Title: Economics of residue harvest: Regional partnership evaluation Authors
Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: September 23, 2012
Publication Date: January 15, 2013
Citation: Archer, D.W., Muth, D.J., Jacobson, J.J., Karlen, D.L. 2013. Economics of residue harvest: Regional partnership evaluation. Proceedings from Sun Grant National Conference: Science for Biomass Feedstock Production and Utilization, New Orleans, LA. Meeting Proceedings. http://sungrant.tennessee.edu/NatConference/. Interpretive Summary: Corn stover (cobs, stalks, and leaves) is being considered for use in making biofuel. If this is to be successful, growers must be able to harvest and deliver enough material at a low enough cost for fuel production to be profitable. Sufficient stover must also be left in the field to maintain soil productivity. Field research data was used to determine the cost of delivering corn stover to an Iowa biorefinery based on three corn stover harvest methods. Results showed that removing greater amounts would be more profitable for the grower and reduce corn stover cost. But, this could lead to excessive removal. Reducing tillage and growing cover crops could allow for more material to be harvested while leaving enough in the field to protect the soil. Limiting stover removal to maintain soil productivity could provide economic benefits of $17 to $21 per acre for growers to reduce tillage and grow cover crops.
Technical Abstract: Economic analyses on the viability of corn (Zea mays, L.) stover harvest for bioenergy production have largely been based on simulation modeling. While some studies have utilized field research data, most field-based analyses have included a limited number of sites and a narrow geographic distribution. An Iowa case study is developed illustrating the use of data extracted from a database of geographically distributed field studies for a region-specific economic analysis. The analysis utilizes grain and residue yield and associated management information from two Iowa field research sites that are Sun Grant Regional Partnership locations associated with the Corn Stover Regional Partnership Team and he Renewable Energy Assessment Project (REAP). This information is used with the Biomass Logistics Model, to quantify costs for delivery of corn stover to a biorefinery for three stover harvest strategies. Results show that economics tends to drive residue harvest toward higher removal rates. However, higher removal rates can degrade soil resources. Limiting harvest quantities to leave sufficient residues to protect against excessive erosion and maintain soil organic carbon levels may provide economic incentives for producers to adopt cropping practices, such as no-till and cover cropping, allowing for higher harvest rates and reducing biomass costs to the biorefinery.