Agricultural Biomass

Resources, Opportunities, and Constraints

Presentation to the Western Governors’ Association Clean and Diversified Energy Advisory Committee

Biomass Task Force

April 14-15, 2005Denver, Colorado

Resources

Soil & Water Quality Improvement

Health Benefits

Potential Resources

Agriculturally-based Biomass Resources and Technologically Viable End-uses

Prominent National Resources & End-Uses

herbaceous energy crops switchgrass and big bluestem – bioethanol, heat, and electricity

agricultural crop residues corn stover, wheat, barley, and oat straw – bioethanol

oilseed crops soybeans, sunflower, canola/rapeseed, perennial oilseeds – biodiesel

agribusiness processing residues edible and inedible tallows and waste greases, walnut shells, potato wastes –

biodiesel, heat, bioethanol

livestock manures dairy and swine operations – heat and electricity

other biochemicals and biomaterials

Advantages of Agriculturally-based Biomass Resources

Energyutilization of sustainable resources – sustainable energy balance

Environmentaldecreased CO2, SOx, and mercury emissionsimproved localized air qualityimproved water qualitypotential for carbon sequestration

Economicimprovement of foreign trade balance

Securitydecreased petroleum dependence

Environmental Advantages of Herbaceous Energy Crops

Rainfall and wind soil erosion reductionHerbaceous energy crops provide excellent

continuous cover significantly reducing surface rainfall impact and wind forces

Surface runoff reductionHerbaceous energy crops have extensive

root systems allowing for greater infiltration (decreased risk of flooding)

Nitrogen and agricultural chemical mitigationHerbaceous energy crops use less nitrogen,

phosphorus, and agricultural chemicals than

conventional commodity crops

Increased soil organic carbonExtensive root system of switchgrass allows for carbon sequestrationSwitchgrass for renewable energy purposes provides a “psuedo closed-carbon” loop → significant reduction in the greenhouse gas CO2

Restoration of marginal lands

Topsoil Completely Eroded from Rainfall Erosion

Marginal Lands in Need of Restoration

Perennial Oilseed Crop SystemsMany factors that disqualify land for annual cropping

may not apply to perennial crops!

Environmental Advantages of Perennial Oilseed ProductionExposure to wind and water erosion occurs primarily during establishment of annual crops is minimized with perennials

Perennials can provide N fixation, decrease in rainfall erosion impact, and provide windbreaks

Perennial oilseeds could reduce NPS pollution while also providing a return to the landowner through alternative energy production (double-benefit)

Energetic Advantages of Perennial Oilseed ProductionSince the living plant, instead of the processing plant, adds the energy benefit, the energy ratio (ER) will be higher

Castor (SW KS & TX)

Chinese Tallow Tree

Agricultural Crop Residue RemovalSustainability Considerations

Residue Required for Erosion Control is a function of:

1) Type of Erosion (wind or rainfall (water))

2) Field management practices (tillage)3) Soil type4) Climate (rainfall, temperature,

retained moisture)5) Physical field characteristics (%

slope, soil erodibility)6) Crop and cropping rotation7) Tolerable Soil Loss, T8) Grain yield (bu/ac)

Tolerable Soil Loss, T

Maximum rate of soil erosion that will not lead to prolonged soil deterioration and/or loss of productivity

Rotation & Field Topology

Field Management

Soil Tilth & Carbon Constraints !!!

Corn Stover – seen as a “waste” resource

ConstraintsAgricultural Biomass Resource & Production

Issues

Land Resourcearable versus non-arable – crops & production competing uses and cost/benefit

Environmental Concerns production versus soil quality (soil erosion)water quality water resourcesoil tilth & carbon cycle

Quantity of Sustainable Resource

Others?

Potential Renewable Energy and Environmental/Pollution Credit Markets for Agriculturally-based Biomass Resources

Renewable Energy Credits and Environmental/Pollution Trading Markets

Sale of end-use energies derived from bioenergy

Air emission credits for CO2, SOx, NOx, mercury

Water quality/pollution trading (sediment, nutrient and chemical savings)

Example modeled cumulative, 24-year soil erosion (total tons) comparison between switchgrass and four conventional commodity crops on two major soil types in Pottawatomie county, Kansas.

Soil Type Switchgrass Corn Soybeans Wheat Grain Sorghum

Pawnee 0.34 30.28 33.42 11.21 33.54 Clime 0.77 68.87 76.98 27.86 76.93