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.
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
Decreased Efficiency WindDrift Evaporation Evaporation from vegetation Evaporation from soil surface Infiltration Runoff Deep percolation
Flood Drip Spray Furrow
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
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) • Unit flow rate • Field slope • Soil texture
Drip Irrigation • Evaporation (Minor Loss) • Minor soil surface evaporation for drip • Deep percolation (Minor Loss) • System uniformity • Total application depth • Runoff (Minor Loss)
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
Low Energy Precision Application (LEPA) • Irrigates with the plant rows • Drops water in the furrow Approximately 90% application efficiency
Efficiency • Standard Multi Sprinkler 75-80% • Moving Multi Sprinkler • LEPA 90+% • High Pressure Gun 60-75% • Standard Flood 40-70% • Drip Irrigation 90% A high efficient irrigation system will help increase the precision of the application of water and nutrients to the plant.
Fertigation / Chemigation The use of an irrigation system to apply the necessary application of nutrients or chemicals to the crop.
Management Need to know and understand the equipment.
Advantages • Uniformity of application • Prescription applications • Economics - expense • Timelines • Incorporation and Activation • Reduced Compaction • Operator hazard
Disadvantages • Calibration of equipment • Additional equipment • Environmental Hazard • Increased application times • Unnecessary Water Applications
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.
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
Site Specific Irrigation/Fertigation Pivot Animation
Sources • www.florence.ars.usda.gov/ • www.betterpivots.com/how.html • http://weather.nmsu.edu/ • www.nrw.gld.gov.au/ • www.ag.ndsu.nodak.edu/abeng/ • www.fertigationsystems.com • http://msucares.com/pubs/pulications/p1551.htm • Dr. Kizer. Oklahoma State University. April 18, 2008