Low Volume Irrigation - Working Copy

Slide 1 Low Volume Irrigation LHAP 302 Slide 2 Design Design goal is to broadcast water as evenly as possible across an entire area. Water is delivered to the surface of the planted area. Design goal is to apply water to a uniform depth, either directly to the plant root zone or in a limited area. Water is delivered at or below the surface of the planted area Installation Most of system installed in underground trenches. In residential applications, most of system installed at or near grade and covered with 2-3 inches of mulch. Typically, installation requires less time. In commercial applications, most of system installed in underground trench and exposure of any drip tubing is minimal Maintenance Problems with system are easy to spot. Many problems require trenching to repair. Solvents are required to repair pipes. Problems with system may be less noticeable. Scheduled maintenance requires greater attention. However, most problems with the system can be repaired faster and more easily than conventional systems. Generally, no solvents are used. TABLE 1-1: CONVENTIONAL VS. LOW-VOLUME IRRIGATION Conventional Irrigation (Spray Heads and Rotors) Low- Volume Irrigation (Xerigation) Rainbird.com Slide 3 Benefits Better Water Management – more efficient Lower Install and Maintenance Costs Improved Plant Health Slide 4 The Design Process for watering shrubs and trees Gather accurate site data Collect information about the site to be irrigated and the plants in the site Soil type Coarse – sands, sandy loams, loamy sands Medium – loams, silt loams, silt Fine – clay loams, sandy clay loams, silty clay loams, clay Climate -temperature and precipitation, PET water source – dirty water, organics, minerals Filtration Required 0.5 GPH 200 mesh 1.0 GPH + 150 mesh dripline 120 mesh Slide 5 General Requirements 2. Determine Plant Types and Water Requirements Individual plants – irrigated by point source emitters - individual emission devices (single/ multi outlet emitters, micro-bubblers) Trees – may need more than one device - space 3-4 bubblers or SQ nozzles evenly around tree Dense plantings – cover area evenly by using line source emitters or microsprays (inline emitter tubing , microsprays) For dense plantings determine base plant ( lowest water needs) Slide 6 Calculating line source determined by soil type Soil type Rs (inches) Es (inches) qs (gph) AR (in/hr) Coarse 18 12 1 1.07 Medium 18 18 1 0.71 Fine 24 18 0.5 0.27 Rs = Row spacingEs = emitter spacingQs = flow rateAR= application or precipitation rate Slide 7 Soil Type Maximum Infiltration Rate Wetting Pattern Maximum Wetted Diameter Available Water (AW) Coarse (sandy loam) .72 - 1.25 inches per hour Coarse 1.0 - 3.0 feet 1.4 inches per foot Medium (loam) .25 - .75 inches per hour Medium 2.0 - 4.0 feet 2 2.0 inches per foot Fine (clay loam) .13 - .25 inches per hour Fine 3.0 - 6.0 feet 2.5 inches per foot Slide 8 Calculating Point Source 1. FIND PLANT COEFFICIENT Plant Type Max appearance (lush) Acceptable appearance Low maintenance (lean and green) Trees 0.9 - 0.95 0.70 – 0.75 0.45-0.50 Shrubs 0.60 - 0.65 0.45 – 0.50 0.30 – 0.35 Desert Plants 0.40 – 0.45 0.30 – 0.35 0.20 – 0.25 Ground cover 0.70 – 0.80 0.50 – 0.60 0.30 – 0.40 Mixed Lscp 0.90 – 1.00 0.75 – 0.80 0.50 – 0.55 Plant type ¼ to ½ ground shaded ½ to 2/3 ground shaded Over ¾ ground shaded Low growing plants <45cm tall 0.35 - 0.45 0.60 – 0.75 0.80 – 0.95 Small shrubs 1 – 1.5m tall 0.35 – 0.50 0.70 – 0.80 0.85 – 0.95 Large shrubs, trees > 4m 0.40 – 0.55 0.75 – 0.95 0.95 – 1.00 Turfgrass n/a n/a 1.00 Vegetation High Average Low Turf/Lndscp Plants 1.2 – 1.4 1.0 0.5 – 0.8 Crop coefficient (KL) = species factor x density factor x microclimate factor Eg: acceptable trees (high end) with ⅔ ground shaded and average microclimate KL = 0.75 x 0.75 x 1 = 0.56 Slide 9 https://www.rainbird.com/sitesdefault/files/media/documents/2018-02/LowVolumeGuide.pdf 2. DETERMINE ETo Alberta Climate Information Website https://agriculture.alberta.ca/acis/ Potential Evapotranspiration rates - from Rainbird Catalogue use if ETo not available Slide 10 3. DETERMINE PLANT CANOPY ( IN FT) Canopy = .7854 x diameter x diameter x .75 .7854 x 5 feet x 5 feet x .75 = 14.73 sq ft 4. WATER REQUIREMENTS For individual plants in GPD (gallons per day) GPD/plant = .623 x Canopy area x KL x ETo application efficiency GPD/plant = .623 x 14.73 x .56 x .20 = 1.03 gallons per day .90 https://www.rainbird.com/sites/default/files/media/documents/2018-02/LowVolumeGuide.pdf Slide 11 Choose a base plant (one with lowest water requirements) for each hydrozone then choose an emission device for that plant Types of Plants Use – accessibility, traffic, vandalism Size of Planted Area – individual vs tubing or tape Soil type and Infiltration rate Coarse soil = high flow, bubblers Very fine soil = low flow, emitters, drip tubing Watering Window Emission devices Page 32 Rainbird Low volume guide http://www.rainbird.ca/documents/drip/LowVolumeGuide.pdf System layout page 55 Choosing Emission Devices Slide 12 5. CHOOSE EMITTERS 1 Gallon per day = 7 gal per week 2 emitters at 0.5 gal per hour for 1 hour per dayor 2 emitters at 1 gal per hour for 30 minutes per day or 2 emitters at 1 gal per hour for 1 hour every 2nd day Choose how many emission devices you need per plant based on the plant water needs. If base plant needs 1 and medium shrubs required twice as much water, they will need 2. Slide 13 Basic Parts of the System http://www.shardsofblue.com/ http://www.sprinkler.com/ Slide 14 Basic microsystem parts https://www.irrigationtutorials.com Slide 15 Choosing an Emission Device Consider……. Type of Plant - water requirements intended Use - traffic, vandalism Size of Planting Area Soil type and Infiltration Rates Water window Cost Rainbird Low Volume Irrigation page 30-31 Slide 16 https://www.rainbird.com/sites/default/files/media/documents/2018-02/LowVolumeGuide.pdf Slide 17 Types of Emission Devices Point Source Point Source Emitters – pressure reduces and regulates amount of water discharged Barbed or threaded Short path emitters Tortuous path (turbulent path) emitters Vortex emitters Diaphragm emitters http://www.lautnerirrigation.com/productsdrip.html Slide 18 http://www.digcorp.com/ http://www.rainbird.com/ http://www.shorelinesprinkling.com/products/drip-irrigation/ Slide 19 http://www.vacavillesprinklerrepair.com/ http://www.lautnerirrigation.com/productsdrip.html Slide 20 Types of Emission Devices Line Source Drip tape or drip tubing Slide 21 Rainbird Low Volume Irrigation Guide page 34 page 13 Slide 22 Watering Trees Slide 23 Square Nozzles Rainbird 3QTR-SQ Nozzle avoids watering the trunk adjusts as the tree grows waters slow and deep Slide 24 https://www.pinterest.com/explore/hunter-irrigation/ https://indonesian.alibaba.com Bubblers - gpm Slide 25 Root trainers http://store.rainbird.com/ Slide 26 Dripline http://www.sgaonline.org.au/ Slide 27 http://jmarvinhandyman.com/ Slide 28 https://geoflow.com/landscape-design/ Slide 29 https://www.rainbird.com/sites/default/files/media/documents/2018-11/TurfCatalog2019-DripIrrigation.pdf https://www.hunterindustries.com/sites/default/files/hunter_catalog_em.pdf https://www.toro.com/en/professional-contractor/irrigation-landscape-drip Parts of a drip system and how to install drip irrigation https://www.youtube.com/watch?v=tmEj3MQPlTY&amp;t=297s Resources for Drip Systems