Post on 13-Nov-2014
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Life blood of the Life blood of the ‘Green’ industry‘Green’ industry
WaterWaterDr. Ted Bilderback – NC State Univ.Dr. Ted Bilderback – NC State Univ.Water Quality :Managing the Chemistry in your Irrigation Water Supply
Dr. Jim Owen – Oregon State Univ.Dr. Jim Owen – Oregon State Univ.
Dr. Stu Warren – Kansas State Univ.Dr. Stu Warren – Kansas State Univ.
WaterWaterDr. Ted Bilderback – NC State Univ.Dr. Ted Bilderback – NC State Univ.
Dr. Jim Owen – Oregon State Univ.Dr. Jim Owen – Oregon State Univ.Sweat the small stuffSweat the small stuff
Dr. Stu Warren – Kansas State Univ.Dr. Stu Warren – Kansas State Univ.
WaterWaterDr. Ted Bilderback – NC State Univ.Dr. Ted Bilderback – NC State Univ.
Dr. Jim Owen – Oregon State Univ.Dr. Jim Owen – Oregon State Univ.
Dr. Stu Warren – Kansas State Univ.Dr. Stu Warren – Kansas State Univ.Getting more plant per gallonGetting more plant per gallon
The Container System
FERTILIZER
SU
BS
TRA
TEIR
RIG
ATIO
NContainer
Substrates
• 2 Parts• Solids• Pores
• aeration• water
Substrates• Re-wet substrate
• Large pores (air)• Small pores (water)
Let the waters flow Let the waters flow
Irrigation• Traditional irrigation
• Single application• Maybe PM cool down
• How much to apply – inches• Timing
• Pre-dawn/early morning• Limit interference with crew• Minimum wind• Minimize loss to evaporation
Two things changed our thinkingTwo things changed our thinking
• Water only means everything to everything
• T.E. Bilderback
• Water- oil of the 21Water- oil of the 21stst Century Century
Water is the oil of the 21st century
• The United Nations has predicted by 2020, water and not oil will be a source of conflicts in the world
American Farm Bureau Federationin
Water Resources Could Be The Next Energy CrisisBy Stewart Truelsen
http://www.fb.org/views/focus/index.html
Mark Twain said it best
• Whiskey for drinking• Water for fighting
The Container System
FERTILIZER
SU
BS
TRA
TEIR
RIG
ATIO
NContainer
Irrigation – Getting more plant per gallon
Irrigation• To increase water efficiency while
maintaining rate of growth?• Irrigation
• Application efficiency• How much applied stays in container?
• Volume• How much does it take to rewet substrate?
• Time of irrigation• Does it make a difference when we irrigate?
Irrigation application efficiency
• Re-wet substrate
Pathways of water through a container
Channel along edgeChannel along edge
Follow large poresFollow large pores
Held in small poresHeld in small pores
Water application efficiencyWater application efficiency
Water application efficiency
• ‘Pulse’ irrigation – applying water in a series of cycles• El Modena Gardens increased
water retention by 30%(Whitesides,
1989)
Cyclic irrigation
Cyclic Irrigation
Water application efficiency
% increase overSubstrate single application
3 PB : 1 P 34% (Fare et al., 1994)
8 PB : 1 S 27% (Groves et al., 1998)
8 PB : 1 S 27% (Ruter, 1998)
8 PB : 1 S 38% (Tyler et al., 1996)
Average 32%
Substrates• Re-wet substrate
• Large pores (air)• Small pores (water)
Cyclic irrigation and water Cyclic irrigation and water movement in containersmovement in containers
1st irrigation cycle 2nd irrigation cycle 3rd irrigation cycle
Cyclic Irrigation• Advantages
• Need to apply less water• Decreased pump run time• Decrease leachate / Decreased runoff
• Disadvantages• Requires automated Controllers & Valves• Management
Irrigation volumeHow much to apply?Traditional: inches of waterDoes that tell you if the substrate is rehydrated?
Leaching FractionLeaching Fraction = Volume Leached / Volume Applied
Leaching Fraction ~ 0.15 – 0.20
Total Water Applied for container diameter area is measured as “total volume” to calculate leaching fraction
Plastic bags work for leaching fractions
Water Applied Water Leached
Leaching fraction
0
5
10
15
20
25
30
0.1 0.2
Days afterinitiation
3575115
Cu
ma
lativ
e w
ate
r a
pp
lied
(g
al)
Leaching fraction (leached / applied)
7 gal per container
Owen. 2006
Leaching fraction
0
5
10
15
20
25
30
0.1 0.2
Days afterinitiation
3575115
Cu
ma
lativ
e w
ate
r a
pp
lied
(g
al)
Leaching fraction (leached / applied)
7 gal per container90,000 gallons of water
saved per growing acre while maintaining
growth
Owen. 2006
Leaching fraction• Advantages
• Based on plant need• Minimize water applied
• Minimize pump run time
• Disadvantages• Management time
Less than uniform irrigation distribution?
Think Leaching Fraction
Group by:Group by:
Water needsWater needs
Container sizeContainer size
SubstrateSubstrate
Does the architecture of a plant’s canopy affect water application?
Umbrella Architecture
Vase Architecture
Canopy Capture
Williamson et al. 2005. SNA
60
80
100
120
140
160
180
200
220
240
260
33 50 72 92 105
Days
Per
cen
tage
irri
gati
on c
aptu
re CotoneasterGardenia
Cotoneaster dammeriCotoneaster dammeri
‘‘SkogholmSkogholm
Gardenia augustaGardenia augusta ‘Chuck Hayes’‘Chuck Hayes’
0
100
200
300
400
500
600
700
800
900
22 29 32 40 47 49 54 66 73 82 92 99 105
Days After Initiation
Dai
ly v
olum
e ap
plie
d (m
l)
CotoneasterVitex
Irrigation volume to maintain 0.2 LF
Williamson et al. 2005. SNA
Cotoneaster dammeriCotoneaster dammeri ‘Skogholm‘Skogholm
Vitex trifoliaVitex trifolia ‘Variegata’‘Variegata’
Best Management Practices
• BMPs• Getting more plant per gallon
• Cyclic application• Irrigation volume
• 0.2 leaching fraction• Irrigation timing
• predawn to early morning
Does it matter when you irrigate?
• What time of day to irrigate?• Pre-dawn• AM• PM• All day
Irrigation timing
• Irrigation timing treatmentsIrrigation timing treatments• Volume: Volume:
0.2 leaching fraction for each timing0.2 leaching fraction for each timing• Timing:Timing:
0200, 0400, and 0600 HR (predawn)0200, 0400, and 0600 HR (predawn)0600, 0900, and 1200 HR (AM)0600, 0900, and 1200 HR (AM)1200, 1500, and 1800 HR (PM)1200, 1500, and 1800 HR (PM)0600, 1200, and 1800 HR (all day)0600, 1200, and 1800 HR (all day)
Dry weight of Cotoneaster dammeri 'Skogholm'
0
20
40
60
80
100
120
Top (g) Root (g) Total Dry Weight(g)
predawn
AM
PM
all day
Dry
wei
gh
t (g
)
b a a a
c b a b
d c a b
Rainfall
0
10
20
30
40
50
60
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Rainfall
Weeks After Initiation
Rai
nfal
l (m
m)
• Repeated study
Rainfall
0
10
20
30
40
50
60
70
80
90
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Rainfall
Weeks After Initiation
Rai
nfal
l (m
m)
Dry weight of Cotoneaster dammeri 'Skogholm'
0
20
40
60
80
100
120
Top (g) Root (g) Total Dry Weight(g)
predawn
AM
PM
all day
Dry
wei
gh
t (g
)
b a a a
c b a b
d c a b
Photosynthesis
0
1.5
3
4.5
6
7.5
9
11:00 AM 1:30 PM 4:00 PM
predawn
AM
PM
all day
Pho
tosy
nthe
sis
Monitoring Water Use
70
75
80
85
90
95
100
18:0
0
20:0
0
22:0
0
01:0
0
03:0
0
06:0
0
08:0
0
10:0
0
13:0
0
15:0
0
18:0
0
20:0
0
22:0
0
Time
Conta
iner
capacity (
%)
Monitoring Water Use
70
75
80
85
90
95
100
18:0
0
20:0
0
22:0
0
01:0
0
03:0
0
06:0
0
08:0
0
10:0
0
13:0
0
15:0
0
18:0
0
20:0
0
22:0
0
Time
Conta
iner
capacity (
%)
Wat
er
gain
Monitoring Water Use
70
75
80
85
90
95
100
18:0
0
20:0
0
22:0
0
01:0
0
03:0
0
06:0
0
08:0
0
10:0
0
13:0
0
15:0
0
18:0
0
20:0
0
22:0
0
Time
Conta
iner
capacity (
%)
Wat
er
gain
Plant water use
Daylight hrs
Monitoring Water Use
70
75
80
85
90
95
100
00:0
0
06:0
0
12:0
0
18:0
0
00:0
0
06:0
0
12:0
0
18:0
0
00:0
0
06:0
0
12:0
0
18:0
0
00:0
0
06:0
0
12:0
0
18:0
0
00:0
0
06:0
0
12:0
0
18:0
0
00:0
0
06:0
0
12:0
0
18:0
0
00:0
0
Time and date
Conta
iner
capacity (
%)
ClaySand
Aug 23 Aug 24 Aug 25 Aug 26 Aug 27 Aug 28
Amendment
Automated Control
85
90
95
100
AM 0.2 LFPM 0.2 LFPM ReplacementOn-demand
Syst
em
wt. a
t conta
iner
capaci
ty (
%)
Time (24 HR)2400 0400 0800 1200 1600 2000 2400
Automated Control
85
90
95
100
AM 0.2 LFPM 0.2 LFPM ReplacementOn-demand
Syst
em
wt. a
t conta
iner
capaci
ty (
%)
Time (24 HR)2400 0400 0800 1200 1600 2000 2400
Monitoring Water Use
80%
85%
90%
95%
100%
Date and time
Perc
en
t w
eig
ht
at
CC Clay-AM
Clay-PM
Aug 24 Aug 25 Aug 26 Aug 27 Aug 28
20
25
30
35
40
45
50
pre-dawnall daypm
Irrigation timing - overhead
Williamson et al. 2005. SNA
Su
bst
rate
Tem
per
atu
re (
C)
Aug 26 Aug 27
20
25
30
35
40
45
50
pre-dawn
all day
pm
Irrigation timing - overhead
Williamson et al. 2005. SNA
Su
bst
rate
Tem
per
atu
re (
C)
Aug 26 Aug 27
12:0012:00
3:003:00
6:006:00
Pre-DawnPre-Dawn
20
25
30
35
40
45
50pre-dawn
all day
pm
Irrigation timing - overhead
Williamson et al. 2005. SNA
Su
bst
rate
Tem
per
atu
re (
C)
Aug 26 Aug 27
3:00 3:00 AMAM
9:00 9:00 PMPM
Irrigation timing
• Advantages• Increases plant growth • Regulate substrate temperature
• Disadvantages• Automated Controllers & Valves• Interfere with workers• Management
Irrigation Decisions
• Cyclic irrigation• Increase application efficiency- 30%
• How much?• Leaching fraction
• 0.1 to 0.2 • When?
• Time of Day
QuestionsQuestions