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Developed by: Hud Minshew, Oregon State University Extension Service Susan Donaldson, University of Nevada Cooperative Extension UNCE, Reno, Nev. Slide 2 Sources of irrigation water: surface versus well water Matching available water to: soils and plants Determining when its time to irrigate Irrigation systems Slide 3 Do you have a water right? Where will your water come from? When or how often will you get your water? www.farmphoto.com Slide 4 Does local law allow use of domestic well water for pasture irrigation? Does your well produce enough water? UNCE, Reno, Nev. Slide 5 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. Slide 6 Do you want to improve existing pasture, or start over? How much time and money do you have? USDA Slide 7 Adapted from PNW 475 by A. Miller Slide 8 A. Miller Alfalfa 4 6+ Rooting Depth in Feet Slide 9 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 Slide 10 Water spreads differently in different soil textures Deepest penetration Moderate spread and infiltration Wide, but more shallow, infiltration CLAY SILT SAND Slide 11 Soil texture Infiltration rate, inches per hour Sand2 - 4 Sandy loam1 - 3 Silt loam, loams0.25 1.5 Silty clay loams, clay0.1 0.3 A. Miller Slide 12 OSU Extension Service Slide 13 A. Miller Slide 14 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. Slide 15 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 dont spring back up when stepped on Slide 16 The Look-and-feel Method USDA NRCS Slide 17 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 Slide 18 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. Slide 19 UNCE, Reno, Nev. Slide 20 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/ Slide 21 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? Slide 22 USDA-NRCS Slide 23 Micro-irrigation Surface Sprinkle USDA NRCS Slide 24 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 Slide 25 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 Slide 26 NRCS Irrigation Page UNCE, Reno, Nev. Slide 27 Slide 28 USDA NRCS Slide 29 Slide 30 UNCE, Reno, Nev. CSU Cooperative Extension Slide 31 USDA NRCS Slide 32 Slide 33 A. Miller Slide 34 Gated pipe USDA NRCS UNCE, Reno, Nev. USDA ERS Slide 35 Surge irrigation ERS USDA Water delivery is controlled by a valve. Slide 36 Alfalfa valves Univ. of Idaho Extension Slide 37 B. Hamblen, CSU Extension Slide 38 Reducing return flows Slide 39 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. Slide 40 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 Slide 41 Powered systems: sprinklers UNCE, Reno, Nev. Slide 42 Center-pivot USDA NRCS Slide 43 USDA NRCS Mont. Slide 44 Low-energy precision-application sprinklers USDA NRCS USGS Slide 45 Traveling guns (big gun) USDA NRCS www.clemson.edu Slide 46 Traveling mini-guns USDA NRCS Slide 47 K-line and Irripod sprinklers K-line and Irripod sprinklers www.k-linena.comkygraziers.com Slide 48 Hand lines ERS USDA USDA NRCS Slide 49 Side roll/wheel lines USDA NRCS Slide 50 Solid-set sprinkler UNCE, Reno, Nev. Slide 51 Univ. of Idaho Extension Slide 52 USDA SCS Slide 53 Drip irrigation USDA ARS USDA NRCS Slide 54 UNCE, Reno, Nev. Slide 55 Checking your system: Does it apply water uniformly? UNCE, Reno, Nev. Slide 56 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 Slide 57 OSU Extension Service Slide 58 Know your sources of irrigation water Know your soil type Monitor soil moisture Improve efficiency of your delivery system when possible Slide 59 Adjust rate of water application to avoid runoff Know your labor availability Match your goals for your land to the irrigation system you select Slide 60 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.