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ARS Home » Plains Area » Lincoln, Nebraska » Agroecosystem Management Research » Research » Publications at this Location » Publication #312624
Title: Nitrogen and tillage management affect corn cellulosic yield, composition, and ethanol potential

Author
item Sindelar, Aaron
item COULTER, JEFFREY - University Of Minnesota
item LAMB, JOHN - University Of Minnesota
item SHEAFFER, CRAIG - University Of Minnesota
item VETSCH, JEFFREY - University Of Minnesota

Submitted to: BioEnergy Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/21/2015
Publication Date: 2/13/2015
Citation: Sindelar, A.J., Coulter, J.A., Lamb, J.A., Sheaffer, C.C., Vetsch, J.A. 2015. Nitrogen and tillage management affect corn cellulosic yield, composition, and ethanol potential. BioEnergy Research. 8(3):1284-1291. DOI: 10.1007/S12155-015-9586-1.

Interpretive Summary: The Upper Midwest will likely serve as an integral provider of corn residues for the production of cellulosic ethanol. Until recently, little research has been conducted on how management decisions affect non-grain components of corn. This research was conducted to understand how yield, nutrient content, and ethanol production of corn stover (all aboveground non-grain material excluding cobs) and cobs are affected by fertilizer N rate and tillage selection, which are two important management decisions made by producers. This research found that biomass yield, carbon and nitrogen content, and potential cellulosic ethanol yield all increased as fertilizer N rate increased for both stover and cobs. Ethanol yield for stover was maximized at fertilizer N rates below the rate that economically optimizes grain yield. The adoption of no-till resulted in lower biomass and potential ethanol yield, but these yields did not differ between strip- and chisel-tillage. This means reduced tillage could be implemented in Minnesota without adversely affecting these yields. While biomass and ethanol yields were of cobs were lower than those for stover, sole harvest of cobs would remove less carbon and nitrogen and, therefore, be more sustainable than removal of all cellulosic material. However, their sole use would result in a larger collection radius for a given biorefinery than for combined stover and cobs.

Technical Abstract: Corn (Zea mays L.) stover and cobs remaining after grain harvest can serve as a feedstock for cellulosic ethanol production. Field trials were conducted at two locations in Minnesota over three years to determine how corn cellulosic yield composition and ethanol yield are influenced by tillage system [chisel tillage (CT), strip-tillage (ST), and no-tillage (NT)] and fertilizer N rate (0, 45, 90, 134, 179, and 234 kg N ha-1). Stover biomass yield, C and N concentrations and content, and potential ethanol yield increased with increasing fertilizer N rate. Stover biomass yield, C content, and potential cellulosic ethanol yield were less with NT than CT and ST by =9, 8, and 8 %, respectively. Theoretical ethanol yield of stover was maximized at a fertilizer N rate lower than the economically optimum N rate (EONR) for grain yield. Cob biomass yield, C concentration and content, N concentration, and potential ethanol yield increased with fertilizer N rate, but not at the same magnitude observed for stover. Tillage system did not influence cob biomass yield, C and N concentrations and content, or potential ethanol yield. These results demonstrate that biomass and ethanol production of stover and cobs can be affected by N and tillage management. Cobs may be a more viable feedstock option than stover because nearly all measured variables were less sensitive to management and their harvest removes less C and N from a field compared to full harvest of combined cobs and stover.