Crop Residue Removal for Biomass Energy Production:
Effects on Soils and Recommendations
Susan S. Andrews, Ph.D.
Leader, Soil Quality National Technology Development Team
USDA-Natural Resource Conservation Service
Updated February 22, 2006
In light of the renewed interested in domestic production of biofuels and other biomass energy, can the
more than 500 million tons of crop residue produced each year be used to meet some of our energy needs?
The answer is not straightforward because residues perform many positive functions for agricultural soils.
Recent studies and reviews attempt to address this issue. Despite some shortcomings, existing research can
be used to guide practices to a great extent, especially for corn stover harvest in the Corn Belt, which has
been studied most extensively. Specific guidelines for residue harvest need to be developed in an effort to
prevent soil degradation resulting from over-harvest.
Soil quality effects:
• Soil Erosion. Surface residues protect soil from water and wind erosion. Residues also increase soil
resistance to runoff events, unless soil infiltration is already impaired. Studies predict that up to 30% of
surface residue can be removed from some no-till systems without increased erosion or runoff.
• Organic Matter and Nutrients. With added nitrogen fertilizers, residues can increase soil organic
matter (SOM). However, roots appear to be the largest contributor to new SOM, making residues less
important for carbon accrual. Residue removal leading to higher erosion and runoff rates would greatly
decrease SOM and nutrients. Residue harvest would also require increased fertilizer inputs to make up
for nutrients removed in the plant material.
• Beneficial and Deleterious Soil Organisms. Residue removal can result in detrimental changes in many
biological soil quality indicators including soil carbon, microbial activity, fungal biomass and ear