Description

The present invention relates to a method of providing an optimal watering cycle of a plant comprising the steps of measuring by one or more sensory means the change in water content in a container holding the plant during a watering cycle of the plant. The present invention further relates to a system for determining an optimal watering cycle of a plant according to this method and a computer program product comprising computer-executable instructions for performing this method.

People have always wanted to keep living plants in their homes, workspaces and public areas, as being surrounded by plants increases productivity and make people healthier and happier. However, the downside of this is that plants need proper care which may often be difficult or lead to additional expenses when some of the plants perish due to improper maintenance.

Companies and offices mostly prefer to delegate their plants’ handling to professionals that work according to regular commuting time having a fixed schedule.

Statistically, the main problem with plant care is that plants die because of incorrect watering cycles - when plants are being either under-watered or over-watered.

Typical watering cycle consists of the following steps:

a) plant is being watered

b) plant is consuming water (including water that is being evaporated) until all the liquid water is all consumed

c) dry-out period when there is no liquid water in the pot.

The dry-out period is the optimal period determined for each type of plant to stay completely dry before it is watered again. It allows the roots to breathe and keeps them from rotting. In reality the dry-outs will be different for different kinds of plants: e.g. the Dracaena reflexa can easily have a 15 day dry-out period, while the Spathiphyllum plants will start wilting on day 1-2 after the plant went dry.

The actual speed of water consumption of a plant depends not only on the plant itself, but also on the environmental factors (length of the day, temperature, climate, etc.).

Naturally, in the warm time of the year the speed of water consumption increases because the light day is longer and the temperatures are higher. In the wintertime usually the opposite trend is observed. When periodically watering a whole group of plant during a year, for example a group of office plants, the fastest drinking plant usually becomes dry long before the next watering date, while the slowest drinking plant still sits in water. Both situations are not optimal for a plant, because in the first case it will wilt without water, and in the second case the roots might start rotting. Statistically much more plants die because they are being over- watered, rather than under watered.

Considering the above, there is a need in the art for a method to improve plant watering, more specifically to improve plant watering periods or cycles, and to optimize these plant watering cycles accommodating the needs per plant or group of plants, reducing the number of perished plants or malnourished plants. In addition there is a need in the art for a simpler and cost effective method for managing plant watering cycles.

It is an object of the present invention, amongst other objects, to address the above need in the art. The object of present invention, amongst other objects, is met by the present invention as outlined in the appended claims.

Specifically, the above object, amongst other objects, is met, according to a first aspect, by the present invention by a method of providing an optimal watering cycle of a plant comprising the steps of

a) measuring by one or more sensory means the change in water content in a container holding the plant during a watering cycle of the plant, wherein said watering cycle is comprised of the steps of

i) adding water to the container holding the plant,

ii) a period of water consumption by the plant,

iii) a dry-out period of the plant when there is no, or almost no water present in the container,

b) calculating a linear speed of consumption of water, based on the change in water content measured in step a) using the following formula (1)

(1) Linear speed of water consumption = total amount of water in container after step i) / (the date when the plant has consumed all the water and the dry-out period starts - the date when the plant was watered) c) calculating the amount of water to be added to the container to provide for an optimal watering cycle of said plant based on the calculated linear speed of water consumption and the following formula (2):

(2) Amount of water to he added to the container = (total duration of the watering cycle (days) - optimal dry-out period (days)) * linear speed of water consumption (g/days) - water amount left in container as per the date when the watering is done. A watering cycle of a plant consists of the steps; plant watering, followed by a period of water consumption by the plant until all the liquid water is consumed, followed by a dry out period in which there is no or little liquid water in the container until a subsequent watering cycle starts. The method of present invention determines the optimal watering cycle of a plant by using the measurements from the sensory means of the water content in the container and calculating the linear speed of water consumption of the plant followed by prediction of a next watering cycle by calculation taking into account data relating to a watering cycles of the plant and dry-out period of the plant. Algorithm (1) elaborates the obtained measurements by the sensory means of the water content in the container and calculates the speed of water consumption, approximating the dependency between the amount of water in the container and time, down to linear function. Algorithm (2) determines the amount of water to be added to the plant on the subsequent watering date at the start of this watering cycle of the plant, so that, given a calculated speed of water consumption and preferably also other incorporated factors, the plant went dry on a certain date and had the optimal dry-out period as per user requirements before the start of said subsequent watering cycle. In case there is still some water left in the container when watering the plant for a subsequent watering cycle, the amount of water to be added to the container calculated in formula 2, includes that the water amount left in container as per the date when the watering is done needs to be subtracted in order to provide the optimal watering cycle of said plant.

The amount of water consumed is defined as the amount of water that has been consumed by a plant within a certain period of time plus the amount of water that is evaporated within the same period. The linear speed of water consumption is defined as the total amount of water consumed within a specified period (which can be calculated as the date when the plant has consumed all the water up to the start of the dry-out period), divided by the number of days in the specified period. The period of consumption (ii) runs until the start of the dry-out period of the plant.

The so-called dry-out period of a plant is a period when the plant has no or minimum water to its disposal and is often a period needed by the plant to allow the roots to breathe and prevent roots from rotting. This dry-out period is very important to the plant’s health. However each plant has a different optimal dry-out period, and even two exactly the same plants can have slightly different optimal dry-out periods depending on where they are placed (e.g. depending on the climate, sun exposure, temperature). Using the method of present invention, dry out periods may be adjusted and optimized over time, when more data is available/collected per plant to obtain the most optimal watering cycle of the plant. The dry-out period of the plant, i.e. when there is no or almost no water available for the plant, can be identified as the point in the trend of the speed of the water consumption when the plant is slowing down drinking significantly compared to the trend in a previous watering cycle. When measuring and determining water content inside the container, for example by a water level indicator, humidity levels by a humidity sensor, or weight using a load cell, a“zero change” in water content measurement indicates that the dry-out period of the plant has started, since no water could be consumed anymore either by the plant or by evaporation in that time period.

According to a preferred embodiment, the present invention relates to the method, wherein the one or more sensory means are selected from the group consisting of a load cell, humidity sensor and/or water level sensor, preferably a load cell. Measuring the changes in water content in the container during the watering cycle of a plant can be performed using several sensory techniques. A water level indicator may be used which is regularly measuring the water level on the bottom of the container that holds the plant. A water level indicator can be used in hydroculture setting or settings using similar substrates suitable for hydroculture, i.e. hydroponic pebbles, without the use of soil. A water level indicator indicates in centimetres or millimetres the amount/volume of water present in the container holding the plant. Another way is by using a humidity sensor which regularly measures the humidity level at a fixed position in a container holding the plant, usually near the roots of a plant. A humidity sensor allows to measure relative or absolute humidity in the substrate, e.g. wood- or coconut chips, or soil. A humidity sensor is especially suitable for plants that are being cultivated in soil, but is less useful in hydroculture setting. Preferably the measuring of the changes in water content is done by use of a load cell to regularly measure the total weight of the plant including the container holding said plant and the growing substrate. The weight of the plant, the weight of the container and the weight of the substrate are considered as constants. Therefore only the amount of water inside the container is considered as a variable and this method of measuring is thus not depending on the type of substrate or cultivation method. The system of present invention can be modular depending on its use or type of plants; for example when used to measure either the water level (for the hydro plants), or the soil humidity (for the soil plants). This modular system enables to select the type and the size of the sensory means that would work the best for a specific type of plant.

Measurements by the sensory means are done in different units such as centimetres (for the water level indicator), g/m3 (for the humidity sensor) or grams (for the load cell) and are converted into the amount of water consumed by the plant (e.g. in litres or millilitres). These sensors need to be calibrated at first use to correlate the measurements with the actual water content in said container. For example, after the water level indicator has been provided into the container, at the first watering of the plant the sensor is calibrated such that as specific increase or decrease in water volume corresponds with a specific increase or decrease in centimetres of the water level in the container. The same holds for a humidity sensor (g/m3 vs. water volume) or load cell (g or kg vs. water volume). To predict a subsequent watering cycle and water needs of a plant in the method of present invention an approximation of the behaviour is performed per plant with the mathematical function such that the further watering cycle accommodates the needs of the specific plant. The sensory means, such as a load cell, periodically weighs the plant including the container that holds water for said plant. With each next measurement the plant has consumed water, and part of the water has been evaporated. The plant also grows leading to an increase in total weight. However the plant’s water consumption is much faster than speed of growing and therefore the changes in water content (in this case weight) due to plant growth are neglected. This method is intended for situations where it is assumed the plant's water content is only altered by addition and consumption of water. The speed of water consumption (or drinking speed) of a plant is approximated by a linear formula (1) per watering cycle.

Formula (2) predicts the recommended amount of water to be put in the container during the watering of the plant . Several variables are taken into account;

- the exact date selected for the next (upcoming, new) watering of the plant,

- the exact date selected for the current watering of the plant,

- the dry-out period of the specific plant,

- the predicted water consumption speed of the plant, and optionally,

- the amount of water currently present in container

Following the suggested watering amount for a group of (mixed type) plants, would result in a situation where all the plants have consumed the water on the same period of time and all plants would have proper dry-out period which is essential for having strong and health plant. Using the method of present inventions, plants would obtain a“personalized” maintenance cycle which is accommodated per type of plant depending on its water consumption and dry-out period properties.

According to a preferred embodiment, the present invention relates to the method, wherein the measuring is performed at least once per 24h, preferable per 12h, more preferably per 6h, most preferably per 4h.

According to another preferred embodiment, the present invention relates to the method, wherein the measuring is performed for at least a week, preferable a month, more preferably six months, most preferably a year. After the yearly data is collected, monthly adjustments (coefficients) can be introduced into the calculation that are extracted from the average trends of the water consumption. On average the data on the water consumption of the plant generated in one year provides a good correlation with monthly changes in weather conditions. Instead of a function that would describe a full behaviour of plant within several cycles, the method analyses each cycle separately. The water consumption behaviour is a property of the plant and therefore plant specific. Therefore, to analyse water consumption behaviour, data is collected per plant comprising sets of measurements by the sensory means, such as a load cell, over time wherein the water is being removed from the system comprising the plant and container holding said water. All data is being collected and stored into a database. The water consumption speed from previous watering cycle can be used for the next watering cycle with the small adjustment for the month coefficient, thereby determining a water cycle per plant that is optimized for plant specific maintenance.

According to yet another preferred embodiment, the present invention relates to the method, wherein the calculated subsequent watering cycle is further modelled by taking into account for the climate in which the plant is located, such as temperature, light, humidity.

According to yet another preferred embodiment, the present invention relates to the method, wherein the calculated subsequent watering cycle is further modelled by taking into account the weather forecast and/or seasonal variation.

To approximate the speed of the water consumption of the plant the last watering cycle has closest behaviour to the next watering cycle and therefore allows to produce predictions when no long historical data is available. The data generated by the calculations can be collected and stored onto a data storage device. When collecting increasingly more data overtime per watering cycle, a drinking trend for every month of the year can be derived and combined with additional factors for an improved prediction on the maintenance cycle, such as drinking speed from the last watering cycle, drinking speed from the same month previous year, month of the year, weather forecast, and light conditions influencing the speed of water consumption by the plant.

According to another preferred embodiment, the present invention relates to the method, wherein data generated in step b) on the linear speed of water consumption is being collected and stored onto a data storage device for use in further modelling of the calculated subsequent watering amount to be added to the container. The total weight of the plant at any moment during its growth and watering cycle can be automatically and continuously measured and recorded by the sensory means, e.g. a load cell, and stored into the database on the data storage device and via the processing means can provide the watering cycle data per plant to an user interface, in order to provide the users real time information per plant based on the change in water content in time. This enables user’s insight into the watering cycles of the plant and to maintain proper plant care.

According to yet another preferred embodiment, the present invention relates to the method, wherein said plant is an indoor plant, preferably a stand alone plant. According to a preferred embodiment, the present invention relates to the method, wherein said plant being cultivated in hydroculture or soil, preferably hydroculture. A plant cultivated in hydroculture, also referred to as hydroponic plant is often fixed in a container filled with aqueous solution that may further comprise dissolved nutrients for the plant’s growth. The hydroponic cultivation method avoids using soils, reducing the chances of disease caused by microorganisms. The hydroponic plants are often used as indoor plants since the plant's growth environment can be controlled more easily. The hydroponic plant's weight is an important parameter for evaluating growth conditions and environment factors affecting the plant's growth.

The present invention, according to a second aspect, relates to a system for providing an optimal watering cycle of a plant according to the method of present invention, wherein the system is comprised of one or more sensory means, a container for holding a plant, a data storage device, and a processor, wherein the one or more sensory means is configured to measure the change in water content in said container during at least one full watering cycle of said plant, wherein said watering cycle is comprised of the steps of

i) adding water to the container holding the plant,

ii) a period of water consumption by the plant,

iii) a dry-out period of the plant when there is no, or almost no water present in the container,

and wherein the processor is configured to calculate a linear speed of consumption of water, based on the changes in water content during the watering cycle and following formula (1)

(1) Linear speed of water consumption = total amount of water in container after step i) / (the date when the plant has consumed all the water and the dry-out period starts - the date when the plant was watered) and,

wherein the processor is configured to calculate the amount of water to be added to the container to provide for an optimal watering cycle of said plant based on the calculated linear speed of water consumption and the following formula (2)

(2) Amount of water to he added to the container = (total duration of the watering cycle (days) - optimal dry-out period (days)) * linear speed of water consumption (g/days) - water amount left in container as per the date when the watering is done.

The system performing the method of present invention takes into account the plant type, and depending on the specific plant the database and software will recommend a watering and proper dry-out period. At the same time, the method also provides users to be able to change the recommended dry-out period for every plant. The method of present invention enables improved suggestions of a dry-out period to a user that is watering the plant, or allows them to choose a custom dry-out period for every plant. The method of present invention provides the user with the remote control over the state of the (indoor) plants, and ability to react to all the unconventional situation or sudden change in water intake. The method provides control over the dry-out period and increases the plant survival rate, hence less expenses on the plant replacements that are usually one of the major liabilities. Due to the method of present invention it is possible to extend the frequency of visits for plant nurture and care without the loss of the service quality, hence lowering operational costs and provide a more optimized and“personalized” plant maintenance. Furthermore, due to the simplicity of the system and method, it allows the professional users of the system (e.g. gardening contractors) for hiring less qualified (hence less costly) personnel to take care of the plants, since all guesswork based on plant knowledge or work experience in relation to plant care is removed. The method is simple to use and provides output that is clear and understandable to users which do not have any gardening experience at all.

According to a preferred embodiment, the present invention relates to the system, wherein the one or more sensory means are selected from the group consisting of a load cell, humidity sensor and/or water level sensor, preferably a load cell. The system of present invention can be modular depending on its use or type of plants; for example when used to measure either the water level (for the hydro plants), or the soil humidity (for the soil plants). The system can consist of the standard power module (including a battery case, antenna, microcontrollers) attached to the one or more sensory means of different kinds and sizes (depending on the type of

plants/container/substrate) via a connector/port. This modular system enables to select the type and the size of the sensory means that would work the best for a specific type of plant. For example, in case of measuring the water level, it is also possible to include a connect (or wire) that will allow to regulate the depth of immersion of the sensory means and make this sensor suitable for different sizes of hydroculture plants.

The present invention, according to a second aspect, relates to a computer program product comprising computer-executable instructions for performing the method of present invention, when the program is run on a computer. Users are able via a mobile application, web panels and/or personal computers or laptops running a computer program product performing the method of present invention and providing the data demonstration of watering cycles per plant or per group of specific plants and to organize an optimal watering management. The combination of real time data obtained with the method of present invention combined with historical data provides the possibility for modelling the future watering cycles. The present invention will be further detailed in the following examples and figures wherein:

Figure 1: A) shows the“old” situation of change in water content during 3 months during plant cultivation, without using the method of present invention. Three types of plants (A, B and C) have been watered 3 times during 3 months, all having different water consumption speed and needs. The plants are being watered every month and the plant that is consuming the water the fastest usually becomes dry long before the next watering date, while the plant that is the slowest water consumer still sits in water. Both situations are not optimal for a plant, because in the first case it will wilt without water, and in the second case the roots might start rotting. B) shows the“new” situation of change in water content during 3 months during plant cultivation of plant types A, B and C using the method of present invention. The method calculates how much water would be optimal to add per watering cycle, i.e. for a plant to consume the water and then have a recommended dry-out period before the next watering cycle is to start.

Example - Optimizing the plant watering cycle of Aglaonema Maria and Dracaena Song of

Jamaica.

A plant A, Aglaonema Maria was placed in a container that was filled with hydrophonic beads. The container was placed in contact with a digital water level meter that measures the water content present in the container. Plant A has a recommended dry-out period of approximately 12 days. A plant B, f.e. Dracaena Song of Jamaica, having a recommended dry-out period of approximately 15 days, was placed in a container that was filled with hydrophonic beads. The container was placed in contact with a digital water level meter that measures the water content present in the container.

Watering every plant separately on different dates, depending on their individual needs, would be too time consuming, and therefore both plants are being scheduled to be watered every month, on the 3 ^rd day of each month. However, since the speed of the water consumption for plant A and B, and their dry-out periods are different, the method of present invention is applied in order to calculate the optimal watering cycle per plant, i.e. how much water should added to plant A and B on the 3rd of each month, such that the plant experiences its recommended dry-out period before a new watering cycle starts.

Given the next watering date on July 3rd and the recommended dry-out period for Plant A of 12 days, it is to be ensured that plant A has consumed all available water in the container by June, 22nd. At the start of the watering cycle it was determined that 2 litre of water present in the container corresponded to 100% on the water level meter. From the watering cycle which was monitored by the water level meter as depicted below, it was calculated that the speed of water consumption of plant A was approximately 7% of the total water content per day, which corresponded to a speed of water consumption of approximately 140 ml/day (See figure 2 for example).

For the optimal subsequent watering cycle of plant A it was calculated that to consume all water present in the container by June, 21st, on June, 3rd the plant should be watered until the water level is at 130%, corresponding to adding 2.6 litres to the container of plant A.

Given the next watering date on July 3rd and the recommended dry-out period for

Plant B of 15 days, it is to be ensured that plant B has consumed all available water in the container by June, 19 ^th . At the start of the watering cycle it was determined that 2 litre of water present in the container corresponded to 100% on the water level meter. From the watering cycle (as was done above for plant A) it was calculated that the speed of water consumption of plant B was approximately 4% of the total water content per day, which corresponded to approximately 80 ml/day. For the subsequent watering cycle of plant B it was calculated that to consume all water present in the container by June, 21st, on June, 3rd the plant should be watered until the water level is at 68%, corresponding to adding -1.4 litres to the container of plant B.