drip irrigation and high tunnels
DESCRIPTION
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
Making a Difference in Minnesota
High Tunnels and Drip Irrigation
© 2009 Regents of the University of Minnesota
Making a Difference in Minnesota
Drip Irrigation Considerationswith
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
[email protected] or 320-589-1711
© 2009 Regents of the University of Minnesota
Reasons for Using Drip/Trickle Irrigationin High Tunnel Production System
•Efficiently & Uniformly Applies Crop Water as Needed
– to maintain optimum growing conditions– for transplant establishment – for uniform plant/produce development
• by enhancing INPUT use efficiency– to protect & enhance yield and quality
•Effectively Applies Some Nutrients in Water
© 2009 Regents of the University of Minnesota
Irrigation System Needs!!!
• Water supply• System performance
– Uniform water application– Flexible & crop specific control– Fertigation?? – Frost protection??– Cooling??
• System Options• Operating Labor• Cost????• Consult Local Experts
© 2009 Regents of the University of Minnesota
Water Supply!!!3 to 10 gallons per minute per tunnel
Dependent on Drip Flow Rate and Tubing Layout
© 2009 Regents of the University of Minnesota
Estimated Daily Crop Water Use “ET” Typical Annual Crop
0.00
0.05
0.10
0.15
0.20
0.25
0.30
14-May
28-May
11-Jun
25-Jun
9-Jul23-Jul
6-Aug20-Aug
3-Sep17-Sep
ET -
Inch
es p
er d
ay
Annual water use = 8 to 18 inches© 2009 Regents of the University of Minnesota
Irrigation Water Applied in 2005Average Inches per Day
High Tunnel Tomatoes at Staples, MN
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
Inch
es o
f wat
er p
er d
ay
may = 5–10 inches more than outside
© 2009 Regents of the University of Minnesota
IRRIGATION WATER USE PERMITMinnesota Rules
www.dnr.state.mn.us/permits/water/index.htmlIN EXCESS OF 10,000 GALLONS PER DAY(= 7 gpm)
GREATER THAN ONE MILLION GALLONS / YEAR
WITHDRAWAL LIMITS ON SURFACE WATER 6 ACRE-INCHES PER ACRE with STREAM FLOW MINIMUM
GROUND WATER LIMITS 12-15 ACRE-INCHES PER ACRE CANNOT CREATE ANY INTERFERENCE WITH DRINKING WELLS
WELL CONSTRUCTION FEE $215 (Mn Dept Health)IRRIGATION APPLICATION FEE $150 - $300(after the fact)ANNUAL REPORT ($140 minimum fee) for 50M Gallons
© 2009 Regents of the University of Minnesota
Water Quality Concerns??• Iron–Calcium-Sand (groundwater)• Algae – Sand – Silt (surface water)
• Water Treatment– Screen/Disc Filters, – Sand filter Tanks– Chemical treatment?????
© 2009 Regents of the University of Minnesota
What are the soil characteristics in the proposed site???
• Rooting potential– Restrictive layer
• Drainage limitations • Soil texture• Water holding capacity• Consult local experts
– NRCS & Extension
© 2009 Regents of the University of Minnesota
Know Your Soil Rooting Depth
and
How Will Water Re-Distribute!
© 2009 Regents of the University of Minnesota
Drip Irrigation System Options!!!
© 2009 Regents of the University of Minnesota
Drip Irrigation SystemCharacteristics!!!
• Low pressure & small water supply• High water application efficiency• Solid-set management
– variety of emitter spacings– Irrigate crops separately
• Moderate Labor– easily automated
• Works well with mulches – plastic
• No frost protection• Emitters’ plug easily• Tube damage
© 2009 Regents of the University of Minnesota
Drip Irrigation Wetted PatternDesign!!!
© 2009 Regents of the University of Minnesota
Line Source Drip Tape
• Tape– Emitters manufactured within the tape wall– Common spacings: 4”, 8", 12", 16", 18", 24’’– Flow rates (GPH) @ 8 psi: .16, .21, .33, .53
• .45GPM/100feet = 27 GPH/100ft or .67GPM = 40GPH/100ft.– Wall thickness (mil): 6, 8, 10, 15
• One to two year of usage– Maximum operating pressures: • 6 mil @ 10 psi– • 8 mil @ 12 psi • 10 mil @ 14 psi •15 mil @ 25 psi– ?? Pressure compensated drippers for more uniformity of
water and fertilizer applications• Surface or sub-surface installations
© 2009 Regents of the University of Minnesota
Line Source Drip Tubing
• Tubing (in-line emitter devices)– heavy wall thickness: 2-3 times tape– Variable spacings: 9, 12, 18, 24, 48”– multi-seasonal use
• 6 to 10 times more costly– pressure compensated dripper options for best uniformity of
water and fertilizer applications and self-flushing: dirt and debris during operation
• Surface or sub-surface installations
© 2009 Regents of the University of Minnesota
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
Drip Irrigation System Design ??One or Two Lateral Lines per Row
© 2009 Regents of the University of Minnesota
Drip Tube Placement
Plants off-set down the row
© 2009 Regents of the University of Minnesota
Drip Tube Placement
• Tube should be installed at same time/prior to mulch• Single-row crops:tomatoes,cucumbers, muskmelons
– Place tube 4 to 5 inches from the center or in the center• Double-row crops: eggplant, peppers and strawberries
– tube should be placed directly on the center of the bed • Placement: keep emitters up and place in a shallow
groove or buried (1-2”) to aid in keeping from shifting in the bed or fasten each end of tubing to keep straight
•Caution – avoid puncturing tube during planting/staking© 2009 Regents of the University of Minnesota
Drip Installation Prior to Plastic MulchHand or Mechanical Installation
© 2009 Regents of the University of Minnesota
Drip Installation Prior to Plastic MulchOn a smooth soil surface & slightly buried
© 2009 Regents of the University of Minnesota
Header Options
© 2009 Regents of the University of Minnesota
Water Supply & Pump
Air - FlushingRelease Valve
High Tunnel House
Shut of fValves
Sub-main
Tee AdapterTo Drip Tubewith Shut of f
Valve
Drip Tubes
Pressure Gauges
Pressure Regulator
Filter
ChemicalInjector
Backf low Device
Control Timer Valve
2004 Jerry Wright, University of Minnesota
Filter
© 2009 Regents of the University of Minnesota
Drip Irrigation SystemOperation & Maintenance!!!
• Easily damaged– Rodents, hoe,
• Emitters’ easily plugged– Iron and calcium– Sand, algae – Some fertilizers
© 2009 Regents of the University of Minnesota
Drip Irrigation Control Assembly© 2009 Regents of the University of Minnesota
Water Supply & Pump
Air - FlushingRelease Valve
High Tunnel House
Shut of fValves
Sub-main
Tee AdapterTo Drip Tubewith Shut of f
Valve
Drip Tubes
Pressure Gauges
Pressure Regulator
Filter
ChemicalInjector
Backf low Device
Control Timer Valve
2004 Jerry Wright, University of Minnesota
Filter
Drip Irrigation Control Assembly© 2009 Regents of the University of Minnesota
Drip Irrigation Control Assembly
Cost: $300–600 + water supply system© 2009 Regents of the University of Minnesota
Trickle Irrigation SystemZone - Design!!!
© 2009 Regents of the University of Minnesota
FERTIGATIONNutrient "spoon-feeding"
• Check out chemical compatibility with irrigation water• Provide backflow protection – MDA Fertigation permit?
© 2009 Regents of the University of Minnesota
CHEMIGATION - FertigationNutrient "spoon-feeding"
• Calibration to a daily or weekly feeding program• Assess backflow protection between water source – ?MDA Permit?© 2009 Regents of the University of Minnesota
When & How Much Should I Water????
© 2009 Regents of the University of Minnesota
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
In-Field Soil Water Assessment
© 2009 Regents of the University of Minnesota
Soil Water Monitoring Sensors
© 2009 Regents of the University of Minnesota
Sensors Installation Steps
• Soak sensors in water 2-3 hours & air dry –repeat cycle 2/3 Xs
• Place in soil profile within plant row at 2 to 3 depth locations
• Mark sensor depths and site• !!! Read Sensors Frequently !!!!© 2009 Regents of the University of Minnesota
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
Installation Tips
• Soak sensors in water 2-3 hours & air dry – repeat cycle 2/3 Xs
• Place in soil profile within plant row at 1 to 2 depth locations
• Mark sensor depths and site• !!! Read Sensors Frequently !!!!
Soil Water Monitoring Sensors
© 2009 Regents of the University of Minnesota
Soil Water Monitoring
Irrometer Co - http://www.irrometer.com/Spectrum Technologies - http://www.specmeters.com© 2009 Regents of the University of Minnesota
Hansen AM400 Soil Moisture Data LoggerWatermark Soil Moisture Date Logger
Automatic Soil Moisture MonitoringSave 10 to 20 minutes Each Day
$500-650
© 2009 Regents of the University of Minnesota
Making a Difference in Minnesota
Extension MaterialsMinnesota High Tunnel Production Manual
http://www.extension.umn.edu/distribution/horticulture/M1218.html or http://www.mfvga.org/
Handbook –“Trickle Irrigation in the Eastern United States” NRAES #4http://www.nraes.org
High Tunnels for the Central Great Plains - Kansashttp://www.hightunnels.org/
High Tunnel Production in Pennsylvania http://plasticulture.cas.psu.edu/H-tunnels.html
Plastic Mulches & Drip for Vegetable Production North Carolina State University Extension
http://www.ces.ncsu.edu/hil/hil-33.html
Micro irrigation in Mulched Bed Production Systems: Irrigation Depths. Florida Cooperative Extension
http://edis.ifas.ufl.edu/AE049
© 2009 Regents of the University of Minnesota
*** Time for Questions ***
© 2009 Regents of the University of Minnesota