WO2016059628A1

WO2016059628A1 - System and method for determining watering needs for field or landscape irrigation

Info

Publication number: WO2016059628A1
Application number: PCT/IL2015/051012
Authority: WO
Inventors: Oleg KOROL; George VEITSMAN
Original assignee: Korol Oleg
Priority date: 2014-10-12
Filing date: 2015-10-11
Publication date: 2016-04-21

Abstract

A system and method for measuring the plant/crop water consumption rate by means of wrapping suitable roots around the water-filled tensiometers when said tensiometers are placed into the ground. Thus the control system is constantly aware of the current plant/crop water consumption rate and schedules the irrigation events in accordance with it. Optionally the water-filled tensiometer(s) are also placed into a water permeable on top and bottom vertical capsule which is insulating the area near the tensiometer from the roots. The substantial change in the difference between the moisture content of a root-insulated capsule and the moisture content indicated by the root wrapped tensiometers outside of it will be deemed, when corroborated by the plant growth stage calendar and/or by other means, to indicate the plant/crop growth stage change. Alternatively determination of the plant growth stage is described based on the field/crop reflectance change or smell change. Subsequently the scheduling as well as the overall water amounts for the irrigation will be adjusted accordingly to the growth stage requirements for said stage duration thereby saving large amounts of water while satisfying the plant/crop water needs exactly and most timely.

Description

SYSTEM AND METHOD FOR DETERMINING WATERING NEEDS FOR FIELD OR LANDSCAPE IRRIGATION

Relationship to other applications:

The present patent application is related, pursuant to the concept of the unity of invention, to US provisional patent application 62/062,888 and claims benefit of the filing date of said provisional application.

Field of the Invention

This invention relates to devices for controlling the functioning of irrigation systems and especially for the determination of water requirements and their timing.

Description of the Prior Art

There are a number of prior art irrigation control systems which typically rely on the pertinent moisture, temperature and other sensors for determining the water quantities required and their timing. For example the patent CN202635265U describes a control system utilizing, for the determination of the water amount required for the irrigation and the time of the irrigation event, soil moisture sensors on multiple levels in combination with soil temperature sensors. Another example of the prior art is the patent application US 13/844,248 This system also offers a predictive capability as it analyzes the current soil moisture conditions, the temperature, the evapotranspiration rate, the stored historical precipitation data and the current weather prognostications. Thus the prior art is based on the systems and methods which do not take into account the plant or crop growth stage which very significantly affects its watering needs as well as the criticality of the irrigation's timeliness; therefore it does not adequately meet the requirement for a most efficient in terms of water usage irrigation control systems which would most reliably assure the plants optimum health and productivity.

Objects and Advantages.

One object of the present invention is to provide an irrigation control system with the ability of measuring plant/crop water consumption rate.

Another object is to provide an irrigation control system with the capability of determining and factoring in the plants or crop growth stage for the more accurate determination of the amounts of water necessary for the irrigation and the criticality of its timing.

Another object is to provide an irrigation control system with the capability of anticipating changes in the amounts of water needed based on the expected transitioning from one stage of the plant/crop growth or development to another and timing the irrigation events accordingly.

Brief Description of the Drawings

Fig 1 illustrates the placement of tensiometers to determine water requirements according to the present invention. Description of Preferred Embodiments.

The first embodiment is as follows; it will comprise a control system which is connected to at least one tensiometer and preferably to a plurality of them. In order to determine the vegetation or crop rate of water consumption the following method is to be used. Roots of the pertinent plant, or tree etc are briefly undug in one narrow hole in the ground and cleaned of soil to a sufficient degree, which can be done by using small gardening hand-held tools or a water hose with a nozzle. The latter can be used to easily produce a narrow hole in the soil leaving the roots clean and readily accessible. The water filled (Fig 1 ) tensiometer (1) is placed into the hole in the soil with sufficient quantity of the soil back-filled into the hole to assure that the tensiometer does not sink any deeper and the small roots of suitable size (1 A) are wrapped around its water seeping part such as the porcelain cylinder (1 B). The tensiometer then is covered with soil and the hole is backfilled; once it and any other tensiometers thus placed are connected to the control system, the installation will be completed. However it is known that the water leaves the soil mostly in two ways; by means of evapotranspiration and by percolation to the lower depths. The rate of the evapotranspiration is determined by the following factors; intensity of the solar radiation, humidity, temperature, wind strength and the stage of the vegetation/crop growth. The latter factor is very significant and also bears on how crucial the sufficient availability of moisture is and thus on the acceptable timeframe for the irrigation event.

The system and method of the second embodiment are intended to determine the change in the evapotranspiration rate in comparison with the evaporation rate. The comparison with the evaporation rate is done to exclude the effects of other factors affecting both evapotranspiration and evaporation rates: solar radiation, humidity, temperature, wind and moisture availability in the soil. Such a change in the difference between the two said rates can be used to determine the plants/crop reaching a different growth/development stage and to adjust the water requirements accordingly. Second embodiment of this invention will comprise an irrigation control system which includes a number of moisture sensors such as tensiometers. At least one of these tensiometers is located in an isolated place such as a length of plastic pipe inserted vertically into the ground to it least the depth which is slightly greater than the maximum root depth. Said soil filled piece of pipe's upper soil surface can be either flush with the surrounding soil surface, if the surface irrigation is used or be at a depth sufficient to assure its irrigation at the same rate as the areas outside the said pipe when the under the surface irrigation is used. The top surface of soil in the pipe (2) needs to be covered with a water permeable barrier (3) to prevent the root growth into the pipe and preferably the bottom surface would also be covered the same way, such as for example the landscaping fabric. Thus said piece of pipe forms a root insulated, water permeable on top and on bottom capsule. Said capsule has to be filled with soil (4) in the last out first in sequence as it was extracted from the hole in the ground when it was being drilled. It is desirable to preserve the soil composition and its structure inside the said capsule - since the composition of the soil is usually different near the surface and at a certain depth. The tensiometers (1 ), when two of them are used, will be placed at different depths; one will be placed near the surface and if there is a second

tensiometer it will be placed closer to the lower end of the capsule. At least one moisture sensor/tensiometer and preferably a plurality of them will be placed outside of the said capsule in a manner described for the first embodiment.

A third embodiment of the present invention will involve the measurement of crop field reflectance and its spectral composition which needs to be done preferably on a daily basis when approaching, according to the crop growth calendar, the point when the plant/crop growth stage changes or when such plant growth stage change is being artificially induced for example by plant growth hormones. Said measurements can be done by known instruments either installed on stationary supports above the crop field or from a flying aerial platform such as a drone or a manned aircraft equipped with reflectance measuring instruments.

A fourth embodiment of the present invention will involve the testing crop field smell by an olfactory sensor which needs to be done preferably on a daily basis when

approaching, according to the crop growth calendar, the point when the plant/crop growth stage changes or when such plant growth stage change is being artificially induced for example by plant growth hormones. Said testing can be done by known olfactory sensors either installed on stationary supports near or above the crop field or from a flying aerial platform such as a drone or a manned aircraft equipped with the necessary instruments.

Sketches and Diagrams.

Drawing provided separately.

Operation.

In operation, in case of the initial installation according to the first embodiment of the system of the present invention the moisture readings provided to control system by the tensiometers surrounded by roots will be directly translated by the control system into the irrigation requirements and the timing with the standard timeframe for the next irrigation event will be set. For the system according to the second embodiment of the present invention the readings from the root surrounded tensiometers and those in the isolated capsule will be compared at the regularly scheduled time intervals. There will always be a difference between them. When that difference substantially changes either way, if that signal conforms with the plant/crop growth stage calendar for the given locality and optionally corroborated by other means - then the change in the plant/crop growth stage will be considered established and taken into account. For the system according to the third embodiment the readings from the field reflectance measurement taking into account the spectral composition of said reflectance will be used to detect the plant/crop growth stage change and likewise will need to be confirmed by said plant/crop growth stage calendar. For the system according to the fourth embodiment the results from the field/crop smell test will be used to detect the plant/crop growth stage change and likewise will need to be confirmed by said plant/crop growth stage calendar. As the criticality of timing of the irrigation events and need for the water amounts delivered is very different for the various growth stages; accordingly the scheduling of the irrigation events will factor that in and the timeframe within which the scheduled irrigation event is to take place will be either narrowed or widened depending on the requirements for a particular said growth stage. In particular the special consideration will be given by the control system to the period of time when the current growth stage, whose duration is known, is expected to end. If the control system can anticipate a drastic change in the irrigation requirements it can adjust its operation on the last day of the current growth stage; either not scheduling an irrigation event when it knows that the water requirements are about to drop off precipitously or scheduling one if it knows of an imminent onset of the higher water requirements whose timely delivery is critical. This will help save the water and optimize the crop yield. Of course the control system can also be expected to take into account in its anticipatory determinations the other known factors currently being used, such as for example the local weather prognostications.

Claims

. Claims. What claimed is.

1. A control system for the determination of the amounts of water to be used and the required timings of the irrigation events, comprising a computer processing unit operatively connected for accepting input from at least one water-filled tensiometer installed in the ground and having suitable plant roots wrapped around it.

2. The system of claim 1 further comprising a generally vertical piece of pipe dug into the ground and filled with soil, wherein said piece of pipe has water permeable, root impermeable barrier at least on its top, with at least one tensiometer installed in said piece of pipe and operatively connected for input into said computer processing unit.

3. The control system of claim 2, which has the functionality for comparing the readings from at least one root-wrapped tensiometer and from at least one said piece of pipe installed tensiometer.

4. The control system of Claim 3 that has the functionality for upon detecting a substantially outside preceding average divergence in said readings, to check the pertinent electronic plant growth calendar for confirming the onset and identifying the new plant growth stage and to retrieve from storage and to apply the water requirement parameters suitable for said growth stage to the determination of the water amount needs and the timing of the irrigation events.

5. The control system for the determination of the amounts of water to be used and the required timings of the irrigation events comprising a computer processing unit, operatively connected for accepting input from at least one water-filled tensiometer installed in the ground, that has the functionality for comparing the reflectance measurements averages over a predetermined period of time with said reflectance's latest measurements.

6. The control system of Claim 5 that has the functionality for upon detecting a substantial deviation from the said reflectance measurement averages to check the pertinent electronic plant growth calendar for confirming the onset and identifying the new plant growth stage and to retrieve from storage and to apply the water requirement parameters suitable for said growth stage to the determination of the water amount needs and the timing of the irrigation events.

7. The control system for the determination of the amounts of water to be used and the required timings of the irrigation events comprising a computer processing unit, operatively connected for accepting input from at least one water-filled tensiometer installed in the ground, that has the functionality for accepting the smell test identification of a new plant/crop growth stage.

8. The control system of Claim 7 that has the functionality for upon receiving smell test identification of a new said growth stage to check the pertinent electronic plant growth calendar for confirming the onset and identity of the new plant growth stage and to retrieve from storage and to apply the water requirement parameters suitable for said growth stage to the determination of the water amount needs and the timing of the irrigation events.