1. Clay amended soilless
substrate: Increasing water and
nutrient efficiency in
containerized crop production
J.S. Owen, Jr.,
Dept. Horticultural Science
Dept. Soil Science
NC STATE UNIVERSITY

2. Overview
¢ Introduction
¢ Experiments
l Clay processing
l Clay rate
l Input efficiency
¢ Conclusion
¢ Future

3. Overview
¢ Introduction
¢ Experiments
l Clay processing
l Clay rate
l Input efficiency
¢ Conclusion
¢ Future

4. Nursery Industry
¢ 3.97 billion dollars in gross sales
USDA, 2004.

5. Nursery Industry
¢ 3.97 billion dollars in gross sales
¢ 73% containerized crop inventory
l Organic substrate
USDA, 2004.

6. Nursery Industry
¢ 3.97 billion dollars in gross sales
¢ 73% containerized crop inventory
l Organic substrate
¢ Southeast
l 41% of 7,742 national operations
l 34% of 20 billion ft2 in total production
USDA, 2004.

7. Problem
¢ Low input efficiencies
l Water 30% to 80%
l N and P 30% to 60%
Tyler et al., 1996, Lea-Cox and Ristvey, 2003; Warren and Bilderback, 2005

8. Problem
¢ Low input efficiencies
l Water 30% to 80%
l N and P 30% to 60%
¢ Water availability and use
Tyler et al., 1996, Lea-Cox and Ristvey, 2003; Warren and Bilderback, 2005

9. Problem
¢ Low input efficiencies
l Water 30% to 80%
l N and P 30% to 60%
¢ Water availability and use
¢ USEPA-MCL regulation and criteria
l Nitrate-N ≤ 10 mg L-1
l Total P ≤ 0.05 mg L-1
Tyler et al., 1996, Lea-Cox and Ristvey, 2003; Warren and Bilderback, 2005

10. ¢ Floriculture and nursery
research initiative
l Environmental resource management
systems for nurseries, greenhouses
and landscapes
• Clemson
• University of Florida
• Horticulture & Breeding Research – USDA
• Floral & Nursery Plants Research – USDA

11. Primary objective
To engineer a pine bark-
based soilless substrate
that increased water and
nutrient efficiency in
containerized nursery crop
production

12. Approach
Container

13. Approach
Yeager et al., 1997

14. Approach
EFFICIENT?
Yeager et al., 1997

15. Infrastructure

16. Approach
Container

17. Approach
Container

18. Amendment

19. Amendment
¢ Peat-based substrate
l Increase available water
l Decrease effluent phosphorus
l Increase pH buffering capacity
l Pre-charged source of nutrient
¢ Pine bark-based substrate
l Increase available water
l Increase plant K and P content
Williams and Neslon, 2000 and 1997; Warren and
Bilderback, 1992; Reed, 1998; Handreck and Black, 2002.

20. Amendment
¢ Mineral aggregate
l Chemical absorbent
l Fertilizer carrier
l Barrier clays
¢ Industrial
l Uniform
l Reproducible
Murray, 2000.

21. Amendment
Raw Clay Selection
& Mining
Secondary
Primary Crusher Crusher
Rotary
Kiln
(LVM) ≤ 800
°C ≈ 120°C
Dryer
Mill (RVM)
Screen
Bag or Bulk
Oil-Dri Corporation of America

22. Amendment
Montmorillonite Palygorskite
Shulze, D.G., 2002. An introduction to soil mineralogy.
In: Soil Mineralogy with Environmental Applications SSSA Book Series no. 7.

23. Amendment
Montmorillonite Palygorskite
Surface Area: 98 m2/g
Surface Area: 122.5 m2/g
Oil-Dri Corporation of America

24. Amendment
Montmorillonite
Natural Heating Low
Occurring Dehydration Volatile
Material
Shulze, D.G., 2002. An introduction to soil mineralogy.
In: Soil Mineralogy with Environmental Applications SSSA Book Series no. 7.

25. Amendment
Palygorskite
Natural Heating Low
Occurring Dehydration Volatile
Material
Shulze, D.G., 2002. An introduction to soil mineralogy.
In: Soil Mineralogy with Environmental Applications SSSA Book Series no. 7.

26. Overview
¢ Introduction
¢ Experiments
l Clay processing
l Clay rate
l Input efficiency
¢ Conclusion
¢ Future

27. Clay Processing
¢ Pine bark-based substrates
l Industrial Mineral Aggregate
• 8% Clay (by vol.)
l Industry Representative Substrate
• 11% Sand (by vol.)

28. Clay Type
¢ Industrial Mineral Aggregate
l Processing
• Particle Size
• 0.25 to 0.85 mm
• 0.85 to 4.75 mm
• Temperature Pre-treatment
• Low volatile material (LVM)
• Regular volatile material (RVM)

29. Clay Processing
¢ 2 x 2 factorial
l RCBD
l 3 replications
¢ Cyclic micro-irrigation
l 1200, 1500, 1800 HR EST
l 0.2 target LF
¢ Medium rate of CRF
¢ Dolomite addition

30. Clay Processing
¢ Data collected
l Dry weight
l Influent
l Effluent
l Effluent N and P content
¢ Use to calculate
l LF = effluent ÷ influent
l WUE = water retained ÷ plant dry mass
l PUE = (plant P ÷ applied P) x 100

31. Field Plots

32. Field Plots

33. Laboratory
¢ Nutrient Analysis
l NH4 – nitrogen
l NO3 – nitrogen
l Dissolved reactive P
¢ North Carolina
Department of
Agriculture
¢ USDA-ARS

34. Analysis
¢ Statistics
l Particle size
• Water
l Temperature
pretreatment
• Effluent DRP
¢ Control
l A priori contrast

35. Clay Processing
200
Substrate amendment
Cumulative water applied (L)
0.25-0.85 mm
0.85-4.75 mm
160 Control
120
80
40
0
0 20 40 60 80 100 120
Day after initiation

36. Clay Processing
200
Substrate amendment
Cumulative water applied (L)
0.25-0.85 mm
0.85-4.75 mm
160 Control 20 L
120
80
40
0
0 20 40 60 80 100 120
Day after initiation

37. Clay Processing
200
Substrate amendment
Cumulative water applied (L)
0.25-0.85 mm
0.85-4.75 mm
160 Control 31 L
120
80
40
0
0 20 40 60 80 100 120
Day after initiation

38. Clay Processing
200
Substrate amendment
Cumulative water applied (L)
0.25-0.85 mm
0.85-4.75 mm
160 Control 31 L
120
80
WUE
731 ml g-1
40 to
599 ml g-1
0
0 20 40 60 80 100 120
Day after initiation

39. Clay Processing
200
Substrate amendment
Cumulative water applied (L)
0.25-0.85 mm
0.85-4.75 mm
160 Control
120 107,000 gallons of water
saved per growing acre
80 while maximizing growth
40
0
0 20 40 60 80 100 120
Day after initiation

40. Clay Processing
70
Substrate amendment
Cumulative effluent DRP (mg)
LVM
60 RVM
Control
50
40
30
20
10
0
0 20 40 60 80 100 120
Day after initiation

41. Clay Processing
70
Substrate amendment
Cumulative effluent DRP (mg)
LVM
60 RVM
Control 19 mg
50
40
30
20
10
0
0 20 40 60 80 100 120
Day after initiation

42. Clay Processing
70
Substrate amendment
Cumulative effluent DRP (mg)
LVM
60 RVM
Control
50
29 mg
40
30
20
10
0
0 20 40 60 80 100 120
Day after initiation

43. Clay Processing
70
Substrate amendment
Cumulative effluent DRP (mg)
LVM
60 RVM
Control
50
40
30
20
PUE
10 Control 27%
Clay 36%
0
0 20 40 60 80 100 120
Day after initiation

44. Clay Processing
¢ Water
l Particle size 24 - 48
• 0.25 to 0.85 mm
• 18% (31L) decrease
¢ Nutrient
l Phosphorus
• Temperature pretreatment
• Low volatile material
• 48% (29 mg) decrease
¢ Equivalent growth
¢ 0.25 to 0.85 mm LVM

45. Clay Processing
¢ Water
l Particle size 24 - 48
• 0.25 to 0.85 mm
• 18% (31L) decrease
¢ Nutrient
l Phosphorus
• Temperature pretreatment
• Low volatile material
• 48% (29 mg) decrease
¢ Equivalent growth
¢ 0.25 to 0.85 mm LVM

46. Overview
¢ Introduction
¢ Experiments
l Clay processing
l Clay rate
l Input efficiency
¢ Conclusion
¢ Future

47. Physical Properties
¢ Clay rate
l 0.25 to 0.85 mm LVM
l 0% to 24% (by vol.)
• 4% increments
¢ Poromoter
¢ Substrate moisture
characteristic curve
¢ 15-bar extraction
¢ Particle size distribution

48. Clay Rate
100
80
Porometer
Results
Volume (%)
60
40
20
0
0 4 8 12 16 20 24
Mineral amendment rate (% vol.)

49. Clay Rate
100
80
Volume (%)
60 Container Capacity
40
Air space
20
0
0 4 8 12 16 20 24
Mineral amendment rate (% vol.)

50. Clay Rate
100
80
Volume (%)
60 Container Capacity
40
20 Available water
0
0 4 8 12 16 20 24
Mineral amendment rate (% vol.)

51. Clay Rate
100
80
Volume (%)
60
40 Unavailable water
20 Available water
0
0 4 8 12 16 20 24
Mineral amendment rate (% vol.)

52. Clay Rate
100
80
Volume (%)
60
40
Air space
20 Available water
0
0 4 8 12 16 20 24
Mineral amendment rate (% vol.)

53. Clay Rate
100
Normal
80 Range
Volume (%)
60
40
Air space
20 Available water
0
0 4 8 12 16 20 24
Mineral amendment rate (% vol.)

54. Materials & Methods
¢ Clay rate (% vol.)
l RCBD
l 0, 8, 12, 16, and 20%
¢ Li-Cor 6400
l Net photosynthesis
l Stomatal conductance
¢ Nutrient analysis
¢ Plant growth

55. Clay Rate
300
250
Top dry mass (g)
200
150
100
50
0
0 8 12 16 20
Amendment rate (% by vol.)

56. Clay Rate
300
250
Top dry mass (g)
200
Max. = 12%
150
100
50
0
0 8 12 16 20
Amendment rate (% by vol.)

57. Clay Rate
P (µmol CO m s ) 12 0.5
g (µmol H O m s )
10
-1
s
0.4
-2
8
2
0.3
6
2
0.2
4
-2
n
-1
2 0.1
0 0
0 8 12 16 20
Amendment rate (% by vol.)

58. Clay Rate
P (µmol CO m s ) 12 0.5
g (µmol H O m s )
10
-1
s
0.4
-2
8
2
0.3
6
2
Max. = 11% 0.2
4
-2
n
-1
2 0.1
0 0
0 8 12 16 20
Amendment rate (% by vol.)

59. Clay Rate
0.5 500
Water use efficinecy (ml g )
g (µmol H O m s )
0.4 400
-1
-2
0.3 300
2
0.2 200
s
0.1 100
-1
0 0
0 8 12 16 20
Amendment rate (% by vol.)

60. Clay Rate
500
Total plant P content (mg) 450
400
350
300
250
0 8 12 16 20
Amendment rate (% vol.)

61. Clay Rate
500
Total plant P content (mg) 450
400
PUE = 46%
350
300
250
0 8 12 16 20
Amendment rate (% vol.)

62. Clay Rate
60 Amendment
Cumulative effluent DRP (mg L )
-1
rate (% vol.)
50 0
12
20
40
30
20
10
0
0 20 40 60 80 100 120
Day after initiaiton

63. Clay Rate
60 Amendment
Cumulative effluent DRP (mg L )
-1
rate (% vol.)
50 0
12
20
40 33 mg
30
20
10
0
0 20 40 60 80 100 120
Day after initiaiton

64. Clay Rate
60 Amendment
Cumulative effluent DRP (mg L )
-1
rate (% vol.)
50 0
12
20
40 33 mg
30
20
10
0
0 20 40 60 80 100 120
Day after initiaiton

65. Clay Rate

66. Clay Rate

67. Clay Rate

68. Phosphorus Speciation
¢ X-ray absorption
near edge surface
(XANES)
spectroscopy
¢ Linear combination
fitting
l Athena Software

69. Phosphorus Speciation

70. Phosphorus Speciation
¢ Linear combination fitting
l Low volatile material
• 75 mol% hydroxyapatite
• 25 mol% metal adsorbed P

71. Phosphorus Speciation
¢ Linear combination fitting
l Low volatile material
• 75 mol% hydroxyapatite
• 25 mol% metal adsorbed P
Ca5 (PO 4 )3 OH(s) + 7H+ (aq) ←⎯→ 5Ca 2 + + 3H2PO-
(aq) 4(aq) + H2O(aq)

72. Phosphorus Speciation
¢ Linear combination fitting
l Low volatile material
• 75 mol% hydroxyapatite
• 25 mol% metal adsorbed P
⎯→ 5Ca 2 + + 3H2PO-
Ca5 (PO 4 )3 OH(s) + 7H+ (aq) ⎯ (aq) 4(aq) + H2O(aq)

73. Clay Rate
¢ Clay rate (% vol.)
l 10% to 12%
• Plant growth
• Net photosynthesis
• Stomatal conductance
• Use efficiency
• Water
• Phosphorus
l Plant mineral content

74. Overview
¢ Introduction
¢ Experiments
l Clay processing
l Clay rate
l Input efficiency
¢ Conclusion
¢ Future

75. Input Efficiency
¢ RCBD with 4 replications
l Cyclic irrigation
• 0100, 0300, 0500 HR EST
¢ Main effects
l Amendment (11% by vol.)
• 0.25 to 0.85 mm LVM
• Washed, builders sand
l Leaching fraction
• 0.2 or 0.1
l P rate
• 1.0x or 0.5x

76. Input Efficiency
300
P rate
0.5
250 1.0
Total plant dry mass (g)
200
150
100
50
0
Sand Clay
Amendment

77. Input Efficiency
300
P rate
0.5
250
Total plant dry mass (g)
1.0
200
31 g A
150 B
100
50
0
Sand Clay
Amendment

78. Input Efficiency
300
P rate
0.5
250
Total plant dry mass (g)
1.0
200 Not
Significant
150
100
50
0
Sand Clay
Amendment

79. Input Efficiency
300
Amendment
Sand
250 Clay
Total plant dry mass (g)
200
150
100
50
0
0.5 1.0
Phosphorus rate

80. Input Efficiency
300
Amendment
Sand
250 Clay
Total plant dry mass (g)
A
200 77 g
150 B
100
50
0
0.5 1.0
Phosphorus rate

81. Input Efficiency
300
Amendment
Sand
250 Clay
Total plant dry mass (g)
31 g A
200
B
150
100
50
0
0.5 1.0
Phosphorus rate

82. Input Efficiency
2.5
Plant top nutrient content (g) Amendment
Sand
2.0 Clay
1.5
1.0
0.5
0.0
N P K Ca Mg S
Elemental nutrient

83. Input Efficiency
2.5
Plant top nutrient content (g) Amendment
38% Sand
2.0 Clay
48%
1.5
1.0
54%
0.5
108%
21%
0.0
N P K Ca Mg S
Elemental nutrient

84. Input Efficiency
100
Amendment
Sand
80 Clay
P use efficiency (%)
60 B
40
20
0
1.0 0.5
Phosphorus rate

85. Input Efficiency
100
Amendment
Sand
80 Clay
P use efficiency (%)
60
40
11% A
20
B
0
1.0 0.5
Phosphorus rate

86. Input Efficiency
100
Amendment
Sand A
80 Clay
P use efficiency (%)
64% B
60
40
B
20
0
1.0 0.5
Phosphorus rate

87. Input Efficiency
120
Treatment
Clay 0.10 LF
100 Clay 0.20 LF
Cumulative influent (L)
80
60
40
20
0
0 20 40 60 80 100 120
Day after initiation

88. Input Efficiency
120
Treatment
Clay 0.10 LF
100 Clay 0.20 LF
Cumulative influent (L)
26 L
80
60
40
20
0
0 20 40 60 80 100 120
Day after initiation

89. Input Efficiency
120
Treatment
Clay 0.10 LF
100 Clay 0.20 LF
Cumulative influent (L)
Sand 0.10 LF
80 Sand 0.20 LF
60
40
20
0
0 20 40 60 80 100 120
Day after initiation

90. Input Efficiency
120
Treatment
Clay 0.10 LF
100 Clay 0.20 LF
Cumulative influent (L)
Sand 0.10 LF
80 Sand 0.20 LF
90,000 gallons of water
60 saved per growing acre
while maintaining
40 growth
20
0
0 20 40 60 80 100 120
Day after initiation

91. Input Efficiency
25 Treatment
Clay 0.1 LF
Clay 0.2 LF
Cumulative effluent (L)
20
15
10
5
0
0 20 40 60 80 100 120
Day after initiation

92. Input Efficiency
25 Treatment
Clay 0.1 LF
Clay 0.2 LF
Cumulative effluent (L)
20
15 16 L
10
5
0
0 20 40 60 80 100 120
Day after initiation

93. Input Efficiency
25 Treatment
Clay 0.1 LF
Clay 0.2 LF
Cumulative effluent (L)
20 Sand 0.1 LF
Sand 0.2 LF
15
10
5
0
0 20 40 60 80 100 120
Day after initiation

94. Input Efficiency
25 Treatment
Clay 0.1 LF
Clay 0.2 LF
Cumulative effluent (L)
20 Sand 0.1 LF
Sand 0.2 LF
15 55,000 gallons per
growing acre
10
5
0
0 20 40 60 80 100 120
Day after initiation

95. Input Efficiency
25
Treatment
Cumulative effluent DRP (mg) Clay 0.1 LF
20 Clay 0.2 LF
Sand 0.1 LF
Sand 0.2 LF
15
10
5
0
0 20 40 60 80 100 120
Day after initiation

96. Input Efficiency
25
Treatment
Cumulative effluent DRP (mg) Clay 0.1 LF
20 Clay 0.2 LF
Sand 0.1 LF
Sand 0.2 LF
15
14 mg
10
5
0
0 20 40 60 80 100 120
Day after initiation

97. Input Efficiency
25
Treatment
Cumulative effluent DRP (mg) Clay 0.1 LF
20 Clay 0.2 LF
Sand 0.1 LF
Sand 0.2 LF
15
10
7 mg
5
0
0 20 40 60 80 100 120
Day after initiation

98. Input Efficiency
¢ Water buffering capacity
l Real-time monitoring
• Weight
• Water loss
• Container capacity

99. 00:00
18:00
Aug 28
Amendment
12:00
Sand
Clay
06:00
00:00
18:00
Aug 27
12:00
06:00
00:00
18:00 Aug 26
Time and date
12:00
06:00
00:00
Input Efficiency
18:00
Aug 25
12:00
06:00
00:00
18:00
Aug 24
12:00
06:00
00:00
18:00
Aug 23
12:00
06:00
00:00
100
95
90
85
80
75
70
Container capacity (%)

100. Input Efficiency
0 Amendment
Clay
Sand
-500
Water loss (ml)
-1000
-1500
-2000 daylight hours
15:30
13:30
19:30
17:30
11:30
21:30
5:30
9:30
7:30
Time (Sept.)

101. Input Efficiency
0 Amendment
Clay
Sand
-500
Water loss (ml)
-1000
-1500
-2000 daylight hours
15:30
13:30
19:30
17:30
11:30
21:30
5:30
9:30
7:30
Time (Sept.)

102. Input Efficiency
0 Amendment
Clay
Sand
-500
Water loss (ml)
-1000
-1500
334 mL
-2000 daylight hours
11:30
13:30
17:30
19:30
21:30
15:30
5:30
7:30
9:30
Time (Sept.)

103. Input Efficiency
0 Amendment
Clay
Sand
-500
Water loss (ml)
4% increase in
-1000
available water which
equates into 500 ml
-1500
-2000 daylight hours
11:30
17:30
13:30
19:30
15:30
21:30
5:30
9:30
7:30
Time (Sept.)

104. Input Efficiency
¢ Phosphorus use efficiency
l ≤64% increase
¢ Water use efficiency
l ≤15% increase (43 mL g-1)
¢ Maximum growth
l ≤46% increase

105. Overview
¢ Introduction
¢ Experiments
l Clay processing
l Clay rate
l Input efficiency
¢ Conclusion
¢ Future

106. Conclusion
¢ Maximum growth
l 0.25 to 0.85 mm
l Low volatile material
l 11% amendment
l 50% reduction of inputs
• Phosphorus
• Water
l Water buffering capacity

107. Overview
¢ Introduction
¢ Experiments
l Clay processing
l Clay rate
l Input efficiency
¢ Conclusion
¢ Future

108. Future Research
¢ Species screen
¢ Nutrient addition
of clay
l Phosphorus
l Potassium
¢ Water
Management

109. Financial Support
NC STATE UNIVERSITY
FNRI

110. Thank you…..
William Reece Mary Lorscheider Kim Hutchison
Beth Harden Dr. Fonteno Dr. Northup
Dr. Beauchemin Mike Jett Dr. Swallow
Sandy Donaghy Bradley Holland Tim Ketchie
Anthony LeBude Michelle McGinnis Cindy Proctor
Carroll Williamson Kristen Walton Brian Jackson
Daniel Norden Greta Bjorkquist Dr. Hunt
Committee:
Dr. Warren Dr. Bilderback
Dr. Cassel Dr. Hesterberg
Horticulture & Soil Science Faculty
& Graduate Students
My family

111. Thank you…..
William Reece Mary Lorscheider Kim Hutchison
Beth Harden Dr. Fonteno Dr. Northup
Dr. Beauchemin Mike Jett Dr. Swallow
Sandy Donaghy Bradley Holland Tim Ketchie
Anthony LeBude Michelle McGinnis Cindy Proctor
Carroll Williamson Kristen Walton Brian Jackson
Daniel Norden Greta Bjorkquist
Committee:
Dr. Warren Dr. Bilderback
Dr. Cassel Dr. Hesterberg
Horticulture & Soil Science Faculty
& Graduate Students
My family