Water-Plant-S
Kitt Farrell-Poe
ASM/SWES 404/504
Soil Relations
4
Today, we will
• Plants and water
• Soil-water concep
• Low-volume irriga
be covering...
use
pts
ation
Plants and Wa
• Plants use sunligh
water ma
maintain temperat
• Transpiration
– plant’s way of keep
– absorbs oxygen, u
carbon dioxide
• factors: humidity,
• Photosynthesis
– plants make their
– absorbs carbon di
ater
ht, carbon dioxide, and
anufacture food and
ture
ping cool
uses sugar and water, gives off
wind, solar radiation
own food
ioxide & water, gives off oxygen
Plants and Wa
• Water movement
– absorbed by root
leaves, and relea
in the leaf (stoma
– also moves
• minerals from so
• sugars and plant
• maintains cell tu
• Transpiration acc
loss
ater
t
ts from soil, moved up stem to
ased through small openings
ata) into the atmosphere
oil to plant through evaporation
t chemicals
urgor pressure
counts for 90% of water
Water-saving
CACTI
OCOTILLO,
PALO VERDE
MESQUITE,
SWEET ACACIA
BRITTLEBUSH,
SILVER CLOUD,
TEXAS RANGER
g strategies of plants
Open stomata at night
Lose leaves during
drought
Smaller leaf surface,
fewer stomata
Light-colored (gray)
leaves
Water-saving s
ACACIA REDOLENS
PITTOSPORUM
AZ SYCAMORE
strategies of plants
S Fuzzy or ridged leaves
Waxy or shiny leaves
(reflective)
Curling leaves in wind
Water Use b
56% of the water used was a
by the Roots
absorbed outside the drip line
Implications for
1.5x
2.4x
4x
placement of emitters
Plant-Water Us
• Evapotranspiratio
– sum of plant tran
from soil surface
use
– measured in inch
se
on (ET)
nspiration and evaporation
e also known as consumptive
hes per day
Evapotranspira
• Potential ET (PET)
mathematical equ
• PET data found
– newspapers
– commercially-av
– Arizona meteorol
http://ag.a
• Specific plant’s ET
published PET and
plants with crop c
ation
estimated from
uations
vailable documents
logical data = AZMET
arizona.edu/azmet
T estimated from
d corrected to individual
coefficient or plant factor
AZMET sites
The Soil Reser
rvoir
• Nutrients
• Water
• Organic matter
• Bacteria
• Air
• Medium to support the
plants
Water Moveme
ent in Soils
Physical Prope
• Texture
• Color
• Structure
• Drainage
• Depth
• Surface Features
erties of Soil
Soil Tests to De
• Laboratory
• Jar test
• Feel test
etermine Texture
Determining t
Soil texture Wha
Coarse Soil particles are
when dry, it falls a
Squeezed when m
crumble easily wh
Medium Has a moderate a
and very little clay
broken. Squeeze
that can be easily
Fine When dry, may fo
wet, the soil is qu
squeezed betwee
soil will form a rib
the Soil Type
at you see and feel
loose. Squeezed in the hand
apart when pressure is released.
moist, it will form a cast, but will
hen touched.
amount of fine grains of sand
y. When dry, it can be readily
ed when wet, it will form a cast
y handled.
orm hard lumps or clods. When
uite plastic and flexible. When
en the thumb and forefinger, the
bbon that will not crack.
Soil-Water Def
• Soil Moisture Tensio
finitions
on
Soil-Water Def
• Soil Moisture Tensio
• Saturation
finitions
on
Soil-Water Def
• Soil Moisture Tensio
• Saturation
• Field Capacity (FC)
finitions
on
Field
Capacity
Soil-Water Def
• Soil Moisture Tensio
• Saturation
• Field Capacity (FC)
• Permanent Wilting P
finitions
on
Point (PWP)
Permanent W
Wilting Point
Soil-Water Def
• Soil Moisture Tension
• Saturation
• Field Capacity (FC)
• Permanent Wilting
Point (PWP)
• Available Water
Holding Capacity
(AWHC)
finitions
n