any combination thereof.

[0062] It is another object of the present invention to disclose the trailed implement or the method as described in any of the above, wherein said soil for indoor remediation is selected from the group consisting of soil from a vertical farming operation, soil from a greenhouse or anycombination thereof.BRIEF DESCRIPTION OF THE FIGURES

[0063] In order to better understand the invention and its implementation in practice, a plurality of embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, wherein

[0064] Fig. 1A-C, 2A-D and 3A-D schematically illustrate embodiments of the disinfection unit of the present invention;

[0065] Fig. 4 schematically illustrates an embodiment of an arrangement of the electrodes;

[0066] Fig. 5 schematically illustrates an embodiment of a group of electrodes;

[0067] Fig. 6 shows an exemplary waveform for the applied power;

[0068] Fig. 7 schematically illustrates two groups of electrodes, showing how the distances between fins and electrodes are measured;

[0069] Fig. 8A-D schematically illustrates an embodiment of the disinfection unit of the present invention;

[0070] Fig. 9A-C schematically illustrates embodiments of fin tips;

[0071] Fig. 10A-D illustrates an embodiment of a rotavator configured to kill pathogens;

[0072] Fig. 11 illustrates an exemplary embodiment of a block diagram of a control system for a soil disinfection unit;

[0073] Fig 12 shows an exemplary embodiment of a flow chart for a soil disinfection unit; and

[0074] Figs. 13A-C and 14A-C depict the effect of applying electric power on the growth of plants.DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0075] The following description is provided, alongside all chapters of the present invention, so as to enable any person skilled in the art to make use of said invention and sets forth the best modes contemplated by the inventor of carrying out this invention. Various modifications, however, willremain apparent to those skilled in the art, since the generic principles of the present invention have been defined specifically to provide a means and method for destroying microorganisms in soil using electric voltage.

[0076] A device for disinfection by applying AC current and voltage, DC current and voltage or both AC and DC current and voltage to the soil is disclosed. The current and voltage, AC, DC or both, is typically applied via electrodes inserted into the soil. Each electrode comprises a plurality of talon-like or hawkbill-like fins, with the curved tips of the fins pointing forward or backward, that cut through the soil and apply the electric power at a preferred depth under the surface of the soil.

[0077] The applied electric power typically kills the pathogen(s) by means of irreversible electroporation and / or irreversible cell wall perforation. In irreversible electroporation , an applied electric field increases the transmembrane potential of a biological cell (plant, animal, microbial, and algae) and initiates pore formation in the cell membrane. Once pores on the order of 0.5 nm are created, the applied electric field can cause them to expand, and the flow of material into and out of the cell will be disrupted. This loss of membrane integrity results in the cell contents diffusing into their surroundings and causes the death of the cell.

[0078] However, the electric power can kill or otherwise disable the pathogens by other means.

[0079] In the embodiments disclosed hereinbelow, the fins are mounted to one or more support plates, a support plate being a plate-like member comprising electrical circuitry configured to receive electric power at a predetermined voltage and current from generator(s) and transformer(s) and to apply the current and voltage to the electrodes, with all of the fins in each electrode being at the same voltage and having the same current flowing through them. The support plate(s) is mounted to a trailer configured to be attached to a tractor. There can be a single support plate for all groups of electrodes, each group of electrodes can have its own support plate, or two or more groups of electrodes can share a support plate.

[0080] The embodiments disclosed herein transport the energy to the soil via the fins. Energy can also be transported to the soil via a fin, a disk cultivator, a rotavator, a cultivator, a frame moving horizontally through the soil, a frame moving vertically through the soil, transporting the soil to an electrified frame, or any combination thereof. Typically, the frame is rectangular, with or without a bottom or a top, but any shape that allows transport of electric power through theincluded soil can be used.

[0081] Preferably, but not necessarily, the trailer is in communication with a soil preparation member so that, after disinfection, the soil can be prepared for planting.

[0082] In some embodiments, the device comprises a "one-stop shop", disinfecting the soil, preparing it for sowing, and sowing the seed. In some variants of the "one stop shop", the soil preparation member comprises the seed drill or other sowing device. In some variants of the "one stop shop", the seed drill or other sowing device is separate from the soil preparation member.

[0083] The trailer has a front side, connectable to a tractor or other motive device and an opposite, rear side. The fins in each electrode are oriented front-to-back. The electrodes are grouped, with each group comprising a plurality of parallel electrodes, with each electrode in the group having the same number of fins, with the fins in all of the electrodes being the same distance apart so that the front edges of each row of fins are in a line parallel to the front edge of the support plate.

[0084] Typically, there is more than one group of electrodes, with the groups of electrodes oriented front-to-back in the trailer.

[0085] Soil disinfection can be in an open area or in an enclosed space. The open area can be, but is not limited to, a field, arable land, agricultural land, cropland, pasture, rangeland, grassland, shrubland, a nursery, an orchard, a garden, a lawn, forestry, silviculture, a sport field, cultivable land, a plantation, a berm, a verge, land requiring remediation, or any combination thereof. The remediation can be to remove plant-damaging pests, animal-damaging pests, plant-damaging pathogens, animal-damaging pathogens, chemicals or any combination thereof. The enclosed space can be inside a barn, a greenhouse, a stable, a dovecot, or any combination thereof. Soil requiring remediation can also be treated in an indoor setting. For non-limiting example, soil from a vertical farming operation or from a greenhouse can be transferred to a treatment center where the soil is disinfected. Such treatment can be carried out indoors to prevent accidental spreading of the pest.

[0086] Greenhouse disinfection can be via any disinfection unit and / or arrangement of electrodes as disclosed herein. The electrodes can be mounted on a support such as, but not limited to, any of the disinfection units as disclosed herein. The support can be movable or stationary. Preferably, the electrodes can be raised and lowered so that they can be inserted into or removed from the soilin the greenhouse. In some embodiments, the support can be moved from one portion of a greenhouse to another or from one soil bed to another. In some embodiments, the electrodes can be moved through the soil; if the electrodes can be raised or lowered, the movement through the soil occurs when the electrodes are in a lowered configuration.

[0087] The distance between the electrodes can be optimized in accordance with the type of soil to be disinfected and / or the type of pest to be eliminated.

[0088] The disinfection unit can be pullable by a tractor (not shown) or it can be self-contained. If self-contained, it can be operable autonomously or by remote control. The disinfection unit can comprise a motor for propulsion, or the disinfection unit can lack a motor and be movable by the tractor or by another external motive power.

[0089] Fig. 1A-C schematically illustrates an exemplary embodiment (1000) of the present system, with Fig. 1A showing a perspective view of the embodiment, Fig. IB showing a front view and Fig. 1C showing a side view.

[0090] As shown in Fig. 1A, the trailer (1000) comprises a hitch (1140) configured to connect the trailer (1000) to a tractor or other means of motive power. A generator (1210) generates electrical power, which is passed through the transformers (1220) to the circuitry (1215) on the support plate (1200), which distributes the power to the electrodes (2200). In this embodiment, each electrode (2200) comprises four fins (2010), and there are three groups (2000) of electrodes (2200). The trailer (trailed implement) (1000) comprises wheels (1910) configured to enable it to move efficiently.

[0091] The energy source can be a generator, batteries, or electricity from the grid. Any means known in the art can be used to power the generator. The generator can be mounted on the trailer (as shown in Fig. 1) or can be separate from the trailer. If the generator (or grid) is separate from the trailer, the power can be transferred to the trailer via a power take off (PTO) or any other means known in the art to transfer power from one device to another.) and wheels (1910) can be seen, as well as the

[0092] In Fig. IB, the hitch (1140 generator (1210), the transformers (1220) and the front fins of the front group of electrodes (2200). In this exemplary embodiment, the width of the trailer is 1930mm and its height is 1812 mm. The trailer can have a width between 1000 mm and 10000 mm and a height between 1000 mm and 5000 mm.

[0093] In Fig. 1C, the hitch (1140) and wheels (1910) can be seen, as well as the generator (1210), two of the transformers (1220), a sensor (2900) and the outermost electrodes (2000) of the groups (2200) of electrodes (2010). In this exemplary embodiment, the length of the trailer is 4673 mm. The length can be in a range from 2000 mm to 20000 mm or any range therebetween. The sensor is selectable from the group consisting of a humidity sensor, a conductivity sensor, a temperature sensor, a voltage sensor, a current sensor, a power level sensor, a distance sensor, or any combination thereof.

[0094] In preferred embodiments, the hitch (1140) comprises a connector to a power take-off of the tractor or to a self-contained power source such as, but not limited to, a battery or an engine.

[0095] In this exemplary embodiment, the tips of the fins point forward, towards the hitch (1140). In other variants of this embodiment, the tips of the fins point backward, away from the hitch (1140) and towards the wheels (1910) at the rear.

[0096] Fig. 2A-D shows another exemplary embodiment (1100) of a disinfection unit. Fig. 2A shows a perspective view, Fig. 2B shows a front view, Fig. 2C shows a side view, and Fig. 2D shows a bottom view.

[0097] In embodiments such as, but not limited to, that shown in Fig. 2A-D, the disinfection unit (1100) comprises a trailed implement movable by a propulsion unit (1300) so that no tractor is needed and the system can be configured to function autonomously or by remote control. At the rear of the disinfection unit (1100) is a soil preparation unit (1920) configured to smooth soil disturbed by the electrodes (2010). In some embodiments, the soil preparation unit (1920) is also configured to prepare the soil for sowing, with the sowing done separately; in other embodiments, the soil preparation unit (1920) is configured to both prepare the soil for sowing and sow the seed. In still other embodiments, the soil preparation unit (1920) is configured to prepare the soil and insert seedlings or plants into the soil. In this embodiment, both the propulsion unit (1300) and the disinfection unit (1100) have wheels (1910) for mobility. In other variants of this embodiment, the propulsion unit is integral with the disinfection unit and all wheels (1920) are attached to the disinfection unit, with at least one of the wheels being in mechanical communication with the propulsion unit.

[0098] In all the embodiments herein, the disinfection unit is controllable by a processor (900), which can be integral with a disinfection unit (1000, 1100), remote from a disinfection unit (1000, 1100), integral with a propulsion unit (1300), remote from a propulsion unit (1300) or any combination thereof.

[0099] In this embodiment and the embodiments hereinbelow, the tips of the fins (2010) point backward, minimizing disturbance of the soil. There are three groups (2000) of electrodes (2200), each electrode comprising 4 fins (2010). The fins (2010) are in rows (2100), with all fins (2010) in each row being of the same size with all adjacent pairs of electrodes being the same distance apart. In each group (2000) of electrodes (2200), all fins (2010) are the same size and shape, with the front-to-back (longitudinal) distances between adjacent fins (2010) being the same and the side-to-side (lateral) distances between adjacent fins (2010) being the same.

[0100] The number of electrodes in a row can be in a range from 1 to 5 or any range therebetween.

[0101] The tips of the fins can point backward or point forward.

[0102] The fins can be knife-shaped, serrated, with at least a portion round in cross section, with at least a portion oval in cross section, with at least a portion elliptical in cross section, with at least a portion rectangular in cross section, with at least a portion polygonal in cross section, or any combination thereof.

[0103] In some embodiments, as shown, there is one support plate (1200) for each group of electrodes (2000). In some embodiments, more than one group of electrodes (2000) shares a support plate.

[0104] Fig. 2B shows a front view of the disinfection unit (1100) and propulsion unit (1300). The front row (2100) of fins (2010) and the front wheels (1910) can be seen.

[0105] Fig. 2C shows a side view of the disinfection unit (1100) and propulsion unit (1300). The disinfection unit (1100) is moved by a propulsion unit (1300) so that no tractor is needed and the system can function autonomously. An exemplary sensor (2900) is shown. At the rear of the disinfection unit (1100) is a soil preparation unit (1920). In some embodiments, the soil preparation unit (1920) prepares the soil for sowing, with the sowing done separately; in some embodiments, the soil preparation unit (1920) both prepares the soil for sowing and sows the seed. In some embodiments, the soil preparation unit (1920) prepares the soil and inserts seedlings or plants intothe soil. Both the propulsion unit (1300) and the disinfection unit (1100) have wheels (1910) for mobility.

[0106] In this embodiment and the embodiments described hereinbelow, the tips of the fins (2010) point backward, minimizing disturbance of the soil and decreasing the piling-up of soil in front of the fins. In these exemplary embodiments, there are three groups (2000) of electrodes (2200), each electrode comprising 4 fins (2010). For each group (2000) of electrodes, the bases of the fins (2010) are in mechanical and electrical communication with a support plate (1200). Preferably, there is one support plate (1200) for each group (2000) of electrodes.

[0107] Fig. 2D shows a bottom view of the disinfection unit (1100) and propulsion unit (1300). The wheels, support plate (1200), an exemplary sensor (2900), and a soil preparation unit (1920) can be seen.

[0108] The sensor is selectable from the group consisting of a humidity sensor, a conductivity sensor, a temperature sensor, a voltage sensor, a current sensor, a power level sensor, a distance sensor, or any combination thereof.

[0109] In preferred embodiments, the fins (2010) are removable and replaceable, so that a damaged or non-functional fin (2010) can be replaced.

[0110] Fig. 3A-D schematically illustrates another exemplary embodiment of the disinfection unit (1100). Fig. 3A shows a perspective view, Fig. 3B-C shows a side view and Fig. 3D shows a front view of the disinfection unit (1100).

[0111] The disinfection unit (1100) comprises a steerable hitching unit (1500), which can be any conventional unit configured to allow mechanical connection and, in some variants, electrical connection, to a propulsion unit. In this exemplary embodiment, the hitching unit (1500) comprises wheels (1910) in mechanical connection with a steering assembly (1141) and in mechanical connection with a support (1148) and a trailer arm (1146) with a pintle ring (1142) at its front edge, the pintle ring (1142) configured to provide mechanical connection between the disinfection unit (1100) and a propulsion unit (not shown). At a side of the trailer arm (1146) is a jack (1144) configured to keep the trailer arm (1146) and pintle ring (1142) off the ground. The steering assembly (1141) comprises a bearing and rod (1149), the bearing configured to allow the hitching unit (1500) to rotate relative to the main frame (1400) of the disinfection unit (1100). In someembodiments, the steerable hitching unit (1500) comprises an electrical connection (not shown) for providing power to the disinfection unit (1100). In some embodiments, the disinfection unit (1100) is self-propelled, comprising an integral propelling unit (1300, see Fig. 2), either comprised within the main frame (1400), or comprised within the hitching unit (1500, see Fig. 2). In some embodiments, the support (1148) and trailer arm (1146) are configured to rotate about an axis parallel to the hitching unit (1500) wheels (See Fig. 3B).

[0112] The main frame (1400) of the disinfection unit (1100) comprises at least one transformer (1220) (in this embodiment, three transformers (1220) in electrical connection with at least one generator (1210) (in this embodiment, one generator (1210), with the transformer(s) (1220) and generator(s) (1210) configured to provide current and voltage to the electrodes (2000).

[0113] A motor (1190) is in mechanical communication with a plurality of risers (1990, 2090), with each riser (1990, 2090) comprising a group (2000) of electrodes (2200). As disclosed above, each electrode (2200) comprises a plurality of fins (2010), with the electrodes mounted on a support plate (1200). In this exemplary embodiment, there are 3 risers, with the frontmost riser (1990) narrower than the rear two risers (2090). In some embodiments, for each pair of risers, one riser in any pair of risers can differ in length and / or width from the other riser in the pair. Typically, each riser comprises one support plate and one group of electrodes, although any riser can comprise more than one support plate and / or more than one group of electrodes.

[0114] The piston riser brackets (1970) connect the risers (1990, 2090) with the riser pistons (1980) via the riser piston pin assembly (2230). The electrode pin boss (2012) connects the electrode support plate to the riser assembly. A transfer assembly (2410) is configured to enable control of the speed of upward and downward movement of the risers (1990, 2090).In this exemplary embodiment, the motor is configured to use diesel fuel, containable in an integral fuel tank (2210). The motor can be any conventional motor, running on a conventional fuel such as, but not limited to, diesel fuel, gasoline, or kerosene, or it can be an electric motor, in which case power would be suppliable via either batteries or via the same source as supplies power to the electrodes (2000).

[0115] The motor (1190) is configured to drive the riser pistons (1980) with the riser pistons (1980) configured to raise and lower the risers (1990, 2090). Preferably, each riser (1990, 2090) comprises at least two riser pistons (1980) configured to raise and lower the groups (2000) ofelectrodes (2200). In this exemplary embodiment, the motor (1190) raises and lowers the risers (1990, 2090) in unison; all rise at the same time and all lower at the same time. In the lowered configuration, the fins (2010) are dragged through the soil. After a predetermined time, which can depend on the soil conditions, the fins (2010) are raised from the ground and lowered again by means of a lever bar for electrode motion (1950), freeing the fins (2010) of soil and weeds that may have collected on their front edges.

[0116] The main frame (1300) comprises wheels (1910) configured to allow easy movement of the disinfection unit (1100).

[0117] At the rear of the disinfection unit (1100) is a soil preparation unit (1920) configured to smooth soil disturbed by the electrodes (2010). In some embodiments, the soil preparation unit (1920) is also configured to prepare the soil for sowing, with the sowing done separately; in other embodiments, the soil preparation unit (1920) is configured to both prepare the soil for sowing and sow the seed. In still other embodiments, the soil preparation unit (1920) is configured to prepare the soil and insert seedlings or plants into the soil. The soil preparation unit (1920) comprises a soil preparation piston (1924) configured to reversibly raise the soil preparation unit (1920) from ground level.

[0118] Fig. 3C-D illustrates exemplary dimensions of an embodiment of the disinfection unit. These dimensions are exemplary and are non-limiting.

[0119] As shown in Fig. 3C, the total length of the disinfection unit, including the hitching unit, is 8871 mm. The front-to-back distance between the wheels is 4021 mm, while the front-to back distance between the rear wheels and the rear side of the soil preparation unit (1920) is 2995 mm. The distance from the rear of the main frame and the rear side of the soil preparation unit (1920) is 1165 mm. The vertical distance between the bottom of the wheels and the top of the main frame is 1565 mm, while the vertical distance between the bottom of the wheels and the top of the risers in their raised position is 2053 mm.

[0120] As shown in Fig. 3D, the lateral center-to-center distance between the wheels is 1930 mm, the diameter of the wheels is 1930 cm, and the total width of the disinfection unit is 2400 mm.

[0121] Some variants of any of the embodiments shown herein are self-propelled, having an integral propelling unit (1300, see Fig. 2A-D) as described hereinabove.

[0122] As shown in Fig. 4, some variants of the embodiments disclosed herein comprise a plurality of sets (2020) of electrodes (2200), enabling the sterilizing of the soil (and, in some variants, other preparation(s) of the soil, such as, but not limited to, those described herein) of a plurality of furrows. As shown in Fig. 4, each electrode (2200) comprises a plurality of fins (2010), in this exemplary embodiment, 4 fins. The electrodes (2200) are arranged in groups (2000), in this exemplary embodiment, 6 groups, with each group (2000) comprising rows (2100) of fins (2010), in this exemplary embodiment, four rows, corresponding the four fins (2010) in each electrode (2200). The distance (2025) between the edge of one set (2020) of electrodes and the edge of an adjacent set of electrodes can be in a range from 100 mm to 1000 mm or any range therebetween.

[0123] The distances between sets of electrodes can differ for different pairs of sets of electrodes.

[0124] Fig. 5 schematically illustrates a group (2000) of electrodes (2200). Preferably, there are, laterally, an odd number of electrodes, in other words, there are an odd number of fins (2010) in each row (2100) of fins (2010). Laterally, alternate electrodes are positive and negative so that, if there are an odd number of fins (2010) in a row (2100), current in the laterally outermost electrodes has the same sign. This is indicated schematically in Fig. 5 by the alternate + (positive) and - (negative) electrodes.

[0125] In less-preferred embodiments, the current is rectified so that alternate electrodes are powered and grounded so that, if there are an odd number of fins (2010) in a row (2100), the laterally outermost electrodes are powered.

[0126] As shown in Fig. 6, in preferred embodiments, the power applied to the electrodes is sinusoidal. In some embodiments, the applied power can comprise a sinusoidal wave, a square wave, a triangular wave or any combination of the above.

[0127] In some embodiments, groups (2000) can differ in fin shape, fin tip angle, fin size (length, width, thickness), direction in which the fins point, longitudinal distance between adjacent fins, lateral distance between adjacent fins, or any combination thereof.

[0128] As shown in Fig. 7, the lateral center-to-center distance (2105) between fins is about 150 mm. The lateral center-to-center distance (2105) can be in a range from 100 mm to 600 mm or any range therebetween. The longitudinal center-to-center distance (2205) between fins is about 50mm. The longitudinal center-to-center distance (2205) can be in a range from 50 mm to 200 mm or any range therebetween.

[0129] The distance (2305) between groups of electrodes is about 250 mm, and can be in a range from 150 mm to 2000 mm or any range therebetween. The distances between groups of electrodes can differ for different pairs or groups of electrodes.

[0130] The fin length in the embodiment shown, from the bottom of the support plate to the distal end of the fin, is 300 mm. In some embodiments, the fin length is 450 mm. The fin length can be in a range from 100 mm to 600 mm or any range therebetween. The length of the fin will depend on the type of pest to be destroyed and the depth in the soil of the region to be disinfected. In some embodiments, the fin extends 300 mm to 350 mm into the soil. The range of depth in the soil can be from 90 mm to 500 mm or any range therebetween.

[0131] Fig. 8A-D schematically illustrated another exemplary embodiment (1100) of a disinfection unit. Fig. 8A shows a perspective view, Fig. 8B shows a front view, and Fig. 8C-D shows a side view.

[0132] The disinfection unit (1100) comprises a steerable hitching unit (1500), which can be any conventional unit configured to allow mechanical connection, and in some variants, electrical connection, to a propulsion unit. In this exemplary embodiment, the hitching unit (1500) comprises wheels (1910) in mechanical connection with a steering assembly (1141) and in mechanical connection with a support (1148) and a trailer arm (1146) with a pintle ring (1142) at its front edge, the pintle ring (1142) configured to provide mechanical connection between the disinfection unit (1100) and a propulsion unit (not shown). At a side of the trailer arm (1146) is a jack (1144) configured to keep the trailer arm (1146) and pintle ring (1142) off the ground. The steering assembly (1141) comprises a bearing and rod (1149), the bearing configured to allow the hitching unit (1500) to rotate relative to the main frame (1400) of the disinfection unit (1100). In some embodiments, the steerable hitching unit (1500) comprises an electrical connection (not shown) for providing power to the disinfection unit (1100). In some embodiments, the disinfection unit (1100) is self-propelled, comprising an integral propelling unit (1300, see Fig. 2), either comprised within the main frame (1400), or comprised within the hitching unit (1500, see Fig. 2). In some embodiments, the support (1148) and trailer arm (1146) are configured to rotate about an axis parallel to the hitching unit (1500) wheels (See Fig. 3B).

[0133] The main frame (1400) of the disinfection unit (1100) comprises at least one transformer (1220) (in this embodiment, three transformers (1220) in electrical connection with at least one generator (1210) (in this embodiment, one generator (1210), with the transformer(s) (1220) and generator(s) (1210) configured to provide current and voltage to the electrodes (2000).

[0134] A motor (1190) is in mechanical communication with a plurality of risers (1990, 2090), with each riser (1990, 2090) comprising a group (2000) of electrodes (2200). As disclosed above, each electrode (2200) comprises a plurality of fins (2010), with the electrodes mounted on a support plate (1200, see Figs. 2-3). In this exemplary embodiment, there are 3 risers, with the frontmost riser (1990) narrower than the rear two risers (2090). In some embodiments, for each pair of risers, one riser in any pair of risers can differ in length and / or width from the other riser in the pair. Typically, each riser comprises one support plate and one group of electrodes, although any riser can comprise more than one support plate and / or more than one group of electrodes.

[0135] In this exemplary embodiment, the motor is configured to use diesel fuel, containable in an integral fuel tank (2210). The motor can be any conventional motor, running on a conventional fuel such as, but not limited to, diesel fuel, gasoline, or kerosene, or it can be an electric motor, in which case power would be suppliable via either batteries or via the same source as supplies power to the electrodes (2000).

[0136] The motor (1190) is configured to drive the riser pistons (1980) with the riser pistons (1980) configured to raise and lower the risers (1990, 2090). Preferably, each riser (1990, 2090) comprises at least two riser pistons (1980) configured to raise and lower the groups (2000) of electrodes (2200). The system is configured so that, for every pair of risers (1990, 2090), when one riser (1990, 2090) (and group (2000) of electrodes (2200)) is in a raised configuration, the other of each pair of groups (2000) of electrodes (2200) is in a lowered configuration. For nonlimiting example, as shown in Fig. 8D, when the first riser (1990) comprising the first group (2000) of electrodes (2200) is in a raised position (white up arrow), the second riser (1990) comprising the second group (2000) of electrodes (2200) is in a lowered position (black down arrow), and the third riser (1990) comprising the third group (2000) of electrodes (2200) is in a raised position (white up arrow). In the next half-cycle, the first riser (1990) will be in a lowered position, the second riser (1990) will be in a raised position, and the third riser (1990) will be in a lowered position.

[0137] In a lowered configuration, the fins (2010) are dragged through the soil. After a predetermined time, which can depend on the soil conditions, the lowered fins (2010) are raised from the ground freeing the fins (2010) of soil and weeds that may have collected on their front edges, while lowering the alternate set(s) of fins into the ground.

[0138] In this exemplary embodiment, there is a radiator (1230) in fluid communication with the motor and, in some embodiments, at least one riser (1990, 2090), to ensure that parts do not overheat.

[0139] The main frame comprises at least one sensor (2900). The sensor is selectable from the group consisting of a humidity sensor, a conductivity sensor, a temperature sensor, a voltage sensor, a current sensor, a power level sensor, a distance sensor, or any combination thereof.

[0140] The main frame (1300) comprises wheels (1910) configured to allow easy movement of the disinfection unit (1100).

[0141] At the rear of the disinfection unit (1100) is a soil preparation unit (1920) configured to smooth soil disturbed by the electrodes (2010). In some embodiments, the soil preparation unit (1920) is also configured to prepare the soil for sowing, with the sowing done separately; in other embodiments, the soil preparation unit (1920) is configured to both prepare the soil for sowing and sow the seed. In still other embodiments, the soil preparation unit (1920) is configured to prepare the soil and insert seedlings or plants into the soil. The soil preparation unit (1920) comprises a soil preparation piston (1924) and pivot bracket (1926) configured to reversibly raise the soil preparation unit (1920) from ground level.

[0142] Typically, there is one transformer per group of electrodes. In the exemplary embodiments shown, there are three transformers, one for each of the groups of electrodes. In some embodiments, there can be one transformer per pair of electrodes.

[0143] In some embodiments, there is one generator of electric power, providing power to all the transformers. In some embodiments, there is one generator per transformer. In some embodiments, there is more than one generator per transformer, and in some embodiments, one generator provides power for more than one transformer. The power from the generator(s) is preferably voltage stabilized and current stabilized.

[0144] The system comprises at least one sensor to determine soil data comprising at least one of the humidity of the soil, the conductivity of the soil and the temperature of the soil and / or to determine operating conditions comprising at least one of temperature of the fins, voltage, current, and power level; at least one power generator configured to generate power at a predetermined current and voltage, a processor to control the current and voltage generated by at least one power generator, the values of the current and voltage depending on the measured parameters; and electrodes to deliver the power at the current, voltage and power values determined by the processor. For example, dry soil, which typically has a high resistance, will require a higher current for disinfection than a soil, such as a wet soil, with a lower resistance.

[0145] The voltage applied between positive (or powered) (+) and negative (or zero) (-) electrodes is in a range between 0.2 kV and 6 kV or any range therebetween.

[0146] The frequency of the applied power is between 50 Hz and 300 Hz or any range therebetween. In some embodiments, the frequency is 100 Hz.

[0147] The applied current is typically in a range from 0.5 A to 50 A or any range therebetween, but can be up to 60 A or any range thereunder. Typically, currents above 50 A are overload currents that can only be sustained for a relatively short time (up to half an hour.)

[0148] The applied power is in a range from 50 kW to 400 kW or any range therebetween.

[0149] In practice, the frequency of the applied power depends on the frequency of the generator and is a constant for the disinfection device. The power is selectable, depending on the properties of the soil and the type of pest to be destroyed, and the voltage is varied, depending on the resistance of the soil. The current is then adjusted to keep the total applied power constant.

[0150] In the exemplary embodiments shown, there are four fins (2010) per electrode (2200). The number of fins per electrode can be in a range from 2 to 10 or any range therebetween.

[0151] The number of electrodes per group (or fins per row) will depend on the width of the support plate and the center-to-center distance between fins (or electrodes). In some embodiments, there can be 4, 11, 15 or 21 electrodes per group, and the number of electrodes per group can be in a range from 2 to 50 or any range therebetween.

[0152] Preferably, either the fins (2010) are reversibly attached to the support plate (1200) or, for each electrode comprising a plurality of fins (2010), the electrodes (2200) are reversibly attachedto the support plate (1200), so that a damaged or otherwise unsatisfactory fin (2010) or electrode (2010) can be replaced.

[0153] In preferred embodiments, the system further comprises a means to enable the system to traverse ground with the electrodes not touching the ground. Typically, this is a motor (1190, see Fig. 8) for reversibly raising the support plate(s) (1200) so that the fins either no longer touch the ground or are configured to enter the ground, but any conventional means of reversibly moving the fins upward and downward can be used.

[0154] Fig. 9A-C schematically illustrates embodiments of fin (2010) tips configured to increase the effective voltage applied to regions in the soil. Figs. 9A-B schematically illustrate embodiments comprising a thin fiber (2018), in some embodiments a nanofiber, to increase the voltage in the soil in the region between the fin (2010) and the fiber (2018), thereby providing either the same pathogen killing efficiency using lower power, or an increased pathogen killing efficiency for the same applied power. In the embodiments of Fig. 9A-B, a support (2016) holds the fiber (2018) away from, but close to, the fin (2010) tip. The distance between the edge of the fin (2010) and the fiber (2018) can be in a range from 1pm to 10cm or any range therebetween. Any non-conductive material with sufficient strength can be used for the support. In Fig. 9A, the edge of the fin under the fiber is substantially straight; in Fig. 9B, the edge of the fin under the fiber is serrated, thereby increasing the electric field in the regions (2019) where the serrations he closest to the fiber (2018). The fiber (2018) can be on the concave side of the fin, on the convex side of the fin, on a straight side of the fin, or any combination thereof.

[0155] Fig. 9C schematically illustrates a knife-like embodiment, where one side of the fin (2010) is thin (2017) and the other side is thick. In the embodiment shown in Fig. 9C, the thin side is the trailing side of the fin, so that the soil will have been broken up by the thick side as the fin (2010) is pulled through the soil. The knife-like fin embodiment can be straight, as shown in Fig. 9C, or can be curved as shown in in Fig. 9A-B. The thin (2017) side can be on the trailing side of the fin, as shown in Fig. 9C, or it can be on the leading side of the fin.

[0156] Fig. 10A-D illustrates an exemplary embodiment of a rotavator (4000) configured to kill pathogens. Fig. 10A shows a perspective view of the rotavator (4000), Fig. 10B shows a side view, Fig. 10C shows a front view and Fig. 10D shows a top view of the rotavator (4000). The rotavator (4000) comprises a plurality of shock discs (4100), with each shock disc (4100) rotatably mountedon an isolation plate (4200) and in electric connection with at least one electric brush (4300) to transfer electric power to the shock disc (4100). As shown, the shock discs (4100) are about 15 cm thick and about 150 cm apart; the thickness of the discs is not germane to the patent, while the distance apart can be in a range from 50 cm to 300 cm or any range therebetween. All of the isolation plates (4200) are mounted to a modular support structure (4400) that comprises control electronics and either power sources or connections to power sources, as disclosed herein.

[0157] Fig. 11 shows an exemplary embodiment of a block diagram (300) of the control system. The human-machine interface (305) accepts information and commands from a user and displays operating information to the user. Data that can be accepted can comprise, but is not limited to, one or more of: type of soil (non-limiting examples: clayey, sandy, loam, silt, alfisol, aridisol, inceptisol), type of pest to be destroyed, size and shape of field, speed of propulsion means, applied power, applied voltage, and generator frequency. Operating information can comprise, but is not limited to, one or more of: fin temperature, air temperature, soil temperature, soil humidity, soil conductivity, fin failure, location of failed fin, electrode failure, location of failed electrode, fin damage, location of damaged fin, electrode damage, location of damaged electrode, generator power, generator frequency, generator overload, transformer overload, transformer output power, transformer output voltage, and transformer output current.

[0158] The processor comprises a process control system (310) configured to input at least one signal from at least one sensor and, in some embodiments, to input other data such as, but not limited to, the speed of the disinfection device (or propulsion unit) and at least one command from a human-machine interface, and to determine from the at least one sensor signal and, if present, at least one other datum, and to output (315) to the generator (320), the transformer (325, 330, 335), or any combination thereof, the current, voltage and power to be applied between at least one pair of electrodes (340, 345, 350) . The processor is further configured to execute at least one set of instructions, the instruction set comprising at least one instruction for controlling a treatment of a portion of the soil. The instruction(s) is selected from the group consisting of: a startup instruction for bringing the system from an inactive state (no power to the electrodes, room temperature electrodes, no power to a unit propelling the system forward, etc.) to an active state (at least one of power at predetermined voltage, current and power level, electrode at a predetermined temperature, soil at a predetermined temperature and predetermined power or speed to a unit propelling the system forward), maintain a predetermined active state for a predetermined time,maintain a predetermined active state for a predetermined distance, change the active state to another active state, and bring the system from an active state to an inactive state.

[0159] An instruction set can be accepted from the human-machine interface or can be stored in a database. It should be noted that an instruction can be “execute a given instruction set, as stored in the database”.

[0160] In preferred embodiments, all control data are displayed by the human-machine interface, enabling a user to remain in full control of the system.

[0161] In some variants of embodiments with more than one power unit, the processor is further configured to determine which power unit(s) are used to supply power to the electrodes and the amount of power supplied by each unit, all of the power unit parameters being changeable depending on the total power required at any given time and the operating characteristics of each power unit, such as, but not limited to, the maximum power (power level, current and voltage) suppliable by the power unit(s), the fraction of maximum power (power level, current and voltage) being utilized, the temperature of the power unit(s) or any combination thereof.

[0162] In some embodiments, the human-machine interface is configured to display electrode voltage, load current, soil temperature, soil humidity, soil conductivity, fin temperature, electrode temperature, generator overload status, transformer overload status or any combination thereof. The human-machine interface is further configured to accept input of electrode voltage, load current, power or any combination thereof to be applied to the electrodes; to activate and deactivate the system, to clear a generator overload status, to clear a transformer overload status, or any combination thereof. In some embodiments, the processor is further configured to automatically perform: setting an electrode voltage, setting a load current, setting power or any combination thereof to be applied to the electrodes; activating and deactivating the system, clearing a generator overload status, clearing a transformer overload status, or any combination thereof. In embodiments with a propulsion unit, engine parameters such as oil pressure, oil temperature, fuel level, coolant level, coolant temperature, motor speed, motor output power, other motor parameters, or any combination thereof.

[0163] In some embodiments, the power unit comprises a plurality of power supplies.

[0164] The power supply(s) can be a part of a tractor, part of a propulsion unit, integral with the disinfection u4nit, a stand-alone power supply or any combination thereof.

[0165] Preferably, a stand-alone power supply will be towable by a propulsion unit such as, but not limited to, a tractor, although some embodiments can have at least one generator in electrical communication with at least one of an independently movable power supply, a power supply towed by an independently movable unit (such as, but not limited to, another tractor), and a stationary power supply.

[0166] Preferably, the generator(s) are pulled by the same propulsion unit as pulls the disinfection unit. However, in less-preferred embodiments, at least one generator can be independently movable, towed by an independently movable unit (such as, but not limited to, another tractor), and stationary.

[0167] The processor can be further configured to determine the speed of the system, either by inputting the speed of a pulling tractor or other propulsion unit and setting the forward speed of the system to equal that of the tractor or other propulsion unit. In some embodiments, the speed of the propulsion unit is set by the processor.

[0168] The processor can be further configured to determine the presence of a mechanical breakdown in at least part of the system. In such embodiments, the processor can perform at least one of: alert the user as to the existence of a breakdown, alert the user as to the nature of the breakdown, alert the user as to the location in the system of the breakdown, and put at least part of the system in an inactive state. In some embodiments, based on sensor input, length of time in use, expected lifetime of components, etc., the processor can be further configured to provide an alert of the probability of a breakdown.

[0169] In some embodiments, the system comprises at least one circuit breaker for the system. Alternatively or additionally, at least one individual power supply can have its own circuit breaker, as can individual transformer(s).

[0170] Fig 12 shows an exemplary embodiment of a flow chart (400) for a soil disinfection unit. When the system is activated, the processor and human-machine interface are activated (405). The user (via the human-machine interface), the processor, or both set the operating parameters (410), such as power level, type of pest, speed, type of soil, etc., as described herein. The sensor(s) areactivated (415) and the disinfection unit starts moving (420). Note that sensor activation and start of movement can occur at any time; the order shown is exemplary. Soil data are measured (425). The processor then determines (430), from the operating parameters and the soil data, the operating values (power and voltage) for the generator(s) and transformer(s), which are applied (435) to the soil. As the disinfection unit moves, the system repeats the steps of measuring soil data (425), determining (430) operating values and applying (435) the operating values to the soil via the electrodes.

[0171] EXAMPLE 1

[0172] The efficacy of treatment for killing nematode species has been examined, since nematodes are a key detrimental factor for many commonly-grown crops, such as, but not limited to, citrus trees, bananas, barley, beans, lettuce, potatoes, melons, strawberries and tomatoes.

[0173] Initial experiments, as shown in Table 1, have indicated current and voltage levels needed to reliably kill nematodes.

[0174] Soil moisture and soil temperature were measured before and after the treatments to maximize the efficiency of the disinfection process. Soil preparation was the same for the five experiments.

[0175] It can be seen that, to kill nematodes, at least 1000 V is needed at a current above about 4.6 A. The optimum exposure time is 4 separate exposures, each of about 10 s.

[0176] Table 1 : Effect of current, voltage and exposure time on killing nematodes in soil

[0177] EXAMPLE 22 /

[0178] The effect of different exposure times on growth of plants was studied.

[0179] Fig. 13A-C shows the results of the growth tests. The plants were planted in soil that contained a predetermined concentration of nematodes, one known to be sufficient to inhibit growth of the plants.

[0180] Fig. 13A shows the growth of the control plants, which had no exposure to current or voltage. Fig. 13B shows the growth of plants which had a short exposure to a predetermined current and voltage at a predetermined power, the voltage, current and power chosen to be effective at killing nematodes. Fig. 13C shows the growth of plants which had a long exposure to the same predetermined current and voltage as the plants of Fig. 13B.

[0181] The control plants of Fig. 13A, which received no exposure to the electric power, were found to be delayed, with sparse leaves and a smooth and undeveloped root system. They are the smallest, have the fewest leaves and have the least root development. The plants of Fig. 13B, which had a short exposure, show considerably more root development than the plants of Fig. 13A. The plants of Fig. 13B are larger and have more leaves. The plants of Fig. 13C, which had a long exposure, show nearly twice as much root development as the plants of Fig. 13B. the plants of Fig. 13C are significantly larger than those of Fig. 13B, have significantly more leaves and appear more mature than the plants of Fig. 13B, with those plants appearing more mature than the plants of Fig. 13A

[0182] EXAMPLE 3

[0183] The effect of different exposure times on disinfection of different types of soil was studied.

[0184] It is well known that soils can have different moisture content at different times and that different types of soil hold moisture in different ways. Since water is a conductor, the resistance of the soil will depend on the soil type and the soil moisture content. Since P=IV=I2R where P is the applied power, I is the current, V is the voltage and R the resistance, for a constant total power applied to soil, the current and voltage applied will depend on the soil resistance R and, therefore, on the soil type and soil moisture.

[0185] For the tests shown in Table 2, a total power of 2500 W was applied to the soil. Two exposure times were used, a short exposure of 6 s and a long exposure of 12 s. The soil types were medium soil and sandy soil.

[0186] The resistance of the medium soil was greater than that of the sandy soil, as the currents were lower for the medium soil than the sandy soil for both a short exposure and a long exposure.The currents were larger for the long exposure than for the short exposure for both soil types, showing that the soil was more moist for the long exposure than for the short exposure.

[0187] The untreated controls showed no disinfection. The treated soils all showed excellent disinfection for both soil types and both exposure times, being above 90% for all treated soils. As expected, disinfection was better for the longer exposure.

[0188] Table 2: Effect of current and exposure time on disinfection of different types of soil

[0189] EXAMPLE 4

[0190] The effect of different exposure times on growth of lettuce was studied.

[0191] Fig. 14A-C shows the results of the growth tests. The lettuce plants were planted in soil that contained a predetermined concentration of nematodes, one known to be sufficient to inhibit growth of the plants.

[0192] Fig. 14A shows the growth of the 7control plants, which had no exposure to current or voltage. Fig. 14B shows the growth of plants which had a short exposure to a predeterminedcurrent and voltage at a predetermined power, the voltage, current and power chosen to be effective at killing nematodes. Fig. 14C shows the growth of plants which had a long exposure to the same predetermined current and voltage as the plants of Fig. 14B.

[0193] The plants on the left in Figs. 14A-C were grown in a cold microclimate, while the plants on the right were grown in a warm microclimate. In all cases, more growth was seen for the plants grown in a warm microclimate, with both larger leaves and larger root balls.

[0194] The control plants of Fig. 14A, which received no exposure to the electric power, were found to be delayed, with sparse leaves and a smooth and undeveloped root system. They are the smallest, have the fewest leaves and have the least root development. The plants of Fig. 14B, which had a short exposure, show considerably more root development than the plants of Fig. 14A. The plants of Fig. 14 are larger and have more leaves. However, some of the leaves are yellowed, showing the effects of damage by the nematodes. The plants of Fig. 14C, which had a long exposure, show nearly twice as much root development as the plants of Fig. 14B. The plants of Fig. 14C are significantly larger than those of Fig. 14B, have significantly more leaves and appear more mature than the plants of Fig. 14B, with those plants appearing more mature than the plants of Fig. 14A.

[0195] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed.

[0196] The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.

Claims

CLAIMS:

1. A trailed implement for electrically disinfecting soil in a land, said trailed implement comprising: a main frame comprising: at least one support plate comprising at least one group of electrodes; in each said at least one group of electrodes, there is at least one first polarity electrode and at least one second polarity electrode, each of said first polarity electrode having a first polarity, each of said first electrode alternating with at least one second polarity electrode, said second polarity electrode having a second polarity, said first polarity and said second polarity being two selected from the group consisting of positive, zero or negative; at least one sensor for detecting soil data; an electrical power source for providing voltage and current to at least one of said at least one first polarity electrode and said at least one second polarity electrode; and a processor for processing said soil data collected by said sensor, said at least one processor configured to determine, from soil data transmitted by said at least one sensor, a value for an electrical parameter selected from the group consisting of voltage, current, power level or any combination thereof required to kill or disable at least one type of pest; and to instruct said electrical power source to apply said electrical parameter to said at least one group of electrodes; wherein each electrode in each of said at least one group of electrodes comprises a plurality of fins, said fins extending downward from said support plate, the front edges of each row of fins forming a line parallel to a front edge of the support plate, said fins being insertable in said soil, said fins administering said electrical power to said soil; further wherein said fins are configured to be movably embedded in soil and to administer said electrical power to said soil; said at least one processor being configured to determine, from soil data transmitted by said at least one sensor, a value for an electrical parameter selected from the group consisting of voltage, current, power level or any combination thereof required to kill or disable at leastone type of pest; and to instruct said electrical power source to apply said electrical parameter to said at least one group of electrodes.

2. A method for disinfecting soil, said method comprising steps of: obtaining a movable trailed implement comprising: a main frame comprising: at least one support plate comprising at least one group of electrodes; in each said at least one group of electrodes, there is at least one first polarity electrode and at least one second polarity electrode, each of said first polarity electrode having a first polarity, each of said first electrode alternating with at least one second polarity electrode, said second polarity electrode having a second polarity, said first polarity and said second polarity being two selected from the group consisting of positive, zero or negative; at least one sensor for detecting soil data; an electrical power source for providing voltage and current to at least one of said at least one first polarity electrode and said at least one second polarity electrode; and a processor for processing said soil data collected by said sensor, said at least one processor configured to determine, from soil data transmitted by said at least one sensor, a value for an electrical parameter selected from the group consisting of voltage, current, power level or any combination thereof required to kill or disable at least one type of pest; and to instruct said electrical power source to apply said electrical parameter to said at least one group of electrodes; and operating said trailed implement; wherein each electrode in each of said at least one group of electrodes comprises a plurality of fins, said fins extending downward from said support plate, the front edges of each row of fins forming a line parallel to a front edge of the support plate, said fins being insertable in said soil, said fins administering said electrical power to said soil; further wherein said fins are configured to be movably embedded in soil and to administer said electrical power to said soil; said at least one processor being configured to determine, from soil data transmitted by said at least one sensor, avalue for an electrical parameter selected from the group consisting of voltage, current, power level or any combination thereof required to kill or disable at least one type of pest; and to instruct said electrical power source to apply said electrical parameter to said at least one group of electrodes.

3. The trailed implement of claim 1 or the method of claim 2, wherein said at least one support plate is configured to have at least two configurations, a raised configuration with the tips of the fins above a plane defined by bases of the wheels and a lowered configuration with the tips of the fins below the plane defined by bases of the wheels, said at least one support plate reciprocally translatable between said raised configuration and said lowered configuration.

4. The trailed implement of claim 3 or the method of claim 3, wherein said at least one support plate comprises more than one support plate, said translation between said raised configuration and said lowered configuration being selected from the group consisting of at least two of said more than one support plate translate in a same direction, at least two of said more than one support plate translate in opposite directions, or any combination thereof.

5. The trailed implement of claim 3 or the method of claim 3, additionally comprising a motor configured to induce said reciprocal translation.

6. The trailed implement of claim 1 or the method of claim 2, wherein tips of said fins point in a direction opposite to the direction of travel of the trailed implement.

7. The trailed implement of claim 1 or the method of claim 2, wherein at least one of the following is true: a. a number of fins per electrode is selected from the group consisting of four or in a range from 2 to 10; b. a number of electrodes in said at least one group of electrodes is selected from the group consisting of 15 or in a range from 10 to 50; c. an absolute value of a voltage applicable to said at least one group of electrodes is in a range between 0.5 kV and 400 kV; d. a frequency of the applied power is selected from the group consisting of 50 Hz, 75 Hz, 100 Hz, or in a range of 50 Hz to 1000 Hz; e. said power level is in a range from 50 kW to 400 kW; orf. an applied current is selected from the group consisting of in a range from 10 A to 30 A, or in a range from 0.5 A to 50 A.

8. The trailed implement of claim 1 or the method of claim 2, wherein the at least one sensor is selected from the group consisting of a humidity sensor, a conductivity sensor, a temperature sensor, a voltage sensor, a current sensor, a power level sensor, a distance sensor, or any combination thereof.

9. The trailed implement of claim 1 or the method of claim 2, additionally comprising at least one circuit breaker.

10. The trailed implement of claim 1 or the method of claim 2, additionally comprising a human-machine interface.

11. The trailed implement of claim 10 or the method of claim 10, wherein the humanmachine interface is configured to display a member of the group consisting of electrode voltage, load current, soil temperature, soil humidity, soil conductivity, track shoe temperature, electrode temperature, generator overload status, transformer overload status or any combination thereof.

12. The trailed implement of claim 10 orthe method of claim 10, wherein the humanmachine interface is configured to provide at least one alert.

13. The trailed implement of claim 12 or the method of claim 12, wherein the at least one alert is selected from the group consisting of alert as to the existence of a breakdown, alert as to the nature of the breakdown, alert as to the location in the system of the breakdown, alert of the probability of a breakdown, alert of an overload, alert of an electrical failure, alert of a short, alert of a failure of a power supply, alert of a failure in a transformer or any combination thereof.

14. The trailed implement of claim 1 or the method of claim 2, wherein at least one of the following is true: a. said soil data is selected from the group consisting of humidity, temperature, conductivity or any combination thereof; b. said trailed implement is configured to be operable in a manner selected from the group consisting of manually, autonomously or any combination thereof; or c. said trailed implement is configured to be remotely controllable.

15. The trailed implement of claim 1 or the method of claim 2, wherein said at least one member of said at least one group of electrodes is configured to be heated by a method selected from the group consisting of induction heating, resistance heating, electric arc heating, dielectric heating or any combination thereof.

16. The trailed implement of claim 1 or the method of claim 2, wherein at least one of the following is true: a. a length of said fin is selected from the group consisting of 300 mm or in a range from 100 mm to 600 mm; b. a lateral center-to-center distance between fins is selected from the group consisting of 150 mm or in a range from 100 mm to 300 mm; c. a longitudinal center-to-center distance between fins is selected from the group consisting of 50 mm or in a range from 100 mm to 3000 mm; or d. said at least one group of electrodes comprising a plurality of groups of electrodes, a distance between any adjacent two of said plurality of groups of electrodes is selected from the group consisting of 250 mm, or in a range from 150 mm to 2000 mm.

17. The trailed implement of claim 1 or the method of claim 2, wherein a number of transformers is selected from the group consisting of one transformer for each of said at least one group of electrodes or in a range from 1 to 12.

18. The trailed implement of claim 1 or the method of claim 2, wherein said trailed implement is either self-contained or is configured to be attachable to another vehicle.

19. The trailed implement of claim 18 or the method of claim 18, wherein said self- contained trailed implement comprises a propulsion unit configured to move said trailed implement.

20. The trailed implement of claim 19 or the method of claim 19, wherein said movement of said trailed implement is either autonomous or by remote control.

21. The trailed implement of claim 18 or the method of claim 18, wherein said trailed implement is attachable to a power take off (PTO).

22. The trailed implement of claim 1 or the method of claim 2, wherein soil to bedisinfected is selected from the group consisting of soil in an open area or soil in an enclosed space.

23. The trailed implement of claim 22 or the method of claim 22, wherein said soil in an open area is selected from the group consisting of a field, arable land, agricultural land, cropland, pasture, rangeland, grassland, shrubland, a nursery, an orchard, a garden, a lawn, forestry, silviculture, a sport field, cultivable land, a plantation, a berm, a verge, land requiring remediation, or any combination thereof.

24. The trailed implement of claim 23 or the method of claim 23, wherein said land requiring remediation is selected from the group consisting of land requiring removal of plant-damaging pests, land requiring removal of plant-damaging pathogens, land requiring removal of animal-damaging pests, land requiring removal of animal-damaging pathogens, land requiring removal of chemicals or any combination thereof.

25. The trailed implement of claim 22 or the method of claim 22, wherein said soil in an enclosed space is selected from the group consisting a bam, a greenhouse, a stable, a dovecot, soil for indoor remediation or any combination thereof.

26. The trailed implement of claim 25 or the method of claim 25, wherein said soil for indoor remediation is selected from the group consisting of soil from a vertical farming operation, soil from a greenhouse or any combination thereof.

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