Establishing and managing perennial grasses for bioenergy

Authors: Mitchell, Robert - Rob

Submitted to: Integrated Crop Management Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 11/13/2013
Publication Date: 12/4/2013
Citation: Mitchell, R.B. Establishing and managing perennial grasses for bioenergy, Proc. 25th Annual Integrated Crop Management Conference, Iowa State University, pp. 49-51. 2013.

Interpretive Summary: Switchgrass, big bluestem, and indiangrass are native perennial warm-season grasses and are promising bioenergy feedstocks, either grown as single-species stands or in low-diversity mixtures. Switchgrass best management practices (BMPs) have been developed for bioenergy production in most areas and BMPs for big bluestem, indiangrass, and sideoats grama have been developed for the Great Plains and Midwest. Perennial grasses likely will be grown on cropland that is marginally productive for row crops, similar to land enrolled in the Conservation Reserve Program. Advancements in herbicides, cultivar development, and planting equipment have resulted in the rapid and repeatable establishment of perennial warm-season grasses in the Great Plains and Midwest. Growing perennial grasses on marginally productive cropland for biomass production will minimize land use competition with annual row crops, reduce erosion, and provide perennial grassland habitat for wildlife.

Technical Abstract: Switchgrass (Panicum virgatum) is native to every U.S. state east of the Rocky Mountains, is the most advanced herbaceous perennial bioenergy feedstock, and best management practices (BMPs) have been developed for bioenergy production in most agro-ecoregions. Additionally, big bluestem (Andropogon gerardii), indiangrass (Sorghastrum nutans), and sideoats grama (Bouteloua curtipendula) are promising bioenergy feedstocks, either grown as single-species stands or in low-diversity mixtures. Native warm-season grasses have a reputation for being difficult to establish. Historically, these grasses often required 2 or 3 years to establish an acceptable stand. However, advancements in herbicides, cultivar development, and planting equipment have improved establishment dramatically. Today, it is feasible to harvest 50% of the cultivar’s yield potential after frost in the seeding year. By the end of the first full growing season after seeding, it is feasible to produce and harvest 75% to 100% of the cultivar’s yield potential. If precipitation is adequate, warm-season grasses are readily established when quality seed of adapted cultivars are used in conjunction with the proper planting date, seeding rate, seeding method, and weed control.