1. Precision Irrigation and Fertigation

2. What is Irrigation?
Irrigation is the application of water to a crop for assisting the production of a crop.
What is precision?
A degree of mutual agreement among a series of individual measurements, values, or results.

3. What are we looking for in precision irrigation?
Irrigation Efficiency and/or Uniform Coverage
Plus site-specific application
Efficiency is what you get out, for what you put in.
Efficiency = output / input OR
Water stored in root zone / water delivered to the field

4. Decreased Efficiency Wind Drift Evaporation
Evaporation from vegetation
Evaporation from soil surface
Infiltration
Runoff
Deep percolation

5. Flood
Drip
Spray
Furrow

6. Spray Irrigation Evaporation (Major Loss) Wind speed Humidity
Air temperature
Canopy density
Sprinkler evaluation
Sprinkler pressure
Deep Percolation (Minor Loss)
System uniformity
Total application depth
Runoff (Minor Loss)
Application rate
Slope
Vegetation Density

7. Furrow Irrigation Evaporation (Minor Loss)
Wind speed
Humidity
Air temperature
Deep percolation (Major Loss)
Unit flow rate
Field length
Soil texture
Field slope
Total application depth
Runoff (Major Loss)

8. Drip Irrigation Evaporation (Minor Loss) Deep percolation (Minor Loss)
Minor soil surface evaporation for drip
Deep percolation (Minor Loss)
System uniformity
Total application depth
Runoff (Minor Loss)

9. How to Improve Irrigation System
Night Irrigation – Low temp, low wind, high humidity
Lower operating pressure – bigger droplet size
Low drift nozzles – bigger droplet size
New Technology

10. Low Energy Precision Application (LEPA)
Irrigates with the plant rows
Drops water in the furrow
Approximately 90% application efficiency

11. Efficiency Standard Multi Sprinkler 75-80% Moving Multi Sprinkler
LEPA %
High Pressure Gun %
Standard Flood %
Drip Irrigation 90%
A high efficient irrigation system will help increase the precision of
the application of water and nutrients to the plant.

12. Fertigation / Chemigation
The use of an irrigation system to apply the necessary application of nutrients or chemicals to the crop.

13. Management
Need to know and understand the equipment.

14. Advantages Uniformity of application Prescription applications
Economics - expense
Timelines
Incorporation and Activation
Reduced Compaction
Operator hazard

15. Disadvantages Calibration of equipment Additional equipment
Environmental Hazard
Increased application times
Unnecessary Water Applications

16. Why use Fertigation? Your irrigation system does the work.
Overfeeding and Underfeeding is decreased.
Dry applications need water to dissolve the granules.
With precise application, the overall amount of chemicals applied is reduced vs. the dry application.

17. Precision Irrigation
The use of fertigation or chemigation with site-specific technology.
Technology
GPS – locate soil type, water holes, weeds, obstructions, and boundaries
GIS (Geographical Information System) works with data captured from spatial reference points.
VRT (Variable-rate controllers) System “Brain” sets the rate of application dependent on soil type, slopes, ponds…etc.
Weather Station / Mesonet (ET rate)
Green Seeker / Weed Seeker
NIR (Near Infrared Band)
Red (Red Band)
Thermo sensor

18. Site Specific Irrigation/Fertigation
Pivot Animation

19. Sources www.florence.ars.usda.gov/ www.betterpivots.com/how.html
Dr. Kizer. Oklahoma State University. April 18, 2008

20. Questions?