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Got Water?. Developed by: Hud Minshew, Oregon State University Extension Service Susan Donaldson, University of Nevada Cooperative Extension. UNCE, Reno, Nev. Today we’ll learn about. Sources of irrigation water: surface versus well water Matching available water to: soils and plants - PowerPoint PPT Presentation
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Got Water?
Developed by: Hud Minshew, Oregon State University Extension Service
Susan Donaldson, University of Nevada Cooperative ExtensionUNCE, Reno, Nev.
Today 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
Where will you get your 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
So you think you’ll use your 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.
Things to know before you 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.
More things to know before
you start to irrigate Do you want to
improve existing pasture, or start over?
How much time and money do you have?
USDA
Where do plants get their water from in the root zone?
Adapted from PNW 475 by A. Miller
Plant rooting depths vary
A. Miller
Alfalfa4’ – 6+’
R
ootin
g D
epth
in F
eet
Before you pick a crop, consider 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
Water spreads differently in different soil textures
Deepest penetration
Moderate spread and infiltration
Wide, but more shallow, infiltration
CLAY
SILT
SAND
Soil texture and drainage
Soil texture Infiltration rate, inches per hour
Sand 2 - 4Sandy loam 1 - 3Silt loam, loams 0.25 – 1.5Silty clay loams, clay 0.1 – 0.3
A. Miller
Available 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
Wat
er C
onte
nt (%
vol
ume)
Available Water
Field Capacity
Wilting Point
Unavailable Water
OSU Extension Service
Available water
A. Miller
The water available to you Does 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.
When is it time to irrigate? Rule of thumb:
◦ When the amount of water-holding capacity is at 50%
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 Method
USDA NRCS
Look-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
Look-and-feel method
Sandy 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.
Screwdriver method
UNCE, Reno, Nev.
Using evapotranspiration data to schedule irrigation
Bureau of Reclamation
COAgMet - local weather station info and daily ET rates. A great resource to know when to
irrigate based on weather and EChttp://www.coagmet.colostate.edu/
Irrigation 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-affected soils
USDA-NRCS
Irrigation methods: selecting the system that’s right for you
Micro-irrigation
Surface
SprinkleUSDA NRCS
Are you using an existing 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
What source of power 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◦This one pictured is not able to support a pressurized irrigation system. Can handle a stock tank though!
USDA NRCS
Surface irrigation (gravity-flow)
NRCS Irrigation Page
UNCE, Reno, Nev.
UNCE, Reno, Nev.
Wild-flood irrigation
UNCE, Reno, Nev.
Field leveling
USDA NRCS
Level- basin irrigation
USDA NRCS
Corrugation
UNCE, Reno, Nev.
CSU Cooperative Extension
Furrow irrigation (level and graded)
USDA NRCS
Furrow irrigation with siphon tubes
USDA NRCS
Components of a border irrigation system
USDA NRCSA. Miller
Gated pipe
USDA NRCS
UNCE, Reno, Nev.
USDA ERS
Surge irrigation
ERS USDA
Water delivery is controlled by a valve.
Alfalfa valves
Univ. of Idaho Extension
Bubbler screen
B. Hamblen, CSU Extension
Reducing return flows
Reusing 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.
Ditch maintenance
Who will do it, and what will it cost?
Dredging and re-digging Weed and vegetation
control Open/close gates Adjusting siphon tubes Permission and access
issuesOSU Extension Service
Powered systems: sprinklers
UNCE, Reno, Nev.
Center-pivot
USDA NRCS
Mini-pivot sprinklers
USDA NRCS Mont.
Low-energy precision-applicationsprinklers
USDA NRCS
USGS
Traveling guns (big gun)
USDA NRCS
www.clemson.edu
Traveling mini-guns
USDA NRCS
K-line® and Irripod® sprinklers
www.k-linena.com kygraziers.com
Hand lines
ERS USDA
USDA NRCS
Side roll/wheel lines
USDA NRCS
USDA NRCS
Solid-set sprinkler
UNCE, Reno, Nev.
Univ. of Idaho Extension
Below-ground popups
USDA SCS
Drip irrigation
Drip irrigation
USDA ARS
USDA NRCS
Subsurface drip irrigationUNCE, Reno, Nev.
Checking your system:Does it apply water uniformly?
UNCE, Reno, Nev.
Improving uniformity Monitor 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 uniformity : a low-cost approach
OSU Extension Service
Irrigation systems summary Know your sources of irrigation
water Know your soil type Monitor soil moisture Improve efficiency of your
delivery system when possible
Irrigation systems summary
Adjust rate of water application to avoid runoff
Know your labor availabilityMatch your goals for your land to the irrigation system you select
Homework Practice 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.