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