THE SUPPLY OF CORN STOVER IN THE MIDWESTERN UNITED STATES

1
THE SUPPLY OF CORN STOVER IN THE MIDWESTERN
UNITED STATES

• Richard G. Nelson1,
• Marie E. Walsh2, and
• John Sheehan3
• 1Kansas State University
• 2University of Tennessee
• 3National Renewable Energy Laboratory

2
Background

• U.S. heavily dependent upon fossil fuels
• Consumes 98 Quads of primary energy annually (86
  from fossil fuels)(year 2002)
• 39 percent of primary energy use from petroleum
  (64 is imported).
• 24 percent of primary energy use from natural gas
• 23 percent of primary energy use from coal
• Annual GHG emissions projected to increase from
  1559 (year 2002) to 2237 mMTce by 2025
• Biomass resources, such as corn stover, can be
  used to produce electricity, transportation
  fuels, and chemicals while providing energy,
  economic, and environmental benefits

3
Project Objectives

• Develop and apply a methodology to estimate
  quantities (dt/ac/yr) of crop residue that must
  be left on the field by individual soil type,
  crop rotation, and tillage practice to keep
  rain/wind erosion at or below the tolerable soil
  loss level (T)
• Estimate crop residue supply curves for a
  continuous corn rotation (weighted by tillage
  practice) for 10 Midwestern states (IA, IL, IN,
  MN, WI, NE, MO, OH, KS, and SD)

4
Agricultural Crop Residue Retention/Removal
Analysis

• Residue Required for Erosion Control is a
  Function of
• 1. Type of Erosion (wind/rain)
• 2. Field operations (tillage scenarios,
  maintenance, etc.)
• Soil Type
• 4. Climate (rainfall, temperature, retained
  moisture)
• 5. Physical field characteristics ( slope, soil
  erodibility)
• 6. Crop and cropping rotation
• 7. Tolerable Soil Loss, T

5
Remaining Residue Methodology

• Identify physical characteristics (soil
  erodibility, percent slope, etc.) of all cropland
  soils in each county
• Apply the Revised Universal Soil Loss Equation
  (RUSLE) and Wind Erosion eQuation (WEQ) to each
  soil type to estimate the quantity of residue
  that must remain on the field throughout the year
  as a function of three tillage scenarios (CT, MT,
  and NT) such that T is not exceeded
• Calculate county-level quantities of corn stover
  (dt/ac) that must remain using an
  acreage-weighted approach

6
Removable Residue Methodology

• County-level quantities of corn stover (dt/ac)
  that can be removed by tillage practice are the
  quantity produced (grain yields times residue
  factors) minus the higher of the rain/wind
  erosion quantities that must remain
• Total county-level quantities of corn stover that
  can be removed (dt) are estimated as
• removable quantities by tillage type total
  corn acres percent of corn acres in each
  tillage type

7
State Average Corn Stover Quantities
State Average Stover Produced, Quantities That Must Remain to Control Erosion by Tillage Practice, and Removable Stover Quantities by Tillage Practice (dt/ac) State Average Stover Produced, Quantities That Must Remain to Control Erosion by Tillage Practice, and Removable Stover Quantities by Tillage Practice (dt/ac) State Average Stover Produced, Quantities That Must Remain to Control Erosion by Tillage Practice, and Removable Stover Quantities by Tillage Practice (dt/ac) State Average Stover Produced, Quantities That Must Remain to Control Erosion by Tillage Practice, and Removable Stover Quantities by Tillage Practice (dt/ac) State Average Stover Produced, Quantities That Must Remain to Control Erosion by Tillage Practice, and Removable Stover Quantities by Tillage Practice (dt/ac) State Average Stover Produced, Quantities That Must Remain to Control Erosion by Tillage Practice, and Removable Stover Quantities by Tillage Practice (dt/ac) State Average Stover Produced, Quantities That Must Remain to Control Erosion by Tillage Practice, and Removable Stover Quantities by Tillage Practice (dt/ac) State Average Stover Produced, Quantities That Must Remain to Control Erosion by Tillage Practice, and Removable Stover Quantities by Tillage Practice (dt/ac)
Average Residue Produced (dt/ac) Average Residues That Must Remain to Control Erosion by Tillage Practice (dt/ac) Average Residues That Must Remain to Control Erosion by Tillage Practice (dt/ac) Average Residues That Must Remain to Control Erosion by Tillage Practice (dt/ac) Average Residues that Can Be Removed by Tillage Practice (dt/ac) Average Residues that Can Be Removed by Tillage Practice (dt/ac) Average Residues that Can Be Removed by Tillage Practice (dt/ac)
CT MT NT CT MT NT
Illinois 4.16 2.60 1.53 0.70 1.78 2.64 3.45
Indiana 3.93 2.54 1.46 0.70 1.68 2.50 3.23
Iowa 4,27 2.66 1.66 0.78 1.74 2.61 3.48
Kansas 3.56 82.96 3.50 2.37 0.00 0.41 1.24
Minnesota 4.08 1.27 0.74 0.27 2.81 3.33 3.81
Missouri 3.28 4.95 3.02 1.63 0.26 0.60 1.65
Nebraska 3.85 62.19 2.40 1.32 0.00 1.49 2.53
Ohio 3.67 3.01 1.80 0.79 1.16 1.94 2.88
South Dakota 3.01 67.08 5.37 1.26 0.00 0.00 1.77
Wisconsin 3.73 3.15 2.04 1.00 0.82 1.69 2.73
CT is conventional tillage MT is mulch
till/reduced till NT is no-till. Source Nelson
2004.
8
Corn Stover Collection Cost Methodology

• Corn stover harvested as large round bales
• Collection costs include mowing/raking/
• baling, picking up, and transport to field edge
• Equipment cost methodology (fuel/lube, repairs,
  capital, insurance/housing, labor, etc.) and
  operating parameters from AAEA and ASAE
• Costs vary as a function of corn stover quantity
  (dt/ac)

9
Corn Stover Collection Costs as a Function of
Removable Quantity
10
Corn Stover Supply Curves
State Quantities of Corn Stover Available for Bioenergy and Bioproducts by Collection Cost (/dt) State Quantities of Corn Stover Available for Bioenergy and Bioproducts by Collection Cost (/dt) State Quantities of Corn Stover Available for Bioenergy and Bioproducts by Collection Cost (/dt) State Quantities of Corn Stover Available for Bioenergy and Bioproducts by Collection Cost (/dt) State Quantities of Corn Stover Available for Bioenergy and Bioproducts by Collection Cost (/dt) State Quantities of Corn Stover Available for Bioenergy and Bioproducts by Collection Cost (/dt) State Quantities of Corn Stover Available for Bioenergy and Bioproducts by Collection Cost (/dt) State Quantities of Corn Stover Available for Bioenergy and Bioproducts by Collection Cost (/dt) State Quantities of Corn Stover Available for Bioenergy and Bioproducts by Collection Cost (/dt) State Quantities of Corn Stover Available for Bioenergy and Bioproducts by Collection Cost (/dt)
12.50 17.50 20.00 25.00 30.00 35.00 40.00 45.00 50.00
Quantity (million dry tons) Quantity (million dry tons) Quantity (million dry tons) Quantity (million dry tons) Quantity (million dry tons) Quantity (million dry tons) Quantity (million dry tons) Quantity (million dry tons) Quantity (million dry tons)
Illinois 0.0 0.0 7.6 19.9 21.5 22.5 22.6 22.8 22.8
Indiana 0.0 0.0 3.6 10.1 10.7 11.1 11.3 11.4 11.4
Iowa 0.0 0.0 11.7 24.2 25.4 26.1 26.4 26.5 26.7
Kansas 0.0 0.0 0.0 0.1 0.4 0.6 0.8 0.8 0.9
Minnesota 0.0 0.0 9.1 18.8 19.0 19.1 19.2 19.2 19.2
Missouri 0.0 0.0 0.5 1.0 1.4 1.7 1.7 1.7 1.8
Nebraska 0.0 0.0 0.8 7.0 8.7 9.1 9.3 9.3 9.3
Ohio 0.0 0.0 1.4 4.1 4.5 4.7 4.9 4.9 4.9
South Dakota 0.0 0.0 0.0 0.7 0.8 0.8 0.9 0.9 0.9
Wisconsin 0.0 0.0 0.2 2.3 2.9 3.2 3.3 3.3 3.4
TOTAL 0.0 0.0 35.0 88.1 95.4 98.9 100.3 100.8 101.4
Source Walsh 2004. Unpublished Analysis
11
On-Going Analysis

• Erosion analyses completed for several crops
  (corn, soybeans, wheat, rye, barley, oats, rice)
  and rotations (e.g., continuous, corn-soybean,
  wheat-fallow, etc.) by soil type and tillage
  practice for continental U.S.
• Soil carbon needs analysis underway
• Incorporation of available quantities and
  collection cost estimates into dynamic
  agricultural sector model already modified to
  include energy crops (POLYSYS) to estimate
  integrated biomass supply curves