Method and apparatus for real-time determination and application of nitrogen fertilizer using rapid, non-destructive crop canopy measurements

• US 6,393,927 B1
• Filed: 10/08/1996
• Issued: 05/28/2002
• Est. Priority Date: 03/24/1995
• Status: Expired due to Fees

• Current Assignee: United States Department Of Agriculture
• Original Assignee: Li & S Company Limited (Yesco Holdings Co., Ltd.)
• Inventors: Wurm, John Henry, Schepers, James S., Holland, Kyle H., Demetriades-Shah, Tanvir H., Blackmer, Tracey M., Biggs, Gregory L.
• Primary Examiner(s): RAEVIS, ROBERT R
• Application Number:
  US08/727,125
• Time in Patent Office: 2,058 Days
• Field of Search: 73/19.01,866,627-629 239/146,722,723,727,728,DIG. 15 222/52 111/904,903,118,127-129 47/48.5,1.5 250/339.01,339.02 356/402,425,432,433,445,448
• US Class Current: 73/866
• CPC Class Codes: A01C 21/007 Determining fertilization requirements

Abstract

A method and apparatus for the real time determination and application of optimum amounts of nitrogen fertilizer to corn and other arable crops such as cotton, sugar beats, wheat, etc. by the use of rapid, non-destructive sensors and various fertilizer application methods. In a first embodiment, optical reflectance measurements of the crop canopy and a reference strip at the fertilizer response plateau are taken by sensors carried by a center pivot irrigation system. A sensor controller receives, stores and analyzes the sensor data as well as position data received from a center pivot controller. The sensor controller then sends commands to the center pivot controller to order fertilizer application, as necessary, through the irrigation system.

A second embodiment of the invention utilizes a tractor drawn fertilizer applicator with the sensors mounted on the application booms. As in the first embodiment, a sensor controller receives, stores and analyzes reference strip and crop canopy reflectance data and sends commands to the tractor fertilizer controller to order fertilizer application. This second embodiment may also utilize the Global Positioning System to provide tractor position for storage along with crop data for later use and comparison.

Claims

1. A method for controlling the application of fertilizer to a crop having a physical characteristic related to the fertilizer requirements of the crop, the crop having a non-reference area and a reference area, comprising the steps of:

providing a sensor which is responsive to said physical characteristics of said crop;

measuring said physical characteristic of said reference crop by passing said sensor over said crop by securement to a center pivot irrigation system and said application of fertilizer is by fertigation;

measuring said physical characteristic of said non-reference crop;

controlling the application of fertilizer to said crop in real time based on a comparison of said reference and non-reference crop physical characteristics; and

computing said sensor position information for storage of crop physical characteristic data.

2. A method for controlling the application of fertilizer to a crop having a physical characteristic related to the fertilizer requirements of the crop, the crop having a non-reference area and a reference area, comprising the steps of:

(a) providing a sensor which is responsive to said physical characteristic of said crop;

(b) measuring said physical characteristic of said reference crop;

(c) measuring said physical characteristic of said non-reference crop;

(d) controlling fertilizer application to said crop in real time based on a comparison of said reference and non-reference crop physical characteristics wherein said measuring is accomplished by passing said sensor over said crop by securement to a tractor drawn fertilizer application system; and

(e) computing sensor position information for storage of crop physical characteristic data using a Global Positioning System.

3. An apparatus for controlling the application of fertilizer to a crop having a physical characteristic related to the fertilizer requirements of the crop, the crop having a non-reference area and a reference area, comprising:

a sensor which is responsive to said physical characteristic of said crop;

means for measuring said physical characteristic of said reference crop;

means for measuring said physical characteristic of said non-reference crop wherein said measuring means comprises securement of said sensor to a center pivot irrigation system;

means for controlling the application of fertilizer to said crop in real time based on a comparison of said reference and non-reference crop physical characteristics; and

means for computing and storing sensor position information.

4. An apparatus for controlling the application of fertilizer to a crop having a physical characteristic related to the fertilizer requirements of the crop, the crop having a non-reference area and a reference area, comprising:

(a) a sensor which is responsive to said physical characteristic of said crop;

(b) means for measuring said physical characteristic of said reference crop;

(c) means for measuring said physical characteristic of said non-reference crop;

(d) means for controlling fertilizer application to said crop in real time based on a comparison of said reference and non-reference crop physical characteristics wherein said measuring means comprises securement of said sensor to a tractor drawn fertilizer application system; and

(e) means for computing sensor position information for storage of crop physical characteristic data using a Global Positioning System.

5. An optical crop sensor for detecting crop density differences based on differences in the crop/soil light reflectance, comprising:

(a) a first detector with a natural sensitivity limited to the visible part of the reflected spectrum;

(b) a second detector sensitive to the near-infrared part of the reflected spectrum;

(c) a diffuser for covering both detectors mounted in a side-by-fashion providing a common optical path.

6. A method for controlling the application of fertilizer to a crop having a physical characteristic related to the fertilizer requirements of the crop, the crop having a non-reference area and a reference area, comprising the steps of:

(a) providing a sensor which is responsive to said physical characteristic of said crop;

(b) measuring said physical characteristic of said reference crop;

(c) measuring said physical characteristic of said non-reference crop;

(d) controlling fertilizer application to said crop in real time based on a comparison of said reference and non-reference crop physical characteristics wherein said measuring is accomplished by passing said sensor over said crop by securement to a tractor drawn fertilizer application system; and

(e) computing sensor position information for storage of crop physical characteristic data using a positioning system.

7. An apparatus for controlling the application of fertilizer to a crop having a physical characteristic related to the fertilizer requirements of the crop, the crop having a non-reference area and a reference area, comprising:

(a) a sensor which is responsive to said physical characteristic of said crop;

(b) means for measuring said physical characteristic of said reference crop;

(c) means for measuring said physical characteristic of said non-reference crop;

(d) means for controlling fertilizer application to said crop in real time based on a comparison of said reference and non-reference crop physical characteristics wherein said measuring means comprises securement of said sensor to a tractor drawn fertilizer application system; and

(e) means for computing sensor position information for storage of crop physical characteristic data using a positioning system.