Irrigation in High Tunnels
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Making a Difference in Minnesota Irrigation Concerns within High Tunnel Production Systems Jerry Wright, Retired Extension Engineer University of Minnesota Extension Bioproducts & Biosystems Engineering Dept West Central Research & Outreach Center - Morris, MN High Tunnel Workshop – December 2, 2009 [email protected] © 2009 Regents of the University of Minnesota
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High Tunnel irrigation overview presented by University of Minnesota retired Extension Engineer, Jerry Wright at the 2009 Minnesota Statewide High Tunnel Conference in Alexandria, MN on Dec. 2-3, 2009.
Transcript of Irrigation in High Tunnels
Making a Difference in Minnesota
Irrigation Concernswithin
High Tunnel Production SystemsJerry Wright, Retired Extension Engineer
University of Minnesota Extension Bioproducts & Biosystems Engineering Dept
West Central Research & Outreach Center - Morris, MNHigh Tunnel Workshop – December 2, 2009
© 2009 Regents of the University of Minnesota
Making a Difference in Minnesota
Jerry Wright, University of Minneota Extension
Uniformity of Irrigation Water
Application• Irrigation Water Quality
– Sedimentation, algae– Water chemistry – salinity,
calcium, iron, pH• Adequate filters after water
source and fertigation system• Water Compatibility
with fertilizer
© 2009 Regents of the University of Minnesota
Making a Difference in Minnesota
Jerry Wright, University of Minneota Extension
Uniformity of Water Application
• Adequate filters after water source and fertigation system
• Check Water Compatibility with fertilizer!!!!! - 2009 Crookston
© 2009 Regents of the University of Minnesota
Making a Difference in Minnesota
Jerry Wright, University of Minneota Extension
Drip Irrigation Control Assembly
© 2009 Regents of the University of Minnesota
Making a Difference in Minnesota
Jerry Wright, University of Minneota Extension
Routine Line & Filter Flushing
© 2009 Regents of the University of Minnesota
Making a Difference in Minnesota
Jerry Wright, University of Minneota Extension
Uniformity of Irrigation Water Application
• Water Pressure Distribution– Along header & lateral lines
• Adequate pipeline diameter to minimize friction losses
• Friction loss through filters, controllers and fertigation valves
• Pressure Regulator & Gages
© 2009 Regents of the University of Minnesota
Jerry Wright, University of Minneota Extension
When & How Much Should I Water????
© 2009 Regents of the University of Minnesota
Making a Difference in Minnesota
Jerry Wright, University of Minneota Extension
High Tunnel - Soil & Plant Water Management
• Irrigation timing and application depth– Over watering leaches nutrients & reduces O2
– Under watering affects fruit growth & quality• Know your systems application rate
– Gallons per linear foot per hour– Inches of water depth per hour
© 2009 Regents of the University of Minnesota
Jerry Wright, University of Minneota Extension
Table 4: Average Application Rate from Drip Irrigation Systems by Jerry Wright, Extension Engineer, University of Minnesota
Email: [email protected] (April 2005)
Drip Tube Flow ********** Wetted Soil Width in Inches *************GPM GPH 8 12 16 20 24
per 100ft per 100ft Average Application Rate - Inches per Hour0.200 12 0.29 0.19 0.14 0.12 0.100.250 15 0.36 0.24 0.18 0.14 0.120.300 18 0.43 0.29 0.22 0.17 0.140.350 21 0.51 0.34 0.25 0.20 0.170.450 27 0.65 0.43 0.32 0.26 0.220.670 40 0.97 0.64 0.48 0.39 0.320.850 51 1.23 0.82 0.61 0.49 0.411.700 102 2.45 1.64 1.23 0.98 0.82
Appl. Rate inches/hour = 12 in/ft * (GPH/100ft)/(7.48 gal/cuft * 100 * wetted width in feet)file: irrigation gallons per ET version 3e.xls
Drip Irrigation SystemWater application rate!!!
© 2009 Regents of the University of Minnesota
Making a Difference in Minnesota
Jerry Wright, University of Minneota Extension
• Know the soil texture and dripirrigation water movement
– wetted soil pattern - width & depth – May need more than one drip line per row/bed
• Understand plants water needs:– Increases with Plant density and foliage size
• Daily crop ET (.1 to .25 inches per day)– .3 to .7 gallons per plant per day (research very limited)
• Different crops may need difference irrigation schedules– Install small control valve on each irrigated row– Plant same crop type and planting date in same row
High Tunnel - Soil & Plant Water Management
© 2009 Regents of the University of Minnesota
Making a Difference in Minnesota
Jerry Wright, University of Minneota Extension
Average Irrigation Applied in High Tunnel TomatoesGallons per Plant per Day - Staples 2005
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
15-M
ay
22-M
ay
29-M
ay
5-J
un
12-J
un
19-J
un
26-J
un
3-J
ul
10-J
ul
17-J
ul
24-J
ul
31-J
ul
7-A
ug
14-A
ug
21-A
ug
28-A
ug
4-S
ep
11-S
ep
18-S
ep
25-S
ep
2-O
ct
9-O
ct
Gal
lon
s p
er P
lan
t p
er d
a
Plt/dy in 18" spacing Plt/dy in 24" spacing
Poly. (Plt/dy in 18" spacing) Poly. (Plt/dy in 24" spacing)
Average Irrigation Applied in High Tunnel TomatoesGallons per Plant per Day - Staples 2005field observations indicate cucumbers can use more water
© 2009 Regents of the University of Minnesota
Making a Difference in Minnesota
Jerry Wright, University of Minneota Extension
In-Field Soil Water Assessment
© 2009 Regents of the University of Minnesota
Jerry Wright, University of Minneota Extension
SOIL WATER DEFICITSfor
Typical Soils & Soil Water TensionsGood Range for High Tunnels - 25 to 40 centibars
Soil water tension in centibars, cbs 10 30 50 70 100 200 1500**
Soil Texture
Soil water deficit – inches per foot of soil
Coarse sand 0 0.1 0.2 0.3 0.4 0.6 0.7 Fine sand 0 0.3 0.4 0.6 0.7 0.9 1.1
Loamy sand 0 0.4 0.5 0.8 0.9 1.1 1.4 Sandy loam 0 0.5 0.7 0.9 1.0 1.3 1.7
Loam 0 0.2 0.5 0.8 1.0 1.6 2.4 **1500 cbs is approximately the permanent wilting point for most plants and the soil water deficit values equal the soil’s available water holding capacity
© 2009 Regents of the University of Minnesota
Jerry Wright, University of Minneota Extension
Soil Water Monitoring Sensors
© 2009 Regents of the University of Minnesota
Jerry Wright, University of Minneota Extension
Soil Water Monitoring
Irrometer Co - http://www.irrometer.com/Spectrum Technologies. - http://www.specmeters.com© 2009 Regents of the University of Minnesota
Making a Difference in Minnesota
Jerry Wright, University of Minneota Extension
High Tunnel - Soil & Plant Water Management
• Automation of irrigation system– Manual On switch with timer shut-off
• Good for small - low flow systems• Too much pressure loss for high flow rates
– Full timer 7day – 24 hour control• Can control one valve or multiple valves• Many sizes available & low friction loss
© 2009 Regents of the University of Minnesota
Jerry Wright, University of Minneota Extension
Automatic Controllers
© 2009 Regents of the University of Minnesota
Jerry Wright, University of Minneota Extension
Failed Irrigation with Automatic Timer
© 2009 Regents of the University of Minnesota
Making a Difference in Minnesota
Jerry Wright, University of Minneota Extension
Closing Comments
• Know your irrigation system• Learn how water moves in your soil• Do not over irrigate!!!!• Automation & Fertigation requires a
watchful eye !!!!
© 2009 Regents of the University of Minnesota
