Robert Hochmuth Multi County Extension Agent Suwannee Valley Agricultural Extension Center, Live Oak
Robert Hochmuth Multi County Extension Agent
Suwannee Valley Agricultural Extension Center, Live Oak
Suwannee Valley Extension Demonstrations for Nutrient &
Irrigation Management
Objective:
• To improve efficiency of nutrient and water delivery by vegetable growers in the Suwannee Valley region using plastic mulch and drip irrigation.
Methods:
• On-Center Research Projects
• Field Days
• Drip Irrigation Schools
• On-Farm Demonstrations
• On-Farm Field Days
• Farmer commodity meetings
0
5
10
15
20
25
24 36 48 60 72 96 115 139 173 192
Dep
th (i
n.)
Water Applied (gals/100ft.)
Dye Tests using Robert's Ro-Drip Tape @ 24gal/100ft at the North Florida Research and Education Center-Suwannee Valley
3/3/2002
5/9/2002
12/3/2002
3/25/2003
Combined Avg.
Linear (Combined Avg.)
Regression line: Depth = 0.1 Vol + 4
• Early Season extended irrigation events pose a great risk for leaching entire fertilizer application under plastic mulched beds
• Early Season (first 4 wks) – greatest risk of leaching
– irrigation was generally reduced by 50%
• Mid Season – Irrigation sensors “caught” rapid increase in water demand (late April – early
May)
• Late Season – Very difficult to over irrigate
– Lowest risk of leaching
• Single irrigation events in sandy soils in SV should be no longer than 1½ hours
• “Blue Dye Don’t Lie”
• Videos available at http://vfd.ifas.ufl.edu
Monitoring Plant Nutrient Levels with Petiole Sap Testing Procedures
• N the “throttle” • K consistent, rarely deficient
• Sap testing used for several years
• Nitrogen and Potassium
• Adjust injections
based on weekly
sap testing results
600
800
1000
1200
1400
1600
PP
M N
itro
gen
Sap test Nitrogen
Nitrogen Upper Limit
Actual Nitrogen
Nitrogen Lower Limit
Samples collected every 7 days.
• Connection of Specific Demonstrations – Soil Moisture Monitoring Sensors – Sap Testing – Blue Dye
• Combination of Methods – SVAEC Trials & Field Days – Drip Irrigation Schools – On-Farm Demonstrations – Virtual Field Day Videos (vfd.ifas.ufl.edu)
• Irrigation Management more Important than Specific Nutrient Rate
• Fertilizer “rate” studies on farms- Caution!