Crop Response to Hybrid Poplar Alternative
Soilless Substrate Component for Pacific
Northwest Ornamental Container Production
H.M. Stoven, J.S. Owen Jr. and J. Klick
North Willamette Res & Ext Ctr, Oregon State University, Aurora, OR
J.E. Altland
Application Technology Research Unit, USDA-ARS, Wooster, OH
W.J. Pruett
Phillips' Soil Products Inc., Canby, OR
The need for alternatives soilless
substrates in the PNW….
Bark shortage – cost, consistancy
Drive for sustainability
Hybrid poplar….
Wade
And boardman
Soilless Substrate
20% (by vol.) screened pumice, 20% fine (<3/8 in
by vol.) Douglas fir bark (DFB) and coarse bark
60%.
Whole Tree Poplar Chip (>3/8 in)
•!0, 20, 40, 60% addition to replace coarse DFB
(by vol.)
Chemical Amendments
•!16 lb/yd Apex 17-6-12 CRF
•!21 lb/yd premix containing lime and gypsum
Crops Investigated
Experiment 1
Cotoneaster dammeri
‘Coral Beauty’
Experiment 2
•!Hydrangea macrophylla
‘Endless Summer’,
•!Juniper horizontalis
‘Youngstown’,
•!Acer palmatum,
•!Euonymus fortunei
‘Moonshadow’
Materials & Methods
Experiment 1 – Cotoneaster
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4 individual plant replications per block
2 gallon containers
Root and shoot dry weight
Water use efficiency of productivity
Moss coverage
pH and EC via pour thru
Physical properties
Materials & Methods
Experiment 2 – 4 taxa
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CRD of 4 treatments
8 individual plant replications
2 gallon containers
Root and shoot dry weight
Growth index
Experiment 1 – Cotoneaster
Physical Properties
Physical Properties
Substrate Shrinkage (1 yr)
a
b
b
b
Moss Coverage
a
b
c
*Significant (p < 0.05 ) quadratic response
Cotoneaster growth response
a
b
b
*Significant (p < 0.05 ) linear response
b
Cotoneaster growth response
40%
poplar
20%
poplar
0% (by vol.) WTP
0% poplar
40% (by vol.) WTP
Whole Plant Water Use
Efficiency
*Significant (p < 0.05 ) quadratic response
Experiment 2
Multiple Taxa
Crop Response
Hydrangea
60% WTP
40% WTP
20% WTP
0% WTP
Juniper
April
2009
60%
60% WTP
poplar
40%
40% WTP
poplar
20%
20% WTP
poplar
0%
0% WTP
poplar
Conclusion
•!20-40% WTP content
provided acceptable growth
•!pH (6.5 to 7.0 ) and EC 1 to
2 dS) were in acceptable
ranges
•!Possible nitrogen correction
needed due to N drawdown
Other materials..
Other materials…
Material preparation
recent research