Irrigation Basics & Considerations for Lavender Presented by John Steuble CID, CLIA
Where To Begin Site Information Water Source Application Equipment Selection Filtration Equipment Selection Controls and Infrastructure
Site Information Gathering all site information is critical for an accurate and efficient system. Accurately Measured Field or a Plot Plan of the property. Include buildings, fences, sheds, roads, ditches, or any other obstructions that may affect your project. Identify different Micro Climates of the areas. Micro climates are areas in the project that are effected by sun, shade, wind directions, elevations and other natural elements. Any Elevation Changes in the project. Elevations differences will affect pressure losses and gains, irrigation runoff, runtimes, and may determine controller options.
Site Information Identify the Soil Type Soil is made up of sand, silt and clay particles The percentage particles is what determines the actual soil texture. There is virtually an unlimited number of soil types possible A moistened soil sample in your hand and squeeze to determine the way it will clump or ribbon. Jar Method with Depth of Layers. Soil absorbs and holds water similar to a sponge. A given texture and volume of soil will hold a given amount of moisture. The intake rate of soil will determine the maximum precipitation rate without run off of sprinkler or emitting device. Soils ability to hold and store moisture will affect the irrigation operational schedule.
Soil Tests
Soil Triangle 6
Soil Infiltration Rates Soil Infiltration Rates In Inches Per Hour Percent of Slope Clay Loam Sand 0% - 4% 0.13 0.44 0.44 0.88 0.88 1.25 5% - 8% 0.1 0.35 0.35 0.7 0.7-1 When dry it forms hard clumps. When damp it is flexible and can be molded A moderate sand or dirt and very little clay. When dry it breaks easily. When wet if forms a lump. Soil particles are loose, sandy grains. When dry it will fall apart when you open your hand. When damp it will form a lump but it will crumble easily when touched.
Soil Wetting Patterns Maximum wetting patterns show the relationship between vertical and horizontal movement of water. Available water (AW) is the amount of water that is readily available for use by plants. 8
Plant Water Requirements Plants come in all shapes, sizes and colors. Different types and sizes of plants also have very different water requirements. It is impossible to know the exact water requirements of plants.
Plant Water Requirements http://www.greenhousegrower.com/production/ manage-soil-moisture-for-proper-irrigation-of-english-lavender/#tinsel/126282/1
Plant Water Requirements Evapotranspiration - ET Evaporation Environmental water loss Transpiration Plant water loss The sum of the water lost from soil and the water used by plants.
Plant Water Requirements ET Information Source http://coagmet.com/
Plant Water Requirements As plants grow in size and volume so does the water requirement. Reference ET is usually based on Alfalfa in our region, other regions can vary. ET c = ET p x K co K co = 1 x K s x K d x K n ET c = Et required for plant ET p = Et potential (Reference ET) K co = Crop coeficent K s = Species factor K d = Density Factor K n = Native Non Native
Drip Line of Plants Area to be covered by irrigation. As plant grows the drip line will increase.
Water Source The water source will determine which type and cost of the equipment you can use. Domestic Water (Municipal Water Supply) Well Water (Domestic or Irrigation) Irrigation Water with a Pump (Surface or Low Head) Irrigation Water where a Pump is not needed (Gravity)
Water Source Once the water source has been determined, you must also determine quantity or flow rate of water you have avalible. Domestic Water Static Pressure Dynamic Pressure Meter or Service Size Irrigation Water Legal Shares HOA Restrictions Static Pressure Dynamic Pressure Service Size
Water Quality Water Source = Water Quality Not all Clean Water is Clean Sand is Not Silt Organic vs. Inorganic
Water Quality Would Most People Drink It? Filtration = Cost $ - $$$$ Dirt Tolerant Equipment = Cost $ - $$
Application Methods Drip Emitter Line Point Source Bubbler (Low Volume) Overhead Micro Spinners Rotor and Spray Flood
Drip Irrigation Point Source Filtration = 100-250 Mesh Can be labor intensive to install Spacing is determined at install Determined Emitters are replaceable Some are cleanable Installs in standard blank drip tube = 60mil+ Durable tube life = 10+seasons
Drip Irrigation Emitter Line (Drip Tape/Tube) Filtration = 120-250 Mesh Requires less labor to install Thin-wall Tape = 5mil-25mil Short tube life = 1-3 seasons Heavy-wall Tape = 45mil-60mil Durable tube life = 3-10+ seasons Pre-Installed Emitter at fixed spacing. 6-36 Variations
Bubblers Require Less filtration than drip Uses larger volumes of water per device than drip Viable in small installations
Overhead Sprinklers Filtration = 14-100 Mesh Low cost per square foot irrigated Requires carful management on lavender. Must water early A.M. to minimize crown moisture and leaf burning Can introduce pathogens in consumable products Can damage the flower portions of the plant.
Flood Irrigation http://swiftsgardeningblog.bl ogspot.com/2011/08/ Least expensive if water to the property under gravity flow.
Filtration Frequently one of the highest cost parts of an irrigation system. Can dictate the usability of the system.
Filtration Options 26
Filtration Options 27
Maintenance A great systems with poor maintenance will soon become a poor systems. Inspection for operation Redundancy of emission devices Establishment vs. # years of growth Flushing and winterization Tubing management
Thank You For Your Attention John Steuble, CID, CLIA John.Steuble@gjpipe.com (970) 243-4604 Grand Junction Pipe and Supply Grand Junction 2868 I-70 Business Loop (970) 243-4604 Carbondale 740 Hwy 133 (970) 963-5700 Gypsum 240 Airpark Drive (970) 524-4440 Montrose 2005 N Townsend (970) 240-2199 Durango 133 Kaycee Lane (970) 385-6733