John Brice Colburn

US Patent:

61385905, Oct 31, 2000

Filed:

Oct 6, 1997

Appl. No.:

8/944843

Inventors:

John W. Colburn - Houston TX

Assignee:

Aguila Corporation - Houston TX

International Classification:

A01C 2300

US Classification:

111118

Abstract:

A real time soil constituent sensor and precision agricultural chemical delivery system may measure simple in situ soil constituents without the aid of externally applied solvents, or such solvents may be utilized intermittently to calibrate the measurements for greater accuracy. A real time complex in situ soil resistivity sensor and prescription agricultural chemical delivery system includes a plurality of ground-engaging tools in association with individual soil electrode arrays which measure complex solute and matrix resistivity levels. Conventional ground-engaging tools may serve as electrodes for impressing a voltage source and serve as a current sink for the purposes of determining complex resistivity values and components thereof in in situ soils. Alternatively, local resistivity measurements in a single tool can also be employed for separation of resistivity contributions of the soil solute and the matrix. For calibration, to enhance the accuracy of in situ measurements of matrix resistivity, a plurality of reference fluids of known conductivity are periodically injected at the interface between electrodes on a single tool and the in situ soil.

US Patent:

56736371, Oct 7, 1997

Filed:

Oct 29, 1993

Appl. No.:

8/144786

Inventors:

John W. Colburn - Houston TX
Sylvia A. M. Colburn - Houston TX

Assignee:

Crop Technology, Inc. - Houston TX

International Classification:

A01C 2300

US Classification:

111118

Abstract:

A real time soil constituent sensor and precision agricultural chemical delivery system may measure simple in situ soil constituents without the aid of externally applied solvents, or such solvents may be utilized intermittently to calibrate the measurements for greater accuracy. A real time complex in situ soil resistivity sensor and prescription agricultural chemical delivery system includes a plurality of ground-engaging tools in association with individual soil electrode arrays which measure complex solute and matrix resistivity levels. Conventional ground-engaging tools may serve as electrodes for impressing a voltage source and serve as a current sink for the purposes of determining complex resistivity values and components thereof in in situ soils. Alternatively, local resistivity measurements in a single tool can also be employed for separation of resistivity contributions of the soil solute and the matrix. For calibration, to enhance the accuracy of in situ measurements of matrix resistivity, a plurality of reference fluids of known conductivity are periodically injected at the interface between electrodes on a single tool and the in situ soil.