2013 Annual Report
1a.Objectives (from AD-416):
This regional CAP project will develop sustainable bioenergy production systems for the Midwest or North Central States of the USA based on perennial grasses grown on marginal croplands in the region. The Bioenergy CAP project has eight different components. ARS scientists in the Northern Plains Area, Midwest Area, and Northeast Area are participating in two components “Feedstock Development” or breeding and “Sustainable Production Systems” or management. Specific objectives are to develop improved cultivars of switchgrass, big bluestem, indiangrass, and native legumes for the North Central USA for conversion to liquid fuels in biorefineries with an emphasis on pyrolysis. Improved management practices will be developed to optimize biomass yields and feedstock quality while reducing economic costs and inputs and enhancing the environmental benefits of utilizing perennial grasses in production systems on marginal lands.
1b.Approach (from AD-416):
Feedstock development work will be conducted by ARS-Lincoln (K. Vogel) and ARS-Madison (M. Casler). Breeding work at Lincoln will develop improved grasses and legumes for the central latitudes of the USA while Madison will develop improved grasses for the northern latitudes. Current work on switchgrass for biomass energy and forage breeding of big bluestem, indiangrass, and native legume will be expanded to include breeding for biomass energy. Sorghum will be used as a model species to test effect of changes in biomass quality on pyrolysis yields. Feedstock production work (R. Mitchell) will have system analyses trials in which large plots (about 0.5 hectare) will be used to obtain sustainability information including C sequestration, greenhouse gas, economic, and system productivity information. Factor analysis trials will have small plot studies that will be used to address specific problem areas such as fertilizer rates, harvest dates, herbicides, and other management variables.
Switchgrass, big bluestem, and indiangrass breeding nurseries were established, maintained, and harvested for biomass or seed in the ARS breeding programs at Lincoln, NE and Madison, NE. Stands were monitored on yield trials of these species established in 2012 at multiple cooperative testing sites throughout the Midwest. Severe drought conditions existed throughout the region in 2012. Adequate stands were achieved at most trials which will be harvested for biomass yield after a killing frost in autumn of 2013. Seed was increased for the release of a new switchgrass cultivar. Genetic studies on breeding progress for improving biomass yields and stands in switchgrass were completed. An improved method for making crosses between switchgrass plants in the greenhouse was successfully validated. A study comparing laboratories on their accuracy and precision for measuring mineral element composition of switchgrass composition was completed. This study will be used to plan laboratory work on measuring minerals in biomass which is important for the pyrolysis conversion platform. Field nurseries were provided to cooperating University of Nebraska scientists conducting research on insects and diseases of these grasses. Biomass samples were provided to ARS scientists at Peoria, IL and Wyndmoor, PA who conducted research on conversion liquid fuels.
Feedstock production research was conducted using two main sets of trials which were successfully established in 2012. Factor analysis trials evaluated the effects of different management practices including fertilizer rates and harvest treatments. Systems analyses trials evaluated the different grasses in pure stands and in mixtures for their long term sustainability values. Biomass yield was determined on some plots at the end of the first growing season in October 2012. Comprehensive soil analyses work was continued. Greenhouse gas production from the different treatments was monitored. Biomass was harvested throughout the growing season in 2013 from the plots to obtain information that will be used for future modeling and prediction research. The samples will be used in conversion and composition research.