Plant Water Use Soil Water Holding Capacity Watering Systems...
Transcript of Plant Water Use Soil Water Holding Capacity Watering Systems...
Plant Water Use
Soil Water Holding Capacity
Watering Systems
Reducing Water Use in a Drought
Waterwise Landscaping or Xeriscape
Laundry to Landscape Greywater & Rainwater Harvesting
http://cagardenweb.ucanr.edu/
Meet the PLANT’s needs
Water moves from roots to shoots (high to low potential)
Transpiration - water exits the leaves through stomata
ET = Evaporation + Transpiration
When a plant is water stressed, it closes stomata & photosynthesis slows
Repeated wilting causes damage
Some plants are better at conserving water………..
Thick, waxy leaves that store water (succulent)
Grey, silvery leaves that reflect light
Small or needle-like leaves
Hairy leaves slow air flow, reducing evaporation
Strong structure that minimizes damage due to wilting
Recognize signs of drought stress Lawns
Retain a footprint for several minutes, brittle
Wilted & bluish gray leaves
Wilting or drooping leaves that do not return to normal by evening
New leaves that are smaller than normal
Grayish, lusterless foliage
Curled or yellow leaves that fold or drop
Water movement in soil
Remember soil lecture?
Clay holds 4X more water than sand, but not always good.
Add organic matter!
Practice moisture testing
Use soil moisture meter or tensiometer (maybe)
Just dig a hole with a trowel at root level and test for moisture with your hand
Veggies, flowers & turf – root zone 6” to 1’
Don’t water groundwater or atmosphere
Watering Systems Automatic sprinklers
Hose end sprinklers
Furrow irrigation
Drip irrigation
i.e. RainDrip w/emitters
DripWorks w/t-tape
Microspray
Soaker hose
Basin irrigation
Hand watering
For Lawns using Overhead Sprinklers
Set out pattern of cans (tuna?)
Turn volume on at set amount (i.e. 1 ½ turns) for hose bib
Run for 20 minutes
Measure water depth in cans
Multiply times 3 to get inches per hour (output)
Compare variability within cans – try to achieve less than 15%
Measure application rate and uniformity
Determining irrigation needs for lawns
Use tables in MG Handbook or Lawn Watering Guide to determine inches per week
Apply volume based on your “can” test in multiple applications
Avoid runoff or puddling
Try timers
Don’t wet tree trunks
Furrow Irrigation Rare in Trinity
Difficult on slopes, need level ground or cross-slope
Drip Irrigation for landscapes, etc
Frequent, slow application to root system
Not all “drip” systems are low volume, which needs pressure reducer down to 10-20 psi
Lower water use, less disease, runoff & groundwater contamination
Soil dries out between irrigation
Drip Irrigation Layout
Drip Irrigation Hints & Cautions Adjust timing spring vs summer
Different manufacturers are not compatible
Use pressure compensating for slopes
Can clog Need filter for surface water, well water
with clay or highly mineralized water
If buried or unmaintained (subsurface), roots intrude or deposits form
Spinner type sprinklers have moving parts that wear out, but spray water further
Supplemental irrigation for germination
Convert sprinkler heads to drip
Irrigating Trees
•Different timer •Calculate water volume needed •Don’t spray trunks
Irrigation of Gardens & Landscape Beds
• Low Volume works well
• Match delivery system to plant
• Drip tape (rows)
• Emitters (individual plants)
• Soaker hose or drip tube (curving row)
• Hand water (container)
• Basin (fruit tree)
Water Conservation for Vegetable Garden
Shorter season crops
Fewer crops
Plant in blocks & vertically
Group plants into zones
Control weeds (don’t water weeds!)
Add organic matter
Mulch!
Irrigation of Fruit Trees • Semi-dwarf trees can use 16
gallons per day during peak heat
• Mulch & eliminate lawn & weeds
• Don’t deficit water early in season
• Check soil moisture
• Measure water applied
• Drought : Try to wet 60% of area that roots will explore
• Don’t water when no leaves
Use double ring tree watering basin
Irrigation Needs of Fruit Trees
Table 16.4 of Handbook
70-100% of ET for good yields
Hot Midsummer Day
1 yr (4 sf) – .6 gal/day
4 yr (100 sf) – 16 gal/day
Standard (300 sf) – 47 gal/day
Deficit watering of fruit trees
Early season water (during bud break, flowering & fruit set) is important
Can decrease watering til fruit is half grown, fruit will catch up when irrigation starts again
Remove ground cover & add mulch to decrease competition for water
Don’t underirrigate young trees
Thin heavier than you usually do
Expect lower production next year
Can post-harvest irrigate, but not when dormant
Irrigation Best Mgmt Practices Create hydrozones (group plants)
Apply the right amount of water
Water deeply & infrequently (but not too deep)
Veggies, flowers & turf – 6” to 1’
Overhead water early in the morning, drip anytime
Irrigation at night reduces water used by 5-7%, but you have to remember to turn it OFF. Timer!
Avoid deep percolation & runoff
Apply water uniformly
Mulch, amend soils with organics, regular maintenance
Planning/Design
Prepare your Soil
Mulching
Minimize turf areas
Plant Zoning
Efficient irrigation
Proper maintenance
7 Basic Principles of Waterwise Landscaping
1-Planning Evaluate your needs
Huge lawn or just children’s play area?
Entertaining? Foot traffic?
Block view of neighbor?
Environmental conditions
Sun, shade, wind, slope, drainage pattern
Make appropriate plant selection for the climate where you live
Mediterranean climate plants are suited to much of California (Cool wet winters, dry
hot summers)
Consider appropriate native plants
2-Prepare your Soil
Amend with Organics!
Remember what we talked about in
Soils – organics increase ability to
hold moisture
3-Mulching A 2-4” layer of organic
mulch can provide many
benefits: water retention,
weed reduction, erosion
control.
Shredded bark, grass
clippings, and compost
are organic mulches
Inorganic mulches include
stone, cloth and plastic.
Pine needles
Pine bark
Proper way to mulch a tree
Organic Mulches
4- Minimize Turf Areas Lawns require large
amounts of water,
fertilizers, money and
time.
Plant only as much as you
need
Plant the appropriate type
of turfgrass for your
climate.
Hardscapes, mulches and
rocks.
✔ Use turf effectively for function rather than appearance only.
✔ Consider substituting ground covers or natural mulches.
✔ Remove lawn one area at a time.
What if I want to get rid of my lawn right now?
Try sheet mulching
Mow as low as you can
Layer of organic material like cardboard, newspapers, or jute floor covering
Cover with 4-5” of mulch & compost
Can cut holes and plant through it later
Rent a turf cutter
Herbicide
BUT – wait til fall to plant landscaping due to initial water needs
• Limit area of annual flower beds
• Use containerized plants
5 - Zoning
Group plants according to the same exposure and water needs
i.e. Sunny, well-drained & moderate water need vs shady & moderate water
Don’t put fruit trees in lawn (or have separate irrigation)
Group low water users that may only need supplemental irrigation in summer.
6- Efficient Irrigation
Zone irrigation systems to match plant requirements Separate irrigation lines can be programmed to meet differences in frequency and duration
Use drip lines and soaker hoses
Irrigate shortly before sunrise. Avoid irrigation during windy periods.
Install permanent, automated irrigation system. Design irrigation systems to emphasize uniformity especially on turf areas
Sprinkler calibration ~ three to four times a year Water use rates vary greatly from season to season
Avoid overspray from sprinklers onto sidewalks, patios or other areas.
Refrain from watering during the winter
Check irrigation system and repair regularly
Mow lawn areas to a height of 3”.
Remove about 1” of grass each
time you mow
Heavy pruning & fertilization
stimulates growth, which
increases water use
Eliminate weeds
7- Proper Maintenance
Household Water Use in California
What is “Greywater” Water from washing machines, showers, bathtubs, bathroom sinks.
Does NOT include water from toilets, kitchen sinks, dishwashers or wash water from diapers.
Greywater Options
Since 2009, can install a washing machine only system without a permit
Need a permit from Building Dept to install a greywater system that
Collects water from showers, sinks or baths
Includes a pump
Or cuts into the plumbing
Laundry to Landscape
•Uses washing machine pump to distribute water •1” PVC tubing •Max 50’ length •Water distinct plants deeply, then move on
Greywater constraints Can contain pathogens
Don’t store for more than 24 hours
Don’t use for irrigating contact food crops
Subsurface disposal to minimize contact (i.e. under mulch)
Don’t allow ponding
Greywater Laundry Detergent Mainstream detergents
are not OK, since they contain salts
Use diverter valve if using detergents or additives
Use intermittent with other irrigation
Liquid is better than powder
Rainwater Harvesting Metal & composite shingle roofs are most efficient
Multiply annual rainfall (in) X roof area (SF) X .623 gallons
1000 SF roof, 40” of rainfall = 25,000 gallons
Rain Harvesting Considerations Less feasible in our
climate
Not potable!
Contains pathogens, metals, contaminants
Use for drip irrigation, not overhead
May need sand filter for composite shingles
Rainwater Harvesting Design First Flush Filtration
Overflow & strainer basket with screen to prevent mosquitoes
Dark colored tank w/ UV inhibitor to prevent algae growth
Cleanout
Pump? Or low flow irrigation downhill
Young Family Ranch #1 1000 square foot roof,
collect 1” rainfall = 623 gallons
500 gallon tank with hose bib at bottom
Use to gravity irrigate fruit trees (low pressure with bubble sprinkler)
Young Family Ranch #2
1000 square foot roof, collect 25” rainfall = 15,000 gallons
Collection tank with pump to uphill tanks
Use to gravity irrigate lawn & vegetable garden
Carol’s Rainwater Harvesting Gutters drain 700 sf of my
roof, takes ¾” of rain to fill tank
My tank is 330 gallons ($300)
Used bucket to transfer water in 2014, now have transfer pump
My flower garden gets 15 gallons per week
1 tank of water lasts for 1 summer
Creative Water Recycling
Wash vegetables in your garden (if potable water)
Take a shower in your garden (soap & shampoo are OK)
Capture sink water to irrigate potted plants
Wash car on lawn