Crop Residues for Advanced Biofuels Workshop: A Synopsis.

Crop residues are being harvested for a variety of purposes including their use as livestock feed and to produce advanced biofuels. Crop residue harvesting, by definition, reduces the potential annual carbon input to the soil from aboveground biomass but does not affect input from plant roots. The maintenance or enhancement of soil organic carbon (SOC) is a critical component of building resilience to drought, reducing erosion, and increasing yield. The impact of harvesting crop residue on soil health is influenced by many factors including (but not limited to), harvest rate and frequency, cultivation intensity, remaining soil cover, crop rotation, use of cover crops, soil texture, climatic conditions, initial soil carbon content, and crop yield. Partial corn stover harvest may ameliorate potential grain yield reductions where high residue accumulation can interfere with planting operations, uniformity of stand emergence, and disease incidence within reduced tillage and/or continuous corn fields. The ASA-CSSA-SSSA Societies held a 3-day Workshop in Sacramento, CA to critically review the science about crop residue removal effects on SOC stocks, and how those effects should be included in life-cycle assessment (LCA) models used to estimate the carbon intensity (CI) of residue-derived biofuels. Results from the ‘Crop Residues for Advanced Biofuels Workshop: exploring soil carbon effects’ will be summarized in this presentation.