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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
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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 • 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
Alfalfa 4’ – 6+’ Rooting Depth in Feet Plant rooting depths vary A. Miller
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 CLAY Wide, but more shallow, infiltration SILT Moderate spread and infiltration SAND Deepest penetration
Soil texture and drainage A. Miller
Available 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 25 to 50% moisture Sandy loam or fine sandy loam at 50 to 75% 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 EC http://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 Surface Sprinkle USDA NRCS Micro-irrigation
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) UNCE, Reno, Nev. NRCS Irrigation Page 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 NRCS A. Miller
Gated pipe UNCE, Reno, Nev. USDA ERS USDA NRCS
Surge irrigation Water delivery is controlled by a valve. ERS USDA
Alfalfa valves Univ. of Idaho Extension
Bubbler screen B. Hamblen, CSU Extension
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 issues OSU Extension Service
Powered systems: sprinklers UNCE, Reno, Nev.
Center-pivot USDA NRCS
Mini-pivot sprinklers USDA NRCS Mont.
Low-energy precision-applicationsprinklers USGS USDA NRCS
Traveling guns (big gun) www.clemson.edu USDA NRCS
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.