Got Water? Developed by: Hud Minshew Oregon State University Extension Service Susan Donaldson University of Nevada Cooperative Extension UNCE, Reno, NV

Today we’ll learn about: Sources of irrigation water: surface vs. well water Matching available water to soils and plants Determining when it’s time to irrigate Methods of irrigation

Where will you get your water? Do you have a water right? Where will your water come from? When or how often will your get your water?

So you think you’ll use your 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, NV

What do you need 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? UNCE, Reno, NV

What do you need to know before you start to irrigate? Do you want to improve existing pasture or to start over? How much time and money do you have? USDA Online Photos

Where do plants get their water from in the root zone? Adapted from PNW 475 by A. Miller

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 = 20-30% Air = 20-30% Mineral Fraction (sand, silt, clay) = 45-50% Organics = 0-5% Composition of a loam soil

Soil texture How does it feel in your hand?

Water spreads differently in different soil textures 2.5 – 5 feet spread 5 – 9 feet spread 9 – 14+ feet spread    CLAY SILT SAND

Soil texture and drainage Sand Silt Loam Clay Loam Coarse Texture Medium Texture Fine Texture

Available water OSU Extension Service

Available water A. Miller

The water available to you Does your surface 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?

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

When is it time to irrigate? Rule of thumb: when the amount of water holding capacity is at 50 percent -- but that’s hard to tell! If your plants are showing stress, then 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 25-50% moisture. Clay, clay loam, or silty clay loam at 50-75% moisture. Irrigation is overdueWill need to irrigate soon USDA NRCS

Look and feel method Sandy loam or fine sandy loam at 50-75% moisture. Sandy loam or fine sandy loam at 25-50% moisture. Irrigation is overdueWill need to irrigate soon

Screwdriver method UNCE, Reno, NV

Using evapotranspiration data to schedule irrigation UNCE, Reno, NV

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 UNCE, Reno, NV

Irrigation systems: advantages and disadvantages Drip Flood Sprinkle NRCS Irrigation Page

Flood irrigation UNCE, Reno, NV NRCS Irrigation Page

Components of a flood irrigation system

Wild flood irrigation UNCE, Reno, NV

Gated pipe NRCS Irrigation Page

Reducing return flows OSU Extension Service

Ditch maintenance Dredging and re- digging Weed and vegetation control Opening and closing of gates Who will do it, and what will it cost? OSU Extension Service

Trickle or drip USDA SCS

Drip irrigation OSU Extension Service

Lateral wheel lines USDA NRCS

Guns USDA NRCS

Sprinklers UNCE, Reno, NV

Portable handlines

Applying water uniformly UNCE, Reno, NV

Improving uniformity Monitor your system during irrigation – 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 availability Match 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 Check List for Landowners Activity Sheet Check the uniformity of your sprinkler system, using any of the methods discussed in this lesson