Process for in-season fertilizer nutrient application based on predicted yield potential

• US 6,880,291 B2
• Filed: 07/12/2002
• Issued: 04/19/2005
• Est. Priority Date: 07/24/2001
• Status: Expired due to Term

• Current Assignee: Board of Regents of Oklahoma State University
• Original Assignee: Board of Regents of Oklahoma State University
• Inventors: Solie, John B., Stone, Marvin L., Johnson, Gordon V., Raun, William R.
• Primary Examiner(s): Gellner, Jeffrey L.
• Application Number:
  US10/195,138
• Publication Number:
  US 20030019152A1
• Time in Patent Office: 1,012 Days
• Field of Search: 47/581.5 C, 47/581.R, 382/110
• US Class Current: 47/58.1SC
• CPC Class Codes: A01C 21/007 Determining fertilization requirements

Abstract

A method for in-season macro and micronutrient application based on predicted yield potential and a nutrient response index. The inventive method includes the steps of: determining a nutrient response index for a field; determining the normalized difference vegetation index (NDVI) of an area to fertilize; determining a predicted crop yield for the area; determining an attainable crop yield for the area; determining the nutrient requirement for the area as the difference between the nutrient removal at the attainable yield minus the nutrient removal at the predicted yield, adjusted by the efficiency of nutrient uptake in the particular crop. In one preferred embodiment, processing requirements at the time of application of the nutrient are eased by generating a lookup table of nutrient requirement relative to measured NDVI prior to application of the nutrient.

Claims

1. A method for in-season nutrient application including the steps of;

(a) determining a nutrient response index for a field;

(b) determining the normalized difference vegetation index of an area to fertilize;

(c) determining a predicted crop yield for said area;

(d) determining an attainable crop yield for said area;

(e) determining nutrient removal at said predicted crop yield;

(f) determining nutrient removal at said attainable crop yield;

(g) determining the amount of additional nutrient which must be supplied to achieve said attainable crop yield; and

(g) providing communication of said amount of nutrient.

2. The method of claim 1 wherein step (a) includes the substeps of:

(a) determine a nutrient response index for a field by the substeps of;

(i) providing a first area treated with a particular nutrient such that said first area is a non-limiting fertilized area;

(ii) providing a second area treated with a predetermined amount of nutrient;

(iii) determining the normalized difference vegetation index for said first area;

(iv) determining the normalized difference vegetation index for said second area; and

(v) dividing said normalized difference vegetation index for said first area by said normalized difference vegetation index for said second area.

3. The method of claim 1 wherein step (b) includes the sub steps of:

(b) determining the normalized difference vegetation index of an area to fertilize by performing the steps of;

(i) determining the reflectance of the vegetation in said area to red light;

(ii) determining the reflectance of the vegetation in said area to near infrared light;

(iii) dividing the difference of the reflectance determined step (b)(ii) minus the reflectance determined in step (b)(i) by the sum of the reflectance determined in step (b)(i) and the reflectance determined in step (b)(ii).

4. The method of claim 3 wherein the reflectance of the vegetation in said area to red light and the reflectance of the vegetation in said area to near infrared light are determined by scanning said vegetation with a reflectance sensor.

5. The method of claim 1 wherein step (c) includes the substeps of:

(c) determining a predicted crop yield for said area by performing the steps of;

(c)(i) determining the number of growing days since the planting of said crop;

(c)(ii) calculating the in-season estimated yield index for said area by dividing the normalized difference vegetation index by the number of growing days;

(c)(iii) calculating the predicted crop yield for said area as a function of the in-season estimated yield index for said area.

6. The method of claim 1 wherein said attainable crop yield is determined by multiplying said predicted crop yield times said response index.

7. A device adapted for use by a digital computer wherein a plurality of computer instructions defining the method of claim 1 are encoded,

said device being readable by said digital computer,

said computer instructions programming said digital computer to perform said method, and,

said device being selected from the group consisting of computer RAM, computer ROM, a PROM chip, flash RAM, a ROM card, a RAM card, a floppy disk, a magnetic disk, a magnetic tape, a magneto-optical disk, an optical disk, a CD-ROM disk, or a DVD disk.

8. A method for determining an application rate for nutrient fertilizer including the steps of;

(a) determining a nutrient response index by measuring the NDVI of a nutrient rich test strip and the NDVI of a test strip fertilized according to conventional practice;

(b) generating a lookup table wherein values stored in the table are indicative of nutrient requirements relative to NDVI values;

(c) transferring said lookup table to an apparatus for delivering the nutrient, said apparatus for delivering the nutrient having at least one sensor thereon for measuring crop NDVI and at least one controllable nozzle thereon for delivery of the nutrient to a crop;

(d) scanning a site with said sensor to determine crop NDVI at said site;

(e) drawing a nutrient requirement from said lookup table based said crop NDVI;

(g) controlling said controllable nozzle to deliver said nutrient requirement to said site.

9. A device adapted for use by a digital computer wherein a plurality of computer instructions defining step (b) of claim 8 are encoded,

said device being readable by said digital computer,

said computer instructions programming said digital computer to perform said method, and,

said device being selected from the group consisting of computer RAM, computer ROM, a PROM chip, flash RAM, a ROM card, a RAM card, a floppy disk, a magnetic disk, a magnetic tape, a magneto-optical disk, an optical disk, a CD-ROM disk, or a DVD disk.