2007 Annual Report 1a.Objectives (from AD-416) The objective of this cooperative research project is to monitor the impact of corn stover harvest in a corn-soybean rotation on soil carbon and productivity under contrasting tillage management. Summarize current state of knowledge and create initial recommendations for residue retention. Monitor the quality of feedstock and biomass ash from a biomass gasifier. Best Management Practices for biomass cropping systems will be developed for environmental and economic sustainability. 1b.Approach (from AD-416) Current soil C levels will be assessed now and after each rotation, yield will be monitored annually. Analyze feedstock material for percent moisture, ash-free biomass, total carbon, nitrogen, sulfur, chlorine, and ash. Feed stocks and ash (not to exceed 200 total samples) from the test burns will be digested in nitric acid utilizing a microwave digester then assayed by ICP for 27 elements (Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, S, Si, Sr, Ti, V, Zn). The pH of the ash will also be determined. 3.Progress Report This report serves to document research conducted under a reimbursable agreement between ARS and the University of Minnesota, Morris. Additional details of research can be found in the report for the parent project 3645-12610-001-00D. During 2006, analysis of feedstock and ash were provided to the University of Minnesota from biomass boiler test runs. Supplemental information from several on-going experiments was collected, which will be relevant in the development of local best management practices. Telephone conversation, email, on and off-site meetings were held for monitoring and planning related activities.