Related Treepower Sites:
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    Planting Research
    Harvesting Research

Field Photography:
    Eucalyptus Trees @ 2nd YR.
    Pictorial History of Site

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Energy Crop Yields for Eucalyptus and Cottonwoods.

Note: You can download a Microsoft Excel Spreadsheet of detailed crop yields (green tons per acre, dry kg/ha) from our Orlando Test Plot Area.

[If the file does not download automatically, a box will appear on your browser asking you to select the application type that you want to open the file in. Most spreadsheet applications are located in your computer's Program File such as Microsoft Excel, Lotus 123, Quatro, ect. Click "browse" and scroll down to your spreadsheet software application and click.]

Orlando Test Plot Summary: The below crop yields are from the University of Florida's research test plot area in Orlando (~6 acres) for cottonwoods and eucalyptus species (amplifolia and grandis) at planting densities of ~1,000 trees per acre (traditional planting of one row of trees per bed).

The highest yields have occurred where weed control (either mulching, composting, or a combination) was performed.

Crop Yields In Green Tons Per Acre Per Year
with mulching and composting

Tree Species:
Year 1 Yields
Year 2 Yields
Two Year Average
Cottonwood
7
30
19
E. amplifolia
7
20
14
E. grandis
12
63
38

Commercial Scale Planting Configurations: At our ~135 acre energy crop tree farm in Lakeland, three planting designs are used:

Single Row Planting   One row of trees planted per bed. On average, beds are spaced on 9 bart centers. Planting density is estimated to be 1,957 trees per acre. Harvesting on single row planted beds would use traditional equipment of skidders and fellerbunchers.

Double Row Planting   Two rows of trees planted per bed. On average, beds are spaced on 9 bart centers. Planting density is estimated to be 3,955 trees per acre. Harvesting on double row planted beds would use equipment currently utilizied for energy crop trees in Europe (e.g., Claas Harvester).

Quadrupible Rows on Macro Beds/Mounds   Four rows of trees planted per bed/mound. Beds spaced on 23 bart centers. Planting density is estimated to be 3,030 trees per acre. Harvesting on quadrupible row planted beds would also use Claas Harvester type equipment.

Tree Yields: As of October 2003, most of our Single Row trees are two and one-half years old. Double and Quadrupible Rows trees are 1 and one-half years old. Two primary factors are limiting our ability to project our energy crop tree yields:

  • A lack of agriculture science precedent in planting
        eucalyptus and cottonwood trees in such high planting
        densities per acre (i.e., traditional spacing is ~600 trees per
        acre).
  • The current maturity of trees -- especially double and
        quadrupible spacings (not even two years old), making it
        difficult to project yield growth curves.

    • Currently, the University of Florida (UF) is providing us their "very preliminary" estimates of yields on single row plantings:

  • High End:   32 green tons (16 dry tons) per acre, per year.
  • Low End:   20 green tons (10 dry tons) per acre, per year.

    • As soon as UF's quantitative data becomes available we will post it. In the interim, any questions on these projections can be forwarded to Dr. Don Rockwood.

    Average Growth In Our Energy Crop Trees Per Year:

    Tree Species:
    Height (feet/meters)
    Diameter (inches/cm)
    Sample Over
    Cottonwood:
     
     
     
    Single Row
    4.25 feet/1.3 meters
    .27"/.7 cm
    2.5 Years
    Double Row
    13 feet/4.0 meters
    1.15"/2.9 cm
    2.5 Years
    Quad Row
    N/A
    N/A
    N/A
    E.Grandis:
     
     
     
    Single Row
    22 feet/6.7 meters
    2 to 3"/5 to 7.6 cm
    2.5 Years
    Double Row
    16.7 feet/5.1 meters
    1.25"/3.15 cm
    2.5 Years
    Quad Row
    15 feet/4.6 meters
    1.5 to 2"/3.8 to 5 cm
    1.5 Years
    E. amplifolia:
     
     
     
    Single Row
    13.5 feet/4.1 meters
    1.3"/3.4 cm
    2.5 Years
    Double Row
    15 feet/4.6 meters
    1.2"/3.1 cm
    2.5 Years
    Quad Row
    too early
    too early
    less 1 Yr

    21/2 year old Eucalyptus (E. grandis, single row),
    averaging +40 feet in height.

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