Watering Your Landscape

Transcription

1 Watering Your Landscape Larry Schwankl Irrigation Specialist UC Cooperative Extension

2 Landscape Irrigation: What Determines Water Use in a Landscape?

3 Landscape Irrigation: What Determines Water Use in a Landscape? 1. Growing environment! Climate - hot, cool, dry, humid, cloudy, windy

4 Landscape Irrigation: What Determines Water Use in a Landscape? 1. Growing environment! Climate - hot, cool, dry, humid, cloudy, windy! Plant exposure - sun, shade

5 Landscape Irrigation: What Determines Water Use in a Landscape? 1. Growing environment! Climate - hot, cool, dry, humid, cloudy, windy! Plant exposure - sun, shade! Surroundings - other plants, hardscape

6 Landscape Irrigation: What Determines Water Use in a Landscape? 1. Growing environment 2. Types of plants! Trees

7 Landscape Irrigation: What Determines Water Use in a Landscape? 1. Growing environment 2. Types of plants! Trees - on a canopy area basis, they can use significantly more than turfgrass.

8 Plant Water Use:! Measure evapotranspiration (ET). Evaporation from the soil + Transpiration from the plant

9 Where do you get ET estimates?

10 Historical ET estimates: Olive historical ET - inches during period Available at

11 Real-Time Weather Monitoring:! Measure evapotranspirtation (ET).! CIMIS weather stations predict the ET of pasture grass (Reference ET = ET o ).

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13 Accessing CIMIS data:! Go through the Department of Water Resources cimis.water.ca..water.ca.gov! Univ.. of CA IPM website:

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16 Weather monitoring:! Measure evapotranspirtation (ET).! Weather stations predict the ET of pasture grass (Reference ET = ET o ).! Convert the reference ET (ET o ) to your plant s ET (ET( crop ) using a crop coefficient (k c ). ET crop

17 Determining Crop ET: Crop ET = Reference ET x Crop Coefficient ET crop = ET o x k k c Crop Coefficient for Olives (k c ) = 0.8

18 Irrigation scheduling example: Available at

19 Irrigation scheduling example:

20 Olive water use example: Date ET o k c ET ET olives (in.) (in.) 7/14/ ET crop = ET o x k c

21 Landscape Irrigation: Tree water use example (walnuts):! 20-foot diameter (10 radius) tree, midsummer Tree area = 3.14 x (radius) 2 = 3.14 x (10) 2 = 314 ft 2 ET o = 0.25 in/day k c = 1.0 (e.g. walnuts) ET tree = 0.25 in/day x 1.0 = 0.25 in/day

22 Landscape Irrigation: What Determines Water Use in a Landscape? 1. Growing environment 2. Types of plants! Trees - on a canopy area basis, they can use significantly more than turfgrass.! Turfgrass - cool season (kc=0.8), warm season (kc=0.6)

23 Landscape Irrigation: Turfgrass water use example:! Warm season grass Area = 314 ft 2 ET o = 0.25 in/day k c = 0.6 (warm season grass) ET tree = 0.25 in/day x 0.6 = 0.15 in/day (Walnut water use was 49 gal/day)

24 Landscape Irrigation: What Determines Water Use in a Landscape? 1. Growing environment 2. Types of plants! Trees - on a canopy area basis, they can use significantly more than turfgrass.! Turfgrass - cool season, warm season! Stand-alone, smaller plants (shrubs, etc)! Wide range of water use, but water use is a function of their canopy size! Can save water if only water the plants, not the bare ground.

25 Landscape Irrigation: What Determines Water Use in a Landscape? 1. Growing environment 2. Types of plants 3. Irrigation system

26 Landscape Irrigation: What Determines Water Use in a Landscape? 1. Growing environment 2. Types of plants 3. Irrigation system! Can the irrigation system provide just the right amount of water to all the plants in the landscape? Without wasting any?

27 Landscape Irrigation: What Determines Water Use in a Landscape? 1. Growing environment 2. Types of plants 3. Irrigation system! Can the irrigation system provide just the right amount of water to all the plants in the landscape? Without wasting any?! Want to apply water only to those areas where plants can take it up. Efficiency

28 Turfgrass Irrigation:! Design! Operation

29 Turf Design from an Irrigation Standpoint: Curves are hard to irrigate - rectangular shapes are easier.

30 Turf Design from an Irrigation Standpoint: Curves are hard to irrigate - rectangular shapes are easier. Small / narrow shapes are hard to irrigate.

31 Turf Design from an Irrigation Standpoint: Curves are hard to irrigate - rectangular shapes are easier. Small / narrow shapes are hard to irrigate. Slopes are harder to irrigate.

32 Sprinkler Design:! Standard sprinkler spacing is head-to-head coverage.! Closer spacing = higher application rate = runoff?

33 Sprinkler Design:! Standard sprinkler spacing is head-to-head coverage.! Too many sprinklers on a line means poor pressure = poor coverage.

34 Sprinkler Design:! Standard sprinkler spacing is head-to-head coverage.! Too many sprinklers on a line means poor pressure = poor coverage.! Keep track of where the pipelines are.

35 Sprinkler Design:! Standard sprinkler spacing is head-to-head coverage.! Too many sprinklers on a line means poor pressure = poor coverage.! Keep track of where the pipelines are.! Error on the side of more valves / stations.

36 Sprinkler Design:! Standard sprinkler spacing is head-to-head coverage.! Too many sprinklers on a line means poor pressure = poor coverage.! Keep track of where the pipelines are.! Error on the side of more valves / stations.! Error on the side of using larger pipe.! Smaller pipe does not increase pressure

37 Sprinkler Design:! Standard sprinkler spacing is head-to-head coverage.! Too many sprinklers on a line means poor pressure = poor coverage.! Keep track of where the pipelines are.! Error on the side of more valves / stations.! Error on the side of using larger pipe.! Make sure the sprinkler pops-up above the grass.

38 Turfgrass Irrigation Management:! Try to avoid daily irrigations.! Odd/even watering requirements.

39 Turfgrass Irrigation Management:! Try to avoid daily irrigations.! Irrigate in the early mornings.

40 Turfgrass Irrigation Management:! Try to avoid daily irrigations.! Irrigate in the early mornings.! If there are brown spots, don t t just increase the run time.

41 Turfgrass Irrigation Management:! Try to avoid daily irrigations.! Irrigate in the early mornings.! If there are brown spots, don t t just increase the run time.! Adjust your controller for changing water needs.! Smart controllers?

42 Summary: How do you get by on less water?! Change your landscape plant selection! Go from high water users (lush trees & turfgrass) ) to lower water users.

43 Summary: How do you get by on less water?! Change your landscape plant selection! Go from high water users (lush trees & turfgrass) ) to lower water users.! Become a more efficient irrigator! Easier to be efficient with drip irrigation.

44 Summary: How do you get by on less water?! Change your landscape plant selection! Go from high water users (lush trees & turfgrass) ) to lower water users.! Become a more efficient irrigator! Easier to be efficient with drip irrigation.! Combination of the two is often the best! Low water use landscape irrigated with drip irrigation.

45 Questions? Larry Schwankl anrcatalog.ucdavis.edu Lawn Watering Guide for CA: Pub Drip Irrig.. In the Home Landscape: Pub Powerpoint presentation at //schwankl.uckac.edu