WO2022161798A1

WO2022161798A1 - Method, vehicle and system for abiotic stress management

Info

Publication number: WO2022161798A1
Application number: PCT/EP2022/050830
Authority: WO
Inventors: Malcolm Faers; Andrew Charles Chapple
Original assignee: Bayer Aktiengesellschaft
Priority date: 2021-01-26
Filing date: 2022-01-17
Publication date: 2022-08-04

Abstract

The present invention relates to a method (10) to identify abiotic stress of crop plants on an agricultural field comprising the steps of a) acquiring height information of a plurality of crop seedlings on an agricultural field and the corresponding geopositional information of the plurality of crop seedlings on the agricultural field; b) generating a crop seedling height map of the plurality of crop seedlings on the agricultural field on the basis of the acquired height information and the corresponding geopositional information of the plurality of crop seedlings on the agricultural field; c) comparing the height of the plurality of the crop seedlings on the crop seedling height map to identify subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height; d) generating a crop plant abiotic stress map wherein the generation of the crop plant abiotic stress map comprises utilization of the identified subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height.

Description

METHOD, VEHICLE AND SYSTEM FOR ABIOTIC STRESS MANAGEMENT

FIELD OF THE INVENTION

The present invention relates to a method for abiotic stress management, to vehicle(s) for abiotic stress management, to a system for abiotic stress management, as well as to a computer program product.

BACKGROUND OF THE INVENTION

The general background of this invention is abiotic stress management of crop plants on an agricultural field. Modem agriculture faces many challenges in producing sufficient food in a safe and sustainable way. One of the challenges that affect the quality and quantity of agricultural produce comes from abiotic stress, which can have significant negative impacts on the yield and quality of agricultural produce. Abiotic stress refers to crop plant growth and development issues that can be associated with low or high temperature, deficient or excessive water, nutritional deficiency, high salinity, heavy metals, and ultraviolet radiation. Often, abiotic stress occurs only on subregions of an agricultural field and early detection of abiotic stress factors would be favorable to avoid negative impacts on the crop growth and development. Remote sensing techniques such as the measurement of spectral reflectance e.g. in the form of spectral vegetation indices can support the identification of abiotic stress of crop plants. However, these approaches have the disadvantage that they can only be used when the plant crop is already in a later vegetative growth stage respectively in a reproductive stage. Therefore, the detection of abiotic stress with conventional methods does not occur at a very early growth and development stage which would however be preferable in order to ensure that the crop plants profit from optimal environmental growing and development conditions through the whole lifecycle of the crop plants.

SUMMARY OF THE INVENTION

It would be advantageous to have improved means for abiotic stress management of crop plants in order to ensure the best possible growing and development conditions. The object of the present invention is solved with the subject matter of the independent claims, wherein further embodiments are incorporated in the dependent claims. It should be noted that the following described aspects and examples of the invention apply also for the method to identify (and manage) abiotic stress of crop plants, the vehicle(s) for abiotic stress management of crop plants, the system for abiotic stress management of crop plants, and for the computer program product.

According to a first aspect, there is provided a method to identify abiotic stress of crop plants on an agricultural field comprising the steps of: a) acquiring height information of a plurality of crop seedlings on an agricultural field and the corresponding geopositional information of the plurality of crop seedlings on the agricultural field, b) generating a crop seedling height map of the plurality of crop seedlings on the agricultural field on the basis of the acquired height information and the corresponding geopositional information of the plurality of crop seedlings on the agricultural field, c) comparing the height of the plurality of the crop seedlings on the crop seedling height map to identify subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height, d) generating a crop plant abiotic stress map wherein the generation of the crop plant abiotic stress map comprises utilization of the identified subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height.

Thus, the height and geolocation of the crop seedlings on the agricultural field is recorded. The height of a seedling cannot be easily estimated with RGB and/or a multispectral camera since the information obtained is in the colour (wavelength) domain without distance information but is preferably recorded with sensors such as LiDAR which collect information in the reflectance time-of-flight domain that provides distance information similar to radar, and from which the height of a seedling can be determined. In addition, an Unmanned Aerial Vehicle (UAV) with such a sensor and a GPS system can be used to record the required data. With the height and geolocation information a crop seedling height map is generated which refers to a two-dimensional or three-dimensional display of the crop seedlings geopositional distribution on an agricultural field and the corresponding height of each crop seedling on the agricultural field. The height of a crop seedling can give an indication of whether the crop seedling suffers from abiotic stress e.g. if not sufficient nutrients are available for the growing process. By height comparison on the crop seedling height map of the agricultural field, subregions on the agricultural field can be identified where crop seedlings are associated with a below average crop seedling height. A crop plant abiotic stress map is generated by utilizing the information about the identified subregions. The crop plant abiotic stress map represents a (at least a) two- dimensional (or three-dimensional) display of the crop seedling geopositional distribution on an agricultural field where an abiotic stress control agent can be applied to appropriately control the abiotic stress on the field. In this manner, abiotic stress can be identified at a very early point in time which allows precision farming abiotic stress control applications to ensure optimal growth and development conditions through the whole lifecycle of the crop plants.

In an example, the method comprises and additional step e) application of an abiotic stress control agent to the agricultural field according to the abiotic stress map.

In other words, the abiotic stress control agent spray map can be used by a vehicle to apply water and/or nutritional agent such as a fertilizer in a precision farming approach at a very early crop growth stage. This has the advantage that due to the precision application approach only resources are applied on the agricultural field where needed. In addition, vehicles such as UAVs with limited load can be used to apply the abiotic stress control agents because the abiotic stress control agents are only partially applied to the agricultural field. With UAVs soil compaction on the agricultural field can be avoided.

In an example, the height information of the plurality of crop seedlings on the agricultural field is acquired within a time period of 1 to 4 weeks after the plurality of crop seeds have been planted on the agricultural field.

The method as suggested herein is targeted to tackle abiotic stress issues of crop plants at a very early point in time and before a later vegetative growth phase of the crops.

In an example, the geopositional information of the plurality of crop seedlings on the agricultural field is acquired with location determining means at the same instance when the height information of the plurality of crop seedlings is acquired.

In other words, the geopositional information and the height data for the crop seedling height map is acquired in one operational process. The sensor measurement of the height data is synchronized with the information from a GPS system.

In an example, the method comprises step aO) (prior to step a) and an alternative step a): a0) acquiring geopositional information of where crop seeds have been planted and/or are being planted on an agricultural field and generating a crop seed map, a) acquiring the height of the plurality of crop seedlings on the agricultural field at the geopositional information on the agricultural field where the plurality of crop seeds have been planted according to the crop seed map.

Thus, the geolocation of the crop seeds in the soil on the agricultural field is recorded during planting. The crop seed map refers to a two-dimensional or three-dimensional display of the crop seed geopositional distribution on an agricultural field after planting. This information is used as a guidance to acquire the height information of the plurality of crop seedlings and supports the unambiguous identification of the crop plants (which are in growth competition with weed plants on the agricultural field).

In an example, the geopositional information of the planted crop seeds on the agricultural field is acquired by at least one sensor that is configured to record geopositional information of the crop seeds impinging on the soil during planting of the crop seeds.

Thus, various known detection techniques can be used to acquire information about the geolocation of the seeds on the agricultural fields. As an example, a metering system with a sensor that senses a passing seed, a timer to timestamp when a seed passes the sensor, in synchronization with GPS system can be used to assess the geoposition of crop seeds on the agricultural field. Alternative techniques include for example image analysis of images acquired with a camera from seeds impinging on the soil during the planting process together with GPS data.

In an example, the height information of the plurality of crop seedlings of the crop seedlings on the agricultural field is acquired with a sensor that is configured to generate pulses of light towards a crop seedling plant and to measure the time for any reflections.

In this manner, known sensors such as a LiDAR sensor (also known as LIDAR and lidar) with high resolution can be used to acquire the height data.

According to a second aspect of the invention, there is provided a vehicle for abiotic stress management of crop plants on an agricultural field. The vehicle comprises at least one crop seedling height sensor, a control and processing unit, and location determining means. The at least one crop seedling height sensor is configured to acquire height information of a plurality of crop seedlings on an agricultural field. The control and processing unit is configured to use the location determining means to acquire the geopositional information of the plurality of crop seedlings on an agricultural field. The control and processing unit is configured to receive the height information of the plurality of crop seedlings on the agricultural field from the at least one crop seedling height sensor and the corresponding geopositional information of the plurality of crop seedlings to generate a crop seedling height map of the plurality of crop seedlings on the agricultural field on the basis of the acquired height information and the corresponding geopositional information of the plurality of crop seedlings on the agricultural field. The control and processing unit is configured to compare the height of the plurality of the crop seedlings on the crop seedling height map to identify subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height. The control and processing unit is configured to generate a crop plant abiotic stress map wherein the generation of the crop plant abiotic stress map comprises utilization of the identified subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height.

In other words, a vehicle acquires crop seedling height information and the corresponding geolocation of the crop seedling plants. The control and processing unit of the vehicle uses the information to generate crop seedling height map and a crop plant abiotic stress map. The calculation and generation of the crop seedling height map and/or the crop plant abiotic stress map can also be done on an external processing unit and the information/analysis can be sent to the vehicle that requires the information/analysis.

In an example, the vehicle for abiotic stress management of crop plants on an agricultural field further comprises a receiver. The control and processing unit is configured to utilize the receiver to receive geopositional information where the plurality of crop seeds have been planted on the agricultural field. The control and processing unit is configured to utilize the geopositional information of the planted crops seeds to guide the vehicle to the plurality of crop seedlings to acquire the height information of the plurality of crop seedlings on the agricultural field with the at least one crop seedling height sensor.

In other words, the geolocation information from the seed map as generated during the planting process is used to guide the vehicle to the plurality of crop plants for the acquisition of the height data. An advantage of this is that no discrimination between a weed plant and a crop plant is necessary. In addition, only height data of crop plants is acquired and no height data of weeds which reduces the data storage and processing amount.

In an example, the vehicle for abiotic stress management of crop plants on an agricultural field comprises an output unit. The output unit is configured to receive the crop plant abiotic stress map for the agricultural field from the control and processing unit. The output unit is configured to output the crop plant abiotic stress map for the agricultural field.

In other words, the crop plant abiotic stress map can e.g. be shown to a user such as a farmer on a monitor, hand held, printer, screen or any other information monitoring device/medium.

In an example, the vehicle for abiotic stress management of crop plants on an agricultural field further comprises at least one abiotic stress control agent spray unit. The at least one abiotic stress control agent spray unit is configured to eject an abiotic stress control agent. The control and processing unit is configured to control the at least one abiotic stress control agent spray unit according to the crop plant abiotic stress map.

Thus, the vehicle is guided to crop plants that suffer under abiotic stress on the agricultural field as indicated in the crop plant abiotic stress map. The vehicle uses its abiotic stress control agent spray unit to apply an abiotic stress control agent to the crop seedling which suffers from abiotic stress and/or the surrounding of such a crop seedling. Such an abiotic stress control agent can e.g. be a nutritional agent such as a fertilizer, a nutrient, a micronutrient and/or water.

In a third aspect of the invention, there is provided a crop plant abiotic stress map generated according to the method as discussed under the first aspect of the invention.

In a fourth aspect of the invention, there is provided a system for abiotic stress management of crop plants on an agricultural field comprising a first vehicle for abiotic stress management of crop plants and a second vehicle for abiotic stress management of crop plants, wherein the first vehicle comprises at least one crop seedling height sensor, a control and processing unit, location determining means, and a transmitter. The second vehicle comprises at least one abiotic stress control agent spray unit, a control and processing unit, and a receiver. The at least one crop seedling height sensor of the first vehicle is configured to acquire height information of a plurality of crop seedlings on an agricultural field. The control and processing unit of the first vehicle is configured to use the location determining means to acquire the geopositional information of the plurality of crop seedlings on an agricultural field. The control and processing unit of the first vehicle is configured to receive the height information of the plurality of crop seedlings on the agricultural field from the at least one crop seedling height sensor and the corresponding geopositional information of the plurality of crop seedlings from the location determining means to generate a crop seedling height map of the plurality of crop seedlings on the agricultural field on the basis of the acquired height information and the corresponding geopositional information of the plurality of crop seedlings on the agricultural field. The control and processing unit of the first vehicle is configured to compare the height of the plurality of the crop seedlings on the crop seedling height map to identify subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height. The control and processing unit of the first vehicle is configured to generate a crop plant abiotic stress map wherein the generation of the crop plant abiotic stress map comprises utilization of the identified subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height. The control and processing unit of the first vehicle is configured to utilize the transmitter to send the crop plant abiotic stress map to the second vehicle. The control and processing unit of the second vehicle is configured to utilize the receiver to receive the crop plant abiotic stress map from the first vehicle. The control and processing unit of the second vehicle is configured to control the at least one abiotic stress control agent spray unit according to the crop plant abiotic stress map.

In other words, the assessment of abiotic stress of the crop plants is performed independently of the abiotic stress control measures. As an example, a drone with a LiDAR sensor and a GPS system can acquire the height and geopositional information of the plurality of crop plants on the agricultural field and generate a crop plant abiotic stress map. The map can be forwarded to another vehicle such as another specialized spraying UAV or a tractor with a boom sprayer. These vehicles are configured to partially treat crop plants on the field which suffer from abiotic stress and which are in need for nutritional agents and/or water according to the crop plant abiotic stress map.

According to another aspect, there is provided a computer program product, which when executed by a processor is configured to carry out the method of the first aspect. Advantageously, the benefits provided by any of the above aspects equally apply to all of the other aspects and vice versa.

The above aspects and examples will become apparent from and be elucidated with reference to the embodiments described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments will be described in the following with reference to the following drawings:

Fig. la) to d) shows a schematic example of the method (10) to identify abiotic stress of crop plants on an agricultural field;

Fig. 2 shows a schematic set up of an example of a vehicle (100) for abiotic stress management of crop plants on an agricultural field;

Fig. 3 shows a schematic set up of an example of a system (200) for abiotic stress management of crop plants on an agricultural field;

Fig. 4 shows a schematic set up of an example of a computer program product (300) for abiotic stress management of crop plants on an agricultural field.

DETAILED DESCRIPTION OF EMBODIMENTS

The invention relates in a first embodiment to a method 10 to identify abiotic stress of crop plants on an agricultural field comprising the steps of a) acquiring height information of a plurality of crop seedlings on an agricultural field and the corresponding geopositional information of the plurality of crop seedlings on the agricultural field, b) generating a crop seedling height map of the plurality of crop seedlings on the agricultural field on the basis of the acquired height information and the corresponding geopositional information of the plurality of crop seedlings on the agricultural field, c) comparing the height of the plurality of the crop seedlings on the crop seedling height map to identify subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height, d) generating a crop plant abiotic stress map wherein the generation of the crop plant abiotic stress map comprises utilization of the identified subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height. In an example, the method 10 to identify abiotic stress of crop plants on an agricultural field is a computer-implemented method.

In an example, abiotic stress of crop plants on an agricultural field can be identified at an early vegetative growth stage (preferably of crop plants that have a height of equal or less than 20 cm, preferably equal or less than 10 cm, more preferably equal or less than 5 cm).

In an example, the identification of individual crop seedling plants can involve the utilization of a machine learning algorithm (e.g. to distinguish crop seedling plants from weeds).

In an example, the machine learning algorithm comprises a decision tree algorithm and/or an artificial neural network.

In an example, the machine learning algorithm has been taught on the basis of a plurality of data of crop seedlings and weeds. In an example, the machine learning algorithm has been taught on the basis of a plurality of sensor data containing a plurality of crops seedlings and a plurality of weed plants at different vegetative growth stages.

In an example, the height information of the plurality of crop seedlings on the agricultural field data (and the corresponding geopositional information) is acquired with a LiDAR sensor, a parallax laser rangefinder sensor, a stereo vision sensor, an IR reflectance sensor, a time of flight sensor, an ultrasonic sensor, and a radar sensor.

In an example, a LiDAR sensor is used.

In an example, a 3D LiDAR sensor is used.

In an example, a plurality of LiDAR scans at various locations across the agricultural field are acquired. This is done in order to provide a highly consistent LiDAR point density (number light detection and ranging measured points per unit area on a given target). One issue to consider for ground-based and/or close to the ground-based LiDAR sensor measurements is the potential unevenness of the point density over a scene where parts of the soil rendered closer to the scanner are more densely covered than the ones far away. This can be addressed by various means such as for example by increasing the pulse repetition rate, changing the scan pattern, and/or the scan rate.

In an example, a LiDAR sensor together with a camera is used. The camera can e.g. identify green parts of the plurality of crop seedlings and this information can be taken into account for the generation of the crop seedling height map, respectively also for the generation of the crop plant abiotic stress map (as e.g. the color information can additionally be used to identify abiotic stress).

In an example, the camera is configured to operate over the visible wavelength range. In an example, the camera is configured to operate in the near infrared range. In an example, the camera is monochromatic. In an example, the camera is configured to acquire colour information (RGB). In an example, the camera is configured to acquire hyperspectral information.

In an example, a “crop seedling” refers to crop in an early vegetative growth stage. For soybeans, as an example, a crop seedling is preferably a crop plant in the VE, VC, VI and/or V2 stage more preferably in the VE and/or VC stage. For corn, as an example, a crop seedling is preferably a corn plant in the VE, VI, V2, V3 and/or V4, stage more preferably in the VE, VI and/or V2 stage.

In an example, the term “geopositional information” refers to the real-world geographic location e.g. as represented in geographic coordinates.

In an example, the height data of the plurality of crop seedlings on the agricultural field and the corresponding geopositional information is acquired with a LiDAR sensor and with a position-determining system such as a GPS-Real Time Kinetic (RTK).

In an example, the resolution of the geopositional information is ± 10 cm, more preferably ± 5 cm, and even more preferably ± 2 cm, which can be obtained with a location determining means system such as a GPS-Real Time Kinetic (RTK) system.

In an example, a crop seedling height map refers to at least two-dimensional (or three- dimensional) display of the geopositional coordinates for the agricultural field, wherein for each geopositional coordinate where a crop seedling is present the corresponding height of the crop seedling is indicated (at the time of measurement). The data resolution of the geoposition (horizontal) is depending on the LiDAR and position determining means used and is preferably at least 2 cm, more preferably 1 cm and even more preferably below 1 cm. As concerns the measurement of an individual crop seedling height, todays LiDAR sensors have a resolution of a view millimeters to detect vertical differences which is sufficient to acquire height data of a plurality of crop seedlings on the agricultural field.

In an example, Fig. 1 a) shows the acquisition of height data of a plurality of crop seedlings on an agricultural field with a vehicle which is - in this example - an UAV. The UAV scans the surface of the agricultural field and acquires the height data required for further processing. Fig. 1 b) shows an example of a crop seedling height map. The height map is (at least) a two-dimensional (or three-dimensional) display of the height of the plurality of crop seedlings and their geopositional distribution on an agricultural field. Each value in a square as shown in Fig. 1 b) represents the height (in cm) of one individual crop seedling plant and their corresponding geoposition on the agricultural field.

In an example, the average crop seedling height on the agricultural field is determined by using the acquired height data of the plurality of crop seedlings on the agricultural field. The average crop seedling height can be used to identify subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height as exemplary shown in Fig. 1 c). The average crop seedling height as determined with the values shown in the map according to Fig. 1 b) is 1.35 cm. Therefore, the arithmetic mean can be used to calculate the average crop seedling height. Those crop seedlings on the agricultural field that have a height which is below the calculated average height are indicated in Fig. 1 c) with a chess pattern.

In an example, the crop plant abiotic stress map is (at least) a two-dimensional (or three- dimensional) display of the crop seedling geopositional distribution on an agricultural field and indicates for which crop seedlings an abiotic stress has been identified. The identification of abiotic stress comprises utilization of the identified subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height.

In an example, the identification of abiotic stress can further comprise utilization of machine learning algorithm to identify abiotic stress with the acquired sensor data (such as LiDAR and/or camera data).

In an example, the machine learning algorithm has been taught on the basis of a plurality of abiotic stress sensor data. In an example, the machine learning algorithm has been taught on the basis of a plurality of sensor data containing a plurality of crops seedlings that suffer from abiotic stress due to low or high temperature, deficient or excessive water, nutritional deficiency, high salinity, heavy metals, and ultraviolet radiation.

In an example, the crop plant abiotic stress map as shown in Fig. 1 d) comprises the utilization of the identified subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height only and therefore corresponds to the height map as shown in Fig. l.c).

In an example, additional abiotic stress information e.g. from acquired image data of a camera can be used for the generation of the crop plant abiotic stress map.

According to an example, the method comprises in step e) the application of an abiotic stress control agent to the agricultural field according to the abiotic stress map.

In an example, the abiotic stress control agent is a nutritional agent such as a fertilizer, a nutrient, a micronutrient and/or water.

In an example, the abiotic stress control agent is applied only to those crop seedlings that are in need of measures against abiotic stress. As shown in Fig. 1 d) this are the crop seedlings that are located in the subregions of the agricultural field as indicated with a chess pattern.

According to an example, the height information of the plurality of crop seedlings on the agricultural field is acquired within a time period of 1 to 4 weeks after the plurality of crop seeds have been planted on the agricultural field.

In an example, the height information of the plurality of crop seedlings on the agricultural field is acquired withing a time period of 1 to 3 weeks after the plurality of crops seeds have been planted on the agricultural field.

According to an example, the geopositional information of the plurality of crop seedlings on the agricultural field is acquired with location determining means at the same instance when the height information of the plurality of crop seedlings is acquired.

In an example, a location determining means comprise one or more of a GPS, an inertial navigation systems, or an image based location system. The GPS system is preferably a GPS-Real Time Kinetic (RTK) system.

In an example, the term “at the same instance” refers to one continuous operation on the agricultural field with the same vehicle.

According to an example, the method comprises: aO) - prior to step a) - acquiring geopositional information of where crop seeds have been planted and/or are being planted on an agricultural field and generating a crop seed map, a) acquiring the height of the plurality of crop seedlings on the agricultural field at the geopositional information on the agricultural field where the plurality of crop seeds have been planted according to the crop seed map.

In an example, information about the geopositional information of planted crop seeds on an agricultural field can be acquired with a camera, laser scanner, a one-dimensional line sensor for detecting seeds, a light beam, and a thermosensor for detecting seeds with an elevated temperature together with a position-determining system. US2014/0076216A1 discusses a method for precision drilling of seed grains and the registration of the seed position in a chart.

In an example, the crop seed map refers to the registration of the seed position in a chart particularly in the form of a at least two-dimensional (or alternatively three-dimensional) display of the crop seed geopositional distribution on an agricultural field after planting.

In an example, the terms “where the crop seeds have been planted or are being planted” refer to time points “at” respectively “shortly after” the planting operation. E.g. when crops seeds have been planted with a vehicle with planting equipment. The data can also be acquired with a vehicle that is different from the seed planting vehicle.

According to an example, the geopositional information of the planted crop seeds on the agricultural field is acquired by at least one sensor that is configured to record geopositional information of the crop seeds impinging on the soil during planting of the crop seeds.

In an example, the at least one sensor that is configured to record geopositional information of the crop seeds impinging on the soil during planting of the crop seeds is selected from the group of a camera, laser scanner, a one-dimensional line sensor for detecting seeds, a light beam, and/or a thermosensor for detecting heated-up seeds; all together (and in synchronization) with a position determining means.

In an example, a location determining means comprise one or more of a GPS, an inertial navigation systems, or an image based location system. The GPS system is preferably a GPS-Real Time Kinetic (RTK) system. The location can be a geographical location, with respect to a precise location on the ground, or can be a location on the ground that is referenced to another position or positions on the ground, such as a boundary of an agricultural field. In other words, an absolute geographical location can be utilized or a location on the ground that need not be known in absolute terms, but that is referenced to a known location can be used.

In an example, the location is an absolute geographical location.

In an example, if a camera is used the location is a location that is determined with reference to a known location or locations. In other words, an image can be determined to be associated with a specific location on the ground, without knowing its precise geographical position, but by knowing the location where an image was acquired with respect to known position(s) on the ground the location where imagery was acquired can be logged. In other words, absolute GPS derived locations of where a vehicle has acquired imagery of the ground could be provided, and/or the locations of where imagery was acquired relative to a known position such as a field boundary could be provided, which again enables the control and processing unit to determine the exact positions where imagery was acquired because they would know the absolute position of the field boundary.

In an example, a GPS unit is used to determine, and/or is used in determining, the location, such as e.g. the location of the camera when specific images were acquired.

In an example, an inertial navigation unit is used alone, or in combination with a GPS unit, to determine the location, such as e.g. the location of the camera when specific images were acquired.

According to an example, the height information of the plurality of crop seedlings of the crop seedlings on the agricultural field is acquired with a sensor that is configured to generate pulses of light towards a crop seedling plant and to measure the time for any reflections.

In an example, the measurement of time for any reflections is done together (and in synchronization) with location determining means. *

In an example, the sensor that is configured to generate pulses of light towards a crop seedling plant on the agricultural field and to measure the time for any reflections is selected from the group of a LiDAR sensor, a parallax laser rangefinder sensor, a stereo vision sensor, an IR reflectance sensor, a time of flight sensor, an ultrasonic sensor, a radar sensor.

In an example, a LiDAR sensor is used.

In an example, a 3D LiDAR sensor is used.

In an example, a LiDAR sensor together with a camera is used. The camera can e.g. identify green parts of crop seedlings, and this information can be taken into account for the generation of the abiotic stress map.

In an example, the LiDAR sensor and/or the camera acquire data/images of a crop seedling plant closer to the horizontal plane (approximately 20-40° from the horizontal).

In an example, the location determining means comprise one or more of a GPS, an inertial navigation systems, or an image based location system. It is also possible that a plurality of sensors use together one location determining means to synchronise geopositional information to each individual sensor data.

Fig. 2 shows a schematic example of a vehicle 100 for abiotic stress management of crop plants on an agricultural field comprising at least one crop seedling height sensor 110, a control and processing unit 120, and location determining means 130. The at least one crop seedling height sensor 110 is configured to acquire height information of a plurality of crop seedlings on an agricultural field. The control and processing unit 120 is configured to use the location determining means 130 to acquire the geopositional information of the plurality of crop seedlings on an agricultural field. The control and processing unit 120 is configured to receive the height information of the plurality of crop seedlings on the agricultural field from the at least one crop seedling height sensor 110 and the corresponding geopositional information of the plurality of crop seedlings to generate a crop seedling height map of the plurality of crop seedlings on the agricultural field on the basis of the acquired height information and the corresponding geopositional information of the plurality of crop seedlings on the agricultural field. The control and processing unit 120 is configured to compare the height of the plurality of the crop seedlings on the crop seedling height map to identify subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height. The control and processing unit 120 is configured to generate a crop plant abiotic stress map wherein the generation of the crop plant abiotic stress map comprises utilization of the identified subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height.

In an example, the vehicle 100 is an Unmanned Ground Vehicle (UGV), a tractor, an Unmanned Aerial Vehicle (UAV), and preferably an UAV.

In an example, the at least one crop seedling height sensor 110 (as described above for the method) is preferably selected from the group of a LiDAR sensor, a parallax laser rangefinder sensor, a stereo vision sensor, an IR reflectance sensor, a time of flight sensor, an ultrasonic sensor, a radar sensor.

In an example, a LiDAR sensor is used.

In an example a 3D LiDAR sensor is used

In an example, a LiDAR sensor together with a camera is used.

In an example, the control and processing unit 120 can completely be part of the vehicle or can have at least one additional external processing unit and the control and processing unit 120 communicates via wireless data transmission with the external processing unit (which can be an external computer, cloud etc.).

In an example, the location determining means 130 comprise one or more of a GPS, an inertial navigation systems, or an image based location system (similarly as described above for the method). It is also possible that a plurality of sensors use together one location determining means to synchronise geopositional information to each individual sensor data.

According to an example, the vehicle 100 for abiotic stress management of crop plants on an agricultural field further comprises a receiver 140. The control and processing unit 120 is configured to utilize the receiver 140 to receive geopositional information where the plurality of crop seeds have been planted on the agricultural field. The control and processing unit 120 is configured to utilize the geopositional information of the planted crops seeds to guide the vehicle to the plurality of crop seedlings to acquire the height information of the plurality of crop seedlings on the agricultural field with the at least one crop seedling height sensor 110.

In an example, the receiver 140 is a transceiver.

In an example, the geopositional information of the plurality of crop seeds is obtained as described in the method above e.g. with a planting vehicle while crop seeds are being planted. The vehicle 100 receives the crop seed map from the planting vehicle directly (or via data cloud or an external processing unit) and uses this information to guide the vehicle 100 to the plurality of crop seedlings to acquire the height information.

According to an example, the vehicle 100 for abiotic stress management of crop plants on an agricultural field comprises an output unit 150. The output unit 150 is configured to receive the crop plant abiotic stress map of the agricultural field from the control and processing unit 120. The output unit 150 is configured to output the crop plant abiotic stress map for the agricultural field.

In an example, the output unit comprises a monitor, a printer, a screen, an information monitoring device and/or any other information monitoring medium.

According to an example, the vehicle 100 further comprises at least one abiotic stress control agent spray unit 160. The at least one abiotic stress control agent spray unit 160 is configured to eject an abiotic stress control agent. The control and processing unit 120 is configured to control the at least one abiotic stress control agent spray unit 160 according to the crop plant abiotic stress map.

In an example, the at least one abiotic stress control agent spray unit comprises at least one spray unit. The at least one spray unit is configured to spray an abiotic stress control agent.

In an example, a spray unit is e.g. a boom sprayer.

In an example, the term “control the at least one abiotic stress control agent spray unit” in the context of a spray unit refers to the control of the start of the spraying process and the control of the stop of the spraying process.

In an example, a spray unit comprises at least one liquid atomizer such as a hydraulic nozzle and/or at least one atomizing disc such as a spinning disc.

In an example, the at least one abiotic stress control agent spray unit comprises a liquid atomizer, a liquid tank and at least one feed pipe. The liquid tank is configured to hold an abiotic stress control agent. The feed pipe is configured to transport the abiotic stress control agent from the liquid tank to the liquid atomizer. The liquid atomizer is configured to spray the abiotic stress control agent.

In an example, the term “abiotic stress control agent” refer(s) to a nutritional agent such as a fertilizer, a nutrient, a micronutrient and/or water.

In an example, the “abiotic stress control agent” is available in liquid form.

In an example, the control and processing unit is configured to control the at least one spray unit to apply the abiotic stress control agent either as a spray of fine droplets, a single jet, a single droplet, or a combination of these, depending on the preferred type of deposit.

According to another example, a further embodiment of the invention relates to a crop plant abiotic stress map as generated according to the method of abiotic stress management as described herein. In an example, the crop plant abiotic stress map is (at least) a two-dimensional (or three-dimensional) display of the crop seedling geopositional distribution on an agricultural field and indicates for which crop seedlings an abiotic stress has been identified (see figure 1, d).

In an example, the information of the crop plant abiotic stress map can be sent to a plurality of other vehicles (such as UAVs) which comprise spray units and are configured to apply abiotic stress control agents according to the crop plant abiotic stress map at various locations on the agricultural field.

Fig. 3 shows a schematic example of a system 200 for abiotic stress management of crop plants on an agricultural field comprising a first vehicle 210 for abiotic stress management of crop plants and a second vehicle 220 for abiotic stress management of crop plants, wherein the first vehicle 210 comprises at least one crop seedling height sensor 211, a control and processing unit 212, location determining means 213, and a transmitter 214. The second vehicle 220 comprises at least one abiotic stress control agent spray unit 221, a control and processing unit 222, and a receiver 223. The at least one crop seedling height sensor 211 of the first vehicle is configured to acquire height information of a plurality of crop seedlings on an agricultural field. The control and processing unit 212 of the first vehicle is configured to use the location determining means 213 to acquire the geopositional information of the plurality of crop seedlings on an agricultural field. The control and processing unit 212 of the first vehicle is configured to receive the height information of the plurality of crop seedlings on the agricultural field from the at least one crop seedling height sensor 211 and the corresponding geopositional information of the plurality of crop seedlings from the location determining means 213 to generate a crop seedling height map of the plurality of crop seedlings on the agricultural field on the basis of the acquired height information and the corresponding geopositional information of the plurality of crop seedlings on the agricultural field. The control and processing unit 212 of the first vehicle is configured to compare the height of the plurality of the crop seedlings on the crop seedling height map to identify subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height. The control and processing unit 212 of the first vehicle is configured to generate a crop plant abiotic stress map wherein the generation of the crop plant abiotic stress map comprises utilization of the identified subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height. The control and processing unit 212 of the first vehicle is configured to utilize the transmitter 214 to send the crop plant abiotic stress map to the second vehicle. The control and processing unit 222 of the second vehicle is configured to utilize the receiver 223 to receive the crop plant abiotic stress map from the first vehicle. The control and processing unit 222 of the second vehicle is configured to control the at least one abiotic stress control agent spray unit 221 according to the crop plant abiotic stress map.

In an example, the at least one crop seedling height sensor 211, the control and processing unit 212, the location determining means 213 are similar to the components as discussed above in the context of the method and the vehicle 100 (110, 120, 130). The transmitter 214 can also be a transceiver.

In an example, the least one abiotic stress control agent spray unit 221, the control and processing unit 222 are similar to the components as discussed above in the context of the method and the vehicle 100 (160, 120). The receiver 223 can also be a transceiver.

In another exemplary embodiment, a computer program or computer program product is provided that is characterized by being configured to execute the method steps of the method according to one of the preceding embodiments, on an appropriate system.

Fig. 4 shows a schematic set up of an example of a computer program product 300 for abiotic stress management of crop plants on an agricultural field, which when executed by a processor is configured to carry out the steps of: a) receiving 310 height information of plurality of crop seedlings on an agricultural field and the corresponding geopositional information of the plurality of crop seedlings on the agricultural field, b) generating 320 a crop seedling height map of the plurality of crop seedlings on the agricultural field on the basis of the received height information and the corresponding geopositional information of the plurality of crop seedlings on the agricultural field in step a), c) comparing 330 the height of the plurality of the crop seedlings on the crop seedling height map, d) identifying 340 subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height, i) generating 350 a crop plant abiotic stress map wherein the generation of the crop plant abiotic stress map comprises utilization of the identified subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height.

According to an example, the computer program product 300 for abiotic stress management comprises the additional step of: f) instructing 360 a vehicle to apply an abiotic stress control agent to at least a part of the agricultural field according to the crop plant abiotic stress map.

The computer program product might be stored on a computer unit, which might also be part of an embodiment. This computing unit may be configured to perform or induce performing of the steps of the method described above. Moreover, it may be configured to operate the components of the above described vehicle(s) and/or system. The computing unit can be configured to operate automatically and/or to execute the orders of a user. A computer program may be loaded into a working memory of a data processor. The data processor may thus be equipped to carry out the method according to one of the preceding embodiments.

This exemplary embodiment of the invention covers both, a computer program that right from the beginning uses the invention and computer program that by means of an update turns an existing program into a program that uses invention. Further on, the computer program product might be able to provide all necessary steps to fulfil the procedure of an exemplary embodiment of the method as described above.

According to a further exemplary embodiment of the present invention, a computer readable medium, such as a CD-ROM, USB stick or the like, is presented wherein the computer readable medium has a computer program product stored on it which is / can be a computer program product as described by the preceding section. A computer program may be stored and/or distributed on a suitable medium, such as an optical storage medium or a solid state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the internet or other wired or wireless telecommunication systems. However, the computer program may also be presented over a network like the World Wide Web and can be downloaded into the working memory of a data processor from such a network.

According to a further exemplary embodiment of the present invention, a medium for making a computer program product available for downloading is provided, which computer program product is arranged to perform a method according to one of the previously described embodiments of the invention.

It has to be noted that embodiments of the invention are described with reference to different subject matters. In particular, some embodiments are described with reference to method type claims whereas other embodiments are described with reference to the vehicle, spray map, and/or system type claims. However, a person skilled in the art will gather from the above and the following description that, unless otherwise notified, in addition to any combination of features belonging to one type of subject matter also any combination between features relating to different subject matters is considered to be disclosed with this application.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. The invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing a claimed invention, from a study of the drawings, the disclosure, and the dependent claims.

In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single processor or other unit may fulfil the functions of several items re-cited in the claims. The mere fact that certain measures are re-cited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

-22- CLAIMS

1. A method (10) to identify abiotic stress of crop plants on an agricultural field comprising the steps of: a) acquiring height information of a plurality of crop seedlings on an agricultural field and the corresponding geopositional information of the plurality of crop seedlings on the agricultural field, b) generating a crop seedling height map of the plurality of crop seedlings on the agricultural field on the basis of the acquired height information and the corresponding geopositional information of the plurality of crop seedlings on the agricultural field, c) comparing the height of the plurality of the crop seedlings on the crop seedling height map to identify subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height, d) generating a crop plant abiotic stress map wherein the generation of the crop plant abiotic stress map comprises utilization of the identified subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height.

2. A method according to claims 1, comprising step e) application of an abiotic stress control agent to the agricultural field according to the abiotic stress map.

3. A method according to any one of the claims 1 to 2, wherein the height information of the plurality of crop seedlings on the agricultural field is acquired within a time period of 1 to 4 weeks after the plurality of crop seeds have been planted on the agricultural field.

4. A method according to any one of the claims 1 to 3, wherein the geopositional information of the plurality of crop seedlings on the agricultural field is acquired with location determining means at the same instance when the height information of the plurality of crop seedlings is acquired. A method according to any one of claims 1 to 3, wherein the method comprises: aO) - prior to step a) - acquiring geopositional information of where crop seeds have been planted and/or are being planted on an agricultural field and generating a crop seed map, a) acquiring the height of the plurality of crop seedlings on the agricultural field at the geopositional information on the agricultural field where the plurality of crop seeds have been planted according to the crop seed map. A method according to claim 5, wherein the geopositional information of the planted crop seeds on the agricultural field is acquired by at least one sensor that is configured to record geopositional information of the crop seeds impinging on the soil during planting of the crop seeds. A method according to any one of the claims 1 to 6, wherein the height information of the plurality of crop seedlings of the crop seedlings on the agricultural field is acquired with a sensor that is configured to generate pulses of light towards a crop seedling plant and to measure the time for any reflections. A vehicle (100) for abiotic stress management of crop plants on an agricultural field comprising at least one crop seedling height sensor (110), a control and processing unit (120), location determining means (130), wherein the at least one crop seedling height sensor (110) is configured to acquire height information of a plurality of crop seedlings on an agricultural field, wherein the control and processing unit (120) is configured to use the location determining means (130) to acquire the geopositional information of the plurality of crop seedlings on an agricultural field, wherein the control and processing unit (120) is configured to receive the height information of the plurality of crop seedlings on the agricultural field from the at least one crop seedling height sensor (110) and the corresponding geopositional information of the plurality of crop seedlings to generate a crop seedling height map of the plurality of crop seedlings on the agricultural field on the basis of the acquired height information and the corresponding geopositional information of the plurality of crop seedlings on the agricultural field, wherein the control and processing unit (120) is configured to compare the height of the plurality of the crop seedlings on the crop seedling height map to identify subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height, wherein the control and processing unit (120) is configured to generate a crop plant abiotic stress map wherein the generation of the crop plant abiotic stress map comprises utilization of the identified subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height. A vehicle (100) for abiotic stress management of crop plants on an agricultural field according to claim 9, wherein the vehicle further comprises a

- receiver (140), wherein the control and processing unit (120) is configured to utilize the receiver (140) to receive geopositional information where the plurality of crop seeds have been planted on the agricultural field, wherein the control and processing unit (120) is configured to utilize the geopositional information of the planted crops seeds to guide the vehicle to the plurality of crop -25- seedlings to acquire the height information of the plurality of crop seedlings on the agricultural field with the at least one crop seedling height sensor (110). A vehicle (100) for abiotic stress management of crop plants on an agricultural field according to any one of claims 8 and 9 comprising: an output unit (150), wherein the output unit (150) is configured to receive the crop plant abiotic stress map for the agricultural field from the control and processing unit (120), wherein the output unit (150) is configured to output the crop plant abiotic stress map for the agricultural field. A vehicle (100) for abiotic stress management of crop plants on an agricultural field according to any one of the claims 8 to 10, wherein the vehicle further comprises: at least one abiotic stress control agent spray unit (160), wherein the at least one abiotic stress control agent spray unit (160) is configured to eject an abiotic stress control agent, wherein the control and processing unit (120) is configured to control the at least one abiotic stress control agent spray unit (160) according to the crop plant abiotic stress map. A crop plant abiotic stress map generated according to any one of the methods described in claims 1 to 7. A system (200) for abiotic stress management of crop plants on an agricultural field comprising a first vehicle (210) for abiotic stress management of crop plants and a second vehicle (220) for abiotic stress management of crop plants, wherein the first vehicle (210) comprises: at least one crop seedling height sensor (211), a control and processing unit (212), -26- locati on determining means (213), a transmitter (214), and wherein the second vehicle (220) comprises: at least one abiotic stress control agent spray unit (221), a control and processing unit (222), a receiver (223), wherein the at least one crop seedling height sensor (211) of the first vehicle is configured to acquire height information of a plurality of crop seedlings on an agricultural field, wherein the control and processing unit (212) of the first vehicle is configured to use the location determining means (213) to acquire the geopositional information of the plurality of crop seedlings on an agricultural field, wherein the control and processing unit (212) of the first vehicle is configured to receive the height information of the plurality of crop seedlings on the agricultural field from the at least one crop seedling height sensor (211) and the corresponding geopositional information of the plurality of crop seedlings from the location determining means (213) to generate a crop seedling height map of the plurality of crop seedlings on the agricultural field on the basis of the acquired height information and the corresponding geopositional information of the plurality of crop seedlings on the agricultural field, wherein the control and processing unit (212) of the first vehicle is configured to compare the height of the plurality of the crop seedlings on the crop seedling height map to identify subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height, wherein the control and processing unit (212) of the first vehicle is configured to generate a crop plant abiotic stress map wherein the generation of the crop plant abiotic stress map comprises utilization of the identified subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height, -27- wherein the control and processing unit (212) of the first vehicle is configured to utilize the transmitter (214) to send the crop plant abiotic stress map to the second vehicle, wherein the control and processing unit (222) of the second vehicle is configured to utilize the receiver (223) to receive the crop plant abiotic stress map from the first vehicle, wherein the control and processing unit (222) of the second vehicle is configured to control the at least one abiotic stress control agent spray unit (221) according to the crop plant abiotic stress map. A computer program product (300) for abiotic stress management of crop plants on an agricultural field, which when executed by a processor is configured to carry out the steps of: a) receiving (310) height information of plurality of crop seedlings on an agricultural field and the corresponding geopositional information of the plurality of crop seedlings on the agricultural field, b) generating (320) a crop seedling height map of the plurality of crop seedlings on the agricultural field on the basis of the received height information and the corresponding geopositional information of the plurality of crop seedlings on the agricultural field in step a), c) comparing (330) the height of the plurality of the crop seedlings on the crop seedling height map, d) identifying (340) subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height, e) generating (350) a crop plant abiotic stress map wherein the generation of the crop plant abiotic stress map comprises utilization of the identified subregions on the agricultural field with crop seedlings that are associated with a below average crop seedling height. -28- A computer program product (300) for abiotic stress management of crop plants according to claim 14 comprising the additional step of: f) instructing (360) a vehicle to apply an abiotic stress control agent to at least a part of the agricultural field according to the crop plant abiotic stress map.