Optimizing warm-season grasses for sustainable bioenergy feedstock production

This research focuses on the selection, management, and genetic improvement of warm-season perennial grasses grown for bioenergy production. Warm-season perennial grasses are of interest because of high biomass yields, low agronomic inputs, and great ecosystem services. First, the biomass production potential of native warm-season grasses monocultures and mixtures was evaluated in Illinois, Nebraska, and Iowa, U.S.A. field trials. At all locations, Kanlow switchgrass and Miscanthus × giganteus were the highest yielding species in monocultures, and mixtures including switchgrass and big bluestem exhibited the highest yield potential in mixtures. Our 6-year results suggest that grass mixtures did not produce more bioenergy feedstock than monocultures in Illinois and Nebraska. Next, digestate, a by-product of anaerobic digestion of sludge, and digestate plus biochar were evaluated as nutrient sources for warm-season perennial grass energy crops. While these grasses have high N-use efficiency, N management is critical for sustainable biomass production, and it is important to identify environmentally friendly, economical nutrient sources. Our results indicate that increased biomass yield resulted from applying digestate and digestate plus biochar. Moreover, using digestate as a nutrient source may create economic opportunities and additional income for the anaerobic digestion industry. Finally, producing perennial energy feedstocks on marginal lands could reduce competition with food crops for higher quality soil settings, maximize producer resources through perennial bioenergy feedstock production, and have significant environmental benefits. Therefore, it is important to identify perennial energy feedstocks that can achieve a high yield potential when grown on marginal lands. Prairie cordgrass has exhibited significant tolerance to freezing temperatures, salinity and hypoxia and could be a potential candidate for a bioenergy feedstock. We generated chromosome doubled prairie cordgrass to determine the effects of environmental adaptation on traits of agronomic interest. Our results suggest that the concentration of amitotic chemicals and exposure time were critical factors for inducing chromosome doubling in prairie cordgrass. In future breeding material, utilizing chromosome doubled prairie cordgrass may allow for increased tolerance to factors of abiotic stress.U of I OnlyAuthor requested U of Illinois access only (OA after 2yrs) in Vireo ETD syste