COVER CROP EFFECTS ON SWEETGUM PRODUCTITY

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COVER CROP EFFECTS ON SWEETGUM PRODUCTITY

• R. k. Malik
• Alabama AM University, Dept. of Plant Soil
  Science, Huntsville (Normal) AL 35762

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INTRODUCTION

• Environmental Crossroads
• Key Issues
• Fossil Fuels
• Oil Embargo 1973-74 recent CRISIS October,
  2000 and now September 11, 2001

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Introduction..

• Renewable Energy Sources
• Biomass Energy - Important Alternative
• Woody Biomass
• Herbaceous Biomass
• Alcohol from grain

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OBJECTIVE

• Study the effects of cover crops on a
• short-rotation hardwood crop (SRWC)
• SWEETGUM (Liquidambar styraciflua L.),
• its growth and biomass production.

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MATERIALS AND METHODS

• LOCATION

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EXPERIMENTAL DESIGN

• Split Plot
• Cover Crops - Main Plot
• Strip Widths - Splits

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PLANT MATERIAL

• TREES
• Sweetgum transplanted March 21-27, 1995
• Row - 3.048 m (10 ft)
• Trees - 1.524 m (5 ft)
• 35 trees per plot, 315 per block, and 945 in
  3 reps

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COVER CROPS

• (A) GRASSES
• 1. Winter annual - Ryegrass (Lolium
  multiflorum L.) - Kino
• 2. Perennial - Tall Fescue (Festuca
  arundinacea L.) - Kentucky 31

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• (B) LEGUMES
• 1. Winter annual - Crimson Clover
  (Trifolium incarnatum L.) - Bigbee
• 2. Perennial - Sericea Lespedeza (Lespedeza
  cuneata (Dumont) G. Don) - Interstate 76

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PLOT LAYOUT

• Single Plot - 21.3 m (70 ft) length
• - 7.5 m (25 ft) width
• 9 plots per block including control, 3blocks
• Each plot surrounded by 25 cm high berm

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STRIP WIDTHS

• Cover crops were maintained at
• 122 cm (4 ft)
• 244 cm (8 ft)
• Control

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DATA ANALYSIS

• Data analyzed using GLM of SAS
• ANOVAs Calculated
• Means separated by Tukeys Studentized Range test
  
• Regression analysis for strip widths
• Pearson Correlation

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RESULTS
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Summary of ANOVA
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Effects of Cover Crops on Diameter Breast Height
(DBH)

• Cover Crop DBH (cm) of Control
• 1. Control 6.70a
• 2. Ryegrass 6.53a 97
• 3. Crimson clover 6.37a 95
• 4. Lespedeza 5.17b 77
• 5. Tall Fescue 5.13b 76

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Effects of Cover Crops on Volume Index (VI)

• Cover Crop VI (cm3) of Control
• 1. Control 24497a
• 2. Ryegrass 23464a 95
• 3. Crimson clover 22699a 93
• 4. Lespedeza 14465b 59
• 5. Tall Fescue 14273b 58

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Effects of Cover Crops on Leaf Nitrogen (LN)

• Cover Crop LN () of Control
• 1. Control 1.08b
• 2. Ryegrass 1.12b 104
• 3. Crimson clover 1.23a 114
• 4. Lespedeza 1.24a 115
• 5. Tall Fescue 1.11b 103

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Pearson Correlation Coefficients
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SUMMARY OF RESULTS

• COVER CROPS
• During first 2 years H, GLD, and VI were
  significantly reduced by all covers, except
  ryegrass.
• By end of 5 years (1999) only Lespedeza and tall
  fescue significantly reduced DBH, VI. Ryegrass,
  crimson clover and control were not significantly
  different .

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SUMMARY OF RESULTS.

• Leaf N was significantly higher in sweetgum
  leaves from plots of crimson clover
  lespedeza.
• STRIP WIDTH
• Had no significant effect on H, DBH VI.
  However, sweetgum leaf N, except from tall
  fescue plots, increased with increasing strip
  width.

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CONCLUSION

• SRWC Sweetgum can be successfully
• grown for bioenergy in Conservation
• Reserve Program (or under utilized land)
• with crimson clover (no re-seeding) and
• ryegrass as a choice of cover crop.

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• Thank YOU very much

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LONG TERM EFFECTS OF COVER CROPS ON SWEETGUM
BIOMASS PRODUCTION

• R. k. Malik (Ravi)
• Alabama AM University
• Department of Plant Soil Science,
• Huntsville (Normal) AL 35762