Irrigation control system

• US 8,714,181 B2
• Filed: 09/22/2011
• Issued: 05/06/2014
• Est. Priority Date: 08/20/2007
• Status: Active Grant

• Current Assignee: Yissum Research Development Company of the Hebrew University of Jerusalem Ltd. (Hebrew University of Jerusalem), Netafim Limited (Orbia Advance Corporation, S.A.B. de C.V.)
• Original Assignee: Yissum Research Development Company of the Hebrew University of Jerusalem Ltd. (Hebrew University of Jerusalem), Netafim Limited (Orbia Advance Corporation, S.A.B. de C.V.)
• Inventors: Shani, Uri, Schweitzer, Abraham
• Primary Examiner(s): SCHNEIDER, CRAIG M
• Application Number:
  US13/240,815
• Publication Number:
  US 20120006421A1
• Time in Patent Office: 957 Days
• Field of Search: 137/78.2, 137/78.3, 239/63, 47/485, 738/26, 738/623.91, 738/37, 738/07, 738/16, 738/25, 738/23, 738/57
• US Class Current: 137/78.3
• CPC Class Codes: A01G 25/167 Control by humidity of the soil itself or of devices simulating soil or of the atmosphere; Soil humidity sensors
• CPC Class Codes: G01N 7/10 by allowing diffusion of components through a porous wall and measuring a pressure or volume difference
• CPC Class Codes: Y02A 40/22 Improving land use; Improving water use or availability; Controlling erosion
• CPC Class Codes: Y10T 137/0318 Processes
• CPC Class Codes: Y10T 137/189 Soil moisture sensing

Abstract

A tensiometer for use in determining matric potential of a soil includes a water inlet; a hydraulic coupler comprising a porous material for providing hydraulic coupling between water that enters the inlet and the soil; and a septum that seals water that enters the inlet against ingress of air via the porous material.

Claims

1. A tensiometer for use in determining matric potential of a soil comprising:

a water inlet;

a hydraulic coupler comprising a porous material for providing hydraulic coupling between water that enters the inlet and the soil;

a septum that seals water that enters the inlet against ingress of air via the porous material; and

a valve adapted to connect the tensiometer to a water source and operable to enable water from the water source to enter the tensiometer and flush the hydraulic coupler.

2. A tensiometer according to claim 1 wherein the porous material is adapted to enable growth of plant roots therein.

3. The tensiometer according to claim 1, wherein:

the tensiometer is connected to the water source via a reservoir; and

the valve is adapted to connect the water source to the reservoir at a point below a waterline of the reservoir.

4. The tensiometer according to claim 1, wherein:

the tensiometer is connected to the water source via a reservoir; and

the valve is operable to enable water from the water source to enter the reservoir and remove air therefrom.

5. Apparatus for use in determining matric potential of a soil comprising:

a plurality of tensiometers in accordance with claim 1; and

a same water reservoir to which said plurality of tensiometers are hydraulically coupled.

6. An irrigation system comprising:

an irrigation pipe having at least one output orifice for outputting water from the pipe; and

a plurality of tensiometers in accordance with claim 1 connected to the irrigation pipe.

7. The irrigation system according to claim 6, wherein:

the irrigation pipe comprises a plurality of integrated emitters, each emitter having an output orifice.

8. The irrigation system according to claim 6, wherein:

each of said plurality of tensiometers is connected to a common water reservoir.

9. The irrigation system according to claim 8, wherein:

the water reservoir comprises a device for providing a measure of pressure in the water reservoir.

10. A tensiometer according to claim 1 wherein:

the tensiometer comprises a housing; and

the hydraulic coupler comprises;

a reservoir-coupling region located inside the housing; and

a soil-coupling region that extends outside of the housing to hydraulically couple the tensiometer to soil.

11. A tensiometer according to claim 10 wherein:

the housing comprises a housing top and a housing bottom; and

the soil-coupling region extends outside of the housing, between the housing top and housing bottom.

12. A tensiometer according to claim 10 wherein:

the housing comprises a housing top and a housing bottom; and

a bottom surface of the housing top is provided with a water flow labyrinth comprising a plurality of baffles configured to disperse water entering the tensiometer.

13. A tensiometer for use in determining matric potential of a soil comprising:

a water inlet;

a hydraulic coupler comprising a porous material for providing hydraulic coupling between water that enters the inlet and the soil;

a valve adapted to connect the tensiometer to a water source and operable to enable water from the water source to enter the tensiometer and flush the hydraulic coupler; and

a septum that seals water that enters the inlet against ingress of air via the porous material;

wherein;

the septum comprises a septum surface, at least a part of which is contiguous with water that enters the water inlet.

14. A tensiometer according to claim 13 wherein the tensiometer comprises a water labyrinth having baffles.

15. A tensiometer according to claim 14 wherein a portion of the septum surface contacts the baffles.

16. A tensiometer according to claim 15 wherein the septum comprises a membrane and the septum surface is a surface of the membrane.

17. A tensiometer according to claim 16 wherein the membrane comprises a plurality of layers.

18. A tensiometer according to claim 17 wherein the layers comprise a first layer having a bubbling pressure greater than about a maximum absolute value of the matric potential of the soil in which the tensiometer is used.

19. A tensiometer according to claim 18 wherein the bubbling pressure is about equal to one atmosphere.

20. A tensiometer according to claim 18 wherein the first layer is supported by at least one support layer.

21. A tensiometer according to claim 20 wherein the first layer is sandwiched between two support layers.

22. Apparatus for use in determining matric potential of a soil comprising:

a tensiometer comprising;

a housing comprising a housing top and a housing bottom;

a water inlet; and

a hydraulic coupler comprising;

a porous material for providing hydraulic coupling between water that enters the inlet and the soil; and

a soil-coupling region extending outside of the housing, between the housing top and housing bottom; and

a valve adapted to connect the tensiometer to a water source and operable to enable water from the water source to enter the tensiometer and flush the hydraulic coupler.

23. An apparatus according to claim 22 wherein:

the hydraulic coupler further comprises;

a reservoir-coupling region located inside the housing.

24. An apparatus according to claim 22, wherein:

the tensiometer is connected to the water source via a reservoir; and

the valve is adapted to connect the water source to the reservoir at a point below a waterline of the reservoir.

25. An apparatus according to claim 22, wherein:

the tensiometer is connected to the water source via a reservoir; and

the valve is operable to enable water from the water source to enter the reservoir and remove air therefrom.

26. Apparatus for use in determining matric potential of a soil comprising:

a tensiometer comprising;

a housing comprising a housing top and a housing bottom;

a water inlet; and

a hydraulic coupler comprising;

a porous material for providing hydraulic coupling between water that enters the inlet and the soil; and

a valve adapted to connect the tensiometer to a water source and operable to enable water from the water source to enter the tensiometer and flush the hydraulic coupler;

wherein;

a bottom surface of the housing top is provided with a water flow labyrinth comprising a plurality of baffles configured to disperse water entering the tensiometer.

27. An apparatus according to claim 26 wherein:

the hydraulic coupler further comprises;

a reservoir-coupling region located inside the housing.

28. A tensiometer for use in determining matric potential of a soil comprising:

a water inlet;

a hydraulic coupler comprising a porous material for providing hydraulic coupling between water that enters the inlet and the soil;

a valve adapted to connect the tensiometer to a water source and operable to enable water from the water source to enter the tensiometer and flush the hydraulic coupler; and

a septum that seals water that enters the inlet against ingress of air via the porous material;

wherein;

the septum has a bubbling pressure greater than about a maximum absolute value of the matric potential of the soil in which the tensiometer is used.

29. A tensiometer for use in determining matric potential of a soil comprising:

a water inlet;

a hydraulic coupler comprising a porous material for providing hydraulic coupling between water that enters the inlet and the soil;

a valve adapted to connect the tensiometer to a water source and operable to enable water from the water source to enter the tensiometer and flush the hydraulic coupler;

a septum that seals water that enters the inlet against ingress of air via the porous material; and

an elastic member that resiliently presses the porous material to the septum.