Biomass and the Environment: Soil and Water Impacts

David Mulla*Professor & Larson Chair for Soil &

Water ResourcesDept. Soil, Water & Climate

University of Minnesota*Coauthors for this talk include: David Pitt, Dept. Landscape Architecture, Carissa Shively-Slotterback, Humphrey School

of Public Affairs and Nicholas Jordan, Dept. Agronomy & Plant Genetics (all University of Minnesota)

Study Area

Current Land Use

Alternative Management Practices•Conservation Tillage:

• Chisel and disk tillage practices are replaced with a conservation tillage practice that leaves 30% residue at time of planting. Field cultivators are still used before planting.

•Stover Removal w/wo Cover Crops•Reduced Phosphorus Fertilizer Rates:

• P fertilizer rates are reduced by half.

•Cropland Conversion to Prairie Grass: • Biomass is harvested. Previous tile drainage systems remain intact.

•Cropland Conversion to Switchgrass: • Biomass is harvested. Previous tile drainage systems remain intact.• Switchgrass plantings in buffer strips is an option.

Methods Use SWAT (Soil Water Assessment Tool) to

analyze how changes in land management in Seven Mile Creek affect ecosystem services and biodiversity conservation

Compare the impact on ecosystem services & biodiversity from: – Current land use– Alternative land management and land use change

scenarios Results for each HRU are transferred to an

Excel spreadsheet and linked to an ArcGIS platform for real-time evaluation of GeoDesign scenarios by stakeholders

Linking Spatial Modeling & GeoDesign

GeoDesign Hardware System

GeoDesign System Architecture

Seven Mile CreekSediment Losses (t/yr)

Stakeholder Driven Designs

Touch Screen Functions

Stakeholder Rules of Thumb Increase landscape diversity Produce food/biofuel without harming

water quality or habitat Improve soil quality Consider feedstock transport distances Buffer waterways Improve wildlife habitat Match crop suitability to soil productivity

Performance Indicators

DischargeSediment lossPhosphorus lossHabitatCarbon sequestrationProfitability

Watershed Performance

Conclusions Novel GeoDesign process was developed Participants from different backgrounds shared

perspectives and worked collaboratively Stakeholders learned quickly, easily grasped

design concepts and used biophysical feedback indicators

Stakeholders incorporated clustering and spatial continuity into their landscape designs

Designs were not only profitable, but also exhibited improved water quality, carbon sequestration and terrestrial bird habitat

Project Funded by USDA-CIG.

Thank You. Questions?