SilvoPasture with Hybrid Poplar and Sheep

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SilvoPasture with Hybrid Poplar and Sheep

• GreenWood Resources
• Columbia Tree Farm
• Clatskanie, Oregon

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GreenWood Resources, Inc.

• Natural resource management company established
  in 1996, based in Portland, Oregon

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GreenWood Resources, Inc.

• Currently manage nearly 15,000 acres of hybrid
  poplar plantations

6,000 acres west of theCascade Mountains
8,700 acres east of theCascade Mountains
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GreenWood Resources, Inc.

• World-wide development and management of poplar
  plantations
• Development of elite hybrid poplar and cottonwood
  genotypes

France
N. America
China
Japan
New Zealand
Chile
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What is Hybrid Poplar?

• Crosses between Populus species
• Black cottonwood (P. trichocarpa)
• Eastern cottonwood (P. deltoides)
• Japanese poplar (P. maximowiczii)
• European black poplar (P. nigra)

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Creating Hybrid Poplars

• Traditional hybridization through controlled
  pollination, propagation and testing of progeny

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Uses of Hybrid Poplar

• Wood products including veneer lumber

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Uses of Hybrid Poplar

• Pulping fibers for the paper industry

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Uses of Hybrid Poplar

• Feedstock for energy industry co-firing with
  coal and liquid fuels

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Uses of Hybrid Poplar

• Land application of municipal effluent
• Phytoremediation of industrial sites and waste
  water treatment

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Uses of Hybrid Poplar

• Carbon sequestration

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The Columbia Tree Farm (CTF)

• Established in 1982

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The Columbia Tree Farm (CTF)

• 50 owned land, 50 leased

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The Columbia Tree Farm (CTF)

• Initially created to support area pulp andpaper
  mills

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The Columbia Tree Farm (CTF)

• Operate as agriculture, employing many
  conventional farm practices and equipment

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Characteristics of the CTF

• Soils are loams to silty loams with high organic
  matter, low clay content
• Excellent soil nutrient capacity
• Moderate temperatures throughout the year
• Rainfall up to 45 annually, primarily in the
  late fall, winter and spring
• Plantations were initially planted with 600 to
  900 trees-per-acre for rotations of 6 to 8 years

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CTF Management Strategy

• Became independent of paper company in December,
  2000
• Free to pursue highest value markets for wood
  products
• Transition to
• Longer rotations, 12 to 15 years
• Wider spacing, density of 300 trees per acre
• Pruning in sequential lifts to produce clear
  lumber
• Larger piece sizes to maximize board-foot yields

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Challenges at the CTF

• Longer period of weed control
• Four versus two years
• Mechanical and chemical control
• Increased cultivation expense
• Increased potential for damage from voles where
  vegetation creates good habitat

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Purpose of SilvoPasture Trial

• Explore the range of plantation ages and stock
  types where sheep grazing could take place
  without injurious effects
• Demonstrate benefits to plantation management and
  sheep ranching
• To see if sheep grazing can be an effectivemeans
  of weed control in wider spaced plantations

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Test Sites

• 4 year oldtrees, from14 cuttings

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Test Sites

• 2 year old trees, from 5 to 6 tall
  whips

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Test Sites

• 1 year old trees, from large 6 to 7 tall whips

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Test Sites

• Thirty-six-tree plots were established inside and
  outside of each grazing plot for evaluation and
  comparison of tree growth and performance

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Preparation of Test Plots

• Sowed cover crop in April, 2004
• Disked between the tree rows
• Forage oats at 50 lbs per acre
• Forage rape at 10 lbs per acre
• 50 lbs N fertilizer per acre

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Preparation of Test Plots

• Oats established well, rape did not establish

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Preparation of Test Plots

• Electric fence and water supplies installed in
  late July, 2004

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Introduction of Sheep

• Sheep placed on August 2nd, 2004
• Sheep were 4 to 4½ month old lambs, and weighed
  60 to 65 pounds
• The number of sheep per plot ranged from 7 to 20
  head, based on quality and quantity of forage
• Targeted one month of grazing within each plot
• Mid-month adjustment made in number of head per
  plot, based on how rapidly the forage was being
  consumed and/or trampled

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Introduction of Sheep

• Sheep were placed on August 2nd, 2004

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Introduction of Sheep

• Sheep were 4 to 4½ month old lambs, and weighed
  60 to 65 pounds

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Introduction of Sheep

• The number of sheep per plot ranged from 7 to 20
  head, based on quality and quantity of forage

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Introduction of Sheep

• Targeted one month of grazing within each plot

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Introduction of Sheep

• Mid-month adjustment in number of head per plot,
  based on how rapidly the forage was being
  consumed and trampled

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Results from Sheep Grazing

• Lambs gained 6 to 7 pounds during 29 days grazing
  on the test plots
• Slightly below average weight gain compared to
  lambs grazing pasture with no supplemental feed
• Failure of rape reduced the quality of forage
  additional weight gains may have been seen had
  it established
• Evaluation of the lambs during and at the end of
  the grazing period showed them to be vigorous
  and healthy

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Results in Age 4 Trees
Tree Age(years) Treatment 2004 DiameterIncrement(inches) 2004 HeightIncrement(feet) Damage
4 Grazed 1.2 11.2 Minor leaf browsing
4 Control 1.1 11.0 Nodamage
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Results in Age 4 Trees
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Results in Age 2 Trees
Tree Age(years) Treatment 2004 DiameterIncrement(inches) 2004 HeightIncrement(feet) Damage
2 Grazed 0.8 7.7 Minor leaf browsing
2 Control 0.7 7.5 Nodamage
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Results in Age 1 Trees
Tree Age(years) Treatment 2004 HeightIncrement(feet) Damage
1 Grazed 0.6 17 showed stem and/or terminal damage
1 Control 0.6 Nodamage
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Conclusions

• Minor positive growth impacts with no damage were
  seen in the 2 and 4 year old grazing plots
• Trees age 2 and older can can be grazed
  successfully
• Trees that are 1 year old, even if established
  from whips, suffer unacceptable levels of browse
  damage
• Sheep remained healthy and vigorous, but weight
  gains were not exceptional

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Observations

• Careful management of livestock density is
  critical
• Current grazing lease rates in the lower Columbia
  River area do not justify the expense of sowing a
  cover crop for forage
• Grazing only native vegetation could prove more
  cost effective and might substitute for one or
  more mechanical cultivations

As a result of this trial, approximately 500
sheep were wintered in several fields of the CTF,
with favorable results reported by two different
ranchers
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Acknowledgements

• This study was funded by a grant from Western
  Sustainable Agriculture Research and Education
  (WSARE), under project number FW04-109
• We wish to acknowledge the contributions of
• McClellan Mac Stewart, Magruder Farms,
  Clatskanie, Oregon, for technical assistance in
  selecting cover crops and managing livestock
• GMO Forestry Fund 3, Boston, Massachusetts, for
  their in-kind contribution of the land and tree
  plantations on which the study was conducted