Got Water? Developed by: Hud Minshew, Oregon State University Extension Service Susan Donaldson,...
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Transcript of Got Water? Developed by: Hud Minshew, Oregon State University Extension Service Susan Donaldson,...
Got Water?Got Water?
Developed by: Developed by: Hud Minshew, Oregon State University Extension ServiceHud Minshew, Oregon State University Extension Service
Susan Donaldson, University of Nevada Cooperative Susan Donaldson, University of Nevada Cooperative ExtensionExtension
UNCE, Reno, Nev.
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Today we’ll learn aboutToday we’ll learn about
Sources of irrigation water: surface versus well water
Matching available water to soils and plants
Determining when it’s time to irrigate
Irrigation systems
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Where will you get your Where will you get your water?water?
Do you have a water right?
Where will your water come from?
When or how often will you get your water?
www.farmphoto.com
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So you think you’ll use your So you think you’ll use your domestic well to irrigate a pasture?domestic well to irrigate a pasture?
Does local law allow use of domestic well water for pasture irrigation?
Does your well produce enough water?
UNCE, Reno, Nev.
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Things to know before Things to know before you start to irrigateyou start to irrigate
What plants do you want to grow?
Do you have enough available water to support the plants?
Are your soils appropriate for growing the plants you selected?
UNCE, Reno, Nev.
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More things to know before More things to know before you start to irrigateyou start to irrigate
Do you want to improve existing pasture, or start over?
How much time and money do you have?USDA Online Photos
Where do plants get their water Where do plants get their water from in the root zone?from in the root zone?
Adapted from PNW 475 by A. Miller
Plant Plant rooting rooting depths depths
varyvary
A. Miller
Alfalfa4’ – 6+’
R
oo
tin
g D
ep
th in
Fe
et
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Before you pick a crop, Before you pick a crop, consider the soilconsider the soil
What is the capability class of the soil?
What are the slopes and aspects?
How deep is the soil?
Does it have adequate drainage and rooting depths?
Is compaction an issue?USDA NRCS
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Water = 20 to 30%
Air = 20 to 30%
Mineral Fraction
(sand, silt,clay) = 45 to 50%
Organic Matter = 0 to 5%
Composition of a loam soilComposition of a loam soil
Soil Soil texturetexture
How does it feel in your hand?
NRCS, Bozeman, Mont..
Water Water spreads spreads differently differently in in different different soil soil texturestextures
Deepest penetration
Moderate spread and infiltration
Wide, but more shallow, infiltration
CLAY
SILT
SAND
Soil texture and drainageSoil texture and drainage
Soil textureInfiltration rate, inches per hour
Sand 2 - 4
Sandy loam 1 - 3
Silt loam, loams 0.25 – 1.5
Silty clay loams, clay 0.1 – 0.3
A. Miller
Available waterAvailable water
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
Sand SandyLoam
Loam SiltLoam
ClayLoam
SiltyClay
Clay
Finer Texture
Wa
ter
Co
nte
nt
(% v
olu
me
)
Available Water
Field Capacity
Wilting Point
Unavailable Water
OSU Extension Service
Available waterAvailable water
A. Miller
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The water available to youThe water available to youDoes your water right
supply enough water?
Will you have water during dry years?
Do you need to reduce your irrigated acreage to match your water supply?
Can you use your water more efficiently?
UNCE, Reno, Nev.
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When is it time to irrigate?When is it time to irrigate?
Rule of thumb: when the amount of water-holding capacity is at 50% – but that’s hard to tell!
If your plants are showing signs of stress, irrigation is overdue
– Look for wilting or grasses that don’t spring back up when stepped on
The Look-and-feel MethodThe Look-and-feel Method
USDA NRCS
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Look-and-feel methodLook-and-feel method
Clay, clay loam or silty clay loam at
25 to 50% moisture
Clay, clay loam or silty clay loam at
50 to 75% moisture
Irrigation is overdue. Will need to irrigate soon. USDA NRCS
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Look-and-feel methodLook-and-feel methodSandy loam or fine sandy
loam at 50 to 75% moisture
Sandy loam or fine sandy loam at
25 to 50% moisture
Irrigation is overdue. Will need to irrigate soon.
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Screwdriver methodScrewdriver method
UNCE, Reno, Nev.
Using evapotranspiration data Using evapotranspiration data to schedule irrigationto schedule irrigation
Bureau of Reclamation
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Irrigation water qualityIrrigation water quality
Does your irrigation water contain trace elements that may affect plant growth?
Is the water salty?
What are upstream users doing that might affect your water quality?
Salt-Salt-affected affected
soilssoils
USDA-NRCS
Irrigation methods: selecting the Irrigation methods: selecting the system that’s right for yousystem that’s right for you
Micro-irrigationMicro-irrigation
SurfaceSurface
SprinkleSprinkleUSDA NRCS
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Are you using an existing Are you using an existing system, or starting over?system, or starting over?
Your flexibility may be limited with an existing system, but costs will be lower
Starting over allows you to carefully match soils, plants and water availability with irrigation systems, but can be costly
New irrigation systems may save time, money or water
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What source of power What source of power will you use?will you use?
None – select an irrigation system that does not require power
Electricity from an existing power line
An internal combustion engine
Solar power
Surface irrigation (gravity-flow)Surface irrigation (gravity-flow)
NRCS Irrigation Page
UNCE, Reno, Nev.
UNCE, Reno, Nev.
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Wild-flood irrigationWild-flood irrigation
UNCE, Reno, Nev.
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Contour-ditch irrigationContour-ditch irrigation
Univ. of Virgin Islands
Field levelingField leveling
USDA NRCS
Level- Level- basin basin
irrigationirrigation
USDA NRCS
CorrugationCorrugation
UNCE, Reno, Nev.
CSU Cooperative Extension
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Furrow irrigation Furrow irrigation (level and graded)(level and graded)
USDA NRCS
USDA NRCS
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Contour-furrow irrigationContour-furrow irrigation
Icrisat.org
Furrow irrigation with Furrow irrigation with siphon tubessiphon tubes
USDA NRCS
USDA NRCS
Components Components of a border of a border irrigation irrigation systemsystem
USDA NRCSA. Miller
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Gated pipeGated pipe
NRCS Irrigation Page
USDA NRCS
UNCE, Reno, Nev.
USDA ERS
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Surge irrigationSurge irrigation
ERS USDA
Water delivery is controlled by a valve.
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Alfalfa valvesAlfalfa valves
Univ. of Idaho Extension
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Bubbler screenBubbler screen
B. Hamblen, CSU Extension
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Reducing return flowsReducing return flows
OSU Extension Service
USDA NRCS
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Reusing tailwaterReusing tailwater
Do you have a legal right to reuse tailwater?
How will you capture and store the water for subsequent use?
Maximizes the use of surface irrigation water.
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Ditch maintenanceDitch maintenance Dredging and redigging
Weed and vegetation control
Opening and closing of gates
Adjusting of siphon tubes
Who will do it, and what will it cost?
Permission and access issues
OSU Extension Service
Powered systems: Powered systems: sprinklerssprinklers
UNCE, Reno, Nev.
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Center-pivotCenter-pivot
USDA NRCS
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Mini-pivot sprinklersMini-pivot sprinklers
USDA NRCS Mont.
Low-energy precision-applicationLow-energy precision-applicationsprinklerssprinklers
USDA NRCS
USGS
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Traveling guns Traveling guns (big gun)(big gun)
USDA NRCS
www.clemson.edu
Traveling mini-gunsTraveling mini-guns
USDA NRCS
K-lineK-line®® and Irripod and Irripod®® sprinklers sprinklers
www.k-linena.com
kygraziers.com
Photo source?
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Hand linesHand lines
ERS USDA
USDA NRCS
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Side roll Side roll wheel lineswheel lines
USDA NRCS
USDA NRCS
Solid-set sprinklerSolid-set sprinkler
UNCE, Reno, Nev.
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Below-ground popupsBelow-ground popups
Univ. of Idaho Extension
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Drip irrigationDrip irrigation
USDA SCS
Graphic by A Miller, adapted from USDA-SCS 1984
Drip irrigationDrip irrigation
USDA ARS
USDA NRCS
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Subsurface drip irrigationSubsurface drip irrigation
UNCE, Reno, Nev.
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ActivityActivity
Create a table showing the pros and cons of each of the
irrigation systems discussed.
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Checking your system:Checking your system:Does it apply water uniformly?Does it apply water uniformly?
UNCE, Reno, Nev.
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Improving uniformityImproving uniformityMonitor your system during irrigation
and check for leaks or clogging of screens
Look for areas that remain too wet or too dry and adjust your irrigation system
Check sprinkler system pressures and nozzles to make sure they are adequate
Consider system upgrades
The can method for measuring The can method for measuring uniformity – a low-cost approachuniformity – a low-cost approach
OSU Extension Service
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Irrigation systems summaryIrrigation systems summary
Know your sources of irrigation water
Know your soil type
Monitor soil moisture
Improve efficiency of your delivery system when possible
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Irrigation systems summaryIrrigation systems summary
Adjust rate of water application to avoid runoff
Know your labor availability
Match your goals for your land to the irrigation system you select
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HomeworkHomeworkPractice the Look-and-feel Method for
determining irrigation.
Inventory your irrigation system, both existing and proposed, using the Irrigation Checklist for Landowners Activity Sheet.
Check the uniformity of your sprinkler system, using any of the methods discussed in this lesson.