1. Variable Rate Application Technology for Florida Citrus
Kieth Hollingsworth, CCA
Chemical Containers Inc.

2. What is Variable Rate Technology ?
Ability to apply different amount of inputs to specific points in the same field.
Applies to fertilizer, pesticides, herbicides, or soil amendments.
Should be incorporated into the total GIS Program.

3. WHERE DO WE BEGIN ?
1) Gather geo-referenced information from our field
2) Analyze data to form management zones
3) Write prescription files and create map
4) Make Precision Application
5) Create record of application

4. Gather DGPS referenced information PEST OR DISEASE PRESSURE
SOIL TYPE
BOUNDRY
MAP
SOIL pH
PEST OR DISEASE PRESSURE
Prescription
Map
PAST HARVEST DATA
NUTRIENT LEVELS

5. VARIABLE RATE APPLICATION EQUIPMENT
THUS THE NEED FOR
VARIABLE RATE APPLICATION EQUIPMENT

6. VARIABLE RATE APPLICATOR
Must know its unique address
Must be able to adjust application rate:
on the fly
according to prescription file
Should create an “as applied map”
an “as applied map” is a report of actual application

7. MID-TECH RX 100p Trimble Ag GPS 124 DGPS Receivers
“Differentially Corrected GPS is necessary for VRA
Correction sources are Beacon, Satellite, or WAAS
Receivers should run at 5 Hz or faster

8. Processor for Variable Rate Software Laptops with a data link
Accepts flash card with field prescription map
Contains variable rate application software
Field Computers
Laptops with a data link

9. VARIABLE RATE SOFTWARE
Communicates with Rate Controller and GPS
Identifies location on prescription map
Analyzes rate based on location
Sends rate to controller
Updates 5 times per second or faster

10. Prescription Map Identifies rate for applicators exact location
Sends rate to controller

11. Mid-Tech TASC 6100 Operator Inputs Granular - boom or swath width
-pounds per pulse (calibration number)
-fertilizer density
Liquid - input nozzle GPM
- active boom width

14. Legacy 6000 Controller with Trimble 106

15. As Applied Map * Receives Data from Rate Controller
* Displays “applied” areas * Creates “application report”

16. VARIABLE RATE LIQUID APPLICATOR
vary rate of carrier
vary rate of each injection pump

17. Carrier : may vary or stay constant
Chemicals : pumps vary rate

18. Real-Time VRA
Application of products based on applicator seeing target
Eye systems that see trees
Weed Seekers that Sense Chlorophyll

19. Electronic “Eye Systems”
Eyes “see tree canopy” and perform a function
May be programmed to turn off where skips occur
Increase or decrease application rate based on tree height

20. Dry Fertilizer Spreader with Three-Eye Setup
Changes Rate Based on Tree Height

21. Temik Application Precision Agriculture Approach

22. In Florida, state regulations require that TEMIK not be applied within 300 feet of any drinking water well. In addition, TEMIK cannot be used on Florida citrus within 1000 feet of a drinking water well regardless of depth of water table, when such soils have a permeability rate greater than 20 inches per hour. These highly permeable soils are: Adamsville, Candler, Neilhurst, Palm Beach, Tavares, Archbold, Cassia, Orsino, Satellite, Astatula, Lake, Paola, and St. Lucie Unless wells are cased to 100 feet or 30’ below the water table.
A Precision Application Approach, aids the applicator in several ways
Identifies wells and their GPS location
Identifies the setback for each well location
enables applicator to view his location in reference to a well location
may be configured to automatically stop Temik application within setback zone and resume application when applicator is clear of zone
maintains true, real-time, “as applied”, data from the Temik application

23. Well Locations The first step is well identification
Wells are located and plotted with a DGPS receiver and field mapping software
All the known well attributes are added to the well location at this time
This may include: casing depth, soil type at well location, setback radius, etc..
This is a permanent record and only needs to be done once unless the well configuration changes

25. Southwest Florida Water Management District
28,288 well locations in their GIS database
each well location has over 50 attributes

26. Image of grove showing well locations

27. Well locations with 300’ setback

28. Well setbacks Well locations are added to the Prescription map
Set back zones are set up for each well

29. Edited prescription map
The well setbacks are clipped out
Those areas are then assigned a zero application rate

30. As Applied Map
Red represents applicator travel with no product being applied
Blue represents applicator travel with product being applied at 20 lb.. per acre

31. Close up of as applied map
Red represents applicator travel with no product being applied
Blue represents applicator travel with product being applied at 20 lbs. per acre

32. Full Scale Rate Control Package
Reads VRT Prescription map and controls application rate
monitors output of applicator and records “as applied” data
DGPS Sub-meter accuracy receiver and antenna
Mid-Tech Legacy 6000 VRT computer and rate controller

33. Data Logging Package with Display
Operator can view grove boundary, well locations with setbacks, as well as his location on the screen
logs “snail trail” of application only
1-2 meter accuracy WAAS antenna / receiver
iPaq package with data logging software

34. Simple Data Logging System
Logs “snail trail” of application only
No display of applicator location, wells, or setback zones
3-5 meter accuracy antenna / receiver
Data logger with hard drive data storage of tri-mode dispatch
(digital, analog, or radio modem)

35. This presentation has been provided courtesy of :
Kieth Hollingsworth
Chemical Containers Inc.
P.O. Box 1307
Lake Wales FL 22859