Drying and Moisture Relations in Corn

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Drying and Moisture Relations in Corn

• Lester O. Pordesimo
• Chad Edens
• Shahab Sokhansanj

Biosystems Engineering and Environmental Science
Oak Ridge National Laboratory
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Corn Stover Processing System
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Issue
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Importance of Moisture

• Safe storage requires 13 MC (wb)
• Mechanical properties of the stover are related
  to moisture content.

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Process Diagram
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Goal

• To develop technology for controlling the
  moisture content of corn stover for safe storage
  and efficient handling.

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Specific Objectives

• Establish data on moisture relations for corn
  stover.
• Determine drying rate of corn stover parts at
  different temperatures.
• To determine the drying rate of corn stover cob,
  leaf, husk, and stalk in the field and by
  artificial drying
• Evaluate methods of artificial drying vs. field
  (sun) drying.

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Results to Date

• Drydown rates and quantification of major corn
  plant parts for a specific hybrid over time
  starting at 2 weeks before approximate full
  kernel development proceeding until four weeks
  after harvest.
• Attempts at estimating corn plant biomass through
  simple corn plant dimensional measurements.

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Results to Date (cont.)

• Comparative rates of drying of cut whole corn
  plants on grass and on asphalt (3 reps).
• Estimation of residual biomass after corn
  harvesting and drying rates of stalk under field
  conditions (3 reps).

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Drydown Trends
Stalk fraction includes leaf sheaths.
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What We Know
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Day 100
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Day 115
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Day 140
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Day 181
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Hand Harvesting and Fractionating Corn Plants

• Location
• The University of Tennessee Knoxville Experiment
  Station Plant Sciences Unit

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Variability in Above Ground Plant Weight
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Height of Stalk to First Ear
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Estimation of Residual Biomass after Corn
Harvesting
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Total Stover Collected from the Ground After
Grain Harvest (Removal Area 20 ft²)
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Total Stover Collected from the Ground After
Grain Harvest (Removal Area 20 ft²)
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Percentages of Stover Fractions Collected on the
Ground After Grain Harvest
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Key Findings

• Differences in drydown between hybrids.
• Published moisture content of corn plant
  fractions at harvest are high.
• Cob and husk are sensitive to rainfall in terms
  of moisture content variation.
• After fully kernel maturity all plant fractions
  drydown to about 10-15 MC, but no lower.

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Key Findings (cont.)

• Stalks are about 2.5 tons/acre. Stalk drymatter
  goes down and becomes almost constant after
  kernel maturity.
• Grain is about 5 tons/acre. Grain drymatter
  content goes up after kernel maturity.
• Leaf drymatter decreases after kernel maturity
  --- mostly due to weathering.

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Key Findings (cont.)

• If stover (meaning without the grain) is divided
  into 10 parts, 5 parts will be stalk. Cobs, husk,
  and leaves will be 1.66 parts each.
• Amount of stalk obtained off the ground after
  combine harvesting is less than that measured by
  cutting whole plants -- shattering of stalks?

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Estimating Corn Plant Biomass through Simple Corn
Plant Dimensional Measurements
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Relationship of Plant Height to Plant Weights
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Correlation of Stalk Diameter to Plant Height
Measurements
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Comparative Rates of Drying of Cut Whole Corn
Plants on Grass and on Asphalt
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Sundrying of Whole Plants on Grass
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Sundrying of Whole Plants on Asphalt
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Questions??
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The challenge
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Remaining Stover When Combine Header Set High